A hydraulic vehicle braking system comprises a master cylinder having at least one piston displacably accommodated therein, a mechanical actuator that is coupled, or can be coupled, to a brake pedal for actuating the piston, and an electromechanical actuator. The electromechanical actuator is likewise provided for actuating the piston and can be activated, at least for boosting or generating brake force, when the brake pedal is actuated. Furthermore, a valve arrangement is provided, which has a first valve per wheel brake for selectively uncoupling the wheel brake from the master cylinder, and a second valve for selectively reducing the brake pressure at the wheel brake. The valve arrangement can be controlled at least within the framework of an ABS control mode.

A method for operating a brake system for motor vehicles comprises in a normal control mode of the system, a displacement of a piston for a pressure supply device is terminated, and inlet valves of the wheel brakes are closed in the event of a specified brake condition. The normal control mode is switched to a special control mode in the event of a specified condition for the pressure supply device. In the event of the specified brake condition in the special control mode, a displacement of the piston of the pressure supply device is terminated by outputting an actuation signal to the pressure supply device, and for at least one selected wheel brake, the corresponding inlet valve is kept open and the corresponding outlet valve is opened at least temporarily while the inlet valves of the remaining wheel brakes are closed.

A hydraulic brake system for a vehicle, including: a wheel brake device configured to generate a braking force based on a pressure of a working fluid; a first brake system including a high-pressure source device including an accumulator and a first pump device that is driven intermittently such that a pressure of the working fluid in the accumulator is not lower than a set lower limit pressure and not higher than a set upper limit pressure; a second brake system including a second pump device; and a main power source that supplies electricity to the first and second brake systems, wherein the hydraulic brake system includes an auxiliary power source that supplies electricity to the first brake system when a failure occurs in the main power source, and wherein the first pump device is continuously driven when the failure occurs irrespective of the pressure in the accumulator.

The hydraulic pressure control includes a valve portion which adjusts a fluid flowing into or flowing out of a hydraulic pressure chamber, a state judging portion which judges whether or not a state of the hydraulic pressure chamber is in a state in which the actual pressure is increasing even the holding signal has been inputted to the valve portion and a control portion which executes a specific control which keeps the actual pressure to the hydraulic pressure within the dead zone when the state judging portion judges that the state of the hydraulic pressure chamber is in a state that the actual pressure fluctuates even the holding signal has been inputted to the valve portion.

A braking system includes an electric motor configured to output a braking force, and a controller configured to control the electric motor. The controller is supplied with electric power from both a main power source and an auxiliary power source. The electric motor has a first state in which the electric motor is supplied with electric power from the main power source when the main power source has a voltage V1 equal to or higher than a threshold value Va; a second state in which the electric motor is supplied with electric power from the auxiliary power source, and the voltage V1 of the main power source is lower than the threshold value Va; and a third state in which the electric motor is supplied with electric power from the main power source, and the voltage V1 of the main power source is lower than the threshold value Va.

The invention relates to a brake device and a method for operating a brake device, wherein said brake device comprises an actuation device, also a booster device, in particular having an electro-hydraulic drive, a piston cylinder device (main cylinder) in order to supply hydraulic pressure medium to the brake circuits, a valve device for controlling or regulating the supply of the pressure medium and an electronic control or regulating device. According to the invention provision is made for additional pressure medium volume to be supplied in a controlled manner to at least one brake circuit by means of a further piston cylinder device, in particular a double stroke piston and at least one valve controlled by the control or regulating device.

An electromechanical brake booster of a braking system of a motor vehicle includes at least one support element (a) that extends essentially in parallel to an adjustment axis of a spindle, (b) that is attached to a gearbox housing bottom of the gearbox, (c) to which a master brake cylinder is attachable, and (d) that is designed to support forces acting on the at least one support element in the axial and/or radial direction.

A hydraulic braking system includes: a master cylinder including a pressurizing piston, a rearward chamber, and a pressure chamber; and a rearward-hydraulic-pressure controller connected to the rearward chamber and including a pressure increase valve and a regulator for controlling a hydraulic pressure in an output chamber. An air detector includes: an upstream detector, including the rearward-hydraulic-pressure controller, for detecting presence or absence of air in an upstream portion based on a relationship between the hydraulic pressure in the output chamber and an open time of the pressure increase valve; and a downstream detector for detecting presence or absence of air in a downstream portion based on a relationship between a stroke of the pressurizing piston and the hydraulic pressure in the output chamber. The downstream portion includes a portion located downstream of the pressure chamber of the master cylinder.

A hydraulic brake system, including: a brake operation member; a brake device; a master cylinder; a communication switching valve; a low-pressure-source shut-off valve; a high-pressure source; a regulator; a pressure adjuster; and a controller, wherein, when a pressurizing state of the master cylinder is switched from a first pressurizing state to a second pressurizing state after initiation of an operation on the brake operation member, the controller executes a pressurizing-state switching control in which switching of a state of the low-pressure-source shut-off valve from an open state to a closed state and switching of a state of the communication switching valve from a closed state to an open state are carried out after a pressure-regulating state of the regulator has been switched from a first pressure-regulating state to a second pressure-regulating state by controlling the pressure adjuster to increase a second pilot pressure while the first pressurizing state is maintained.

The braking device for a vehicle includes an operation judging portion which judges whether or not the operating amount in the increasing stage is equal to or more than a predetermined threshold amount or whether or not an increasing speed of the operating amount in the increasing stage is equal to or more than a predetermined threshold speed and a control portion which selects the first operating mode as the operating mode from a start of the increasing stage until a first timing or a second timing and selects the second operating mode as the operating mode in the increasing stage after the first timing or the second timing and at the same time maintains the drive hydraulic pressure in the increasing stage after the first timing or the second timing.