A braking system includes a master cylinder including a master cylinder output, at least one wheel cylinder, a shuttle valve including a shuttle, a volume booster distinct from the master cylinder, a first hydraulic fluid path connecting the master cylinder output to the at least one wheel cylinder through the volume booster and the shuttle valve and a second hydraulic fluid path connecting the master cylinder output to the at least one wheel cylinder through the shuttle valve, bypassing the volume booster. Only one of the first hydraulic fluid path or the second hydraulic fluid path is operable at any one time.

A method for operating a hydraulic brake system of a motor vehicle having a brake booster and a hydraulic brake boost wherein a brake pressure is detected and an underpressure, prevailing in an underpressure chamber of the brake booster is estimated on the basis of the detected brake pressure. The hydraulic brake boost controlled based on the estimated underpressure, with the estimated underpressure taking into account an actuation of the hydraulic brake boost.

A vehicle brake system includes a dual acting plunger assembly. The dual acting plunger assembly comprises a housing, an anti-rotation tube secured to a ball screw assembly, and a torque coupler. The torque coupler is attached between the housing and anti-rotation tube, wherein the torque coupler allows rotation between the housing and the anti-rotation tube.

A brake booster includes an input element actuatable by a driver, an actuator for generating a support force, an output element that receives at least one of an input or support force and that applies an actuating force to a piston of a brake master cylinder, a force transmission unit having elastic properties and transmitting the input and/or support forces to the output element, and a preload unit acting on the force transmission unit to apply a force couple to the force transmission unit when the brake booster is in idle mode. A method for operating the brake booster includes generating a support force prior to a braking intent to be anticipated or immediately after detection of a braking intent, in a time span before or immediately after detection of an actuation of the input element.

The present disclosure in some embodiments provides a brake apparatus for a vehicle, comprising: a reservoir configured to store a working fluid; a master cylinder connected to the reservoir; a hydraulic circuit connected to a wheel brake; a primary brake unit configured to supply a hydraulic pressure to the wheel brake through the hydraulic circuit; and a secondary brake unit configured to supply a hydraulic pressure to the wheel brake through the hydraulic circuit, wherein the hydraulic circuit comprises: a first hydraulic circuit coupled to the reservoir, the master cylinder, and the secondary brake unit; a second hydraulic circuit coupled to the reservoir and the primary brake unit; and a third hydraulic circuit coupled to the primary brake unit, the secondary brake unit, and the wheel brake.

A holding valve (61) is provided on an individual flow passage (51) connecting a main flow passage (52) and a wheel cylinder (42) to each other. The holding valve (61) permits communication between an upstream side and a downstream side in an open state to transmit the hydraulic pressure from an accumulator (32) to the wheel cylinder (42), and shuts off the communication between the upstream side and the downstream side in a closed state. Moreover, a pressure reducing valve (62) for realizing communication or shutoff between a reservoir (22) and a main flow passage (52) and between the reservoir (22) and the wheel cylinder (42) is provided on a pressure reducing individual flow passage (56) for connecting a reservoir flow passage (57) and the individual flow passage (51) to each other. Then, when a driver carries out a return operation on a brake pedal (10) during antiskid control, a brake ECU (100) inhibits the holding valve (61) in the closed state from shifting to the open state, maintains the holding valve (61) in the open state, and controls the pressure reducing valve (62) corresponding to this holding valve (61) to shift to the open state. As a result, a hydraulic pressure in the main flow passage (52) is decreased via the holding valve (61) and the pressure reducing valve (62) in the open state.

A method is described for operating a hydraulic braking device of a vehicle, in particular a motor vehicle, including at least one brake booster, which sets a brake boost as a function of a driver's braking command. It is provided that the driver's braking command is ascertained via a vacuum sensor assigned to a pneumatic brake booster and a hydraulic brake boost is set.

This hydraulic braking device is provided with: a tubular cylinder; an assisting piston, which is housed in the cylinder so as to be able to move reciprocally, faces a reservoir formed inside the cylinder, and assists a master piston, in a master cylinder, that generates hydraulic pressure for generating a braking force by reciprocally moving from one side to the other as a result of a fluid flowing into the reservoir from a supply source; and a seal member, which is elastically deformable and which seals the reservoir. When the assisting piston is at a location on one side, the reservoir is compartmentalized into a first chamber that communicates with the supply source, and a second chamber that communicates with the first chamber through a restricting flow passage, and the seal member seals the second chamber.

A hydraulic-pressure control device includes a regulator including a housing, a control piston in the housing, an input chamber at a rear of the piston, and an output chamber in front of the piston; and an input-hydraulic-pressure control device which controls hydraulic pressure in the input chamber to move the piston forward or backward to raise or reduce hydraulic pressure in the output chamber. The input-hydraulic-pressure control device includes a moving-direction control unit which, when a difference obtained by subtracting an actual hydraulic pressure in the output chamber from a target hydraulic pressure in the output chamber is less than a pressurization-side set value, controls the hydraulic pressure in the input chamber to move the piston backward; and when the difference is greater than a reduction-side set value, controls the hydraulic pressure in the input chamber to move the piston forward.

A braking system includes a master cylinder including a master cylinder output, at least one wheel cylinder, a shuttle valve including a shuttle, a volume booster distinct from the master cylinder, a first hydraulic fluid path connecting the master cylinder output to the at least one wheel cylinder through the volume booster and the shuttle valve and a second hydraulic fluid path connecting the master cylinder output to the at least one wheel cylinder through the shuttle valve, bypassing the volume booster. Only one of the first hydraulic fluid path or the second hydraulic fluid path is operable at any one time.