A method for monitoring a hydraulic brake system for a motor vehicle, wherein a diagnostic valve is omitted and, instead, air volume and leakage are identified by a volume balance during generation of a dynamic pressure. An associated brake system is also disclosed.

A brake system may include an actuating device, in particular a brake pedal; a first piston-cylinder unit having two pistons subjecting the brake circuits to a pressure medium via a valve device, wherein one of the pistons can be actuated by the actuation device; a second piston-cylinder unit having an electric motor drive, a transmission at least one piston to supply at least one of the brake circuits with a pressure medium via a valve device; and a motor pump unit with a valve device to supply the brake circuits with a pressure medium. The brake system may also include a hydraulic travel simulator with a pressure or working chamber which is connected to the first piston-cylinder unit.

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 pre-filling device for a braking system. The pre-filling device includes a pre-filling channel, a pre-filling pressure being inside the channel when the braking system is in a rest and hydro-boost position, and a mechanical valve configured to be opened following a transition from the rest and hydro-boost position to a working position of the braking system; and a hydraulic valve cooperating with the mechanical valve setting the pre-filling pressure inside the channel. The hydraulic valve includes in a first area, facing the mechanical valve, a hole communicating with the channel, and in a second area, hydraulically isolated from the first area, a preloaded resilient element in a chamber held at atmospheric pressure. The hydraulic valve is configured to be connected or not to be connected, by a reciprocating movement inside the channel, to a hydro-booster device and to keep a predetermined pre-filling pressure upon varying of the hydro-boost pressure.

A control device for a vehicle hydraulic braking system, including an electronic device for transferring brake fluid into at least one wheel brake cylinder without a force transmission connection to the brake actuating element, or that is hydraulically decoupleable from the brake actuating element, with a motorized brake pressure buildup device; ascertaining whether wheel locking of at least one wheel of the vehicle that is braked with the at least one wheel brake cylinder is present or at risk; temporarily effectuating, at least at times, a counterforce on the brake actuating element acting against the actuation of the brake actuating element by the driver when it is ascertained that wheel locking is present or at risk and/or when the electronic brake force distribution function and/or the antilocking function are/is executed. Also described is a hydraulic braking system for a vehicle, and a method for operating such a braking system.

A hydraulic device for controlling braking for farm tractors, earthmovers and like machines, comprises a master cylinder and brake booster. A piston of the brake booster defines first and second chambers which, under rest conditions, are in communication and, during braking, are cut off with the first chamber being put in communication with a discharge chamber of the master cylinder. The piston of the master cylinder is driven by a drive piston shaped to define with a plunger of the piston of the brake booster a hollow space through which the first chamber communicates with either the second chamber or the discharge chamber, depending on device operating conditions. In the plunger, a seat for a gasket-valve is arranged to cooperate with the drive piston, during braking, to prevent fluid leakage between the second and the first chamber as a consequence of the sliding of the drive piston caused by braking.

An electric booster may include: a motor part configured to be driven by power applied thereto; a body part mounted and fixed onto the motor part; a cylinder part coupled to the body part; a screw part connected to the motor part and rotated; a nut part embedded in the body part, and screwed to the screw part so as to linearly move; a first piston part constraining an end of the screw part, and moved to the cylinder part while being pressed by the nut part; a first elastic part supporting the first piston part; a second piston part supported by the first elastic part; and a second elastic part supporting the second piston part.

A braking apparatus of a vehicle may include: a first master cylinder configured to create hydraulic pressure as a brake pedal is pressed; a second master cylinder configured to create braking pressure through a piston which is pressed by the hydraulic pressure created by the first master cylinder and a nut moved by rotation of a motor; and a control unit, configured to: calculate a required displacement position of the nut based on a pedal stroke of the brake pedal, and update the required displacement position based on a displacement position of the nut at a dead stroke end point where the pedal stroke moves away from a dead stroke section of the first master cylinder.

A brake system may include an actuating device, in particular a brake pedal; a first piston-cylinder unit having two pistons subjecting the brake circuits to a pressure medium via a valve device, wherein one of the pistons can be actuated by the actuation device; a second piston-cylinder unit having an electric motor drive, a transmission at least one piston to supply at least one of the brake circuits with a pressure medium via a valve device; and a motor pump unit with a valve device to supply the brake circuits with a pressure medium. The brake system may also include a hydraulic travel simulator with a pressure or working chamber which is connected to the first piston-cylinder unit.

A hydraulic block of a slip regulation of a hydraulic vehicle power brake system that has a master brake cylinder bore and forms a master brake cylinder. In order to prevent a hard impact of a piston of the master brake cylinder against an end stop when the master brake cylinder is released, in particular when there is an abrupt release, for example when the foot slides off a foot brake pedal, a hydraulic return damper that is integrated in the piston is provided.