The present invention concerns a hydraulic pressure amplifier device comprising a casing (10) having two chambers (12, 14) of different cross-sections which house a staged piston (20) comprising two piston sections (22, 24) with cross-sections respectively el matching the chambers (12, 14), and means (30) for controlling the movement of the piston (20), characterised by the fact that the control means (30) are formed of an electronic control driven by means for estimating the ends-of-stroke of the piston (20) without an end-of-stroke sensor or mechanical stop.

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 safety system brake system comprises a hydraulic pressure-providing device having a pressure chamber connected to at least one brake circuit by a separating valve and into which pressure chamber a piston is moved to build up pressure. The pressure chamber is a two-stage pressure chamber having first and second sub-chambers. During pressure build-up the piston is moved into the first and then the second sub-chamber. The two sub-chamber are hydraulically closed off from each other when the piston is moved a specified distance into the second sub-chamber. A first check valve is connected to the first sub-chamber on a suction side and to a brake fluid reservoir on a blocking side. A second check valve is connected to the second sub-chamber on a suction side, and to the suction side of the first check valve on the blocking side.

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 brake system for a vehicle having a master brake cylinder, which provides a pressure signal, having a brake-medium reservoir connected to the master brake cylinder, and a first brake circuit, which is coupled by a first input to the master brake cylinder and by a second input to the brake-medium reservoir, and having at least one first wheel-brake cylinder, which is mounted at a first wheel, in order to exert a force corresponding to the pressure signal onto the first wheel, and having a separator valve, which is configured between the first input and the first wheel-brake cylinder, to prevent further transmission of the pressure signal upon receipt of a supplied closing signal; and having a control valve, which is configured between the first input and the first wheel-brake cylinder; in order to control an inflow of a brake medium from brake-medium reservoir to the first wheel-brake cylinder. In addition, a method for controlling a corresponding brake system is also described.

A boost arrangement for pressurizing a master cylinder of a vehicle braking system of a vehicle includes a housing, a primary piston and a secondary piston. The housing defines a boost chamber filled with brake fluid. The primary piston is disposed in the boost chamber and defines an opening extending therethrough. The secondary piston has an end extending into the opening defined by the primary piston.

The present disclosure relates to a master cylinder and an electronic brake system having the same. The master cylinder includes a cylinder block having a bore of a multi-stage form in a longitudinal direction therein, a first master chamber and a second master chamber sequentially arranged in series in the bore, a first master piston provided to move in connection with an operation of a brake pedal and to pressurize the first master chamber, a second master piston provided to be displaceable by a displacement of the first master piston or a hydraulic pressure in the first master chamber and to pressurize the second master chamber, and a pedal simulator interposed between the first master piston and the second master piston to provide a reaction force to the brake pedal, wherein a cross-sectional area of the first master piston is provided to be relatively larger than a cross-sectional area of the second master piston.

A brake control device includes: a liquid pressure line provided for each vehicle wheel and supplied with a brake liquid pressure; a pressurization unit configured to supply a pressurization brake liquid pressure to the liquid pressure line; an abnormality detection unit configured to detect an abnormality of the liquid pressure line at a time the brake liquid pressure of the liquid pressure line is not greater than a threshold value; and a pressurization adjustment unit configured to continuously supply the pressurization brake liquid pressure to the liquid pressure line of the normal vehicle wheel having a low abnormality occurrence risk and suppress the supply pressure of the pressurization brake liquid pressure to the liquid pressure line of the vehicle wheel having a high abnormality occurrence risk until the abnormality of the liquid pressure line is detected by the abnormality detection unit.

An integrated electro-hydraulic brake system includes a power source unit storing a pressure, discharging oil from a reservoir to an accumulator, and a motor driving the pump; and an integrated hydraulic control device including a master cylinder and generating a hydraulic pressure, a reservoir connected above the master cylinder and storing oil, an in-valve and an out-valve controlling pressure delivered from the accumulator to a wheel cylinder. The power source unit is provided as a separate unit to isolate operating noises, and the integrated hydraulic control device and the power source unit are connected by an external pipe, and the out-valve is provided as a normally open type-solenoid valve that is used at low current ranges, normally maintains an open state in order to reduce heat generation, but is closed when a close signal is received, compared to a normally close type-solenoid valve that normally maintains a close state.

A master brake cylinder for a braking system of a vehicle has: a first filling volume, which is fillable with liquid, and whose first dimension is variable by adjusting at least one first piston wall; a second filling volume, which is fillable with liquid, and whose dimension is variable by adjusting at least one second piston wall; and a valve unit, the first filling volume being connected via the valve unit to the second filling volume in such a way that when the valve unit is switched into a first valve state, a joint first pressure chamber pressure prevails in the first filling volume and in the second filling volume.