Electronic brake system is disclosed. An electronic brake system includes, a pressure sensor including a first pressure sensor configured to measure a hydraulic pressure of the accumulator, a second pressure sensor configured to measure a hydraulic pressure of the first hydraulic circuit, and a third pressure sensor configured to measure a hydraulic pressure of the second hydraulic circuit, a driver including one or more apply valves and release valves configured to control the hydraulic pressures of the first hydraulic circuit and the second hydraulic circuit, a determiner configured to determine that at least one of the first hydraulic circuit and the second hydraulic circuit has failed when an absolute value of a slope of the pressure measured by the first pressure sensor is greater than a preset first threshold value and the pressure measured by the first pressure sensor is less than a preset second threshold value and a controller configured to close apply valves of the first hydraulic circuit and the second hydraulic circuit when the failure has been determined, determine that a leak has occurred in one of the first and second hydraulic circuits having an amount of pressure change greater than that of the other hydraulic circuit measured on the basis of the second pressure sensor and the third pressure sensor, and control braking using only the hydraulic circuit operating normally.

A PCM (50) that is an engine control device functions to acquire a master vac negative pressure which is the negative pressure of a stabilized chamber of a master vac (126) which amplifies a brake pedal depressing force applied to a brake pedal (102), and also acquire a brake working fluid pressure that is a braking hydraulic pressure produced by a master cylinder (144) in accordance with the brake pedal depressing force amplified by the master vac (126), and in a case where both accelerator pedal (104) and a brake pedal (102) are depressed or actuated simultaneously, determine whether or not it is necessary to decrease engine output based on such master vac negative pressure and brake working fluid pressure to execute the output decreasing control for decreasing the engine output.

A brake system includes a master cylinder configured to generate a hydraulic pressure, a primary brake actuator configured to increase and decrease the hydraulic pressure generated in the master cylinder, a secondary brake actuator connected in series with and downstream of the master cylinder and in series with and upstream of the primary brake actuator, and configured to increase and decrease the hydraulic pressure generated in the master cylinder, and at least one wheel cylinder configured to apply brake torque to a wheel of a vehicle based on the hydraulic pressure generated by the master cylinder and increased or decreased by the primary actuator or the secondary actuator. An automatic brake hold control method includes sequential performing an automatic brake hold control on at least one wheel cylinder by the primary brake actuator and then the secondary brake actuator.

A hydraulic brake master cylinder (12) for a vehicle braking system defines a first smaller fluid path (70, 50, 56, 34, 42, 44) and a second larger fluid path (72, 50, 56, 34, 44, 42) for connecting a working chamber (32) with a fluid reservoir at ambient pressure when the cylinder piston (28) is retracted and the brakes are not applied. A pressure relief valve (76) normally closes the second fluid path but is arranged to open when subject to a pressure differential at or above a threshold value. The first fluid path allows a restricted return flow of fluid to the reservoir should a standard knock-back event occur. If a larger knock-back event occurs causing a fluid pressure spike at or above the threshold value, the pressure relief valve (76) opens to allow a higher volume return flow through the second fluid path to dissipate the pressure quickly.

A electric brake system includes a main device that provides a first hydraulic pressure to a plurality of wheel cylinders respectively installed on a plurality of wheels, based on a position of a brake pedal: and art auxiliary device that provides a second hydraulic pressure to first and second wheel cylinders respectively installed on first and second wheels among the plurality of wheels based on the position of the brake pedal in a state in which the main device does not generate the first hydraulic pressure. The auxiliary device receives power from a power network different from that of the main device, and the auxiliary device controls at least one of first and second parking brakes respectively installed on third and fourth wheels among the plurality of wheels. In such an electric brake system, when the main device fails or is out of control, the auxiliary device may auxiliary generate the hydraulic pressure required for braking and may generate braking force using the parking brake.

A transportation vehicle with a brake system designed for rapid deceleration of a moving vehicle, which enhances the effectiveness of vehicular braking in emergency situations, and increases the safety of automobile traffic on roads, which results in greater road-traffic safety due to enhanced reliability and higher effectiveness of braking under emergency situations. A vehicular hydraulic brake system having a master brake cylinder with a hydraulic reservoir supplying a brake fluid, a control foot pedal and a vacuum booster connected to an operating brake cylinder of each wheel. The brake system has emergency braking assemblies mounted before the operating brake cylinders of at least rear wheels. The emergency braking assembly includes an electrical mechanism operating in a reciprocating manner and has a rod attached to a piston of a hydraulic cylinder. An inlet hole of the hydraulic cylinder is connected to a pipeline in communication with the master braking cylinder. An outlet hole of the hydraulic cylinder is in communication with the operating brake cylinder. A top portion of the hydraulic cylinder has a compensation port in close proximity to the electrical mechanism, said compensation port being connected to the pipeline in communication with the master braking cylinder. A bottom portion of the hydraulic cylinder of the emergency braking assembly is disposed not lower than a top level of the operating brake cylinder.

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.

An integrated braking device for a vehicle equipped with wheel brakes includes a reservoir, master cylinder, bi-directional pumps each using hydraulic pressure oil from the reservoir for generating hydraulic pressure in first direction to apply braking force to the wheel brakes or generating hydraulic pressure in opposing second direction to control the hydraulic pressure oil from flowing to the reservoir, a hydraulic motor for driving the bi-directional pumps, inlet valves for controlling a hydraulic pressure from flowing from the bi-directional pumps to the wheel brakes, traction control valves each disposed between the master cylinder and each bi-directional pump to control flow of the hydraulic pressure oil inside the master cylinder, and a braking control unit for braking the vehicle by transmitting a driving signal to solenoid valves in the integrated braking device, the bi-directional pumps, and the hydraulic motor to control a flow of the hydraulic pressure.

An actuating device for a motor vehicle brake may include an actuating device/brake pedal, a pressure supply device driven by an electric motor, a (master) piston-cylinder unit that may be actuated by the actuating device, and which is connected hydraulically with a fluid reservoir, a valve assembly for wheel-specifically adjusting brake pressures and for connecting or disconnecting the wheel brakes to/from the pressure supply device and the piston-cylinder unit, an electronic control unit, and one or more sensor devices that may be used to provide sense various conditions and to provide inputs to the electronic control unit.

A braking system for a vehicle may include a hydraulic brake pedal system having a master cylinder having at least one pressure chamber, from which a hydraulic output is coupled to at least one brake circuit via an infeed switch valve. The master cylinder is coupled to a reservoir via at least one opening via a hydraulic connection. A failure of a pressure chamber seal of the at least one pressure chamber of the master cylinder is safeguarded by at least one redundancy, and the failure of the pressure chamber seal or the redundancy of the pressure chamber seal of the at least one pressure chamber of the master cylinder can be diagnosed.