A method for operating an electrohydraulic brake installation for a motor vehicle having at least first, second, third and fourth hydraulically actuatable wheel brakes, a first brake system including a master brake cylinder actuatable by a brake pedal and hydraulically connected by at least one electrically actuatable isolating valve to the four wheel brakes, and including a first electrically controllable pressure provision device hydraulically connected to the four wheel brakes via at least one electrically actuatable sequence valve, and a second brake system including a second electrically controllable pressure provision device hydraulically connected to the first and the third wheel brake, and including in each case one isolating valve for the first and third wheel brake. The isolating valve is arranged in each case in a hydraulic connection between the first brake system and the corresponding wheel brake.

A brake device may include: a master cylinder including a master piston moved in connection with a pedal, and a master cylinder body having the master piston movably inserted therein and containing fluid of which hydraulic pressure is varied when the master piston is moved; a pedal force generation part housed in the master cylinder body, and restricting a motion of the master piston while interfering with the master piston depending on the motion of the master piston; a braking actuator configured to generate hydraulic pressure; an actuator connection part connecting the braking actuator to a brake mounted on a wheel; and a master connection part connecting the master cylinder to the actuator connection part.

This vehicle brake device performs raising processing for raising, by a predetermined raising amount, the target hydraulic pressure of hydraulic fluid when the pressure of the hydraulic fluid starts increasing in order to suppress a delay in response to the increase in the pressure of hydraulic fluid during switching processing for gradually switching at least part of regenerative braking force to hydraulic braking force, and includes a judging portion which judges whether or not required braking force or deceleration is reduced during cooperative control; and a raising amount setting portion which during the raising processing, sets a second predetermined pressure as a raising amount if the judgement result of the judging portion is positive, the second predetermined pressure being smaller than a first predetermined pressure that is the raising amount when the determination result of the determination result is negative.

An electronic brake system and a method for operating the same are disclosed. The electronic brake system includes a hydraulic-pressure supply device and a hydraulic-pressure control unit. The hydraulic-pressure supply device operates a hydraulic piston using an electric signal corresponding to a displacement of a brake pedal, and thus generates hydraulic pressure. The hydraulic-pressure control unit controls hydraulic pressure of a pressure medium supplied to individual wheel cylinders. The electronic brake system controls a plurality of valves mounted to the hydraulic-pressure control unit, and thus performs a normal operation mode, an abnormal operation mode, a regenerative braking mode, and an inspection mode using the valves.

Disclosed herein are an electric brake system and an operating method thereof. The electric brake system includes a master cylinder to discharge a pressurized medium in accordance with displacement of a brake pedal, a simulation device to provide a driver with a pedal feeling, a hydraulic pressure supply device to generate a hydraulic pressure by operating a hydraulic piston in accordance with an electrical signal output in response to the displacement of the brake pedal, and a hydraulic control unit to control a hydraulic pressure of the pressurized medium supplied to each wheel cylinder. The electric brake system may perform a normal mode, an abnormal mode, and an inspection mode.

Disclosed herein are an electric brake system and an operating method thereof. The electric bake system includes a master cylinder discharging pressure medium according to a displacement of a brake pedal, a simulator providing a sense of pedal to a driver, a hydraulic supplier generating hydraulic pressure by operating a hydraulic piston in response to an electrical signal output by corresponding to the displacement of the brake pedal, and a hydraulic control unit controlling hydraulic pressure of the pressure medium supplied to each wheel cylinder. The electric brake system performs a normal operation mode having a low pressure mode and a high pressure mode, an abnormal operation mode and an inspection mode.

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.

Provided is a brake apparatus capable of securing a braking force on a vehicle even at the time of a fluid leak. The brake apparatus performs control so as to continue generation of a brake hydraulic pressure to be supplied to a wheel cylinder with use of a second hydraulic source if a fluid leak of brake fluid is determined based on a preset relationship between a hydraulic pressure of a first hydraulic source and a stroke of a brake pedal.

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.

Disclosed is a brake apparatus capable of minimizing the stress of valves. The brake apparatus comprises: a first wheel cylinder provided in a first wheel; a second wheel cylinder provided in a second wheel; a first outlet valve for controlling discharge of brake oil from the first wheel cylinder; a second outlet valve for controlling discharge of the brake oil from the second wheel cylinder; and a controller which opens and then closes one of the first and second outlet valves in response to a first braking command generated when a brake pedal deviates from a standard position, and opens and then closes the other outlet valve of the first and second outlet valves in response to a first brake suspending command generated when the brake pedal is restored to the standard position.