Brake system with two pressure sources, and two methods for operating a brake system

A brake system, comprising four hydraulically actuatable wheel brakes, wherein each of the four hydraulically actuatable wheel brakes is assigned one outlet valve which is closed when electrically deenergized, and wherein each of the four hydraulically actuatable wheel brakes is assigned one inlet valve which is open when electrically deenergized,

• comprising a simulator which is actuatable by a brake pedal,
• wherein two pressure provision devices are provided for actively building up pressure in the four hydraulically actuatable wheel brakes,
• wherein two brake circuits are hydraulically formed, wherein each of the two brake circuits includes one of the two pressure provision devices hydraulically connected to two of the four hydraulically actuatable wheel brakes,
• wherein two separate on-board electrical systems are provided, and wherein each of the two pressure provision devices is fed by one of the two on-board electrical systems, and wherein an isolating device is provided having (i) a connecting position in which the two brake circuits are hydraulically connected to one another such that each of the four hydraulically actuatable wheel brakes is hydraulically connected to both of the two pressure provision devices, and (ii) an isolating position in which the two brake circuits are hydraulically isolated from one another such that each of the four hydraulically actuatable wheel brakes is hydraulically connected to exactly one of the two pressure provision devices, and
• wherein each of the two pressure provision devices is directly and non-separably hydraulically connected to two of the inlet valves, which are open when electrically deenergized, of two of the four hydraulically actuatable wheel brakes of one of the two brake circuits and is separably connected to two more of the inlet valves, which are open when electrically deenergized, of the other two of the four hydraulically actuatable wheel brakes of the other one of the two brake circuits by means of the isolating device.

A brake system, comprising four hydraulically actuatable wheel brakes, wherein each of the four hydraulically actuatable wheel brakes is assigned one outlet valve which is closed when electrically deenergized, and wherein each of the four hydraulically actuatable wheel brakes is assigned one inlet valve which is open when electrically deenergized,

• comprising a simulator which is actuatable by a brake pedal,
• wherein two pressure provision devices are provided for actively building up pressure in the four hydraulically actuatable wheel brakes,
• wherein two brake circuits are hydraulically formed, wherein each of the two brake circuits includes one of the two pressure provision devices hydraulically connected to two of the four hydraulically actuatable wheel brakes,
• wherein two separate on-board electrical systems are provided, and wherein each of the two pressure provision devices is fed by one of the two on-board electrical systems, and
• wherein an isolating device is provided having (i) a connecting position in which the two brake circuits are hydraulically connected to one another such that each of the four hydraulically actuatable wheel brakes is hydraulically connected to both of the two pressure provision devices, and (ii) an isolating position in which the two brake circuits are hydraulically isolated from one another such that each of the four hydraulically actuatable wheel brakes is hydraulically connected to exactly one of the two pressure provision devices,
• wherein at least one of the two pressure provision devices is directly and non-separably hydraulically connected to two of the inlet valves, which are open when electrically deenergized, of two of the four hydraulically actuatable wheel brakes of one of the two brake circuits and is separably connected to two more of the inlet valves, which are open when electrically deenergized, of the other two of the four hydraulically actuatable wheel brakes of the other one of the two brake circuits by means of the isolating device, and
• wherein the isolating device is fed by each of the two on-board electrical systems.