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US 2014/0110997 A1Published application
Brake System for Motor Vehicles and Method for Operating the Brake System
AssigneeContinential Teves AG & Co. oHG
InventorsHarald Biller, Harald Biller
Life of this patent
Estimating the term…
Abstract
A motor vehicle brake system and method operable in a brake by wire and in a fallback operating mode. In addition to a first pressure supply unit a second electrically controllable pressure supply unit having at least one intake port and one pressure port, the intake port of which is connected or connectable to one of the pressure chambers and the pressure port of which is connectable or connected to the brake circuit associated with the pressure chamber. The second pressure supply unit is arranged in the hydraulic connection between one of the pressure chambers of the brake master cylinder and the brake circuit associated with the pressure chamber.
Claims15
A brake system for motor vehicles which in a brake-by-wire operating mode can be activated both by the vehicle driver and independently of the vehicle driver, and is normally operated in the brake-by-wire operating mode and can be operated in at least one fallback operating mode, comprising
- a brake master cylinder (2) having a housing (21) and two pistons (15, 16) which defined in the housing (21) two pressure chambers (17, 18) to each of which a respective brake circuit (I, II) having wheel brakes (8, 9, 10, 11) is connectable or connected,
- a brake pedal (1) coupled to the brake master cylinder for actuating the brake master cylinder (2),
- an electrically operable, normally open isolation valve (23a, 23b) for each of the brake circuits (I, II) for isolating the pressure chambers (17, 18) from the respective brake circuit,
- an electrically operable, normally open inlet valve and an electrically operable, normally closed outlet valve for each wheel brake for setting wheel-individual brake pressures of a pressure medium,
- a first electrically controllable pressure supply unit (5) which having a cylinder-piston arrangement with a piston (36) of which is operable by an electro mechanical actuator (35),
- an electrically operable normally closed sequence valve (26a, 26b) for each of the brake circuits (I, II) for hydraulically connecting the first pressure supply unit (5) to the brake circuits,
- a simulation device (3) which is hydraulically connectable by means of an electrically or mechanically operable simulator release valve (32) to at least one of the pressure chambers (17) of the brake master cylinder (2) and which communicates to the vehicle driver a predetermined brake pedal feel in the brake-by-wire operating mode,
- a first electronic control and regulation unit (12) for activating the first pressure supply unit (5), the isolation valves (23a, 23b), the sequence valves (26a, 26b) and the simulator release valve (32), and
- a second electrically controllable pressure supply unit (49, 149) having at least one intake port and one pressure port, whereof the intake port is connected or connectable to one of the pressure chambers (17, 18) and the pressure port is connectable or connected to one of the brake circuits (I, II) associated with the pressure chamber, the pressure supply unit (49, 149) being able to draw pressure medium from the pressure chamber in an unenergized state of the isolation valves and of the inlet and the outlet valves.
6 more elements
A method for operating a brake system, comprising the steps of
- providing a brake master cylinder (2) having a housing (21) and two pistons (15, 16) which define in the housing (21) two pressure chambers (17, 18) to each of which a respective of two brake circuits (I, II) having wheel brakes (8, 9, 10, 11) is connectable or connected,
- providing a brake pedal (1) coupled to the brake master cylinder for actuating the brake master cylinder (2),
- providing an electrically operated, normally open isolation valve (23a, 23b) for each of the brake circuits (I, II) for isolating the pressure chamber (17, 18) from the brake circuits,
- providing an electrically operated, normally open inlet valve and an electrically operated, normally closed outlet valve for each wheel brake for setting wheel-individual brake pressures of a pressure medium,
- providing a first electrically controllable pressure supply unit (5) which is formed by a cylinder-piston arrangement the piston (36) of which is operated by an electrome-chanical actuator (35),
- providing an electrically operated normally closed sequence valve (26a, 26b) for each of the brake circuits (I, II) for hydraulically connecting the first pressure supply unit (5) to each of the brake circuits,
- providing a simulation device (3) which is hydraulically connectable by means of an electrically or mechanically operated simulator release valve (32) to at least one pressure chamber (17) of the brake master cylinder (2) and which communicates to the vehicle driver a desired brake pedal feel in the brake-by-wire operating mode,
- providing a first electronic control and regulation unit (12) for activating the first pressure supply unit (5), the isolation valves (23a, 23b), the sequence valves (26a, 26b) and the simulator release valve (32),
- providing a second electrically controllable pressure supply unit (49, 149) having at least one intake port and one pressure port, whereof the intake port is connected or connectable to one of the pressure chambers (17, 18) and the pressure port is connectable or connected to one of the brake circuits (I, II) associated with the pressure chamber, the pressure supply unit (49, 149) being able to draw pressure medium from the pressure chamber in an unenergized state of the isolation valves and of the inlet and outlet valves,
- operating the braking system wherein in an unenergized state of the isolation valves and of the inlet and outlet valves of the brake system, by means of the second electrically controllable pressure supply unit (49, 149) wherein the pressure medium is drawn from the pressure chamber or the pressure chambers (17, 18) of the brake master cylinder (2) and fed in a pressure-boosted manner into the associated of the brake circuits (I, II), if a pressure build-up or pressure reduction cannot be carried out by means of the first pressure supply unit (5) and the vehicle driver actuates the brake pedal (1).
7 more elements
Dependencies are inferred from the claim text.