Add-on module for an electrohydraulic brake assembly, and brake assembly system comprising an add-on module of said type

1. An auxiliary module for an electrohydraulic brake assembly, for use in highly automated driving, comprising:

a hydraulics unit comprising a hydraulics housing with a pressure provision device provided at least partially within the hydraulics housing for building up pressure in at least two brakes,

at least one reservoir for brake fluid within the hydraulics housing of the hydraulics unit,

a first wheel brake feed line configured to be connected to a first wheel brake line of the brake assembly,

a second wheel brake feed line configured to be connected to a second wheel brake line of the brake assembly, and

an isolating valve which is open when electrically deenergized connected into each of the first and second wheel brake feed lines,

wherein the at least one reservoir is connected to a hydraulic equalization line positioned at least partially within the hydraulics housing to form a connection to atmospheric pressure.

2. The auxiliary module as claimed in claim 1 , wherein the pressure provision device comprises at least one pump which is driven by an electric motor and a suction side of the at least one pump is hydraulically connected to the respective reservoir.

3. The auxiliary module as claimed in claim 2 , wherein the at least one reservoir for brake fluid comprises exactly two reservoirs for brake fluid, and the at least one pump comprises exactly two pumps, and wherein each of the two pumps is, at the suction side, hydraulically connected via a suction line to exactly one of the two reservoirs.

4. The auxiliary module as claimed in claim 2 , wherein each pump is, at a respective pressure side, connected to a respective one of the first and second wheel brake feed lines which is connected to a hydraulic wheel brake.

5. The auxiliary module as claimed in claim 4 , wherein, from the respective wheel brake feed line, a hydraulic return line branches off which is hydraulically connected to in each case one reservoir.

6. The auxiliary module as claimed in claim 5 , wherein a return valve which is closed when electrically deenergized is connected into the respective return line.

7. The auxiliary module as claimed in claim 4 , wherein the respective wheel brake feed line is connected to a pressure sensor which measures the pressure in the wheel brake feed line.

8. The auxiliary module as claimed in claim 2 , configured such that a respective pump of the at least one pump draws in medium from the respective reservoir from the bottom.

9. The auxiliary module as claimed in claim 2 , wherein a pipe is arranged in the at least one reservoir such that the pump draws in the brake fluid from the bottom of the at least one reservoir.

10. The auxiliary module as claimed in claim 1 , comprising a hydraulics housing for the hydraulics unit, a motor housing, and an electronics housing.

11. The auxiliary module as claimed in claim 10 , wherein the hydraulics housing is arranged between the electronics housing and the motor housing.

12. The auxiliary module as claimed in claim 3 , wherein the two pumps are driven by a common electric motor.

13. The auxiliary module as claimed in claim 1 , wherein the hydraulic equalization line lacks any valve therein.

14. The auxiliary module as claimed in claim 1 , wherein the at least one reservoir for brake fluid comprises one reservoir for brake fluid for each of the at least two brakes, wherein each of the reservoirs are connected to the hydraulic equalization line to form the connection to atmospheric pressure.

15. An auxiliary module for an electrohydraulic brake assembly, for use in highly automated driving, comprising:

a hydraulics unit comprising a hydraulics housing with a pressure provision device provided at least partially within the hydraulics housing for building up pressure in at least two brakes,

a first wheel brake feed line configured to be connected to a first wheel brake line of the brake assembly,

a second wheel brake feed line configured to be connected to a second wheel brake line of the brake assembly, and

an isolating valve which is open when electrically deenergized connected into each of the first and second wheel brake feed lines, and

at least one reservoir for brake fluid within the hydraulics housing of the hydraulics unit,

wherein the pressure provision device comprises at least one pump which is driven by an electric motor and a suction side of the at least one pump is hydraulically connected to the respective reservoir,

wherein the at least one reservoir for brake fluid comprises exactly two reservoirs for brake fluid, and the at least one pump comprises exactly two pumps, and wherein each of the two pumps is, at the suction side, hydraulically connected via a suction line to exactly one of the two reservoirs, and

wherein a valve which is closed when electrically deenergized is connected into the respective suction line.

16. A brake assembly system, for highly automated driving, comprising a brake assembly, comprising:

hydraulically actuatable wheel brakes;

at least one electrically actuatable wheel valve for each wheel brake, for setting wheel-specific brake pressures;

a master brake cylinder which is connected and/or connectable to the wheel brakes;

a pressure medium reservoir tank which is at atmospheric pressure; and

an electrically controllable pressure provision device for the actuation of the wheel brakes, having a hydraulic pressure space, wherein the respective wheel brake is hydraulically connected to the pressure space by a wheel brake line; and

a module comprising:

a hydraulics unit with a pressure provision device for building up pressure in at least two brakes, and

at least one reservoir for brake fluid integrated into the hydraulics unit;

wherein the at least one reservoir is connected to a hydraulic equalization line which is provided for forming a connection to the atmosphere, and wherein the equalization line is connected to the pressure medium reservoir tank of the brake assembly,

wherein a first wheel brake line of the brake assembly opens into a first wheel brake feed line of the auxiliary module, and wherein a second wheel brake line of the brake system opens into a second wheel brake feed line of the auxiliary module, and wherein an isolating valve which is open when electrically deenergized is connected into the respective wheel brake feed line.

17. The brake assembly system as claimed in claim 16 , wherein the equalization line is formed at least partially as a steel line.

18. The brake assembly system as claimed in claim 16 , wherein the two wheel brake feed lines are connected to front-wheel brakes.