Electrohydraulic power braking system
In the field of autonomous driving, a power braking system having two piston-cylinder units, one of which electromechanically generates a hydraulic brake pressure by means of an electric motor and the other of which communicates with the former in such a way that under pressure it generates a brake pressure in a second brake circuit. The second piston-cylinder unit hydraulically separates two brake circuits from each other.
1 . An electrohydraulic power braking system, comprising:
a first piston-cylinder unit including a first piston which, to generate a hydraulic brake pressure with power, can be displaced using a first electric motor via a rotation/translation converter gear in a first cylinder of the first piston-cylinder unit; and
a second piston-cylinder unit including a second piston and a second cylinder, the second cylinder communicating with the first cylinder of the first piston-cylinder unit in such a way that the hydraulic brake pressure of the first cylinder exerts pressure on a rear face of the second piston in the second cylinder of the second piston-cylinder unit in such a way that the second piston generates a hydraulic brake pressure in the second cylinder of the second piston-cylinder unit on a front face facing away from its rear face,
wherein the first piston of the first piston-cylinder unit has a larger diameter than the second piston of the second piston-cylinder unit.
2 . The electrohydraulic power braking system according to claim 1 , wherein the power braking system includes a first brake circuit connected to the first cylinder of the first piston-cylinder unit or on the rear face of the second piston to the second cylinder, and a second braking circuit connected on the front face of the second piston to the second cylinder of the second piston-cylinder unit.
3 . The electrohydraulic power braking system according to claim 1 , wherein the first electric motor and the rotation/translation converter gear are arranged coaxially with the first cylinder of the first piston-cylinder unit.
4 . The electrohydraulic power braking system according to claim 1 , further comprising:
a power brake pressure generator with which a hydraulic brake pressure can be generated as an alternative to generating brake pressure with the first and second piston-cylinder units.
5 . The electrohydraulic power braking system according to claim 4 , wherein the power braking system comprises a slip control system including the power brake pressure generator.
6 . The electrohydraulic power braking system according to claim 4 , wherein the power braking system comprises a redundant power supply and/or a redundant electronic controller for the first electric motor of the first piston-cylinder unit and the power brake pressure generator or a slip control system.
7 . The electrohydraulic power braking system according to claim 1 , wherein the first piston of the first piston-cylinder unit is connected in a tension-resistant and pressure-resistant manner to the rotation/translation converter gear in such a way that the first piston can be displaced using the first electric motor via the rotation/translation converter gear in two opposite directions in the second cylinder of the second piston-cylinder unit.
8 . An electrohydraulic power braking system, comprising:
a first piston-cylinder unit including a first piston which, to generate a hydraulic brake pressure with power, can be displaced using a first electric motor via a rotation/translation converter gear in a first cylinder of the first piston-cylinder unit;
a second piston-cylinder unit including a second piston and a second cylinder, the second cylinder communicating with the first cylinder of the first piston-cylinder unit in such a way that the hydraulic brake pressure of the first cylinder exerts pressure on a rear face of the second piston in the second cylinder of the second piston-cylinder unit in such a way that the second piston generates a hydraulic brake pressure in the second cylinder of the second piston-cylinder unit on a front face facing away from its rear face;
a first brake circuit connected to the first cylinder of the first piston-cylinder unit or on the rear face of the second piston to the second cylinder;
a second braking circuit connected on the front face of the second piston to the second cylinder of the second piston-cylinder unit;
a brake fluid reservoir; and
a check valve which connects the first cylinder of the first piston-cylinder unit or the second cylinder of the second piston-cylinder unit and the first brake circuit or the second brake circuit to the brake fluid reservoir and which allows throughflow in a direction of the first cylinder or second cylinder and in a direction of the first brake circuit or the second brake circuit.
9 . The electrohydraulic power braking system according to claim 8 , further comprising:
a connection valve through which the first cylinder of the first piston-cylinder unit and/or the second cylinder of the second piston-cylinder unit is connected to the brake fluid reservoir.
10 . An electrohydraulic power braking system, comprising:
a first piston-cylinder unit including a first piston which, to generate a hydraulic brake pressure with power, can be displaced using a first electric motor via a rotation/translation converter gear in a first cylinder of the first piston-cylinder unit; and
a second piston-cylinder unit including a second piston and a second cylinder, the second cylinder communicating with the first cylinder of the first piston-cylinder unit in such a way that the hydraulic brake pressure of the first cylinder exerts pressure on a rear face of the second piston in the second cylinder of the second piston-cylinder unit in such a way that the second piston generates a hydraulic brake pressure in the second cylinder of the second piston-cylinder unit on a front face facing away from its rear face,
wherein the power braking system comprises no actuation by muscle power.