Multiple-Circuit, Hydraulically Open Brake System, in Particular for a Highly Automated or Autonomous Vehicle

• US 20190322261A1
• Filed: 04/11/2019
• Published: 10/24/2019
• Est. Priority Date: 04/20/2018
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hienz, Bernd, Brenndoerfer, Daniel, Drotleff, Dirk, Kleemann, Ralf, Friedrich, Thomas
• Granted Patent: US 11,148,651 B2
• Time in Patent Office: Days
• CPC Class Codes: B60T 13/16 using pumps directly, i.e. without interposition of accumulators or reservoirs
• CPC Class Codes: B60T 13/166 Part of the system directly actuated by booster pressure
• CPC Class Codes: B60T 13/58 Combined or convertible systems
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 13/745 acting on a hydraulic system, e.g. a master cylinder
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B60T 2270/402 Back-up
• CPC Class Codes: B60T 2270/403 Brake circuit failure
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 8/17 Using electrical or electronic regulation means to control braking detecting or indicating faulty operation B60T8/885

Abstract

A multiple-circuit, hydraulically open brake has two single-circuit pressure generators hydraulically connected in parallel between at least one fluid container and at least two wheel brakes and a modulation unit for individual brake pressure modulation in the at least two wheel brakes. A first pressure generator is assigned to a main system which has a first energy supply and a first evaluation and control unit, and a second single-circuit pressure generator is assigned to a secondary system, which has a second energy supply which is independent of the first energy supply, and a second evaluation and control unit. The second evaluation and control unit controls the second pressure generator. Components of the modulation unit are assigned to the main system so that the modulation unit and the first pressure generator are controlled by the first evaluation and control unit and supplied with energy by the first energy supply.

Claims

1. A multiple-circuit, hydraulically open brake system, comprising:

at least two wheel brakes, which are each assigned to a respective brake circuit having a pressure-relief path;

a first single-circuit pressure generator;

a second single-circuit pressure generator, the first and second single-circuit pressure generators being hydraulically connected in parallel between at least one fluid container and the at least two wheel brakes; and

a modulation unit configured to modulate respective hydraulic connections between the first and second single-circuit pressure generators to the at least two wheel brakes and for the individual brake pressure modulation in the at least two wheel brakes,

wherein the first single-circuit pressure generator is assigned to a main system which has a first energy supply, a first evaluation and control unit, a first shut-off valve, and a second shut-off valve, the first shut-off valve configured to connect the first single-circuit pressure generator to at least one first wheel brake of the at least two wheel brakes assigned to a first respective brake circuit, and the second shut-off valve configured to connect the first single-circuit pressure generator to at least one second wheel brake of a second respective brake circuit,

wherein the second single-circuit pressure generator is assigned to a secondary system, which has a second energy supply which is independent of the first energy supply, a second evaluation and control unit, a third shut-off valve, and a fourth shut-off valve, the third shut-off valve configured to connect the second single-circuit pressure generator to the at least one first wheel brake of the first brake circuit, and the fourth shut-off valve configured to connect the second single-circuit pressure generator to the at least one second wheel brake of the second brake circuit,

wherein the second evaluation and control unit controls the second single-circuit pressure generator,

wherein components of the modulation unit are assigned to the main system so that said components of the modulation unit and the first single-circuit pressure generator are controlled by the first evaluation and control unit and supplied with energy by the first energy supply.

2. The brake system according to claim 1, wherein at least one of the first and second evaluation and control units is configured to control the first, second, third, and fourth shut-off valves in such a way that, when one of the first and second single-circuit pressure generators is activated, a hydraulic fluid is not conducted through the other of the first and second single-circuit pressure generators.

3. The brake system according to claim 2, wherein:

the first and second shut-off valves are each configured as magnetic valves that are closed when de-energized,

the third and fourth shut-off valves are each configured as magnetic valves which are open when de-energized, and

the first evaluation and control unit controls the first, second, third, and fourth shut-off valves.

4. The brake system according to claim 2, wherein:

the first and second shut-off valves are each configured as magnetic valves which are open when de-energized,

the third and fourth shut-off valves are each configured as magnetic valves which are closed when de-energized, and

the second evaluation and control unit controls the first, second, third, and fourth shut-off valves.

5. The brake system according to claim 2, wherein:

the first and fourth shut-off valves are each configured as magnetic valves which are open when de-energized,

the second and third shut-off valves are each configured as magnetic valves which are closed when de-energized,

the first evaluation and control unit controls the second and fourth shut-off valves, and

the second evaluation and control unit controls the first and third shut-off valves.

6. The brake system according to claim 1, wherein:

the at least one fluid container includes a common fluid container shared by the main system and the secondary system, or

the at least one fluid container includes a first fluid container having at least one fluid chamber assigned to the main system and a second fluid container having at least one fluid chamber is assigned to the secondary system.

7. The brake system according to claim 1, wherein the first single-circuit pressure generator is configured as one of a plunger system and a pump system.

8. The brake system according to claim 6, further comprising:

at least one suction line having a non-return valve that hydraulically connects the first single-circuit pressure generator to the first fluid container.

9. The brake system according to claim 1, wherein the second single-circuit pressure generator is configured as one of a plunger system and a pump system.

10. The brake system according to claim 1, wherein at least one of the first and second single-circuit pressure generators is configured as a plunger system comprising:

a piston-cylinder unit having a piston and a chamber; and

a drive configured to move the piston against the force of a return spring for pressure adjustment in the chamber.

11. The brake system according to claim 1, wherein at least one of the first and second single-circuit pressure generators is configured as a pump system comprising a pump and a drive that drives the pump.

12. The brake system according to claim 6, wherein, during an individual brake pressure modulation in the at least one wheel brake, brake fluid released from the at least one wheel brake is returned via the at least one pressure-relief path either to the first fluid container or to the second fluid container.

13. The brake system according to claim 1, further comprising a common hydraulic block in which the first pressure generator, the second pressure generator, and the modulation unit are arranged.

14. The brake system according to claim 1, further comprising:

a first hydraulic block in which the first pressure generator and the modulation unit are arranged; and

a second hydraulic block in which the second pressure generator is arranged.

15. A method for operating a multiple-circuit, hydraulically open brake system, the brake system including:

at least two wheel brakes, which are each assigned to a respective brake circuit having a pressure-relief path;

a first single-circuit pressure generator;

a second single-circuit pressure generator, the first and second single-circuit pressure generators being hydraulically connected in parallel between at least one fluid container and the at least two wheel brakes; and

a modulation unit configured to modulate respective hydraulic connections between the first and second single-circuit pressure generators to the at least two wheel brakes and for the individual brake pressure modulation in the at least two wheel brakes;

wherein the first single-circuit pressure generator is assigned to a main system which has a first energy supply, a first evaluation and control unit, a first shut-off valve, and a second shut-off valve, the first shut-off valve configured to connect the first single-circuit pressure generator to at least one first wheel brake of the at least two wheel brakes assigned to a first respective brake circuit, and the second shut-off valve configured to connect the first single-circuit pressure generator to at least one second wheel brake of a second respective brake circuit;

wherein the second single-circuit pressure generator is assigned to a secondary system, which has a second energy supply which is independent of the first energy supply, a second evaluation and control unit, a third shut-off valve, and a fourth shut-off valve, the third shut-off valve configured to connect the second single-circuit pressure generator to the at least one first wheel brake of the first brake circuit, and the fourth shut-off valve configured to connect the second single-circuit pressure generator to the at least one second wheel brake of the second brake circuit;

wherein the second evaluation and control unit controls the second single-circuit pressure generator;

wherein components of the modulation unit are assigned to the main system so that said components of the modulation unit and the first single-circuit pressure generator are controlled by the first evaluation and control unit and supplied with energy by the first energy supply, the method comprising;

in normal operation;

operating the main system to increase, reduce, or maintain the pressure in the brake circuits via the first single-circuit pressure generator; and

performing the individual brake pressure modulation in the at least two wheel brakes with the modulation unit; and

when the main system fails;

operating the secondary system to increase, reduce, or maintain the pressure in the brake circuits via the second single-circuit pressure generator; and

omitting the individual brake pressure modulation in the at least two wheel brakes.

16. The method according to claim 15 further comprising, in normal operation:

operating the first shut-off valve and the second shut-off valve into an open state;

operating the third shut-off valve and the fourth shut-off valve into a closed state; and

controlling a drive of the first single-circuit pressure generator to increase, reduce, or maintain pressure in the brake circuits.

17. The method according to claim 15, the performing of the individual pressure modulation, in normal operation, further comprising:

to increase pressure in an assigned wheel brake of the at least two wheel brakes, opening an inlet valve associated with the assigned wheel brake and closing an outlet valve associated with the assigned wheel brake;

to maintain pressure in the assigned wheel brake, closing the inlet valve and the outlet valve; and

to reduce pressure in the assigned wheel brake, opening the outlet valve.

18. The method according to claim 15, further comprising, when the main system fails:

operating the first shut-off valve and the second shut-off valve are transferred into a closed state;

operating the third shut-off valve and the fourth shut-off valve into an open state; and

controlling the drive of the second single-circuit pressure generator being controlled accordingly to increase pressure or to reduce pressure or to maintain pressure in the brake circuits.

19. The method according to claim 15, further comprising:

when a leakage is detected in one of the brake circuits, closing one of the first, second, third, and fourth shut-off valves that is associated with the one brake circuit in which the leakage is detected.

20. The method according to claim 15, further comprising:

when a leakage is detected in one of the at least two wheel brakes, closing an inlet valve associated with the one of the at least two wheel brakes in which the leakage is detected.