BRAKING SYSTEM FOR A MOTOR VEHICLE AS WELL AS METHOD FOR OPERATING A BRAKING SYSTEM

Abstract

A braking system for a motor vehicle, having at least one brake pressure source and at least one wheel brake. In this case, it is provided that the at least one wheel brake is fluidically connected to the at least one brake pressure source via several brake pressure control devices, which are fluidically connected in parallel, wherein each of the brake pressure control devices has at least one pressure build-up valve and at least one pressure reduction valve, and that the brake pressure control devices are fluidically connected to the at least one brake pressure source via a common valve device, wherein the valve device always fluidically connects one of the brake pressure control devices to the at least one brake pressure source. The disclosure further relates to a method for operating a braking system for a motor vehicle.

Claims

1. A braking system for a motor vehicle, comprising: at least one brake pressure source and at least one wheel brake, wherein the at least one wheel brake is fluidically connected to the at least one brake pressure source via several brake pressure control devices, which are fluidically connected in parallel, wherein each of the brake pressure control devices has at least one pressure build-up valve and at least one pressure reduction valve, and that the brake pressure control devices are fluidically connected to the at least one brake pressure source via a common valve device, wherein the valve device always fluidically connects one of the brake pressure control devices to the at least one brake pressure source.

2. The braking system according to claim 1, wherein the at least one pressure build-up valve and the at least one pressure reduction valve are assigned to a brake circuit and each of the brake pressure control devices has at least one further pressure build-up valve and at least one further pressure reduction valve, which are assigned to a further brake circuit, wherein the brake circuit and the further brake circuit, fluidically independently of one another, are fluidically connected to the at least one brake pressure source via the valve device.

3. The braking system according to claim 1, wherein the wheel brake is fluidically connected to the brake pressure source via the brake circuit of the brake pressure control device, and a further wheel brake is fluidically connected to the brake pressure source via the further brake circuit of the brake pressure control devices.

4. The braking system according to claim 1, wherein, for each of the brake pressure control devices, the pressure reduction valve is fluidically connected to the at least one brake pressure source via an isolation valve of the respective brake pressure control device, and the pressure reduction valve is fluidically connected to the at least one brake pressure source via a further isolation valve of the respective brake pressure control device.

5. The braking system according to claim 1, wherein each of the brake pressure control devices has at least one brake pump, the intake side of which is fluidically connected to the wheel brake via the respective pressure reduction valve, and the pressure side of which is fluidically connected to the wheel brake via the respective pressure build-up valve.

6. The braking system according to claim 1, wherein the pressure side of the brake pump is fluidically connected to the brake pressure source via the isolation valve, and the intake side of the brake pump is fluidically connected to the brake pressure source via the further isolation valve.

7. The braking system according to claim 1, wherein the brake pressure control devices are connected to different electrical circuits, wherein the valve device switches from the first brake pressure control device to a second of the brake pressure control devices in the absence of current in a first of the electrical circuits assigned to a first of the brake pressure control devices.

8. The braking system according to claim 1, wherein the brake pressure control devices comprise at least three brake pressure control devices, and the valve device is multistage, wherein a first stage of the valve device is fluidically connected to the at least one brake pressure source on the input side and to the first brake pressure control device and a second stage of the valve device on the output side, and the second stage of the valve device is connected to the first stage of the valve device on the input side and to the second brake pressure control device and a third of the brake pressure control devices on the output side.

9. The braking system according to claim 1, wherein the brake pressure control devices are present as equivalent parts.

10. A method for operating a braking system for a motor vehicle, comprising: a braking system, wherein the braking system has at least one brake pressure source and at least one wheel brake, wherein the at least one wheel brake is fluidically connected to the at least one brake pressure source via several brake pressure control devices, which are fluidically connected in parallel, wherein each of the brake pressure control devices has at least one pressure build-up valve and at least one pressure reduction valve, and that the brake pressure control devices are fluidically connected to the at least one brake pressure source via a common valve device, wherein the valve device always fluidically connects one of the brake pressure control devices to the at least one brake pressure source.

11. The braking system according to claim 2, wherein the wheel brake is fluidically connected to the brake pressure source via the brake circuit of the brake pressure control device, and a further wheel brake is fluidically connected to the brake pressure source via the further brake circuit of the brake pressure control devices.

12. The braking system according to claim 2, wherein, for each of the brake pressure control devices, the pressure reduction valve is fluidically connected to the at least one brake pressure source via an isolation valve of the respective brake pressure control device, and the pressure reduction valve is fluidically connected to the at least one brake pressure source via a further isolation valve of the respective brake pressure control device.

13. The braking system according to claim 3, wherein, for each of the brake pressure control devices, the pressure reduction valve is fluidically connected to the at least one brake pressure source via an isolation valve of the respective brake pressure control device, and the pressure reduction valve is fluidically connected to the at least one brake pressure source via a further isolation valve of the respective brake pressure control device.

14. The braking system according to claim 2, wherein each of the brake pressure control devices has at least one brake pump, the intake side of which is fluidically connected to the wheel brake via the respective pressure reduction valve, and the pressure side of which is fluidically connected to the wheel brake via the respective pressure build-up valve.

15. The braking system according to claim 3, wherein each of the brake pressure control devices has at least one brake pump, the intake side of which is fluidically connected to the wheel brake via the respective pressure reduction valve, and the pressure side of which is fluidically connected to the wheel brake via the respective pressure build-up valve.

16. The braking system according to claim 4, wherein each of the brake pressure control devices has at least one brake pump, the intake side of which is fluidically connected to the wheel brake via the respective pressure reduction valve, and the pressure side of which is fluidically connected to the wheel brake via the respective pressure build-up valve.

17. The braking system according to claim 2, wherein the pressure side of the brake pump is fluidically connected to the brake pressure source via the isolation valve, and the intake side of the brake pump is fluidically connected to the brake pressure source via the further isolation valve.

18. The braking system according to claim 3, wherein the pressure side of the brake pump is fluidically connected to the brake pressure source via the isolation valve, and the intake side of the brake pump is fluidically connected to the brake pressure source via the further isolation valve.

19. The braking system according to claim 4, wherein the pressure side of the brake pump is fluidically connected to the brake pressure source via the isolation valve, and the intake side of the brake pump is fluidically connected to the brake pressure source via the further isolation valve.

20. The braking system according to claim 5, wherein the pressure side of the brake pump is fluidically connected to the brake pressure source via the isolation valve, and the intake side of the brake pump is fluidically connected to the brake pressure source via the further isolation valve.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0038] The disclosure is explained in more detail in the following by exemplary embodiments, without limiting the invention. In doing so, the only

[0039] FIG. 1 shows a schematic representation of a braking system for a motor vehicle.

DETAILED DESCRIPTION

[0040] The FIG. 1 shows a schematic representation of a braking system 1 for a motor vehicle. The braking system 1 has at least one brake pressure source 2 as well as at least one wheel brake 3, several wheel brakes 3, 4, 5, and 6 in the exemplary embodiment shown here, as essential components. The wheel brakes 3, 4, 5, and 6 are fluidically connected to the brake pressure source 2, namely via brake pressure control device 7, 8, and 9, which are fluidically connected in parallel, as well as via a common valve device 10. The wheel brakes 3, 4, 5, and 6 are subsequently also designated as the first wheel brake 3, second wheel brake 4, third wheel brake 5, and fourth wheel brake 6, and the brake pressure control devices 7, 8, and 9 are also designated as the first brake pressure control device 7, second brake pressure control device, and third brake pressure control device 9.

[0041] Each of brake pressure control devices 7, 8, and 9 has a brake circuit 11 as well as a further brake circuit 12. Two wheel brakes 3, 4, 5, and 6 are fluidically connected to each of the brake circuits 11 and 12 of each of brake pressure control devices 7, 8, and 9. Thus, wheel brakes 3 and 4 are fluidically connected to the first brake circuit 11 of the brake pressure control device 7, 8, and 9, and wheel brakes 5 and 6 are fluidically connected to the second brake circuit 12 of brake pressure control device 7, 8, and 9.

[0042] Each brake circuit 11 and 12 has a separate input 13 and/or 14 of respective brake pressure control device 7, 8, and 9. Inputs 13 and 14 of brake pressure control device 7, 8, and 9 are each connected to the brake pressure source 2 independently of one another, namely via the valve device 10. The valve device 10 has outputs for each of inputs 13 and each of inputs 14, that is six outputs in total. The valve device 10 has two inputs on the input side, which are fluidically connected to the brake pressure source 2 separately from one another. As a whole, the braking system 1 is thus designed as a multi-circuit, particularly as a two-circuit, braking system 1.

[0043] Each brake circuit 11 and 12 of each of brake pressure control devices 7, 8, 9 has several pressure build-up valves 15 and 16 as well as several pressure reduction valves 17 and 18. Pressure build-up valves 15 and 16 are preferably each designed as currentless open switching valves, and pressure reduction valves 17 and 18 are each designed as currentless closed switching valves. In the case of the first brake circuit 11, the pressure build-up valve 15 and the pressure reduction valve 17 are fluidically connected to wheel brake 3, and in the case of the second brake circuit, they are fluidically connected to wheel brake 5. In the case of the first brake circuit 11, the pressure build-up valve 16 and the pressure reduction valve 17 are fluidically connected to the second wheel brake 4, and in the case of the second brake circuit 12, they are fluidically connected to the fourth wheel brake 6. For example, wheel brakes 3 and 4 are assigned to a front wheel axle, and wheel brakes 5 and 6 are assigned to a rear axle of the motor vehicle. In this case, wheel brakes 3 and 5, for example, are assigned to a first track, and wheel brakes 4 and 6 are assigned to a second track different from the first track.

[0044] Each brake circuit 11 and 12 of each of brake pressure control devices 7, 8, and 9 has an isolation valve 19 and a further isolation valve 20. For each of brake circuits 11 and 12, pressure build-up valves 15 and 16 are fluidically connected to the respective input 13 and/or 14 via isolation valve 19, and pressure reduction valves 17 and 18 are fluidically connected to the respective input via isolation valve 20, with the fluid connection also being to the brake pressure source 2 and/or the valve device 10 at the same time. In addition, a brake pump 21 and/or 22 is assigned to each of the brake circuits 11 and 12, wherein brake pumps 21 and 22 of each brake pressure control device 7, 8 and 9 are driven or can be driven by a common motor 23. A pressure side of the respective brake pump 21 and/or 22 is fluidically connected to the respective input 13 and/or 14 and, with them, to the brake pressure shaft 2 via the respective isolation valve 19, and an intake side of the respective brake pump 21 and/or 22 is fluidically connected to the brake pressure shaft 2 via corresponding isolation valve 20, said fluid connection, in turn, being via the valve device 10.

[0045] In the exemplary embodiment shown here, the valve device 10 is constructed to be multistage and has, in this respect, a first stage 24 with a first switching valve 25 and a second stage 26 with a second switching valve 27. The two switching valves 25 and 27 are each designed as a 6/2-way valve such that the valve device 10 as a whole is present as an 8/3-way valve. The first switching valve 25 is connected to the brake pressure shaft 2 on the input side and connected to the brake pressure control device 7 on the output side as well as to the second switching valve 27. The second switching valve 27 in this respect is connected to the first switching valve 25 on the input side. The second switching valve 27 is connected to brake pressure control device 8 and to brake pressure control device 9 on the output side.

[0046] In a first switch position of the first switching valve 25, the brake pressure source 2, in this respect, is fluidically connected to brake pressure control device 7 via the valve device 10. In contrast, in a second switch position of the first switching valve 25, the brake pressure source 2 is fluidically connected to the second switching valve 27. In a first switch position of the second switching valve 27, switching valve 25 is fluidically connected to brake pressure control device 8, and in a second switch position, it is fluidically connected to brake pressure control device 9. If the first switching valve 25 is in its second switch position, the brake pressure source 2 is thus fluidically connected to brake pressure control device 8 in the first switch position of the second switching valve, and said brake pressure source is fluidically connected to brake pressure control device 9 in the second switch position of the second switching valve 27.

[0047] Switching valves 25 and 27 are each designed such that they are present without current in their second switch position. Preferably, the first switching valve 25 is connected to the same electrical circuit as the first brake pressure control device 7. In contrast, the second switching valve 27 is preferably connected to the same electrical circuit as brake pressure control device 8. Brake pressure control devices 7, 8, and 9 are especially preferably connected to electrical circuits separate from one another, that is the first brake pressure control device 7 is connected to a first electrical circuit, the second brake pressure control device 8 is connected to a second electrical circuit, and the third brake pressure control device 9 is connected to a third electrical circuit. A fallback level for the braking system 1 is hereby achieved in an especially reliable form and manner in event of failure of one of the brake pressure control devices 7, 8, and 9 and/or one of the corresponding electrical circuits.