HYDRAULIC ARRANGEMENT, DIAGNOSTIC METHOD, AND BRAKE SYSTEM

Abstract

A hydraulic arrangement for a brake system is disclosed. The hydraulic arrangement comprises a pressure-providing device, a reservoir for storing a pressure medium and a bleed line. The pressure-providing device has at least one pressure chamber which can be connected to a brake circuit. The reservoir has a first partial reservoir, which can be connected via a first reservoir line to a first pressure chamber of a piston-cylinder arrangement. The first pressure chamber of the piston-cylinder arrangement is delimited by a piston, which can be adjusted by an actuating device. The bleed line connects a bleed outlet of the pressure-providing device to the first reservoir line. A diagnostic method and brake system are also disclosed.

Claims

1. A hydraulic arrangement for a brake system, comprising a pressure-providing device having at least one pressure chamber which can be connected to a brake circuit; a reservoir for storing a pressure medium, wherein the reservoir has a first partial reservoir, which can be connected via a first reservoir line to a first pressure chamber of a piston-cylinder arrangement, wherein the first pressure chamber of the piston-cylinder arrangement is delimited by a piston, which can be adjusted by an actuating device; and a bleed line, which connects a bleed outlet of the pressure-providing device to the first reservoir line.

2. The hydraulic arrangement according to claim 1, wherein a valve, is arranged in the bleed line.

3. The hydraulic arrangement according to claim 2, wherein the valve is a non-return valve, a suction side of which is connected in a direction of the first reservoir line and a blocking side of which is connected in a direction of the bleed outlet.

4. The hydraulic arrangement according to claim 1, wherein the hydraulic arrangement has a switchable valve, which is arranged in the first reservoir line, wherein the bleed line opens into a section of the first reservoir line which is arranged between the switchable valve and the first pressure chamber of the piston-cylinder arrangement.

5. The hydraulic arrangement according to claim 1, wherein the piston-cylinder arrangement has an output piston, wherein the first pressure chamber of the piston-cylinder arrangement is delimited by an input piston and an output piston.

6. The hydraulic arrangement according to claim 1, wherein the pressure-providing device has a piston which is designed to connect the bleed outlet and/or the bleed line to the at least one pressure chamber of the pressure-providing device in one position.

7. The hydraulic arrangement according to claim 6, wherein the pressure-providing device has a first pressure chamber and a second pressure chamber, wherein the piston of the pressure-providing device separates the first pressure chamber and the second pressure chamber from one another, and wherein the piston is designed to connect the bleed outlet and/or the bleed line to the second pressure chamber (4) of the pressure-providing device in a rearward position.

8. The hydraulic arrangement according to claim 7, wherein the first and/or second pressure chamber of the pressure-providing device is or are connected via a line to a primary three-way valve, and to a secondary three-way valve, of the brake circuit.

9. The hydraulic arrangement according to claim 6, wherein the piston of the pressure-providing device has a connecting channel, which is designed to connect the bleed outlet and/or the bleed line to the at least one or to the second pressure chamber of the pressure-providing device.

10. The hydraulic arrangement according to claim 9, wherein the bleed outlet is arranged between two seals, which are in engagement with the cylindrical outer surface of the piston of the pressure-providing device.

11. The hydraulic arrangement according to claim 8, wherein the piston-cylinder arrangement has a second pressure chamber delimited by an output piston, wherein the second pressure chamber of the piston-cylinder arrangement is connected via a line to the secondary three-way valve, and/or in that the first pressure chamber of the piston-cylinder arrangement is connected via a line to the primary three-way valve.

12. The hydraulic arrangement according to claim 8, wherein the hydraulic arrangement has a pedal simulator arrangement having a simulator valve, wherein the pedal simulator arrangement is connected via a line to the primary three-way valve and/or to the first pressure chamber of the piston-cylinder arrangement.

13. The hydraulic arrangement according to claim 8, wherein the hydraulic arrangement has a plurality of pressure application valves, wherein at least one pressure application valve is connected via a line to the primary three-way valve, and/or at least one pressure application valve is connected via a line to the secondary three-way valve.

14. The hydraulic arrangement according to claim 8, wherein the primary three-way valve is connected in terms of flow to a first wheel brake and a third wheel brake via respective pressure application valves, and/or the secondary three-way valve is connected in terms of flow to a second wheel brake and a fourth wheel brake via respective pressure application valves.

15. The hydraulic arrangement according to claim 1, wherein the reservoir has a second partial reservoir, which is connected via a second reservoir line to the second pressure chamber of the piston-cylinder arrangement, and/or the reservoir has a third partial reservoir, which can be connected via a third reservoir line to the first pressure chamber of the pressure-providing device.

16. The hydraulic arrangement according to claim 1, wherein the hydraulic arrangement has a pressure sensor, for detecting a pressure present in the line connecting the first pressure chamber of the piston-cylinder arrangement and the primary three-way valve.

17. A diagnostic method for identifying a leak in a valve which is arranged in a bleed line of a hydraulic arrangement of a brake system, wherein the diagnostic method comprises the following steps: deactivating, a plurality of pressure application valves; activating, a primary three-way valve to hold and/or enclose a pressure medium, in a pressure chamber of a piston-cylinder arrangement, wherein the pressure chamber of the piston-cylinder arrangement is delimited by a piston, which can be adjusted by an actuating device; applying pressure via a simulator piston of a pedal simulator arrangement in order to achieve a predetermined pressure level in a line leading to the pressure chamber of the piston-cylinder arrangement and/or to the valve of the bleed line; connecting the bleed line to a booster circuit and/or brake circuit; identifying a leak in the valve of the bleed line if the pressure in the line leading to the pressure chamber of the piston-cylinder arrangement and/or to the valve of the bleed line, falls below a predetermined pressure value.

18. The diagnostic method according to claim 17, wherein the step of applying a pressure comprises actuating the pedal simulator arrangement, to exert the pressure.

19. The diagnostic method according to claim 17, wherein the step of applying a pressure comprises moving the simulator piston (43) into an extended position.

20. The diagnostic method according to claim 17, wherein the predetermined pressure level is achieved on a suction side of the valve of the bleed line.

21. The diagnostic method according to claim 17, wherein the step of connecting the bleed line to the booster circuit and/or the brake circuit comprises connecting a blocking side of the valve of the bleed line to the booster circuit and/or the brake circuit.

22. The diagnostic method according to claim 17, wherein the step of connecting the bleed line to the booster circuit and/or brake circuit comprises actuating a piston of a pressure-providing device within at least one pressure chamber of the pressure-providing device, wherein the at least one pressure chamber is connected to the booster circuit and/or brake circuit, wherein the piston of the pressure-providing device is moved into a home position and/or retracted position, in which the bleed line is connected to the booster circuit and/or brake circuit, via a connecting channel in the piston of the pressure-providing device.

23. The diagnostic method according to claim 17, wherein the predetermined pressure level and/or the predetermined pressure value is substantially 15 bar.

24. The diagnostic method according to claim 17, wherein the pressure is detected and compared with the predetermined pressure value by a pressure sensor, and/or a leak in the valve of the bleed line is identified if the detected pressure falls below the predetermined pressure value.

25. The diagnostic method according to claim 17, wherein, before the step of deactivating the plurality of pressure application valves and/or of activating the primary three-way valve the pressure chamber of the piston-cylinder arrangement (12), and/or the pedal simulator arrangement are pre-charged, with pressure medium, wherein, pre-charging is accomplished by actuation of the pressure-providing device by movement of the piston of the pressure-providing device into an extended position, and/or wherein, in the extended position of the piston of the pressure-providing device, the bleed line is separated from the booster circuit and/or brake circuit, and/or wherein, before the pre-charging step, the primary three-way valve is or becomes deactivated, for the purpose of connecting, the pressure-providing device to the pressure chamber thereof.

26. The diagnostic method according to claim 25, wherein, before the pre-charging step, the plurality of pressure application valves, a secondary three-way valve, a simulator valve and/or a simulator test valve are activated.

27. (canceled)

Description

BRIEF DESCRIPTION OF DRAWINGS

[0050] Exemplary arrangements of the disclosure are described in greater detail below with reference to figures, which are schematic and illustrative and of which:

[0051] FIG. 1 shows a hydraulic arrangement for a brake system of a vehicle;

[0052] FIG. 2 shows the hydraulic arrangement according to FIG. 1 in an exemplary configuration for pre-charging the system; and

[0053] FIG. 3 shows the hydraulic arrangement according to FIG. 1 in an exemplary configuration for testing the tightness of the valve in the bleed line.

DETAILED DESCRIPTION

[0054] FIG. 1 shows schematically a hydraulic arrangement 1 for a brake system, for example a brake system of a vehicle. The hydraulic arrangement 1 has a pressure-providing device 2 (DAP) with at least one pressure chamber, in this exemplary arrangement, a first pressure chamber 3 and a second pressure chamber 4, which can be connected to a brake circuit 5. The hydraulic arrangement 1 furthermore has a reservoir 6 for storing a pressure medium, such as hydraulic fluid and/or brake fluid. The reservoir 6 has a first partial reservoir 7, a second partial reservoir 8 and a third partial reservoir 9. The first partial reservoir 7 is connected via a first reservoir line 10 to a first pressure chamber 11 of a piston-cylinder arrangement 12. The first pressure chamber 11 of the piston-cylinder arrangement 12 is delimited by a piston 14, such as an input piston 14, which is adjustable by an actuating device 13, in this case a brake pedal device 13. The hydraulic arrangement 1 has a bleed line 15, which connects a bleed outlet 16 of the pressure-providing device 2 to the first reservoir line 10.

[0055] A valve 17, for example a checking and/or non-return valve, is arranged in the bleed line 15 and is designed as a non-return valve, the suction side of which is connected in the direction of the first reservoir line 10 and the blocking side of which is connected in the direction of the bleed outlet 16. The hydraulic arrangement 1 furthermore has a switchable simulator test valve 18, which is arranged in the first reservoir line 10. The bleed line 15 opens into a section 19 of the first reservoir line 10 which is arranged between the simulator test valve 18 and the first pressure chamber 11 of the piston-cylinder arrangement 12.

[0056] The pressure-providing device 2 has a piston 20, which is designed to connect the bleed outlet 16 and the bleed line 15 to the second pressure chamber 4 of the pressure-providing device 2 in one position, in one exemplary arrangement, a rearward position, such as an end position. The piston 20 of the pressure-providing device 2 separates the first pressure chamber 3 and the second pressure chamber 4 from one another. The first pressure chamber 3 and the second pressure chamber 4 of the pressure-providing device 2 are connected via a line 21 to a switchable primary three-way valve 22 and a switchable secondary three-way valve 23 of the brake circuit 5.

[0057] The piston-cylinder arrangement 12 furthermore has an output piston 24, wherein the first pressure chamber 11 of the piston-cylinder arrangement 12 is delimited by the input piston 14 and the output piston 24. The piston-cylinder arrangement 12 has a second pressure chamber 25 delimited by the output piston 12, wherein the second pressure chamber 25 of the piston-cylinder arrangement 12 is connected via a line 26 to the secondary three-way valve 23. The first pressure chamber 11 of the piston-cylinder arrangement 12 is connected via a line 27 to the primary three-way valve 22.

[0058] The hydraulic arrangement 1 furthermore has a pedal simulator arrangement 28 having a switchable simulator valve 29 and a simulator piston 43. The pedal simulator arrangement 28 is connected via a line 30 to the primary three-way valve 22 and to the first pressure chamber 11 of the piston-cylinder arrangement 12.

[0059] Furthermore, the hydraulic arrangement 1 has a plurality of switchable pressure application valves 31. At least one pressure application valve 31, in this case two pressure application valves 31, is/are connected via a line 32 to the primary three-way valve 22, and at least one pressure application valve 31, in this case two pressure application valves 31, is/are connected via a line 33 to the secondary three-way valve 23. The primary three-way valve 22 is connected in terms of flow to a first wheel brake 34 and a third wheel brake 35 via respective pressure application valves 31, and the secondary three-way valve 23 is connected in terms of flow to a second wheel brake 36 and a fourth wheel brake 37 via respective pressure application valves 31.

[0060] The second partial reservoir 8 of the reservoir 6 is connected via a second reservoir line 38 to the second pressure chamber 25 of the piston-cylinder arrangement 12, and the third partial reservoir 9 of the reservoir 6 is connected via a third reservoir line 39 to the first pressure chamber 3 of the pressure-providing device 2.

[0061] The piston 20 of the pressure-providing device 2 has a connecting channel 40. The connecting channel 40 is designed to connect the bleed outlet 16 and the bleed line 15 to the at least one or to the second pressure chamber 4 of the pressure-providing device 2. The bleed outlet 16 is arranged between two seals 41, which are in engagement with the cylindrical outer surface of the piston 20 of the pressure-providing device 2.

[0062] Furthermore, the hydraulic arrangement 1 has a pressure sensor 42 for example, a master cylinder primary pressure sensor 42, for detecting a pressure present in the line 27 connecting the first pressure chamber 11 of the piston-cylinder arrangement 12 and the primary three-way valve 22.

[0063] FIGS. 2 and 3 schematically show the hydraulic arrangement 1 described with reference to FIG. 1 in a configuration for pre-charging the system (FIG. 2) and in a configuration for testing a tightness of the valve 17 in the bleed line 15 (FIG. 3). The arrows shown in FIGS. 2 and 3 illustrate the direction of flow and/or direction of pressure of the pressure medium and the direction of movement of the pistons.

[0064] A diagnostic method for identifying a leak in the valve 17, such as a checking valve and/or a non-return valve which is arranged in the bleed line 15 of the hydraulic arrangement 1 can comprise the step of: deactivating, in particular deenergizing, the plurality of pressure application valves 31. The pressure application valves 31 then assume the state shown in FIG. 3.

[0065] The diagnostic method may further comprise a step of: activating, in one exemplary arrangement, energizing, the primary three-way valve 22 to hold and/or enclose the pressure medium, such as hydraulic fluid and/or brake fluid, in the first pressure chamber 11 of the piston-cylinder arrangement 12. The primary three-way valve 22 then assumes the state shown in FIG. 3.

[0066] The diagnostic method may further comprise a step of: applying pressure via the simulator piston 43 of the pedal simulator arrangement 28 in order to achieve a predetermined pressure level, for example in a line 27 leading to the pressure chamber 11 of the piston-cylinder arrangement 12 and to the valve 17 of the bleed line 15. The step of applying a pressure comprises actuating the pedal simulator arrangement 28, in particular actuating the simulator piston 43 of the pedal simulator arrangement 28, to exert the pressure. During this process, the simulator piston 43 is moved into an extended position. This is illustrated schematically by the arrows in FIG. 3. The predetermined pressure level is achieved on the suction side of the valve 17 of the bleed line 15.

[0067] The diagnostic method may further comprise a step of: connecting the bleed line 15 to a booster circuit 44 and/or brake circuit 5. The step of connecting the bleed line 15 to the booster circuit 44 and/or the brake circuit 5 comprises connecting the blocking side of the valve 17 of the bleed line 15 to the booster circuit 44 and/or the brake circuit 5. During this process, the pressure-providing device 2 is actuated, for example, the piston 20 of the pressure-providing device 2 is moved within the pressure chamber of the pressure-providing device 2, wherein the pressure chamber is connected to the booster circuit 44 and/or brake circuit 5. During this process, the piston 20 of the pressure-providing device 2 is moved into a home position and/or retracted position, in which the bleed line 15 is connected to the booster circuit 44 and/or brake circuit 5, for example via the connecting channel 40 in the piston 20 of the pressure-providing device 2. This is illustrated schematically by the arrow in FIG. 3.

[0068] The diagnostic method may further comprise the step of: identifying a leak in the valve 17 of the bleed line 15 if the pressure, for example in the line 27 leading to the first pressure chamber 11 of the piston-cylinder arrangement 12 and to the valve 17 of the bleed line 15, falls below a predetermined pressure value. The predetermined pressure level and/or the predetermined pressure value can be substantially 15 bar. The pressure is detected and compared with the predetermined pressure value by the pressure sensor 42, such as a master cylinder primary pressure sensor, and a leak in the valve 17 of the bleed line 15 is identified if the detected pressure falls below the predetermined pressure value.

[0069] Before the step of deactivating the plurality of pressure application valves 31 and before activating the primary three-way valve, the piston-cylinder arrangement 12, for example, the first pressure chamber 11 of the piston-cylinder arrangement 12 and the pedal simulator arrangement 28, is pre-charged, in particular with pressure medium (cf. FIG. 2).

[0070] Pre-charging is accomplished by actuation of the pressure-providing device 2, for example by movement of the piston 20 of the pressure-providing device 2 into an extended position, wherein, in the extended position of the piston 20 of the pressure-providing device 2, the bleed line 15 is separated from the booster circuit 44 and/or brake circuit 5. This is illustrated schematically by the arrows in FIG. 2.

[0071] Before the pre-charging step, the primary three-way valve 22 is deactivated, in particular de-energized, for the purpose of connecting, for example hydraulically, the pressure-providing device 2 to the piston-cylinder arrangement 12, for example to the first pressure chamber 11 thereof. The primary three-way valve 22 then assumes the state shown in FIG. 2.

[0072] Furthermore, before the pre-charging step, the plurality of pressure application valves 31, the secondary three-way valve 23, the simulator valve 29 and the simulator test valve 18 are activated, for example, energized. These valves then assume the state shown in FIG. 2.

[0073] In other respects, reference is additionally made, in particular, to FIG. 1 and the associated description.

[0074] “Can” denotes optional features of the disclosure. Accordingly, there are also developments and/or exemplary arrangements of the disclosure that have the respective feature or features in addition or as an alternative.

[0075] If required, isolated features can also be selected from the combinations of features disclosed here and, breaking up a structural and/or functional relationship which may exist between said features, can be used in combination with other features to delimit the subject matter of a claim. The sequence and/or number of steps of the method can be varied.