Method for operating brake system upon detection of leak and control device for carrying out such method
The method and control device for hydraulic brake systems maintain pressure by transferring medium between reservoir chambers using an electronically controlled pump and valve configuration, addressing the issue of leaks and ensuring operational readiness during power outages.
Patent Information
- Application Number
- CN202380084667.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-19
- Filing Date
- 2023-12-12
- Publication Date
- 2025-07-15
AI Technical Summary
Hydraulic braking systems are prone to loss of pressure medium when wheels are leaked, especially when power is out, and modern electrical dual-loop systems are more susceptible to impact.
When a leakage is detected, a pressure medium pump is used to transfer the pressure medium from the leaked brake control circuit to the unleaked circuit, and the remaining pressure medium is protected by a pressure source and a check valve to ensure that the brake system can still be operated in the standby state.
When the brake system detects leakage, it can protect the pressure medium from loss, ensuring that necessary braking intervention can still be carried out in standby state, and avoid complete failure of the system.
Smart Images
Figure CN120322362A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for operating a braking system in the event of a detected leak, the braking system having an electrically actuable pressure source which is connected via a first pressure line and a pressure supply valve to a first brake control circuit and via the pressure supply valve and additionally via a brake circuit isolation valve to a second brake control circuit, pressurized pressure medium being supplied from a first chamber of a pressure medium reservoir to the brake control circuits, each brake control circuit having its own inlet valve and its own outlet valve, each brake control circuit being connected to the pressure source via its own inlet valve, each brake control circuit being connected to a second chamber of the pressure medium reservoir via its own outlet valve, all the outlet valves being connected via a common outlet connection line to the second chamber of the pressure medium reservoir, the pressure source being connected to the first chamber via a check valve, the common outlet connection line being connected via a pressure medium pump to the second brake control circuit, and the pressure source being connected to the first chamber of the pressure medium reservoir via a first valve. The present invention further relates to a control device for a braking system, the control device having a processor for carrying out such a method. Background Art
[0002] Hydraulic braking systems are prone to leaks of pressure medium. This can involve connections, valves or actuators in the piping system, such as calipers or pumps. In the worst case, the entire braking system may drain so that it cannot operate. In the case of a motor vehicle, a basic requirement of the braking system is that when the control unit is de-energized (i.e., in the standby / non-operating mode of the braking system), the wheels or wheel brakes must be connected to the pressure medium reservoir so that the pressure medium is stored in the system without pressure.
[0003] Especially in the case of a wheel leak, complete loss of the brake fluid can occur very quickly in the dormant state, especially if valves that open when de-energized are used.
[0004] Newer braking systems usually no longer have a classical dual or multi-circuit, i.e., different wheel brakes can no longer be permanently separated into two separate pressure medium circuits, but only have an electrical dual circuit which only functions when the electronics are activated. Therefore, these systems are particularly vulnerable to wheel leaks in the dormant state.
[0005] The pressure medium reservoir can have a plurality of chambers which are partially separated from each other. In the case of a wheel leak, one chamber can thus be emptied while there is still a supply of pressure medium in another or several other chambers. However, during normal operation, due to the connection of these pressure medium circuits, the remaining pressure medium may be lost due to the leak and thus render the braking system unusable further. Summary of the Invention
[0006] Accordingly, it would be desirable to provide a method and a control device which allow the above-mentioned brake system to operate at least partially in a safety mode such that the most necessary brake interventions remain possible, but no additional pressure medium is lost due to a leak.
[0007] Accordingly, a suitable method provides that, in the case of the above-mentioned brake system, in the event of a leak in the second brake control circuit, in order to continue operating the brake system using only the first brake control circuit, a valve that allows the second chamber of the pressure medium reservoir to be connected via a pressure medium pump to the pressure source and / or the first chamber of the pressure medium reservoir is opened, and the pressure medium pump is actuated, so that the pressure medium is pumped from the second chamber of the pressure medium reservoir into the pressure source and / or the first chamber of the pressure medium reservoir through the connection formed, then the brake circuit isolation valve is closed, and the first brake control circuit is operated using the pressure medium from the first chamber of the pressure medium reservoir with the aid of the pressure source. In the event that the brake system is to be put into a standby state, the pressure medium is pre-pumped from the pressure source into the second chamber of the pressure medium reservoir by operating the pressure source.
[0008] Accordingly, with a lockable brake circuit isolation valve, during brake operation, only the pressure medium in the first chamber of the pressure medium reservoir can be used to operate the first brake control circuit with the aid of the associated pressure source. In the standby state, the brake fluid in the second chamber of the pressure medium reservoir is protected. For forward and reverse pumping, both the pressure source and the pressure medium pump are advantageously used depending on the pumping direction.
[0009] In an advantageous configuration of the method, in a third step, after pumping the pressure medium of the pressure source into the second chamber of the pressure medium reservoir, the pressure medium is drawn from the first chamber of the pressure medium reservoir into the pressure source and then pumped back into the second chamber of the pressure medium reservoir.
[0010] In this way, not only is the pressure medium from the pressure source in the second chamber of the pressure medium reservoir protected during the standby phase, but also the pressure medium from the first chamber of the pressure medium reservoir.
[0011] This can be carried out several times in succession until all the pressure medium in the first chamber of the pressure medium reservoir has been pumped into the second chamber of the pressure medium reservoir and is protected there against loss in the event of a leak in the second brake control circuit.
[0012] In an advantageous configuration of the method, in the event of a leak in the second brake control circuit, in order to further operate the brake system using only the first brake control circuit, to fill the pressure source with pressure medium from the second chamber of the pressure medium reservoir, the pressure supply valve and the brake circuit isolation valve are opened, and the pressure medium pump is actuated. In the event that the brake system is to be brought into a standby state, the first valve and the brake circuit isolation valve are pre-closed, at least one outlet valve and at least one inlet valve of the first brake control circuit and the pressure supply valve are opened, and the pressure medium is conveyed from the pressure source to the second chamber of the pressure medium reservoir by operating the pressure source.
[0013] Accordingly, the advantageous valves available for each re-pumping operation are opened.
[0014] This object is also achieved by a method for operating a brake system in the event of a detected leak, the brake system having an electrically actuable pressure source which is connected to a first brake control circuit via a first pressure line and a pressure supply valve and to a second brake control circuit via the pressure supply valve and additionally via a brake circuit isolation valve, supplying pressure medium under pressure to the brake control circuits from a first chamber and / or a third chamber of a pressure medium reservoir, each brake control circuit having its own inlet valve and its own outlet valve, each brake control circuit being connected to the pressure source via its respective inlet valve, each brake control circuit being connected to the second chamber of the pressure medium reservoir via its respective outlet valve, all the outlet valves being connected to the second chamber of the pressure medium reservoir via a common outlet connection line, the pressure source being connected to the first chamber or the third chamber via a check valve, the common outlet connection line being connected to the second brake control circuit via a pressure medium pump, the pressure source being connected to the first chamber of the pressure medium reservoir via a first valve, the method having the following steps:
[0015] In the event of a leak in the second brake control circuit, in order to further operate the brake system using only the first brake control circuit, the valve allowing the second chamber of the pressure medium reservoir to be connected to the first pressure line via the pressure medium pump is opened, and the pressure medium pump is actuated, so that the pressure medium is pumped from the second chamber of the pressure medium reservoir into the first pressure line through the connection formed, then the brake circuit isolation valve is closed, and the first brake control circuit is operated using the pressure medium from the first chamber of the pressure medium reservoir by means of the pressure source.
[0016] Since the pressure source is not emptied in the event of a wheel leak, filling the first pressure line by means of the pressure medium pump is sufficient for emergency operation.
[0017] This object is also achieved by a control device for a brake system, the control device having a processor for performing one of the above methods.
[0018] For this purpose, the processor is designed to execute such a method by executing corresponding computer commands. For this purpose, the computer commands are stored in the memory of the control device or externally to the control device and are called and executed by the processor. Description of the Drawings
[0019] The present invention will be described in more detail below with reference to exemplary embodiments with the aid of the drawings, in which:
[0020] Figure 1 a schematic hydraulic circuit diagram of a braking system for a method according to the invention is shown,
[0021] Figure 2 shows a front wheel leakage illustration in the braking system according to Figure 1 ;
[0022] Figure 3 shows an example of a repumping operation in the braking system according to Figure 1 ;
[0023] Figure 4 shows an example of a reverse repumping operation in the braking system according to Figure 1 ;
[0024] Figure 5 a further schematic hydraulic circuit diagram of a braking system for a method according to the invention is shown. Detailed Description of the Invention
[0025] Figure 1 A highly schematic exemplary embodiment of a braking system 1 for a motor vehicle is shown. According to the exemplary embodiment, the braking system 1 is designed to actuate four hydraulically actuable wheel brakes 7a, 7b, 7c and 7d. According to the exemplary embodiment, the wheel brakes 7a and 7b are assigned to the front axle of the motor vehicle, and the wheel brakes 7c and 7d are assigned to the rear axle. The wheel brakes 7a and 7b of the front axle are part of a second brake control circuit 6b, and the wheel brakes 7c and 7d of the rear axle are part of a first brake control circuit 6a.
[0026] The braking system 1 has a pressure medium reservoir 3, which has two at least partially separated chambers, wherein a first chamber 3a is assigned a first reservoir interface and a second chamber 3b is assigned a second reservoir interface.
[0027] In a braking system 1, an electrically actuable pressure source 2 and wheel-specific brake pressure regulating valves which are components of brake control circuits 6a, 6b are arranged. The brake pressure regulating valves are designed as electrically actuable inlet valves 8a, 8b, 8c and 8d and electrically actuable outlet valves 9a, 9b, 9c and 9d for each wheel brake 7a to 7d. The outlet valves 9a, 9b, 9c, 9d are connected via a common outlet connection line 13 to a second chamber 3b of a pressure medium reservoir 3.
[0028] The pressure source 2 is connected on the pressure side via a first pressure line 14 and a pressure supply valve 5 to a second pressure line 15 to which the inlet valves 8c and 8d of the first brake control circuit 6a are connected. Thus, the wheel brakes 7c and 7d can be actuated directly by means of the pressure source 2.
[0029] The pressure source 2 is additionally connected via the pressure supply valve 5, a fourth pressure line 16, a brake circuit isolation valve 4 and a third pressure line 12 to the inlet valves 8a and 8b of the second brake control circuit 6b. Thus, the wheel brakes 7a and 7b of the front axle can likewise be actuated directly by means of the pressure source 2. However, if a leak has been detected, for example, the second brake control circuit 6b can also be isolated from the pressure source 2 by means of the brake circuit isolation valve 4.
[0030] By means of the pressure supply valve 5, the pressure source 2 can be isolated from the brake control circuits 6a, 6b to lock, for example, the pressure medium in the pressure source 2 so that this pressure medium is not lost in the event of a leak in the wheel brakes, for example. Additionally, the pressure supply valve 5 can be closed, whereupon the pressure source 2 can suck in pressure medium via a check valve from a first chamber 3a of the pressure medium reservoir 3 by retraction.
[0031] At least one electronic control device 20 is provided, which is shown highly schematically in Figure 1 Each electronic control device includes electrical and / or electronic components (for example, a microcontroller, a power module, a valve driver, other electronic components, etc.) for actuating the electrically actuable components of the braking system 1 and optionally associated sensors. For the sake of clarity, the connecting lines to such actuators and sensors have been omitted.
[0032] The electronic control device 20 controls the pressure source 2. According to an example, the pressure source 2 is supplied with energy (from a power source not shown) via the electronic control device 20.
[0033] The electronically controllable pressure source 2 is in the form of, for example, a hydraulic cylinder-piston device (or a single-circuit electrohydraulic actuator (linear actuator)), the piston of which can be actuated by an electric motor via a rotary-translatory mechanism and in particular can be pushed out and retracted in order to build up and relieve pressure in a pressure chamber. The piston delimits the pressure chamber of the pressure source 2. A rotor position sensor of the electric motor is provided for controlling the electric motor, which sensor detects the rotor position of the electric motor and is only indicated schematically.
[0034] Irrespective of the actuation state of the piston, the pressure chamber is connected via a (supplementary) line to the pressure medium reservoir 3 or its first chamber 3a. A non-return valve which closes in the direction of the pressure medium reservoir 3 is arranged in this line. The cylinder-piston device 2 can additionally have a compensation port (not shown). By retracting the piston, pressure medium can be drawn from the pressure medium reservoir 3 into the pressure chamber.
[0035] The brake system 1 additionally has a pressure medium pump 10, which is connected on the inlet side via an outlet connection line 13 to the second chamber 3b of the pressure medium reservoir 3. On the output side, the pressure medium pump is connected via a third pressure line 12 to the inlet valves 8a, 8b of the second brake control circuit 6b.
[0036] The pressure medium pump 10 can thus supply pressure medium to the second brake control circuit 6b and actuate it. The pressure medium pump 10 can likewise be supplied with energy and controlled by the control device 20 and in particular be switched on and off.
[0037] Since the brake circuit isolation valve 4 is also connected via a fourth pressure line 16 and a second pressure line 15 to the first brake control circuit 6a, the pressure medium pump 10 can also supply pressure medium to the first brake control circuit 6a via this brake circuit isolation valve 4.
[0038] In Figure 1 the exemplary embodiment, the electronically controllable pressure medium pump 10 is designed as a double-piston pump, the two pressure sides and the two suction sides of which are connected to one another respectively.
[0039] The pressure medium pump 10 has non-return valves on both its pressure side and its suction side, such that the pressure medium can only be conveyed in the direction from the second chamber 3b of the pressure medium reservoir 3 to the brake control circuits 6a, 6b.
[0040] In Figure 1In the braking system 1, the pressure source 2 is additionally connected via an isolation valve 11 to a first chamber 3a of a pressure medium reservoir 3. Also via this isolation valve 11, the pressure source 2 can suck pressure medium from the first chamber 3a of the pressure medium reservoir 3. However, it is also possible to pump pressure medium from a second chamber 3b of the pressure medium reservoir 3 into the first chamber 3a of the pressure medium reservoir 3 via this isolation valve 11 by means of a pressure medium pump 10 so that it can be used for the operation of the first braking control circuit 6a.
[0041] In Figure 2 , the use of Figure 1 An example of the braking system 1 shows a situation where there is a leak at a wheel brake 7b of one of the second braking control circuits 6b of the front axle. Identical parts have the same reference numerals. When the braking system 1 is in the standby state, valves that allow the wheel brakes 7a to 7d to be connected to the first chamber 3a of the pressure medium reservoir 3 are opened to create an unpressurized state. Specifically, the isolation valve 11, the pressure supply valve 5, the brake circuit isolation valve 4, and the inlet valves 8a - 8d of the braking control circuits 6a, 6b are opened. However, due to the front axle leak, the first chamber 3a of the pressure medium reservoir 3 may thus be emptied. This is schematically shown by the thickened connecting line from the first chamber 3a of the pressure medium reservoir 3 via the opened valves 11, 5, 4, 8b to the leaking front wheel brake 7b.
[0042] However, in order to be able to continue operating the braking system 1 at least in the emergency operation mode, according to the present invention, first in the example of the leaking front axle, all the pressure medium still available in the braking system 1 is pumped into the pressure source 2 and / or the first chamber 3a of the pressure medium reservoir 3 by means of a pressure medium pump 10. In this case, the available pressure medium is located in the pressure source 2 and the first chamber 3a of the pressure medium reservoir 3 connected thereto. Then the brake circuit isolation valve 4 of the front axle and the inlet valves 8a, 8b of the second braking control circuit 6b are closed. In Figure 3 This re - pumping process is shown by the thickened line between the second chamber 3b of the pressure medium reservoir 3 and the pressure source 2 and the first chamber 3a of the pressure medium reservoir 3. Pumping pressure medium from the second chamber 3b of the pressure medium reservoir 3 into the first chamber 3a of the pressure medium reservoir 3 via the isolation valve 11 is an alternative.
[0043] In this state of the braking system 1, by means of the pressure source 2, the first braking control circuit 6a can now be actuated by the pressure medium in the pressure source 2 and / or the first chamber 3a of the pressure medium reservoir 3, while the second braking control circuit 6b is shut down due to the leak.
[0044] However, when the brake system 1 enters the standby state, the pressure medium in the first chamber 3a of the pressure medium reservoir 3 and the pressure source 2 must be protected again, because otherwise, due to the valves being open in the standby state, this pressure medium may or actually will be lost due to a leak in the front axle.
[0045] This is achieved by Figure 4 pumping the pressure medium from the pressure source 2 and the first chamber 3a of the pressure medium reservoir 3 back into the second chamber 3b of the pressure medium reservoir 3 by means of the pressure source 2, so that it is protected there by closing the outlet valves 9a to 9d. For this purpose, the pressure source 2 sucks the pressure medium from the first chamber 3a of the pressure medium reservoir 3 via a check valve or isolation valve 11 and pumps the pressure medium back into the second chamber 3b of the pressure medium reservoir 3 via the first pressure line 14, the pressure supply valve 5, the second pressure line 15, at least one open inlet valve 8a - 8d, at least one associated outlet valve 9a - 9d, and the outlet connection line 13, in order to protect the medium by subsequently closing the outlet valves 9a - 9d.
[0046] In a subsequent operating state of the brake system 1, the thus - protected pressure medium can then be pumped back into the pressure source 2 and / or the first chamber 3a of the pressure medium reservoir 3 again, as described with respect to Figure 3 that.
[0047] In Figure 5 a further highly schematic exemplary embodiment of a brake system 1 for a motor vehicle is shown. According to the exemplary embodiment, the brake system 1 likewise has four hydraulically actuable wheel brakes 7a, 7b, 7c, and 7d. According to the exemplary embodiment, the wheel brakes 7a and 7b are assigned to the front axle of the motor vehicle, and the wheel brakes 7c and 7d are assigned to the rear axle. The wheel brakes 7a and 7b of the front axle are part of the second brake control circuit 6b, and the wheel brakes 7c and 7d of the rear axle are part of the first brake control circuit 6a.
[0048] The brake system 1 likewise has a pressure medium reservoir 3, which in this case has three at least partially separated chambers, where the first chamber 3a is assigned a first reservoir interface, the second chamber 3b is assigned a second reservoir interface, and the third chamber 3c is assigned a third reservoir interface.
[0049] In the brake system 1, the electrically actuable pressure source 2 and the wheel - specific brake pressure regulating valves 8a, 8b, 8c, 8d and 9a, 9b, 9c, 9d are arranged as part of the brake control circuits 6a, 6b. The outlet valves 9a, 9b, 9c, 9d contained therein are connected via a common outlet connection line 31 to the second chamber 3b of the pressure medium reservoir 3.
[0050] The pressure source 2 is connected on the pressure side via a pressure supply valve 5 to the inlet valves 8c and 8d of the first brake control circuit 6a. The wheel brakes 7c and 7d can thus be actuated directly by means of the pressure source 2.
[0051] The pressure source 2 is additionally connected via the pressure supply valve 5 and a brake circuit isolation valve 33 to the inlet valves 8a and 8b of the second brake control circuit 6b. The wheel brakes 7a and 7b of the front axle can thus likewise be actuated directly by means of the pressure source 2. However, if a leak has been detected, for example, the second brake control circuit 6b can also be isolated from the pressure source 2 by means of the brake circuit isolation valve 33.
[0052] By means of the pressure supply valve 5, the pressure source 2 can be isolated from the brake control circuits 6a, 6b. Additionally, the pressure supply valve 5 can be closed so that the pressure source 2 can draw in pressure medium via the isolation valve 34 from the first chamber 3a of the pressure medium reservoir 3 or via the check valve 4 from the third chamber 3c by retracting.
[0053] There is provided at least one electronic control device 20, which is shown highly schematically in Figure 1 Each electronic control device includes electrical and / or electronic components (for example, a microcontroller, a power module, a valve driver, other electronic components, etc.) for actuating the electrically actuatable components of the brake system 1 and optionally associated sensors. For the sake of clarity, the connecting lines to such actuators and sensors have been omitted.
[0054] The electronic control device 20 controls the pressure source 2. According to an example, the pressure source 2 is supplied with energy (from a power source not shown) via the electronic control device 20.
[0055] The brake system 1 additionally has a pressure medium pump 30, which is connected on the inlet side via an outlet connecting line 31 to a pressure medium container 32, which is connected to the second chamber 3b of the pressure medium reservoir 3. On the output side, the pressure medium pump is connected to the inlet valves 8a, 8b of the second brake control circuit 6b.
[0056] The pressure medium pump 30 can thus supply pressure medium to the second brake control circuit 6b and actuate this second brake control circuit. The pressure medium pump 30 can likewise be supplied with energy and controlled, in particular switched on and off, by the control device 20.
[0057] Since the pressure medium pump 30 is also connected via the brake circuit isolation valve 33 to the first brake control circuit 6a, the pressure medium pump 30 can also supply pressure medium to the first brake control circuit 6a via this brake circuit isolation valve 33.
[0058] InFigure 5 In an exemplary embodiment, the electro - controllable pressure medium pump 30 is designed as a double - piston pump, with its two pressure sides and two suction sides connected to each other respectively.
[0059] The pressure medium pump 30 has check valves on both its pressure side and suction side, such that the pressure medium can only be conveyed in the direction from the pressure medium container 32 to the brake control circuits 6a, 6b.
[0060] In Figure 5 In the brake system 1, the pressure source 2 is additionally connected via an isolation valve 34 to the first chamber 3a of the pressure medium reservoir 3. Through this isolation valve 34, the pressure source 2 can suck the pressure medium from the first chamber 3a of the pressure medium reservoir 3. However, it is also possible to pump the pressure medium from the pressure source 2 into the first chamber 3a of the pressure medium reservoir 3 via this isolation valve 34.
[0061] In Figure 5 In an exemplary embodiment, the brake system 1 is divided into two subsystems 35 and 36, where the first subsystem 35 mainly includes the pressure source 2, the isolation valve 34, and the pressure medium reservoir 3, while the second subsystem 36 mainly includes the pressure medium pump 30, additional valves, and the pressure medium container 32. The electronic pedal 37 generates a signal related to the driver's braking request and sends the signal to the two subsystems 35, 36 of the brake system 1.
[0062] Since the pressure source 2 is not emptied in the case of wheel leakage, it is sufficient to fill the first pressure line 14 from the second chamber 3b by the pressure medium pump 10 or 30 for emergency operation.
Claims
1. A method for operating a brake system (1) in the event of a detected leak, the brake system having an electrically actuable pressure source (2) which is connected via a first pressure line (14) and a pressure supply valve (5) to a first brake control circuit (6a) and via the pressure supply valve (5) and additionally via a brake circuit isolation valve (4; 33) to a second brake control circuit (6b), with pressurized pressure medium being supplied from a first chamber (3a) and / or a third chamber (3c) of a pressure medium reservoir (3) to the brake control circuits (6a, 6b). Each brake control circuit (6a, 6b) has respective inlet valves (8a - 8d) and respective outlet valves (9a - 9d). Each brake control circuit is connected via its respective inlet valve to the pressure source (2), and each brake control circuit is connected via its respective outlet valve to a second chamber (3b) of the pressure medium reservoir (3). All the outlet valves (9a - 9d) are connected via a common outlet connection line (13; 31) to the second chamber (3b) of the pressure medium reservoir (3). The pressure source (2) is connected via a check valve (37) to the first chamber (3a) or the third chamber (3c). The common outlet connection line (13; 31) is connected via a pressure medium pump (10; 30) to the second brake control circuit (6b). The pressure source (2) is connected via a first valve (11; 34) to the first chamber (3a) of the pressure medium reservoir (3). The method has the following steps: In the event of a leak in the second brake control circuit (6b), in order to continue operating the brake system (1) using only the first brake control circuit (6a), open the valve which allows the second chamber (3b) of the pressure medium reservoir (3) to be connected via the pressure medium pump (10; 30) to the pressure source (2) and / or the first chamber (3a) of the pressure medium reservoir (3), and operate the pressure medium pump (10; 30) so that pressure medium is pumped from the second chamber (3b) of the pressure medium reservoir (3) into the pressure source (2) and / or the first chamber (3a) of the pressure medium reservoir (3) via the connection thus formed. Then close the brake circuit isolation valve (4; 33) and operate the first brake control circuit (6a) using the pressure medium from the first chamber (3a) of the pressure medium reservoir (3) by means of the pressure source (2). In the event that the brake system (1) is to be put into a standby state, first pump the pressure medium from the pressure source (2) into the second chamber (3b) of the pressure medium reservoir (3) by operating the pressure source (2).
2. The method according to claim 1, wherein In this third step, after pumping the pressure medium of the pressure source (2) into the second chamber (3b) of the pressure medium reservoir (3), draw the pressure medium from the first chamber (3a) of the pressure medium reservoir (3) into the pressure source (2) and then pump it back into the second chamber (3b) of the pressure medium reservoir (3).
3. The method according to claim 2, wherein The repumping of the pressure medium from the first chamber (3a) of the pressure medium reservoir (3) to the pressure source (2) and the repumping of the pressure medium from the pressure source (2) to the second chamber (3b) of the pressure medium reservoir (3) are carried out a plurality of times until the pressure medium in the first chamber (3a) of the pressure medium reservoir (3) has been repumped into the second chamber (3b) of the pressure medium reservoir (3).
4. The method according to any one of claims 1 to 3, wherein in the case of a leak in the second brake control circuit (6b), in order to further operate the brake system using only the first brake control circuit (6b), in order to fill the pressure source (2) with the pressure medium from the second chamber (3b) of the pressure medium reservoir (3), the pressure supply valve (5) and the brake circuit isolation valve (4) are opened, and the pressure medium pump (10; 30) is actuated. in the case where the brake system (1) is to be brought into the standby state, the first valve (11; 34) and the brake circuit isolation valve (4; 33) are pre-closed, at least one outlet valve (9c, 9d) and at least one inlet valve (8c, 8d) of the first brake control circuit (6a) and the pressure supply valve (5) are opened, and the pressure medium is conveyed from the pressure source (2) to the second chamber (3b) of the pressure medium reservoir (3) by operating the pressure source (2).
5. A method for operating a brake system (1) in the event of a detected leak, the brake system having an electrically actuatable pressure source (2) which is connected to a first brake control circuit (6a) via a first pressure line (14) and a pressure supply valve (5) and is connected to a second brake control circuit (6b) via the pressure supply valve (5) and additionally via a brake circuit isolation valve (4; 33), with pressurized pressure medium being supplied from a first chamber (3a) and / or a third chamber (3c) of a pressure medium reservoir (3) to the brake control circuits (6a, 6b). Each brake control circuit (6a, 6b) has respective inlet valves (8a - 8d) and respective outlet valves (9a - 9d), each brake control circuit is connected to the pressure source (2) via its respective inlet valve, each brake control circuit is connected to the second chamber (3b) of the pressure medium reservoir (3) via its respective outlet valve, and all the outlet valves (9a - 9d) are connected to the second chamber (3b) of the pressure medium reservoir (3) via a common outlet connection line (13; 31). The pressure source (2) is connected to the first chamber (3a) or the third chamber (3c) via a check valve (37), and the common outlet connection line (13; 31) is connected to the second brake control circuit (6b) via a pressure medium pump (10; 30). The pressure source (2) is connected to the first chamber (3a) of the pressure medium reservoir (3) via a first valve (11; 34). The method has the following steps: In the event of a leak in the second brake control circuit (6b), in order to further operate the brake system (1) using only the first brake control circuit (6a), a valve that allows the second chamber (3b) of the pressure medium reservoir (3) to be connected to the first pressure line (14) via the pressure medium pump (10; 30) is opened, and the pressure medium pump (10; 30) is actuated, so that the pressure medium is pumped from the second chamber (3b) of the pressure medium reservoir (3) into the first pressure line (14) through the connection formed. Then the brake circuit isolation valves (4; 33) are closed, and the first brake control circuit (6a) is operated using the pressure medium from the first chamber (3a) of the pressure medium reservoir (3) with the aid of the pressure source (2).
6. A control device for a brake system, the control device having a processor for performing the method according to one of claims 1 to 5.