Brake system for a motor vehicle and assembly for a brake system

Abstract

A braking system for a motor vehicle comprising a first assembly (100) in which a first electrically actuated pressure source (5) and a master brake cylinder (1) that can be actuated by a brake pedal (12) are arranged, and a second assembly (200) in which a second electrically actuated pressure source (2) and an electrically actuated inlet valve (6a-6d) are arranged for each wheel brake, wherein the second electrically actuated pressure source (2) is hydraulically connected to the inlet valves (6a-6d), and the first assembly (100) is provided with a single pressure port (60) for transmitting brake pressure to the second assembly (200) for actuating the wheel brakes (8a-8d), and the first pressure source (5) and the master brake cylinder (1) are connected to the pressure port (60) via a system pressure line (38).

Description

[Technical field]

[0001] The present invention relates to a braking system for a motor vehicle comprising a master brake cylinder actuable by a brake pedal, a first electrically actuated pressure source, a second electrically actuated pressure source, and an electrically actuated inlet valve for each wheel brake.The present invention further relates to an assembly for a braking system comprising an electrically actuated pressure source and a master brake cylinder that can be actuated by the brake pedal. [Background technology]

[0002] DE 10 2018 222 478 A1 discloses a braking system with a master brake cylinder actuable by a brake pedal, two electrically controlled pressure sources and an inlet valve for each wheel brake, where the master brake cylinder and one of the electrically controlled pressure sources are arranged in a first assembly and the other electrically controlled pressure source and the inlet valve are arranged in a second assembly. In this case, the first and second assemblies are interconnected by at least two pressure-resistant hydraulic connection elements. Correspondingly, the first assembly comprises two or more pressure ports, via which the brake pressure is transmitted from the first assembly to the second assembly to actuate the wheel brakes. Summary of the Invention [Problem to be solved by the invention]

[0003] It is an object of the present invention to provide an improved brake system and an improved assembly for a brake system for hydraulically actuated wheel brakes, which can be manufactured in a cost-effective manner. Furthermore, the brake systems required for highly automated driving must provide high availability.

[0004] Another object of the present invention is to minimize the number of hydraulic connections in the brake system, particularly between assemblies, and the number of hydraulic connections or ports in the assemblies of the brake system. [Means for solving the problem]

[0005] The above object is achieved according to the invention by a braking system according to claim 1 and an assembly according to claim 14.

[0006] The invention is based on the idea that a braking system comprises a first assembly in which a first electrically actuated pressure source and a master brake cylinder that can be actuated by the brake pedal are arranged, and a second assembly in which a second electrically actuated pressure source and at least one electrically actuated inlet valve are arranged for each wheel brake, the second electrically actuated pressure source being hydraulically connected to the inlet valve. In this case, the first assembly comprises at most one pressure port for transmitting brake pressure to the second assembly for actuating the wheel brakes, the first pressure source and the master brake cylinder being connected to this pressure port via a system pressure line. In other words, the first pressure source and the master brake cylinder are connected together to a single pressure port of the first assembly.

[0007] The braking system offers the advantage that two electrically actuated pressure sources allow for highly automated operation, while also providing a mechanical / hydraulic fallback mode in case of complete electrical failure, where the braking system can be manufactured in a cost-effective manner due to the low number of ports / hydraulic connections on the individual assemblies.

[0008] The braking system is configured for at least two hydraulically actuated wheel brakes for a motor vehicle, preferably the braking system is for at least four hydraulically actuated wheel brakes, and the second assembly includes at least one electrically actuated inlet valve for each wheel brake, and a second electrically actuated pressure source is hydraulically connected to the at least four inlet valves.

[0009] The braking system preferably comprises a pressure medium reservoir which is under atmospheric pressure. The pressure medium reservoir is particularly preferably arranged on the first assembly.

[0010] Preferably, the braking system comprises one outlet valve per wheel brake, by means of which each wheel brake is connected to the pressure medium reservoir.

[0011] Preferably, all of the inlet valves are connected to a single pressure port of the first assembly, so that all of the inlet valves can be actuated by either the first electrically operated pressure source or the master brake cylinder.

[0012] Preferably, the first pressure source and the master brake cylinder are connected to a pressure port via a system pressure line internal to the first assembly.

[0013] According to one preferred development of the brake system according to the invention, the first assembly and the second assembly are interconnected by at most one pressure-resistant hydraulic connecting element, which is connected to a pressure port of the first assembly.

[0014] Particularly preferably, all inlet valves are connected to a brake supply line arranged in the second assembly, which in turn is connected to a single pressure port of the first assembly, in particular via a pressure-resistant hydraulic connecting element.

[0015] Preferably, the first assembly is pressure-tightly connected to the second assembly only via the pressure port.

[0016] Preferably, the first pressure source is connected to the pressure port such that in the event of failure of the first pressure source, pressure medium does not flow into this connection.

[0017] Preferably, the first pressure source is connected to the system pressure line via an electrically actuated sequence valve disposed in the first assembly. Particularly preferably, the sequence valve is configured to be normally closed.

[0018] Preferably, the pressure port can be connected to a pressure medium reservoir, particularly preferably, the pressure port can be connected to the pressure medium reservoir via a master brake cylinder.

[0019] According to one preferred development of the brake system according to the invention, when the brake pedal is not actuated and the first assembly is de-energized, the pressure port is connected to the pressure medium reservoir. Particularly preferably, when the brake pedal is not actuated and the first assembly is de-energized, the pressure port is connected to the pressure medium reservoir via the master brake cylinder. In this situation, the pressure port and thus the connected wheel brakes are depressurized.

[0020] Preferably, the master brake cylinder comprises at least one expansion port via which the pressure chamber of the master brake cylinder is connected to the pressure medium reservoir when the brake pedal is not actuated.

[0021] The master brake cylinder or its pressure chamber is preferably connected to the system pressure line or pressure port via an electrically operated isolation valve arranged in the first assembly, particularly preferably configured to be normally open in order to ensure connection to the pressure medium reservoir when the first assembly is de-energized.

[0022] A simulator hydraulically connected to the master brake cylinder is preferably disposed in the first assembly, the simulator providing a brake pedal feel to the driver in a by-wire mode of operation.

[0023] The master brake cylinder is preferably connected to the simulator via an electrically operated simulator valve, which is particularly preferably arranged in the first assembly, and which is particularly preferably configured to be normally closed, such that when the first assembly is de-energized the simulator is switched off and cannot receive pressure medium.

[0024] Preferably, the first assembly additionally comprises a pressure equalization port for connection to a pressure medium reservoir. Particularly preferably, the first assembly has no further hydraulic ports apart from the pressure port and the pressure equalization port.

[0025] The expansion port of the master brake cylinder is preferably connected to the pressure equalization port.

[0026] Preferably, the first electrically operated pressure source is connected to the pressure equalization port so that the pressure medium can be replenished, particularly preferably via a check valve which opens on the side of the first pressure source. The check valve is particularly preferably arranged in the first assembly.

[0027] Alternatively, the first assembly preferably comprises, in addition to the pressure port, a first pressure equalization port for connection to a pressure medium reservoir and a second pressure equalization port for connection to a pressure medium reservoir. Particularly preferably, the electrically operated pressure source is connected to the first pressure equalization port via a check valve that opens on the side of the pressure source. Particularly preferably, the expansion port of the master brake cylinder is connected to the second pressure equalization port.

[0028] The first assembly preferably has no other electrically actuated valves other than the isolation valves, sequence valves, and simulator valves.

[0029] The first assembly has no other electrically actuated valves other than an electrically actuated isolation valve connecting the master brake cylinder to the system pressure line, an electrically actuated sequence valve connecting the first pressure source to the system pressure line, and an electrically actuated simulator valve hydraulically connecting the master brake cylinder to a simulator located in the first assembly.

[0030] According to one preferred development of the brake system according to the invention, the second assembly comprises a hydraulic wheel port per wheel brake for connection to the wheel brake, a pressure equalization port for connection to a pressure medium reservoir and one, in particular the only, pressure port for connection to the first assembly.

[0031] The second assembly preferably has at least two, particularly preferably at least four hydraulic wheel ports for connecting to the wheel brakes, a pressure equalization port for connecting to a pressure medium reservoir and one, particularly only one, pressure port for connecting to the first assembly.

[0032] The pressure port of the second assembly is preferably connected to the pressure port of the first assembly via a pressure-resistant hydraulic connection element. Particularly preferably, the second assembly does not have a separate hydraulic connection.

[0033] Preferably, in the second assembly, a brake supply line connects the inlet valves, particularly preferably at least four inlet valves, to a pressure port of the second assembly and to a second pressure source.

[0034] The pressure equalization port of the first assembly and the pressure equalization port of the second assembly are preferably connected to different chambers of the pressure medium reservoir.

[0035] The second pressure source is preferably connected on the suction side to the pressure medium reservoir, in particular without the interposition of an electrically actuated valve.

[0036] The second pressure source is preferably connected on the suction side to the pressure medium reservoir without an intervening valve.

[0037] The second pressure source is preferably connected to the pressure medium reservoir via a pressure equalization port of the second assembly.

[0038] The pressure port of the first assembly (or system pressure line) and the second pressure source (or its pressure side) are preferably connected to a brake supply line to which an inlet valve is connected, particularly preferably at least four inlet valves.

[0039] The second assembly preferably comprises a brake supply line to which an inlet valve, in particular at least four inlet valves, is connected and which is connected to a pressure port of the first assembly (or system pressure line) and to a second pressure source (hydraulic).

[0040] Preferably, the braking system comprises an inlet valve and an outlet valve for regulating a wheel-specific brake pressure for each wheel brake, the wheel-specific brake pressure being derived from the brake supply pressure in the brake supply line, and in the non-starting state, the inlet valve applies the brake supply pressure to the wheel brake and the outlet valve blocks the flow of pressure medium from the wheel brake.

[0041] Particularly preferably, all outlet valves are connected via a common return line to a pressure medium reservoir which is at atmospheric pressure. Most particularly preferably, all outlet valves are connected to a pressure equalization port of the second assembly.

[0042] The pressure port of the first assembly (or the system pressure line) is preferably connected to the brake supply line via a second electrically operated isolation valve. The second isolation valve is particularly preferably arranged in the second assembly. Particularly preferably, the second isolation valve is normally open.

[0043] According to one preferred development of the brake system according to the invention, in the case of at least two hydraulically actuated wheel brakes, an electrically actuated circuit isolation valve is arranged in the brake supply line such that, upon closing of the circuit isolation valve, the brake supply line is hydraulically isolated into a first line portion and a second line portion, the first line portion being hydraulically connected to the second pressure source and to at least one of the at least two inlet valves and the second line portion being hydraulically connected to the pressure port of the first assembly and to the other inlet valve.

[0044] According to one preferred development of the brake system according to the invention, in the case of at least four hydraulically actuated wheel brakes, an electrically actuated circuit isolation valve is arranged in the brake supply line such that, upon closing of the circuit isolation valve, the brake supply line is hydraulically separated into a first line portion and a second line portion, the first line portion being hydraulically connected to the second pressure source and to at least two of the at least four inlet valves and the second line portion being hydraulically connected to the pressure port of the first assembly and to the other inlet valves, in particular to at least two of the at least four inlet valves.

[0045] The circuit isolation valve is preferably disposed in the second assembly.

[0046] The circuit isolation valve is preferably actuated by the electronic controller of the second assembly such that in the event of a failure of the first assembly, circuit isolation can still be provided by the circuit isolation valve.

[0047] The circuit isolation valve is preferably normally open so that it does not have to be actuated by one of the pressure sources or the master brake cylinder to apply all of the wheel brakes.

[0048] A first pressure sensor for measuring the pressure developed by the master brake cylinder is preferably disposed in the first assembly.

[0049] A second pressure sensor is preferably arranged in the second assembly, measuring the pressure in the brake supply line, in particular the pressure in the second line section.

[0050] A third pressure sensor measuring the inlet pressure of the second assembly is preferably arranged in the second assembly, and particularly preferably, the third pressure sensor is arranged hydraulically before the second isolation valve, i.e. between the first assembly and the second isolation valve.

[0051] Preferably, a second simulator and a second simulator valve are disposed in the second assembly, the second simulator being connected to the pressure port of the first assembly via the second simulator valve.

[0052] According to one preferred development of the brake system according to the invention, the first assembly comprises a first electronic controller for actuating the electrically actuated components of the first assembly, and the second assembly comprises a second electronic controller for actuating the electrically actuated components of the second assembly.

[0053] The brake system preferably comprises a first and a second electrical compartment, electrically independent of each other, with the first pressure source and the first electronic controller assigned to the first electrical compartment, and the second pressure source, the second electronic controller, and the inlet valve and optionally the circuit isolation valve assigned to the second electrical compartment. Particularly preferably, the circuit isolation valve is assigned to the second electrical compartment. Thus, in the event of a failure of the first electrical compartment, circuit isolation can still be achieved by the circuit isolation valve.

[0054] The first electronic controller or the first electrical section is preferably powered from a first source of electrical energy and the second electronic controller or the second electrical section is preferably powered from a second source of electrical energy that is independent of the first source of electrical energy, such that the first energy source is part of the first electrical section and the second energy source is part of the second electrical section.

[0055] According to one development of the invention, the first assembly and the second assembly are interconnected by at most one pressure-resistant hydraulic connection element, there may be other non-pressure-resistant connection elements between the first assembly and the second assembly.

[0056] The first assembly and the second assembly are preferably configured to be interconnected by at most one pressure-tight hydraulic connection element. Optionally, the first assembly and the second assembly may be interconnected by an additional hydraulic connection element, but at most one, i.e. only one, of the hydraulic connection elements is configured to be pressure-tight between the first assembly and the second assembly. In that case, the additional hydraulic connection element is not configured to be pressure-tight.

[0057] Preferably, the first assembly and the second assembly are interconnected by only one hydraulic connection element, which is configured to be pressure-tight. There may be an additional non-pressure-tight connection element to the pressure medium reservoir.

[0058] Compared to the implementation in just one assembly, the division into two assemblies has the advantage that both assemblies are smaller, lighter and therefore easier to handle. The assemblies can also be manufactured more easily in existing production plants. However, when divided into two assemblies, each hydraulic connection between these assemblies brings about considerable complexity and expense. It is therefore particularly advantageous to keep the number of hydraulic connections as small as possible. It has been found to be advantageous to separate the various functions of the hydraulic connections as clearly as possible. That is to say, the connections through which the pressure medium is drawn in can be designed with the largest possible diameter so that the hydraulic resistance is as small as possible. For this purpose, it is advantageous if such connections do not have to be pressure-resistant. Conversely, pressure-resistant connections should not have a suction function.

[0059] The first pressure source is preferably formed by a cylinder-piston arrangement with a hydraulic pressure chamber, the piston of which is advanced and retracted by an electromechanical actuator. The suction port of the first pressure source is preferably hydraulically connected to a pressure medium reservoir via a check valve which opens on the side of the pressure chamber.

[0060] The suction side of the second pressure source is preferably connected to the return line of the outlet valve to the pressure medium reservoir.

[0061] The pressure side of the second pressure source is preferably connected to the first line portion of the brake supply line.

[0062] According to one development of the invention, the second pressure source has a double-circuit or multi-circuit configuration. The second pressure source is particularly preferably in the form of a dual-piston or multi-piston pump.

[0063] Particularly preferably, the pressure sides of the dual or multi-circuit pressure sources are interconnected and the suction sides of the dual or multi-circuit pressure sources are interconnected.

[0064] The braking system according to the invention is particularly suitable for highly automated driving functions.

[0065] With regard to an assembly for a braking system for at least two, preferably at least four, hydraulically actuated wheel brakes, the invention is based on the idea that the assembly comprises an electrically actuated pressure source and a master brake cylinder that can be actuated by the brake pedal. In this case, the assembly comprises at most one pressure port for transmitting brake pressure to the wheel brakes. For this purpose, the electrically actuated pressure source and the master brake cylinder are hydraulically connected to this pressure port via a system pressure line. In other words, the electrically actuated pressure source and the master brake cylinder that can be actuated by the brake pedal are connected together to a single pressure port of the assembly, which transmits brake pressure to actuate the wheel brakes.

[0066] The assembly offers the advantage of being cost-effective to manufacture due to the small number of ports or hydraulic connections.

[0067] Preferably, a pressure medium reservoir under atmospheric pressure is arranged on the (first) assembly for supplying pressure medium to the electrically operated pressure source and to the master brake cylinder.

[0068] Preferably, the (first) electrically actuated pressure source is connected to the pressure port or system pressure line via an electrically actuated sequence valve. Particularly preferably, the sequence valve is configured to be normally closed, so that in the event of failure of the electrically actuated pressure source, pressure medium does not flow into the connection to the pressure source.

[0069] Preferably, the (first) assembly is configured such that when the brake pedal is not actuated and the assembly is de-energized, the pressure port is connected to a pressure equalization port of the assembly (100) for connection to a pressure medium reservoir or to a pressure medium reservoir that is at atmospheric pressure. In such a situation, the pressure port (and thus the wheel brakes connected to the pressure port) is depressurized. Particularly preferably, the pressure port is connected to the pressure medium reservoir via a master brake cylinder.

[0070] Preferably, the master brake cylinder is provided with at least one expansion port via which the pressure chamber of the master brake cylinder is connected to a pressure medium reservoir in which the pressure chamber is at atmospheric pressure when the brake pedal is not actuated.

[0071] Preferably, the master brake cylinder or its pressure chamber is connected to the pressure port or the system pressure line via an electrically operated isolation valve. The isolation valve is particularly preferably configured to be normally open. Particularly preferably, no further electrically operated valves other than the isolation valve are arranged in the hydraulic connection between the master brake cylinder and the pressure port.

[0072] The (first) assembly preferably comprises a simulator hydraulically connected to a master brake cylinder. The master brake cylinder is particularly preferably connected to the simulator via an electrically operated simulator valve. Most particularly preferably, the simulator valve is configured to be normally closed. Most particularly preferably, a check valve allowing the flow of pressure medium from the simulator towards the master brake cylinder is not connected in parallel with the simulator valve.

[0073] Preferably, in addition to the pressure port, the (first) assembly comprises a pressure equalisation port for connection to a pressure medium reservoir.

[0074] Preferably, the (first) assembly has no other hydraulic ports other than the pressure port and the pressure equalization port.

[0075] The expansion port of the master brake cylinder is preferably connected to the pressure equalization port.

[0076] Preferably, an electrically operated pressure source is connected to the pressure equalization port via a check valve that opens on the side of the pressure source so that the pressure medium can be replenished.

[0077] Alternatively, the (first) assembly preferably comprises, in addition to the pressure port, a first pressure equalization port for connection to a pressure medium reservoir and a second pressure equalization port for connection to a pressure medium reservoir. Particularly preferably, an electrically operated pressure source is connected to the first pressure equalization port via a check valve that opens on the side of the pressure source. Particularly preferably, the expansion port of the master brake cylinder is connected to the second pressure equalization port.

[0078] The (first) assembly preferably has no other electrically actuated valves other than the isolation, sequence and simulator valves.

[0079] Preferably, the braking system comprises an assembly according to the invention as a first assembly.

[0080] Further preferred embodiments of the invention emerge from the dependent claims and the following description with reference to the drawings. [Brief description of the drawings]

[0081] [Figure 1] 1 is a schematic diagram of an exemplary embodiment of an assembly for a braking system according to the present invention; [Diagram 2] 1 is a schematic diagram of an exemplary embodiment of a braking system according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0082] FIG. 1 is a schematic diagram of an exemplary embodiment of an assembly for a braking system for a motor vehicle according to the invention.

[0083] According to this example, the assembly 100 is in the form of an electro-hydraulic brake control unit (HECU1) comprising a valve block HCU1 and a first electronic controller 101 (ECU1).

[0084] The assembly 100 comprises a (first) electrically operated pressure source 5 and a master brake cylinder 1 which can be actuated by a brake pedal 12 .

[0085] According to this example, a pressure medium reservoir 4 , which is at atmospheric pressure, is arranged on the assembly 100 .

[0086] According to the present example, the master brake cylinder 1 has a single circuit configuration and comprises a piston 11 which defines a hydraulic pressure chamber 10. The pressure chamber 10 is connected to the pressure medium reservoir 4 via a radial bore (expansion port) formed in the piston 11 and a corresponding pressure equalization line 43, this hydraulic connection being capable of being interrupted by a relative movement of the piston 11. The pressure chamber 10 contains a restoring spring which positions the piston 11 in a starting position when the master brake cylinder 1 is not actuated. Thus, when the brake pedal 12 is not actuated, the pressure chamber 10 of the master brake cylinder 1 is connected to the pressure medium reservoir 4 via the expansion port and the pressure equalization line 43. According to the present example, the pressure chamber 10 is connected to the hydraulic pressure equalization port 63 of the assembly 100 which is connected to the first chamber 401 of the pressure medium reservoir 4.

[0087] Furthermore, the assembly 100 comprises a simulator 3 (also called brake pedal feel simulator or path simulator) which generates a brake pedal feel for the driver, in particular in a by-wire operating mode. The simulator 3 is hydraulically coupled to the master brake cylinder 1 and essentially comprises, for example, a simulator chamber 301, a simulator rear chamber 302 and a simulator piston 303 which separates the two chambers 301, 302 from each other. The simulator piston 303 is supported on a valve block of the assembly by an elastic element 304 (for example a simulator spring) arranged in the simulator rear chamber 302. According to the present example, the simulator chamber 301 can be connected to the pressure chamber 10 of the master brake cylinder 1 by an electrically actuated simulator valve 28 which is advantageously arranged to be normally closed. The simulator valve 28 is used to switch the simulator 3 on and off.

[0088] The electrically controlled pressure source 5 of the assembly 100 is in the form of a hydraulic cylinder-piston arrangement (or a single circuit electro-hydraulic actuator (linear actuator)) whose piston 36 can be actuated, in particular advanced and retracted, by a diagrammatically illustrated electric motor 35, through the intermediation of a also diagrammatically illustrated rotation-translation mechanism 39, in order to raise and dissipate pressure in a pressure chamber 37. The piston 36 defines the pressure chamber 37 of the pressure source 5. For starting the electric motor, a rotor position sensor 44 (shown only diagrammatically) is provided which detects the rotor position of the electric motor 35.

[0089] Regardless of the operating state of the piston 36, the pressure chamber 37 is connected via a (refill) line 42 to a hydraulic equalization port 63 of the assembly 100, which is connected to the pressure medium reservoir 4 or to its first chamber 401. In the line 42 a check valve 53 is arranged which closes on the side of the pressure medium reservoir 4.

[0090] The assembly 100 has no other hydraulic ports other than the pressure equalization port 63 and the pressure port 60 .

[0091] The pressure source 5 and the master brake cylinder 1 are both connected to a system pressure line 38 which is connected to a pressure port 60 of the assembly 100. The assembly 100 has only one pressure port, namely the pressure port 60, for transmitting brake pressure to the wheel brakes or for actuating the wheel brakes. Two pressure generating devices designed to generate brake pressure for actuating the wheel brakes, namely the master brake cylinder 1 and the electrical pressure source 5, are connected to this single pressure port 60 of the assembly 100 via the system pressure line 38.

[0092] The master brake cylinder 1 or its pressure chamber 10 is connected to a system pressure line 38 and thus to a single pressure port 60 of the assembly 100 via an electrically operated isolation valve 23 which is advantageously arranged to be normally open. No further electrically operated valves other than the isolation valve 23 are arranged in the hydraulic connection between the master brake cylinder 1 and the pressure port 60.

[0093] According to this example, the master brake cylinder 1 is connected to the isolation valve 23 and the simulator valve 28 by a hydraulic line 48 .

[0094] The pressure source 5 or its pressure chamber 37 is connected to the system pressure line 38 and thus to the single pressure port 60 of the assembly 100 via a sequence valve 27 that is configured to be normally closed. The pressure source 5 is thus connected to the pressure port 60 in such a way that no pressure medium can flow into this connection in the event of a failure of the pressure source 5. According to this example, no further electrically operated valves, other than the sequence valve 27, are arranged in the hydraulic connection between the pressure source 5 and the pressure port 60.

[0095] 2 is a schematic diagram of an exemplary embodiment of a braking system for a motor vehicle according to the invention. According to this example, the braking system is designed to operate four hydraulically actuated wheel brakes 8a-8d. According to this example, the wheel brakes 8a, 8b are assigned to the rear axle (rear) of the vehicle and the wheel brakes 8c, 8d are assigned to the front axle (front) of the vehicle.

[0096] The brake system comprises a first assembly 100 configured as a first electro-hydraulic brake control unit (HECU1) comprising, in this example, a valve block HCU1 and a first electronic controller 101 (ECU1), and a second assembly 200 configured as a second electro-hydraulic brake control unit (HECU2) comprising, in this example, a valve block HCU2 and a second electronic controller 201 (ECU2).

[0097] The first assembly 100 in FIG. 2 corresponds to the assembly 100 in FIG.

[0098] In the first assembly 100, according to this example, a pressure medium reservoir 4 is arranged which comprises two chambers, the first chamber 401 being assigned a first reservoir port and the second chamber 402 being assigned a second reservoir port.

[0099] The second assembly 200 comprises a second electrically actuated pressure source 2 and at least one electrically actuated inlet valve 6a-6d per wheel brake, the second electrically actuated pressure source 2 being hydraulically connected to the four inlet valves 6a-6d.

[0100] For transmitting the brake pressure for actuating the wheel brakes 8a-8d, the single pressure port 60 of the first assembly 100 is connected to the pressure port 61 of the second assembly 200 via a hydraulic pressure-resistant connecting element 80. The connection 80 is according to the present example the only hydraulic pressure connection and is the only hydraulic connection between the first assembly 100 and the second assembly 200. The connection 80 is a hydraulic connection for transmitting the brake pressure for actuating the wheel brakes 8a-8d. The connecting element 80 must therefore be pressure-resistant.

[0101] The pressure port 60, and thus the first pressure source 5 and the master brake cylinder 1, as well as the second pressure source 2, are connected on the pressure side to a brake supply line 13 to which the four inlet valves 6a-6d are connected. In this way, all four wheel brakes 8a-8d can be optionally actuated by the first pressure source 5 and / or the second pressure source 2 and / or the master brake cylinder 1, depending on the operating mode.

[0102] An electrically operated circuit isolation valve 40 is arranged in the brake supply line 13, so that when the circuit isolation valve 40 is closed, the brake supply line 13 is divided into a first line portion 13a, to which the inlet valves 6a, 6b and the wheel brakes 8a, 8b are connected, and a second line portion 13b, to which the inlet valves 6c, 6d and the wheel brakes 8c, 8d are connected. The second pressure source 2 is hydraulically connected to the first line portion 13a, and the pressure port 60, and thus the first pressure source 5 and the master brake cylinder 1, are hydraulically connected to the second line portion 13b. Thus, when the circuit isolation valve 40 is closed, the brake system is separated or divided into two hydraulic brake circuits I and II. In this case, in the first brake circuit I, the pressure source 2 is connected (via the first line portion 13a) only to the wheel brakes 8a and 8b, and in the second brake circuit II, the pressure port 60 or 61 is connected (via the second line portion 13b) only to the wheel brakes 8c and 8d. The circuit isolation valve 40 is advantageously arranged to be normally open.

[0103] According to this example, the braking system comprises for each hydraulically actuated wheel brake 8a-8d an inlet valve 6a-6d and an outlet valve 7a-7d, which are hydraulically interconnected in pairs via a central port and are connected, respectively, to the hydraulic wheel ports 9a-9d of the second assembly 200 to which the corresponding wheel brake 8a-8d is connected. A non-return valve 70a-70d opening on the side of the brake supply line 13 is connected in parallel to each of the inlet valves 6a-6d. The outlet ports of the outlet valves 7a-7d are connected via a common return line 14 to the hydraulic equalization port 62, which is connected to the pressure medium reservoir 4 or to its second chamber 402. The input ports of all inlet valves 6a-6d can be supplied with pressure by the brake supply line 13 (i.e. when the circuit isolation valve 40 is open), by the first pressure source 5, or, for example, by the second pressure source 2 if the first pressure source 5 fails, or, for example, by the master brake cylinder 1 if both the first pressure source 5 and the second pressure source 2 fail (hydraulic fallback mode).

[0104] According to this example, the second electrically controlled pressure source 2 of the second assembly 200 is in the form of a dual piston pump, the two pressure outputs of which are interconnected (at a pressure side 220 of the pressure source 2) and the two suction sides of which are interconnected (at a suction side 221 of the pressure source 2). The suction side 221 is connected to the return line 14 and thus to the pressure equalization port 62 and the pressure medium reservoir 4. The pressure side 220 is connected to the first line portion 13a of the brake supply line 13.

[0105] The pressure equalization port 62, and thus the suction side 221 of the second pressure source 2, is connected directly to the pressure medium reservoir 4 via a line or hose 90. This connection 90 is not under pressure and can therefore have a large diameter. According to the present example, the line 90 is connected to the second chamber 402 of the pressure medium reservoir 4.

[0106] According to this example, an electrically operated isolation valve 26, which is advantageously normally open, is arranged in the second assembly 200 in addition to the pressure source 2 and the brake pressure regulator valves 6a-6d, 7a-7d. The isolation valve 26 is hydraulically arranged between the pressure port 61 of the second assembly 200 and the second line portion 13b of the brake supply line 13. In this way, the pressure port 60 of the first assembly 100 or the system pressure line 38 of the first assembly 100 is separably connected to the second line portion 13b or the brake supply line 13 via the isolation valve 26.

[0107] According to the present example, the braking system comprises a pressure sensor 19 in brake circuit II (line portion 13b), which is therefore assigned to the second pressure source 2. However, it is also possible to arrange the pressure sensor 19 in brake circuit I or to provide a second pressure sensor, so that each of the two brake circuits I and II can be monitored directly by a pressure sensor.

[0108] According to the present example, for leakage monitoring, the brake system is provided with a level measuring device 50 for measuring the level of the pressure medium in the pressure medium reservoir 4 .

[0109] According to this example, components 5, 53, 27, 1, 23, 3, 28 and line portions 38, 42, 43, 48 are arranged in a first valve block HCU1, and components 2, 6a-6d, 70a-70d, 7a-7d, 40, 26, 19 and line portions 13a, 13b, 14 (as well as the line portions between the inlet and outlet valves on one side and the wheel ports on the other side) are arranged in a second valve block HCU2.

[0110] Each valve block HCU1, HCU2 is assigned an electronic controller 101, 201 (ECU1, ECU2). Each electronic controller 101, 201 comprises electrical and / or electronic elements (e.g. microcontrollers, power modules, valve drivers, other electronic components, etc.) for actuating the electrically actuated components of the associated valve block and optionally the assigned sensors. The valve blocks and the electronic controllers are advantageously configured as an electro-hydraulic unit (HECU) in a known manner.

[0111] A first electrical compartment A and a second electrical compartment B, electrically independent of each other, are provided for the electrical mounting, connection and supply of individual electrical or electrically actuable, operable, assessable or similar components of the brake system.

[0112] In the drawing, electrical components assigned to or belonging to a first electrical partition A are indicated by arrow A, and electrical components assigned to or belonging to a second electrical partition B are indicated by arrow B.

[0113] The electronic controller 101 is assigned to or belongs to a first electrical partition A, while the second electronic controller 201 is assigned to or belongs to a second electrical partition B. Thus, the electronic controller 101 and the second electronic controller 201 are electrically independent.

[0114] To supply electrical energy to the brake system, a first source of electrical energy 103, e.g. a vehicle electrical system, and a second source of electrical energy 203, independent of the first source of electrical energy, e.g. a vehicle electrical system, are provided. The first source of electrical energy 103 supplies energy to a first electrical section A, and the second source of electrical energy 203 supplies energy to a second electrical section B.

[0115] The first electronic controller 101 activates the first pressure source 5. The first pressure source 5 is thus assigned to or associated with the first electrical partition A. According to the present example, the first pressure source 5 is supplied with energy (from the first electrical energy source 103) via the first electronic controller 101.

[0116] The second electronic controller 201 activates the second pressure source 2. The second pressure source 2 is thus assigned to or associated with the second electrical partition B. According to this example, the second pressure source 2 is supplied with energy (from the second electrical energy source 203) via the second electronic controller 201.

[0117] According to this example, the first pressure source 5 may be or is started exclusively by the first electronic controller 101 and the second pressure source 2 may be or is started exclusively by the second electronic controller 201.

[0118] The remaining components of the brake system are advantageously assigned to either the first electronic controller 101 (partition A) or the second electronic controller 201 (partition B), i.e. said components are started or actuated by said controller and / or supplied with electrical energy by said controller and / or connected on the signal side to said controller and / or evaluated by said controller. In order to avoid further redundancies, advantageously a component can be started or actuated, or can be supplied with electrical energy, or connected on the signal side or evaluated only (i.e. exclusively) by one of the two electronic controllers 101, 201, but not by the other electronic controller.

[0119] The first electronic controller 101 actuates the electrically actuated components of the first assembly 100 and the second electronic controller 201 actuates the electrically actuated components of the second assembly 200 .

[0120] Thus, the inlet valves 6a-6d and the outlet valves 7a-7d are assigned to the second electrical section B and are actuated by the second electronic controller 201. The circuit isolation valve 40 is similarly assigned to the second electrical section B and is actuated by the second electronic controller 201.

[0121] The first assembly 100 (pressure port 60 ) and the isolation valve 26 for hydraulic isolation of the brake supply line 13 are also assigned to the second electrical compartment B and are actuated by the second electronic controller 201 .

[0122] A pressure sensor 19 is also assigned to the second electrical compartment B. The signals from said sensors are supplied to a second electronic controller 201 where they are evaluated and processed.

[0123] However, the sequence valve 27 , the isolation valve 23 and the simulator valve 28 are assigned to the first electrical section A and are actuated by the first electronic controller 101 .

[0124] Furthermore, the signal from the liquid level measuring device 50 is supplied to the first electronic controller 101 where it is evaluated and processed.

[0125] The braking system preferably comprises electrically operated parking brakes on the rear wheels (at the rear), which are advantageously initiated and actuated by a first electronic controller 101 (designated A on the wheel brakes 8a, 8b in FIG. 1).

[0126] The braking system according to the present example, comprising a first assembly 100, allows for highly automated operation in that it includes two electrically actuated pressure sources 5, 2, and provides a mechanical / hydraulic fall-back mode (by means of a master brake cylinder 1) in case of a complete electrical failure. The first assembly 100 advantageously comprises the primary pressure source of the two electrically actuated pressure sources (5), the master brake cylinder 1 which can be actuated by the driver via the brake pedal 12, and a pedal feel simulator 3.

[0127] The second assembly 200 according to this example may also be used in combination with a first assembly with a single pressure port that does not have a master brake cylinder with a simulator, which is an advantage of the present invention.

[0128] However, other second assemblies can also be combined with the first assembly 100 according to the example of FIG.

[0129] The first assembly 100 only has a single pressure port 60. At the same time, this pressure port 60 can be connected to the atmosphere and is always connected to the atmosphere when the first assembly 100 has an electrical failure and the brake pedal 12 is not actuated.

[0130] For this purpose, the master brake cylinder 1 is preferably connected to a pressure port 60 via an electrically operated isolation valve 23, which is provided with an expansion port and is particularly preferably normally open. Furthermore, the master brake cylinder 1 is connected to the pedal feel simulator 3 via an electrically operated simulator valve 28, which is particularly preferably normally closed. A primary pressure source 5 is connected to the pressure port 60, more preferably in such a way that no pressure medium flows into this connection in the event of failure of the primary pressure source 5. Preferably, an electrically operated sequence valve 27, which is particularly preferably normally closed, is arranged in this connection.

[0131] In normal operation, when the brake pedal 12 is actuated or the autopilot wants to brake, the isolation valve 23 is closed, the simulator valve 28 is open and the sequence valve 27 is opened. The pedal feel is generated by the pedal feel simulator 3. The pressure build-up for actuating the wheel brakes 8a-8d is provided by the two pressure sources 5 and 2, either individually or together. The wheel-specific pressure regulation is provided by the second assembly 200.

[0132] In the event of a failure of the second assembly 200, the first assembly 100 can similarly increase the wheel brake pressure and centrally regulate the wheel brake pressure of all the wheel brakes 8a-8d together.

[0133] After failure of the first assembly 100, braking is performed differently by the autopilot and the driver.

[0134] If the first assembly 100 fails and the autopilot sends a braking request, the second assembly 200 ramps up and modulates the wheel brake pressure corresponding to how it would be done in a braking system without a mechanical / hydraulic fallback mode.

[0135] If the first assembly 100 fails and the pedal 12 is actuated, after failure of the first assembly 100 the master brake cylinder 1 is connected to the pressure port 60 of the first assembly 100 via the isolation valve 23 which is normally open. During pedal actuation the second assembly 200 remains passive and can transmit the pressure generated by the driver to the wheel brakes 8a-8d. However, depending on the configuration of the second assembly 200 it is also possible to assist the driver by means of a second pressure source 2.

[0136] In the example braking system of FIG. 2, as soon as pressure sensor 19 detects the pressure generated in master brake cylinder 1, electrically actuated circuit dividing valve 40 is closed, allowing second pressure source 2 to increase the pressure of the assigned wheel brakes above that of the master brake cylinder.

[0137] A second assembly 200 is optionally supplemented to allow even more functionality when the first assembly 100 fails. For example, a (third) pressure sensor can be installed in the pressure connection of the two assemblies 100, 200 (preferably before the isolation valve 26 of the second assembly 200) to detect the driver's demand. Then, when pressure rises in the master brake cylinder 1, the isolation valve 26 is closed and the second pressure source 2 increases the pressure in all the wheel brakes 8a-8d.

[0138] Optionally, the pressure connection of the two assemblies 100, 200 can also be attached to a second simulator (pedal feel simulator) via a second simulator valve, which is preferably normally closed, the second simulator valve and the second simulator being arranged in the second assembly 200.

Claims

1. A braking system for a motor vehicle, for at least two hydraulically actuated wheel brakes (8a-8d), comprising: a first assembly (100) in which a first electrically operated pressure source (5) and a master brake cylinder (1) that can be actuated by a brake pedal (12) are arranged; a second assembly (200) in which a second electrically operated pressure source (2) and at least one electrically operated inlet valve (6a-6d) per wheel brake are arranged, said second electrically operated pressure source (2) being hydraulically connected to said inlet valves (6a-6d); A brake system comprising:

1. A brake system comprising: a first assembly (100) having at most one pressure port (60) for transmitting brake pressure to said second assembly (200) for actuating said wheel brakes (8a-8d), said first pressure source (5) and said master brake cylinder (1) being connected to said pressure port (60) via a system pressure line (38).

2. A braking system according to claim 1, characterized in that all said inlet valves (6a-6d) are connected to said single pressure port (60) of said first assembly (100).

3. 3. The brake system according to claim 1 or 2, characterized in that the first assembly (100) and the second assembly (200) are interconnected by at most one pressure-resistant hydraulic connection element (80), the pressure-resistant hydraulic connection element (80) being connected to the pressure port (60) of the first assembly (100).

4. 4. The brake system according to claim 1, wherein the first assembly (100) has no other electrically operated valves other than an electrically operated isolation valve (23) connecting the master brake cylinder (1) to the system pressure line (38), an electrically operated sequence valve (27) connecting the first pressure source (5) to the system pressure line (38), and an electrically operated simulator valve (28) hydraulically connecting the master brake cylinder (1) to a simulator (3) arranged in the first assembly (100).

5. 5. The braking system according to claim 1, wherein the first assembly (100) additionally comprises a pressure equalization port (63) arranged on the first assembly (100) for connection to a pressure medium reservoir (4) under atmospheric pressure.

6. 6. A braking system according to claim 1, characterized in that when the brake pedal (12) is not actuated and the first assembly (100) is de-energized, the pressure port (60) is connected to a pressure medium reservoir (4) which is under atmospheric pressure, in particular by means of at least one expansion port of the master brake cylinder (1).

7. 7. A brake system according to claim 1, characterized in that for connection to the wheel brakes (8a-8d), the second assembly (200) comprises hydraulic wheel ports (9a-9d) per wheel brake, a pressure equalization port (62) for connection to a pressure medium reservoir (4) arranged on the first assembly (100), and a single pressure port (61) for connection to the first assembly (100), the pressure port (61) of the second assembly (200) being connected to the pressure port (60) of the first assembly (100).

8. 8. The braking system according to claim 7, characterized in that the pressure equalization port (63) of the first assembly (100) and the pressure equalization port (62) of the second assembly (200) are connected to different chambers (401, 402) of the pressure medium reservoir (4).

9. 9. The braking system according to claim 7 or 8, characterized in that in the second assembly (200), a brake supply line (13) connects the at least two inlet valves (6a-6d) to the pressure port (61) of the second assembly (200) and to the second pressure source (2).

10. 10. The braking system of claim 9, wherein the pressure port (60) of the first assembly (100) is connected to the brake supply line (13) by a second electrically operated isolation valve (26) arranged in the second assembly (200).

11. 11. The brake system according to claim 9 or 10, characterized in that an electrically operated circuit isolation valve (40) arranged in the second assembly (200) is arranged in the brake supply line (13) such that, upon closing of the circuit isolation valve (40), the brake supply line (13) is hydraulically isolated into a first line portion (13a) and a second line portion (13b), the first line portion (13a) being hydraulically connected to the second pressure source (2) and to at least one of the at least two inlet valves (6a, 6b), and the second line portion (13b) being hydraulically connected to the pressure port (60) of the first assembly (100) and to the other of the at least two inlet valves (6c, 6d).

12. Brake system according to any one of claims 9 to 11, characterised in that in the second assembly (200) a pressure sensor (19) is arranged for measuring the pressure in the brake supply line (13).

13. A braking system according to any one of the preceding claims, characterized in that the first assembly (100) is in the form of an assembly according to any one of the preceding claims 14 to 19.

14. Assembly (100) for a braking system for at least two hydraulically actuated wheel brakes (8a-8d), in which a first electrically actuated pressure source (5) and a master brake cylinder (1) that can be actuated by a brake pedal (12) are arranged, characterized in that said assembly (100) comprises at most one pressure port (60) for transmitting brake pressure to said wheel brakes (8a-8d), said first pressure source (5) and said master brake cylinder (1) being connected to said pressure port (60) by a system pressure line (38).

15. Assembly (100) according to claim 14, characterized in that said pressure source (5) is connected to said pressure port (60) by means of an electrically actuated sequence valve (27).

16. Assembly (100) according to claim 14 or 15, characterized in that the assembly comprises a simulator (3) connected to the master brake cylinder (1) by an electrically operated simulator valve (28), and the master brake cylinder (1) is connected to the pressure port (60) by an electrically operated isolation valve (23).

17. 17. The assembly (100) according to claim 16, characterized in that no further electrically operated valves other than the isolation valve (23) are arranged in the hydraulic connection between the master brake cylinder (1) and the pressure port (60).

18. Assembly (100) according to claim 16 or 17, characterized in that the assembly (100) does not have any other electrically operated valves other than the isolation valve (23), the sequence valve (27) and the simulator valve (28).

19. Assembly (100) according to any one of claims 14 to 18, characterized in that the assembly is configured such that when the brake pedal (12) is not actuated and the assembly (100) is de-energized, the pressure port (60) is connected to a pressure equalization port (63) of the assembly (100) for connection to a pressure medium reservoir (4).

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