Electromechanical brake system with pneumatic actuation of the trailer

Abstract

The invention relates to a pneumatic trailer valve arrangement (1) for an electromechanical brake system (202), comprising a trailer control valve (10) having a supply connection (11), a trailer feed connection (12) for providing supply pressure (pV) for a trailer, a trailer brake pressure connection (14) for providing a trailer brake pressure (pBA) for the trailer, an electromagnetic pilot control unit (110) which is designed to control the trailer brake pressure (pBA) at the trailer brake pressure connection (12) depending on trailer switching signals (S1, S2, S3) received at the trailer control valve (10), and having a pneumatic redundancy connection (16) for receiving a redundancy pressure (pR), wherein the trailer control valve (10) controls the trailer brake pressure (pBA) redundantly depending on the redundancy pressure (pR). The invention also provides a redundancy valve unit (20) having a redundancy output (22) for providing the redundancy pressure (pR), wherein the redundancy valve unit (20) is designed to provide the redundancy pressure (pR) at the redundancy output (22) depending on received redundancy switching signals (SR1, SR2).

Description

[0001] Electromechanical braking system with pneumatic control of the trailer

[0002] The invention relates to a pneumatic trailer valve assembly for a braking system, in particular an electromechanical braking system comprising a pneumatic trailer control valve. The invention further relates to an electromechanical braking system for a commercial vehicle having a pneumatic trailer valve assembly, a commercial vehicle, and a method.

[0003] Braking systems used today for commercial vehicles are generally pneumatic braking systems that operate with compressed air. This applies to both towing vehicles and trailers, with one or more compressed air circuits being provided in the towing vehicle, and the towing vehicle's braking system featuring valves to supply compressed air to targeted pneumatically actuated brake actuators on the wheels, thus decelerating the towing vehicle. Trailers for such commercial vehicles also include a pneumatic braking system, but are supplied by an air treatment unit in the towing vehicle. For this purpose, both the towing vehicle and the trailer have two pneumatic connections: a "supply" coupling head and a "brake" coupling head.The "Supply" coupling head supplies reservoir pressure from the towing vehicle to the trailer, which is then used in the trailer to fill a designated trailer reservoir. The "Brake" coupling head, on the other hand, transmits a control pressure that specifies the brake pressure level for the trailer.

[0004] With increasing electrification in the automotive sector, the braking systems of towing vehicles are also becoming more electrified. For this reason, electromechanical braking systems have been increasingly developed and deployed in recent years. These systems no longer operate with compressed air in the towing vehicle, but instead control electric brake actuators, and in which the deceleration of the towing vehicle is achieved by electromechanical actuators.

[0005] Nevertheless, there is a need to continue to tow trailers that have a conventional pneumatic braking system with electrified towing vehicles and to control the trailer's pneumatic braking system.

[0006] A trailer control valve for this purpose is known from EP 3 822 133 A1. The trailer control valve comprises at least two electrical connections configured to receive two independent but redundant electrical control signals containing the signal for a preset brake control pressure, at least one valve configured to adjust a constant air pressure of an air pressure source to the preset brake control pressure, a brake supply pressure connection, which is a pneumatic outlet and is configured to provide the preset brake supply pressure to the pneumatic trailer braking system, and a brake control pressure connection, which is a second pneumatic outlet and is configured to provide the preset brake control pressure to the pneumatic braking system of the trailer. The compressed air source is arranged within the trailer control valve.

[0007] Furthermore, EP 3 822 134 B1 discloses a trailer control module which is provided for a braking system of a motor vehicle having a trailer comprising a pneumatic braking system which is designed to provide a preset braking control output pressure to the pneumatic braking system of the trailer.According to this disclosure, the trailer control module comprises at least two electrical ports configured to receive two independent but redundant electrical control input signals, including the signal for a preset brake control output pressure, at least one air pressure source input configured to receive compressed air from a compressed air source, at least one valve configured to regulate the constant air pressure from the air pressure source to the preset brake output pressure, at least one brake supply pressure port configured to provide the brake supply output pressure to the trailer's pneumatic brake system, and at least one brake control pressure port configured to provide the preset brake control output pressure to the trailer's pneumatic brake system.The trailer control module disclosed herein is characterized in that it comprises at least two control solenoid groups, each of which comprises at least one load valve and at least one exhaust valve, and forms part of the control channel.

[0008] Even though both solutions work, further improvements are necessary, especially in terms of installation space and a reduction in the number of individual components.

[0009] The invention solves the problem in a first aspect by a pneumatic trailer valve arrangement for a braking system, in particular an electromechanical braking system, comprising a trailer control valve with a supply connection for receiving supply pressure, a trailer supply connection for providing supply pressure for a trailer, a trailer brake pressure connection for providing a trailer brake pressure for the trailer, an electromagnetic pilot control unit which is designed to control the trailer brake pressure at the trailer brake pressure connection as a function of trailer switching signals received at the trailer control valve, and with a pneumatic redundancy connection for receiving a redundancy pressure, wherein the trailer control valve is designed to control the trailer brake pressure redundantly as a function of the redundancy pressure at the trailer brake pressure connection as a function of the trailer switching signals.Furthermore, the pneumatic trailer valve arrangement comprises a redundancy valve unit with a supply connection for receiving supply pressure and a redundancy output for providing the redundancy pressure, wherein the redundancy valve unit is designed to provide the redundancy pressure at the redundancy output depending on redundancy switching signals received at the redundancy valve unit. The invention is based on the finding that a conventional trailer control valve can also be provided in an electromechanical braking system for an electromechanically braked commercial vehicle if the corresponding peripherals are also provided for the redundancy case. According to the invention, the redundancy valve unit is provided for this purpose, which in a redundancy case, namely when trailer switching signals cannot be provided or cannot be provided correctly, supplies the redundancy pressure and makes it available to the trailer control valve.Both the trailer control valve and the redundancy valve unit are supplied with supply pressure and have a supply connection for this purpose. The corresponding reservoir or compressor can be connected to both supply connections: the supply connection of the trailer control valve and the supply connection of the redundancy valve unit. In this respect, these two units can receive the same supply pressure. It can also be provided that the trailer control valve and the redundancy valve unit each have their own compressed air supply, compressor, or air treatment unit assigned to them. The redundancy valve unit is dedicated only to the trailer control valve, and the redundancy output of the redundancy valve unit is connected exclusively to the trailer control valve, more precisely, to the pneumatic redundancy connection of the trailer control valve.During normal operation, the trailer control valve can receive the corresponding trailer switching signals from a higher-level control unit, such as a central control unit of the electromechanical braking system, or directly from an electrical brake value sensor, such as an electric brake pedal. The higher-level control unit, such as the central control unit, can also be connected to a unit for autonomous driving and receive braking request signals, trajectory planning, and the like from this. Depending on this, the higher-level control unit, such as the central control unit, can then provide the trailer switching signals to the trailer control valve. The redundancy valve unit can also receive the redundancy switching signals from a higher-level control unit, such as the central control unit, or another redundant control unit.The redundancy valve unit can also receive the redundancy switching signals from an electrical brake signal sensor, such as an electric brake pedal. In one variant, the redundancy switching signals are identical or analog, or are generated and provided depending on the trailer switching signals.

[0010] In a first preferred embodiment, the redundancy port of the trailer control valve is connected to the pilot control unit of the trailer control valve. The trailer control valve preferably also comprises a main valve unit, and the pilot control unit provides a first control pressure to the main valve unit, which then volume-amplified the first control pressure and outputs it as trailer brake pressure to the trailer brake pressure port. By connecting the redundancy port to the pilot control unit, it is sufficient for the redundancy pressure to be a small-volume control pressure, which can then be volume-amplified by the main valve unit of the trailer control valve. It is not necessary for the redundancy pressure itself to be a large-volume working pressure, which can then be used directly to ventilate pneumatic brake actuators.

[0011] In a further preferred embodiment, the trailer control valve has a redundancy shutoff valve for blocking the redundancy connection. The redundancy shutoff valve preferably blocks the redundancy connection in an energized position and releases the redundancy connection when de-energized. This ensures that the redundancy pressure cannot be provided by energizing the redundancy shutoff valve, in order to prevent an unintentional control of the redundancy pressure. In the event that the trailer control valve is de-energized, the redundancy shutoff valve is preferably opened so that the redundancy pressure can be controlled. In a preferred development, the trailer switching signals and the redundancy switching signals are provided by two independent and at least partially functionally replacing electrical control units.For example, the trailer switching signals are provided by a primary central control unit, and the redundancy switching signals are provided by a secondary central control unit, which functionally at least partially replaces the primary central control unit. It can also be provided that the primary and secondary central control units each provide both the trailer switching signals and the redundancy switching signals to enable an additional level of redundancy.

[0012] In one variant, the redundancy valve unit has a redundancy valve unit housing and can be installed as a standalone module in the braking system. This allows the two units to be arranged separately from each other in the braking system, thereby reducing the footprint of the devices. Furthermore, the redundancy valve unit can be used and deployed as a retrofit part in conjunction with a conventionally designed trailer control valve. It can be provided that the redundancy valve unit with its redundancy valve unit housing is flanged directly to the trailer control valve, thus creating a modular system.

[0013] In a further preferred embodiment, it can be provided that the redundancy valve unit is integrated into a further functional module of the braking system. In this variant, it is not necessary for the redundancy valve unit to have its own redundancy valve unit housing; rather, it is preferred that the redundancy valve unit, i.e., its functional elements, are integrated into a further functional module. The further functional module is preferably selected from: primary brake control unit, secondary brake control unit, air treatment unit. It can also be provided that the redundancy valve unit is integrated into a parking brake valve unit or the trailer control valve. It can also be provided that the redundancy valve unit is integrated into a steering system, a transmission, a brake pedal, or other units such as a battery control unit.

[0014] According to a further preferred embodiment, the redundancy valve unit has an electromagnetic redundancy pilot control unit and a redundancy main valve unit, wherein the redundancy pilot control unit controls a redundancy control pressure at the redundancy main valve unit depending on the redundancy switching signals, and the redundancy main valve unit controls a redundancy pressure depending on the redundancy control pressure. The redundancy main valve unit preferably amplifies the volume of the redundancy control pressure and then controls it. This allows air consumption to be reduced, which is particularly preferred in the use according to the invention within the framework of the electromechanical braking system, since electromechanical braking systems generally have smaller compressed air reservoirs or smaller air treatment units, since these are only intended for the case where a non-electrified trailer is to be towed with the towing vehicle.This variant also makes it possible to reduce the footprint of the individual modules, thereby reducing the overall installation space.

[0015] Furthermore, it is preferred that the redundancy pilot control unit has an inlet valve and an outlet valve, wherein the inlet valve is connected to the supply connection, receives supply pressure, and can be switched by a first redundancy switching signal to control the redundancy control pressure at the redundancy main valve unit, and wherein the outlet valve is connected to a vent and can be switched by a second redundancy signal to vent the redundancy control pressure. The inlet valve and the outlet valve are preferably each designed as monostable 2 / 2-way valves. However, a 3 / 2-way valve can also be used instead, which then functions as a combined inlet-outlet valve. Preferably, the inlet valve is closed when de-energized, and the outlet valve is open when de-energized. In this way, it can be ensured that no brake pressure is controlled in the de-energized state.The redundancy main valve unit preferably comprises a redundancy relay valve with a pneumatic control connection at which the redundancy control pressure is controlled. The redundancy relay valve volume-amplified the redundancy control pressure and provides the volume-amplified redundancy control pressure at the redundancy output. In a further preferred embodiment, the redundancy valve unit comprises a bistable function, so that a controlled redundancy pressure can remain controlled even if the redundancy switching signals are lost. In one variant, the bistable function comprises an electromagnetic bistable valve. An electromagnetic bistable valve can, for example, comprise two magnetic detent positions defined by two end magnets. Such an electromagnetic bistable valve always remains in one of the two end positions, even if the power supply is lost.

[0016] In a further variant, the bistable function can also include pneumatic self-locking. Bistability can also be achieved purely pneumatically by connecting valves accordingly, as is generally known. Even if the corresponding control pressure for switching the valve is lost, the valve position can then be maintained, particularly through pneumatic self-locking.

[0017] In a second aspect, the aforementioned object is achieved by an electromechanical braking system for a commercial vehicle having a primary brake control unit and a secondary brake control unit, a first energy source that supplies the primary brake control unit with electrical energy, and a second energy source that supplies the secondary brake control unit with electrical energy. The electromechanical braking system further comprises at least first and second electromechanical front-axle brake actuators and at least first and second electromechanical rear-axle brake actuators, which can be controlled by the primary brake control unit and the secondary brake control unit to implement a braking request.The electromechanical braking system further comprises a pneumatic trailer valve assembly, which is preferably formed according to one of the above-described preferred embodiments of a pneumatic trailer valve assembly according to the first aspect of the invention. The trailer control valve of the trailer valve assembly is connected to the primary brake control unit and receives trailer switching signals therefrom. The redundant valve unit of the trailer valve assembly is connected to the secondary brake control unit and receives redundant switching signals therefrom.

[0018] It should be understood that the pneumatic trailer valve assembly according to the first aspect of the invention and the electromechanical braking system according to the second aspect of the invention have identical and similar sub-aspects, as particularly set forth in the dependent claims. In this respect, reference is made in full to the above description.

[0019] In one variant, the redundancy valve unit comprises a redundancy valve unit housing and is installed as a standalone module in the braking system. Alternatively, the redundancy valve unit is integrated into the secondary brake control unit. Alternatively, the electromechanical braking system includes an air treatment unit, with the redundancy valve unit integrated into the air treatment unit.

[0020] The primary brake control unit and the secondary brake control unit are preferably designed such that they can at least partially replace each other functionally. In particular, the secondary brake control unit serves as a backup control unit, taking over control of the electromechanical braking system in the event that the primary brake control unit is not functioning or is not functioning properly. It can also be provided that they jointly assume control, for example, so that functional functions of the primary brake control unit would continue to be executed, while non-functional functions of the primary brake control unit are replaced by the secondary brake control unit. This can be the case, for example, if the trailer control valve cannot be electrically controlled or can no longer be controlled properly.In this case, it is preferred that the secondary brake control unit controls the redundancy valve unit in order to control the trailer brake pressure redundantly, but purely pneumatically. In a third aspect, the invention achieves the object mentioned above by means of a commercial vehicle having a front axle and at least one rear axle and an electromechanical braking system according to one of the above-described preferred embodiments of an electromechanical braking system according to the second aspect of the invention. It should be understood that the commercial vehicle according to the third aspect of the invention and the electromechanical braking system according to the second aspect of the invention have the same or similar sub-aspects, as set out in particular in the dependent claims. In this respect, reference is made in full to the above description of the first and second aspects of the invention.

[0021] In a third aspect, the invention achieves the object mentioned above by a method for redundantly braking a trailer of a towing vehicle-trailer combination, wherein the towing vehicle has an electromechanical braking system, which is preferably designed according to one of the above-described preferred embodiments of an electromechanical braking system according to the second aspect of the invention, and the trailer has a pneumatic braking system. In the method, in an operating case, trailer switching signals are provided to a trailer control valve from a primary brake control unit, and the trailer control valve controls a trailer brake pressure at a trailer brake pressure connection depending on the trailer switching signals.In the event of a fault in which the provision of the trailer switching signals is partially or completely prevented, a redundancy valve unit controls a pneumatic redundancy pressure at a redundancy connection of the trailer control valve and the trailer control valve controls the trailer brake pressure redundantly depending on the redundancy pressure at the trailer brake pressure connection.

[0022] Again, it should be understood that the method according to the fourth aspect of the invention, the pneumatic trailer valve assembly according to the first aspect of the invention, the electromechanical braking system according to the second aspect of the invention, and the commercial vehicle according to the third aspect of the invention have identical and similar sub-aspects, as set forth in particular in the dependent claims. In this respect, reference is also made in full to the above description for the preferred development of the method.

[0023] In a preferred embodiment of the method, it is provided that the redundancy valve unit receives redundancy switching signals from a secondary brake control unit and controls redundancy pressure depending on redundancy switching signals.

[0024] Embodiments of the invention will now be described below with reference to the drawings. These are not necessarily intended to represent the embodiments to scale; rather, the drawings are schematic and / or slightly distorted where this is useful for explanation. With regard to additions to the teachings immediately apparent from the drawings, reference is made to the relevant prior art. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, in the drawings and in the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiments shown and described below, or limited to an object that would be limited compared to the object claimed in the claims. For specified dimensioning ranges, values ​​within the stated limits are also intended to be disclosed as limit values ​​and to be usable and claimable as desired. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions. Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawings, which show:

[0025] Fig. 1 is a schematic representation of an electromechanical braking system in a first embodiment;

[0026] Fig. 2 is a schematic representation of an electromechanical braking system in a second embodiment;

[0027] Fig. 3 is a schematic representation of an electromechanical braking system in a third embodiment;

[0028] Fig. 4 is a schematic representation of a pneumatic trailer valve arrangement in a first embodiment;

[0029] Fig. 5 is a schematic representation of a pneumatic trailer valve arrangement in a second embodiment; and in

[0030] Fig. 6 is a schematic representation of a pneumatic trailer valve arrangement in a third embodiment.

[0031] An electromechanical braking system 202 is provided for a commercial vehicle 200, which here is configured as a two-axle commercial vehicle 200 and has a front axle (VA) and a rear axle (HA). It should be understood that such commercial vehicles 200 can also have a second rear axle and can be configured as multi-axle vehicles. The electromechanical braking system 202 has a primary operating level 204 and a secondary redundancy level 206, which can take over the deceleration of the commercial vehicle 200 in the event that the operating level 204 is not functioning or is not functioning properly. The primary operating level 204 is powered by a first energy source 210 and includes a primary brake control unit 50.The primary brake control unit 50 is connected via a primary vehicle bus 212 to other units of the commercial vehicle 200, such as a unit for autonomous driving 222, in order to receive and implement trajectories, braking requests, or maneuvers from them. The electromechanical braking system 202 also includes a brake value transmitter 208, which can be designed, for example, as an electric brake pedal. The brake value transmitter 208 is connected to the primary brake control unit 50 in a basically known manner. The primary brake control unit 50 is further connected to first and second electromechanical front axle brake actuators 230a, 230b and first and second electromechanical rear axle brake actuators 232a, 232b, and provides control signals SB1, SB2 to them.In the secondary redundancy level 206, the electromechanical braking system 202 includes a secondary brake control unit 60, which can at least partially functionally replace the primary brake control unit 50. The secondary brake control unit 60 assumes control of the electromechanical braking system 202 in the event that the primary brake control unit 60 is not functioning or is not functioning properly. The secondary brake control unit 60 is also connected to the brake value transmitter 208 and receives signals from other units, such as in particular the autonomous driving unit 222, via a secondary vehicle bus 214. The secondary brake control unit 60 is also connected to the first and second electromechanical front axle brake actuators 230a, 230b and the first and second electromechanical rear axle brake actuators 232a, 232b and can provide redundant control signals SB3, SB4 to them in the event of redundancy.For this purpose, the first and second electromechanical front axle brake actuators 230a, 230b and the first and second electromechanical rear axle brake actuators 232a, 232b are connected to both the first and second energy sources 210, 220.

[0032] The electromechanical braking system 202 is designed to control a trailer (not shown). For this purpose, the electromechanical braking system 202 comprises a pneumatic trailer valve assembly 1, which also makes it possible to control conventional trailers with a purely pneumatic trailer braking system. The pneumatic trailer valve assembly 1 comprises a trailer control valve 10, which can basically be designed in a known manner. The trailer control valve 10 has a trailer supply connection 12 ("red coupling head" or "coupling head supply"), via which a supply pressure pV can be transferred to the trailer. In addition, the trailer control valve 10 has a trailer brake pressure connection 14 ("yellow coupling head" or "coupling head brake"), via which a trailer brake pressure pBA can be transferred to the trailer.The trailer brake pressure pBA is a control pressure that indicates the level of the brake pressure applied to trailer brake actuators in the trailer.

[0033] The trailer control valve 10 also has a supply connection 11, via which the trailer control valve 10 receives supply pressure pV from a compressed air supply 2 provided for this purpose. The trailer control valve 10 has various electromagnetic valves, as will be described below with reference to Figs. 4 to 6. To switch these electromagnetic valves, the trailer control valve 10 is connected to the primary brake control unit 50 via an electrical line 9 and receives trailer switching signals S1, S2, S3 from the latter. In the exemplary embodiment shown here (Fig. 1), the trailer control valve 10 does not have its own intelligence; rather, the electromagnetic valves (cf. Fig. 6 below) are switched directly by the primary brake control unit 50.In other embodiments, it can also be provided that the trailer control valve 10 has its own intelligence and, in this respect, braking requests, trajectories or other requests are transmitted from the primary brake control unit 50 or via the primary or secondary vehicle bus 212, 214, which are then independently implemented by the trailer control valve 10 in order to control the trailer brake pressure pBA in this way.

[0034] An electrical connection between the secondary brake control unit 60 and the trailer control valve 10 is not directly provided, but could be provided analogously to the electrical line 9 in the event that in redundant operation the secondary brake control unit 60 is also to directly control and switch the trailer control valve 10. For redundant operation, in the exemplary embodiment shown here (Fig. 1), a pneumatic control of the trailer brake pressure pBA is specifically provided. For this purpose, the pneumatic trailer valve arrangement 1 has a redundancy valve unit 20. The redundancy valve unit 20 also has electromagnetic valves, as will be explained in more detail below with reference to Figs. 4 to 6. The redundancy valve unit 20 is connected to the secondary brake control unit 60 and receives redundancy switching signals SR1, SR2 from it.In other embodiments, the redundancy switching signals SR1, SR2 can also be provided by the primary brake control unit 50 or another higher-level control unit. It can also be provided that the redundancy valve unit 20 has its own intelligence and can therefore also be connected to the primary and / or secondary vehicle bus 212, 214. The redundancy valve unit 20 has a supply connection 21, which is also connected to the compressed air supply 2. In other embodiments, it can also be provided that a separate, separately provided compressed air supply is provided for the redundancy valve unit 20, or that the redundancy valve unit 20 is directly connected to a compressor. The redundancy valve unit 20 has a redundancy output 22 for providing a redundancy pressure pR, which is controlled as a function of the received redundancy switching signals SR1, SR2.The redundancy output 22 is connected exclusively to a redundancy port 16 of the trailer control valve 10, which receives the redundancy pressure pR from the redundancy valve unit 20. The trailer control valve 10 is configured to receive and convert the redundancy pressure pR in order to control the trailer brake pressure pBA based thereon.

[0035] In the embodiment shown here (Fig. 1), the redundancy valve unit 20 comprises its own redundancy valve unit housing 23 and is provided as a separate module in the electromechanical braking system 202. This allows, in particular, an existing and already available trailer control valve 10, such as is available from known pneumatic braking systems, to be implemented in the electromechanical braking system 202 and controlled via the redundancy valve unit 20.

[0036] Fig. 2 shows the electromechanical braking system 202 in a second exemplary embodiment. Identical and similar elements are provided with the same reference numerals as in the first exemplary embodiment (Fig. 1), so that reference is made in full to the above description of the first exemplary embodiment (Fig. 1). In the following, the differences from the first exemplary embodiment are particularly highlighted, while similarities are not discussed in detail.

[0037] The essential difference between the first embodiment (Fig. 1) and the second embodiment (Fig. 2) is that the redundancy valve unit 20 is integrated into the secondary brake control unit 60. Therefore, the redundancy valve unit 20 does not require its own redundancy valve unit housing 23, but is part of the secondary brake control unit 60.

[0038] Fig. 3 shows a third embodiment of the electromechanical braking system 202. Once again, identical and similar elements are provided with the same reference numerals as in the first two embodiments. In this respect, differences are again emphasized, while similarities are not discussed further.

[0039] The essential difference from the first two exemplary embodiments (Fig. 1, Fig. 2) is that the electromechanical braking system 202 in the third exemplary embodiment (Fig. 3) has an electronic air treatment unit 70. The electronic air treatment unit 70 is connected to the second energy source 220, but can also be connected alternatively or additionally to the first energy source 210. Furthermore, it is connected to the secondary vehicle bus 214, but can also be connected additionally or alternatively to the primary vehicle bus 212. The electronic air treatment unit 70 is also connected to the compressed air supply 2 and supplies it with compressed air in order to provide supply pressure pV. In the exemplary embodiment shown here, the redundancy valve unit 20 is integrated into the air treatment unit 70.However, it should be understood that even in electromechanical braking systems 202 with an air treatment unit 70, the redundancy valve unit 20 can be designed as shown in the first or second embodiment (Fig. 1, Fig. 2). The integration of the redundancy valve unit 20 into the air treatment unit 70 can lead to a reduced footprint of the electromechanical braking system 202 and to the elimination of electrical and / or pneumatic lines.

[0040] Fig. 4 to 6 now show three different embodiments of the pneumatic trailer valve arrangement 1, wherein the internal circuit diagram is shown.

[0041] With reference to Fig. 4 on the left-hand side, the trailer control valve 10 is shown, which here is designed as a trailer control module 4 with a trailer control module housing 6. The trailer control valve 10 comprises an electrical connection 8, via which the trailer control valve 10 is connected to the primary brake control unit 50 and receives the first, second and third trailer switching signals S1, S2, S3 from there. In addition to the connections already described, namely the supply connection 11 for receiving supply pressure pV, which is connected to the compressed air supply 2, the trailer supply connection 12, the trailer brake pressure connection 14 and the redundancy connection 16, the trailer control valve 10 also comprises a vent 3, which vents into the environment in the usual way, optionally with the interposition of a silencer.

[0042] Inside, the trailer control valve 10 has, in a basically known manner, a pilot control unit 110 and a main valve unit 112. The pilot control unit 110 provides a first control pressure pS1 to the main valve unit 112, which controls the trailer brake pressure pBA based on the receipt of the first control pressure pS1. For this purpose, the pilot control unit 110 comprises an inlet valve 113 and an outlet valve 114, each of which is designed here as a 2 / 2-way valve. The inlet valve 113 and the outlet valve 114 can also be combined as a single 3 / 2-way valve, which can then be referred to as an inlet-outlet valve. The inlet valve 113 has a first inlet valve port 113.1, which is connected to the supply port 11 and receives supply pressure. A second inlet valve connection 113.2 is connected to a control pressure line 115 into which the first control pressure pS1 is output.The inlet valve 113 is monostable and de-energized in the first closed switching position shown in Fig. 4. By providing the first switching signal S1, the inlet valve 113 can be moved to the second switching position not shown in Fig. 4, in which the first and second inlet valve connections 113.1, 113.2 are connected. In the second, energized switching position, the first control pressure pS1 is controlled. The outlet valve 114 serves to vent the first control pressure pS1 or the control pressure line 115. The outlet valve 114 is also designed as a 2 / 2-way valve and has a first outlet valve connection 114.1, which is connected to the control pressure line 115, and a second outlet valve connection 114.2, which is connected or connectable to the vent 3, in the embodiment shown here via a redundancy shut-off valve 30, which will be described below.The outlet valve 114 is monostable and de-energized in the first open switching position shown in Fig. 4 and can be moved into the closed switching position not shown in Fig. 4 by providing the second switching signal S2.

[0043] The main valve unit 112 comprises a relay valve 116, with a relay valve supply connection 116.1, which is connected or connectable to the supply connection 11, a relay valve working connection 116.2, which is connected to the trailer brake pressure connection 14 and controls the trailer brake pressure pBA, a relay valve vent connection 116.3, which is connected to one or the vent 3, and a relay valve

[0044] Control port 116.4, which is connected to the control pressure line 15 and receives the first control pressure pS1. Relay valve 116 serves to receive the first control pressure pS1, amplify its volume, and output the volume-amplified pressure as trailer brake pressure pBA at the trailer brake pressure port 14.

[0045] A breakaway safety valve 117 is connected upstream of the relay valve 116, which ensures that the relay valve 116 is no longer supplied with supply pressure pV when the trailer is separated from the towing vehicle.

[0046] To detect the controlled trailer brake pressure pBA, the trailer control valve 10 also includes a pressure sensor 118, which can provide a pressure signal SD to the primary brake control unit 50.

[0047] As already mentioned above, the trailer control valve 10 also includes a redundancy shutoff valve 30, which serves to block or release the redundancy port 16 of the trailer control valve 10. The redundancy pressure pR is received at the redundancy port 16 from the redundancy valve unit 20. According to the exemplary embodiment shown here, the redundancy pressure pR is controlled via the vent path of the trailer control valve 10 and can be controlled via the redundancy shutoff valve 30 and the open outlet valve 114 into the control pressure line 115 and thus provided at the relay valve control port 116.4. In this way, the relay valve 116 can then control the trailer brake pressure pBA based on the redundancy pressure pR. In other variants, it can also be provided that the redundancy pressure pR is provided directly as volume pressure and can be controlled without volume amplification by the relay valve 116 at the trailer brake pressure connection 14.

[0048] The redundancy shutoff valve 30 is designed here as an electromagnetic 3 / 2-way valve and has a first redundancy shutoff valve connection 30.1 connected to the vent 3, a second redundancy shutoff valve connection 30.2 connected to the outlet valve 114, more precisely the second outlet valve connection 114.2, and a third redundancy shutoff valve connection 30.3 connected to the redundancy connection 16. The redundancy shutoff valve 30 is designed to be monostable and, in a first de-energized switching position, connects the third redundancy shutoff valve connection 30.3 to the second redundancy shutoff valve connection 30.2, so that the redundancy pressure pR can be controlled without current. When energized, the redundancy shutoff valve 30 switches to the second switching position not shown in Fig. 4 and connects the first redundancy shutoff valve connection 30.1 with the second redundancy shutoff valve connection 30.2, so that the outlet valve 114 is subsequently connected to the vent 3.During normal operation of the commercial vehicle 200, the third switching signal S3 should be provided to lock out the redundancy pressure pR and to enable venting of the first control pressure pS1 via the vent 3. In the event of a fault, when the first, second, and third switching signals S1, S2, S3 can no longer be provided, the inlet valve 113, the outlet valve 114, and the redundancy shutoff valve 30 are each in the switching positions shown in Fig. 4, so that the redundancy pressure pR can be provided by the redundancy shutoff valve 30, the outlet valve 114 to the relay valve 116.

[0049] The redundancy valve unit 20 is shown schematically here, and it should be understood that, as shown in Fig. 1, it can be designed as a standalone unit with a redundancy valve unit housing 23, and can also be integrated into another unit, as shown in Figs. 2 and 3. In this respect, Figs. 4 to 6 are to be understood only schematically. It is also conceivable that the redundancy valve unit 20 is integrated with the trailer control valve 10.

[0050] In the exemplary embodiment shown here, the redundancy valve unit 20 comprises a redundancy pilot control unit 150 and a redundancy main valve unit 160. In other embodiments, it can also be provided that there is no separation between the redundancy pilot control unit and the redundancy main valve unit, but rather only directly connected valves are provided. The redundancy pilot control unit 150 and the redundancy main valve unit 160 are designed similarly to the pilot control unit 110 and the main valve unit 112 of the trailer control valve 10. The redundancy pilot control unit 150 has an inlet valve 152 and an outlet valve 154. The inlet valve 152 is designed as a 2 / 2-way valve and has a first inlet valve connection 152.1, which is connected to the supply connection 21 of the redundancy valve unit 20 and receives supply pressure pV. A second inlet valve connection 152.2 is connected to a redundancy control pressure line 156 and controls the redundancy control pressure pSR therein. The inlet valve 152 is monostable and de-energized in the first switching position shown in Fig. 4, in which the first and second inlet valve connections 152.1, 152.2 are separated. The outlet valve 154 is also designed as a 2 / 2-way valve and has a first outlet valve connection 154.1 and a second outlet valve connection 154.2, wherein the first outlet valve connection 154.1 is connected to the redundancy control pressure line 156 and the second outlet valve connection 154.2 is connected to one or the vent 3.

[0051] The redundancy valve unit 20 has an electrical redundancy valve unit connection 24, via which the redundancy valve unit 20 is connected to the secondary brake control unit 60 and receives the first and second redundancy switching signals SR1, SR2 from the secondary brake control unit. The inlet valve 152 can be switched by the first redundancy switching signal SR1, and the outlet valve 154 can be switched by the second redundancy switching signal SR2.

[0052] The redundancy main valve unit 160 comprises a redundancy relay valve 162 with a redundancy relay valve supply port 162.1 connected to the supply port 21, a redundancy relay valve working port 162.2 connected to the redundancy outlet 22 and providing the redundancy pressure pR thereto, a redundancy relay valve vent port 162.3, and a redundancy relay valve control port 162.4 connected to the redundancy control pressure line 156 and receiving the redundancy control pressure pSR. The redundancy relay valve 162 volume-amplified the redundancy control pressure pSR and then outputs it as the redundancy pressure pR at the redundancy outlet 22. To detect the output redundancy pressure pR, the redundancy valve unit 20 also includes a redundancy pressure sensor 164, which can provide a redundancy pressure signal SRD to the secondary brake control unit 60.

[0053] Fig. 5 shows a second embodiment of the pneumatic trailer valve assembly 1, and identical and similar elements are denoted by the same reference numerals as in the first embodiment according to Fig. 4. In the following, the differences from the embodiment according to Fig. 4 are particularly highlighted, while similarities are essentially not discussed.

[0054] The differences here lie in the design of the redundancy valve unit 20, more precisely, in the design of the redundancy pilot control unit 150; the redundancy main valve unit 160 is identical to the redundancy valve unit 160 according to the embodiment shown in Fig. 4.

[0055] In contrast to the embodiment shown in Fig. 4, the redundancy pilot control unit 150 in the embodiment shown in Fig. 5 is bistable. For this purpose, the redundancy pilot control unit 150 has an electromagnetic bistable valve 170. The electromagnetic bistable valve 170 is designed as a 3 / 2-way valve and has two stable detent positions. It has a first bistable valve connection 170.1, which is connected to the vent 3, a second bistable valve connection 170.2, which is connected or connectable to the redundancy main valve unit 160, and a third bistable valve connection 170.3, which is connected to the supply connection 21 and receives supply pressure pV. The bistable valve 170 can be switched based on the second redundancy switching signal SR2 and has a first magnet 170a and a second magnet 170b to provide the two stable detent positions. In the first position, shown in Fig.In the switching position not shown in Fig. 5, the first bistable valve port 170.1 is connected to the second bistable valve port 170.2 so that the redundancy control pressure line 156 can be vented. In the second switching position shown in Fig. 5, the third bistable valve port 170.3 is connected to the second bistable valve port 170.2 so that the redundancy control pressure line 156 can be vented. A holding valve 172, which is designed as a 2 / 2-way valve, is inserted between the bistable valve 170 and the redundancy main valve unit 160. In the through position, to which it is monostable and preloaded and which is shown in Fig. 5, the redundancy control pressure pSR can be both controlled and vented. In the second switching position of the holding valve 172, not shown in Fig. 5, a pressure controlled at the redundancy main valve unit 160 can be locked.

[0056] Such bistability is particularly preferred when the trailer is to be braked permanently, for example when the vehicle combination is to be parked safely in the event of a fault.

[0057] Fig. 6 now shows a third variant of the pneumatic trailer valve arrangement 1, which again has bistability in the redundancy valve unit 20. Again, identical and similar elements are provided with the same reference numerals as in the previous description, so that reference is made in full to the above description. In the following, the differences from the first and second exemplary embodiments of the pneumatic trailer valve arrangement 1, as shown in Figs. 4 and 5, are particularly highlighted. The third exemplary embodiment of the pneumatic trailer valve arrangement 1 is based on the first exemplary embodiment of the pneumatic trailer valve arrangement 1, but comprises a self-holding device, here a pneumatic self-holding device 180. The pneumatic self-holding device 180 is designed such that it comprises a return line 182 with a throttle 183, which connects the redundancy relay valve working connection 162.2 with the redundancy relay valve control port 162.4. This means that the redundancy pressure pR output at the redundancy relay valve working port 162.2 is fed back in a throttled manner and made available at the redundancy relay valve control port 162.4, thereby achieving pneumatic self-holding. Even if the outlet valve 154 is brought into the venting position (not shown in Fig. 6), in which the first is connected to the second outlet valve port 154.1, 154.2, the self-holding can be maintained due to the throttle. For this reason, the inlet valve 152 can also assume a different monostable position than the inlet valve 152 according to the first embodiment (Fig. 4). A permanent supply of supply pressure via the inlet valve is not necessary to maintain the redundancy pressure pR.

[0058] Reference symbol (part of the description)

[0059] 1 pneumatic trailer valve assembly

[0060] 2 compressed air supply

[0061] 3 Ventilation

[0062] 4 Trailer control module

[0063] 6 trailer control module housing

[0064] 8 electrical termination

[0065] 9 electrical cable

[0066] 10 Trailer control valve

[0067] 1 1 Trailer control valve supply connection

[0068] 12 Trailer supply connection

[0069] 14 Trailer brake pressure connection

[0070] 16 Redundancy connection

[0071] 20 Redundancy valve unit

[0072] 21 Supply connection of the redundancy valve unit

[0073] 22 Redundancy output

[0074] 23 Redundancy valve unit housing

[0075] 24 electrical redundancy valve unit connection

[0076] 30 Redundancy shut-off valve

[0077] 30.1 first redundancy shut-off valve connection

[0078] 30.2 second redundancy shut-off valve connection

[0079] 30.3 third redundancy shut-off valve connection

[0080] 50 primary brake control unit

[0081] 60 secondary brake control unit

[0082] 70 Air treatment unit

[0083] 1 10 Pilot control unit Main valve unit Inlet valve First inlet valve connection Second inlet valve connection Outlet valve First outlet valve connection Second outlet valve connection Control pressure line Relay valve Relay valve supply connection Relay valve working connection Relay valve vent connection Relay valve control connection Breakaway safety valve Pressure sensor Redundancy pilot control unit Inlet valve First inlet valve connection Second inlet valve connection Outlet valve First outlet valve connection Second outlet valve connection Redundancy control pressure line Redundancy main valve unit Redundancy relay valve Redundancy relay valve supply connection Redundancy relay valve working connection Redundancy relay valve vent connection Redundancy relay valve control connection Redundancy pressure sensor Electromagnetic bistable valve Holding valve Pneumatic self-locking 182 Return line

[0084] 183 Thrush

[0085] 200 commercial vehicles

[0086] 202 Brake system

[0087] 204 primary operating level

[0088] 206 secondary redundancy level

[0089] 208 brake signal sensor

[0090] 210 first energy source

[0091] 212 primary vehicle bus

[0092] 214 secondary vehicle bus

[0093] 220 second energy source

[0094] 222 Unit for autonomous driving

[0095] 230a, 230b first and second electromechanical front axle brake actuators

[0096] 232a, 232b first and second electromechanical rear axle brake actuators pBA trailer brake pressure pR redundancy pressure pS1 first control pressure pSR redundancy control pressure pV supply pressure

[0097] 51 first trailer switching signal

[0098] 52 second trailer switching signal

[0099] 53 third trailer switching signal

[0100] SB1 -SB4 first to fourth control signals

[0101] SD pressure signal

[0102] SR1 first redundancy switching signal

[0103] SR2 second redundancy switching signal

[0104] SRD redundancy pressure signal

[0105] VA front axle

[0106] HA rear axle

Claims

Patent claims 1. Pneumatic trailer valve arrangement (1) for a braking system (202), in particular an electromechanical braking system, comprising a trailer control valve (10) with a supply connection (11) for receiving supply pressure (pV), a trailer supply connection (12) for providing supply pressure (pV) for a trailer, a trailer brake pressure connection (14) for providing a trailer brake pressure (pBA) for the trailer, an electromagnetic pilot control unit (110) which is designed to control the trailer brake pressure (pBA) at the trailer brake pressure connection (12) as a function of trailer switching signals (S1, S2, S3) received at the trailer control valve (10), and with a pneumatic redundancy connection (16) for receiving a redundancy pressure (pR), wherein the trailer control valve (10) is designed to, in the absence of the trailer switching signals (S1, S2,S3) to control the trailer brake pressure (pBA) redundantly depending on the redundancy pressure (pR) at the trailer brake pressure connection (14); and comprising a redundancy valve unit (20) with a supply connection (21) for receiving supply pressure (pV) and a redundancy output (22) for providing the redundancy pressure (pR), wherein the redundancy valve unit (20) is designed to provide the redundancy pressure (pR) at the redundancy output (22) depending on redundancy switching signals (SR1, SR2) received at the redundancy valve unit (20).

2. Pneumatic trailer valve arrangement (1) according to claim 1, wherein the redundancy connection (16) is connected to the pilot control unit (110).

3. Pneumatic trailer valve arrangement (1) according to claim 1 or 2, wherein the trailer control valve (10) has a redundancy shut-off valve (30) for blocking the redundancy connection (16).

4. Pneumatic trailer valve arrangement (1) according to one of the preceding claims, wherein the trailer switching signals (S1, S2, S3) and the redun- dance switching signals (SR1, SR2) are provided by two independent and functionally at least partially replacing electronic control units (50, 60).

5. Pneumatic trailer valve arrangement (1) according to one of the preceding claims, wherein the redundancy valve unit (20) has a redundancy valve unit housing (23) and can be installed as an independent module in the braking system (202).

6. Pneumatic trailer valve arrangement (1) according to one of the preceding claims 1 to 4, wherein the redundancy valve unit (20) is integrated into a further functional module of the braking system (202).

7. Pneumatic trailer valve assembly (1) according to claim 6, wherein the functional module is selected from: primary brake control unit (50), secondary brake control unit (60), air treatment unit (70).

8. Pneumatic trailer valve arrangement (1) according to one of the preceding claims, wherein the redundancy valve unit (20) has an electromagnetic redundancy pilot control unit (150) and a redundancy main valve unit (160), wherein the redundancy pilot control unit (150) controls a redundancy control pressure (pSR) at the redundancy main valve unit (160) as a function of the redundancy switching signals (SR1, SR2), and the redundancy main valve unit (160) controls the redundancy pressure (pR) as a function of the redundancy control pressure (pSR).

9. Pneumatic trailer valve arrangement (1) according to claim 8, wherein the redundancy pilot control unit (150) has an inlet valve (152) and an outlet valve (154), wherein the inlet valve (152) is connected to the supply connection (21), receives supply pressure (pV) and is switchable by a first redundancy switching signal (SR1) to control the redundancy control pressure (pSR) at the redundancy main valve unit (160), and wherein the outlet valve (154) is connected to a vent (3) and can be switched by a second redundancy signal (SR2) to vent the redundancy control pressure (pSR).

10. Pneumatic trailer valve arrangement (1) according to one of the preceding claims, wherein the redundancy valve unit (20) comprises a bistable function, so that a controlled redundancy pressure (pR) can remain controlled even if the redundancy switching signals (SR1, SR2) are lost.

11. Pneumatic trailer valve assembly (1) according to claim 10, wherein the bistable function comprises an electromagnetic bistable valve (170).

12. Pneumatic trailer valve assembly (1) according to claim 10, wherein the bistable function comprises a pneumatic self-holding (180).

13. An electromechanical braking system (202) for a commercial vehicle, comprising a primary brake control unit (50) and a secondary brake control unit (60), a first energy source (210) that supplies the primary brake control unit (50) with electrical energy, and a second energy source (220) that supplies the secondary brake control unit (60) with electrical energy; at least first and second electromechanical front axle brake actuators (230a, 230b) and at least first and second electromechanical rear axle brake actuators (232a, 232b) that can be controlled by the primary brake control unit (50) and the secondary brake control unit (60) to implement a braking request;and a pneumatic trailer valve arrangement (1) according to one of claims 1 to 12, wherein the trailer control valve (10) is connected to the primary brake control unit (50) and receives trailer switching signals (S1, S2, S3) therefrom, and the redundancy valve unit (20) is connected to the secondary brake control unit (60) and receives redundancy switching signals (SR1, SR2) therefrom.

14. Electromechanical braking system (202) according to claim 13, wherein the redundancy valve unit (20) has a redundancy valve unit housing and is installed as an independent module in the braking system (202).

15. Electromechanical braking system (202) according to claim 13, wherein the redundancy valve unit (20) is integrated into the secondary brake control unit (60).

16. Electromechanical braking system (202) according to claim 13, comprising an air treatment unit (70), wherein the redundancy valve unit (20) is integrated into the air treatment unit (70).

17. Commercial vehicle (200) with a front axle (VA) and at least one rear axle (HA), and an electromechanical braking system (202) according to one of claims 13 to 16.

18. A method for redundantly braking a trailer of a towing vehicle-trailer combination, wherein the towing vehicle has an electromechanical braking system (202), preferably according to one of claims 13 to 16, and the trailer has a pneumatic braking system, wherein in an operating case, trailer switching signals (S1, S2, S3) are provided to a trailer control valve (10) from a primary brake control unit (60), and the trailer control valve (10) controls a trailer brake pressure (pBA) at a trailer brake pressure connection (14) as a function of the trailer switching signals (S1, S2, S3), and in a fault case in which the provision of the trailer switching signals (S1, S2, S3) is partially or completely prevented,a redundancy valve unit (20) controls a pneumatic redundancy pressure (pR) at a redundancy connection (16) of the trailer control valve (10), and the trailer control valve (10) controls the trailer brake pressure (pBA) redundantly depending on the redundancy pressure (pR) at the trailer brake pressure connection (14).

19. The method according to claim 19, wherein the redundancy valve unit (20) receives redundancy switching signals (SR1, SR2) from a secondary brake control unit (60) and controls the redundancy pressure (pR) in dependence on the redundancy switching signals (SR1, SR2).

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