Electropneumatic device with protection valve unit

Abstract

The invention relates to an electro-pneumatic device (1) for an electronically controllable pneumatic brake system (102), comprising: a compressed-air reservoir (4) for providing a reserve pressure (pV); a brake pressure modulator (2) receiving the reserve pressure (pV) and regulating a brake pressure (pB) on a brake pressure interface (6) in dependence on an electronic brake request signal (SB); a protection valve unit (10) having a protection valve inlet (10.1), a first protection valve outlet (10.2) and a second protection valve outlet (10.3), wherein the protection valve inlet (10.1) receives the brake pressure (pB) and is able to provide the brake pressure to the first and second protection valve outlets (10.2, 10.3); a first brake pressure line (12) and a second brake pressure line (14); and a brake actuator (16) connected to the brake pressure lines (12, 14). The protection valve unit (10) is set up to inhibit the regulation of the brake pressure at the first protection valve outlet (10.2) in the event of a leak in the first brake pressure line (12) and to inhibit the regulation of the brake pressure at the second protection valve outlet (10.3) in the event of a leak in the second brake pressure line (14).

Description

TECHNICAL FIELD

[0001] The invention relates to an electro-pneumatic device for an electronically controllable pneumatic brake system, comprising a compressed-air reservoir for providing a reservoir pressure, an electro-pneumatic brake pressure modulator which receives the reservoir pressure of the compressed-air reservoir and which regulates a brake pressure at a brake pressure interface depending on an electronic brake request signal, and a brake actuator which receives the brake pressure. The invention also relates to a method and to a commercial vehicle. BACKGROUND

[0002] In a pneumatic brake system, a brake pressure is usually delivered by a brake pressure modulator to a brake actuator in order to slow down or stop the vehicle. Such a brake pressure modulator can be, for example, a front axle modulator, a rear axle modulator, an additional axle modulator, a parking brake modulator, a trailer brake pressure modulator or a trailer control valve, etc. As brake actuators, for example, a common service brake actuator, a spring-energized brake cylinder or a so-called combined cylinder having a service brake portion and a spring-energized portion can be used. Unlike a service brake which is tightened when a brake pressure is applied, a spring-energized actuator is loosened by the application of a brake pressure and tightened by a spring force when the brake pressure disappears.

[0003] A leak in the brake pressure line is undesirable in all cases. If a leak in the brake pressure line occurs in a service brake, the brake pressure provided escapes into the environment and the respective wheel cannot be braked or can no longer be braked completely. As a measure, either the respective axle is no longer braked and the vehicle is slowed down by the other axles, or the braking of the axle is redundantly implemented by other actuators, for example the spring-energized portion of a combined cylinder. In the case of a leak in the compressed-air line to a spring-energized brake cylinder, the spring-energized brake cylinder is vented and thus the parking brake is applied. However, due to such a leak, the spring-energized brake cylinder can no longer be vented and the parking brake can no longer be loosened. In this state, i.e. when the parking brake is applied, the vehicle cannot be moved or towed.

[0004] In order to prevent this, it is known, for example from DE 10 2007 016 335 A1, that in this case the spring-energized brake cylinder is loosened by a second brake circuit which is fed by a second compressed-air reservoir. The second brake circuit is then connected to the respective spring-energized brake cylinder by an electromagnetically switchable two-position three-way directional valve and a directional valve in order to be able to loosen it in the event of a failure of the first brake circuit, for example due to a leak or a line break. The disadvantage of this solution is that an additional electromagnetic valve is installed and that a redundant dynamic brake by means of the additional electromagnetic valve is also only achieved to a limited extent. A similar solution is known from EP 3 356 192 A1.

[0005] It is known in the context of brakes for rail vehicles and locomotives to brake different axles using a protection against hose rupture valve, as described in DE 1 282 392. A hose rupture of an axle does not result in the further axles no longer being able to be braked. Rather, the axle with the ruptured hose is no longer supplied with compressed air. However, this construction is very complex and requires a greater volume. Furthermore, there are problems in the complex coordination of the throttling due to the asymmetrical air consumption. This solution is therefore not suitable for commercial vehicles in which a wheel-specific braking is required in order to maintain the vehicle stability. SUMMARY

[0006] The task of the present invention is to provide an electro-pneumatic device of the aforementioned type which not only safely brakes an axle even in the event of a brake pressure line leak or line rupture, but also safely and simply releases the spring-energized brake cylinder in the event of a brake pressure line leak or rupture. In particular, the electro-pneumatic device of the present invention should be suitable for autonomous or semi-autonomous vehicles in which the driver cannot intervene manually.

[0007] The task is solved by the present invention in the case of an electro-pneumatic device of the aforementioned type in a first aspect in that a protection valve unit is provided which has a protection valve inlet, a first protection valve outlet and a second protection valve outlet, wherein the protection valve inlet is connected to the brake pressure interface of the brake pressure modulator, receives the brake pressure and provides it to the first and second protection valve outlets, and a first brake pressure line connected to the first protection valve outlet and a second brake pressure line connected to the second protection valve outlet, wherein the first and second brake pressure lines are connected to the brake pressure actuator. Furthermore, the protection valve unit is set up to inhibit or prevent the brake pressure from being regulated at the first protection valve outlet in the event of a leak in the first brake pressure line and to inhibit or prevent the brake pressure from being regulated at the second protection valve outlet in the event of a leak in the second brake pressure line. The first and second brake pressure lines thus redundantly connect the brake pressure modulator to the brake pressure actuator. In this way, the brake pressure actuator can still be supplied with brake pressure when one of the first and second brake pressure lines is leaking or ruptured. The protection valve unit is used to regulate the brake pressure in the first and second brake pressure lines, on the one hand. For example, it can be provided that only the first brake pressure line is applied in normal operation and only the second brake pressure line is applied in the event of a rupture or leak thereof. However, it can also be provided that the brake pressure is provided approximately uniformly through both brake pressure lines in normal operation. Furthermore, the protection valve unit is used to throttle or block the line that has ruptured or leaked. In this way, on the one hand, the reservoir is prevented from possibly idling, and on the other hand, a possible no longer braking or spring-energized brake cylinder is prevented from being compressed and being unable to be opened.

[0008] This is advantageous, in particular, in autonomous or semi-autonomous vehicles. The inventors have recognized that special means are required for the implementation of a fault-tolerant system for the operation of autonomous or semi-autonomous vehicles, in particular, which can be carried out without human intervention. With the present invention, a pneumatic means has been implemented which fulfills this task.

[0009] In a first preferred embodiment, a reversing valve is also provided, which is connected on the one hand to the first and second brake pressure lines and on the other hand to the brake pressure actuator. This reversing valve is preferably designed as a selector valve and preferably has a first reversing valve connection, a second reversing valve connection and a third reversing valve connection. The third reversing valve connection is connected to the brake pressure actuator. The first reversing valve connection is preferably connected to the first brake pressure line and the second reversing valve connection is connected to the second brake pressure line. The reversing valve is preferably configured in such a way that the higher pressure present at the first and second reversing valve connections is correspondingly tapped at the third reversing valve connection. Each of the other reversing valve connections is preferably closed. The reversing valve can be arranged directly on the brake pressure actuator or integrated in the brake pressure actuator.

[0010] It is furthermore preferred that the protection valve unit is arranged directly on the brake pressure modulator and integrated with the brake pressure modulator. Thereby, a robust unit is implemented and further potential sources of failure between the brake pressure modulator and the protection valve unit are avoided.

[0011] It can furthermore be provided that the electro-pneumatic means has a second brake actuator, which is connected to the first and second brake pressure lines to receive brake pressure. Preferably, a second reversing valve is also arranged between the second brake pressure actuator and the first and second brake pressure lines. The second reversing valve can preferably be configured and arranged as a reversing valve as described above. In this way, two brake pressure actuators can be supplied with brake pressure by means of the brake pressure modulator and the protection valve unit, in particular, when the brake pressure actuators are configured as single-channel. However, for example, three, four, five or six further brake pressure actuators can also be actuated by means of the protection valve unit. It can also be provided that the protection valve unit is configured as multi-channel itself. The multi-channel brake pressure modulator can also be equipped with only one protection valve unit, which can in this case be single-channel or multi-channel.

[0012] In a preferred refinement, it is provided that the brake pressure modulator is connected to a second compressed air reservoir and the second compressed air reservoir provides a second reservoir pressure to the brake pressure modulator. Thereby, a further redundancy is implemented. Between the first and second compressed air reservoirs and the brake pressure modulator, a reversing valve is preferably arranged, so that the brake pressure modulator is provided with the respective higher reservoir pressure of the first and second reservoir pressure from the first and second compressed air reservoirs.

[0013] Preferably, the electro-pneumatic device has a first diagnostic unit for detecting a leak in the first brake pressure line and a second diagnostic unit for detecting a leak in the second brake pressure line, wherein the first and second diagnostic units are connected to the same electronic control unit. Preferably, a first pressure sensor for detecting the brake pressure in the first brake pressure line and a second pressure sensor for detecting the brake pressure in the second brake pressure line are also provided, wherein the first and second pressure sensors are preferably connected to the same electronic control unit. The first and second pressure sensors can be assigned to or part of the first and second diagnostic units. For example, the first and second diagnostic units or pressure sensors are connected to a central unit of the brake system in which the electro-pneumatic device according to the application is configured, or the first and second diagnostic units or pressure sensors provide their signals via a vehicle bus or other bus system, or the first and second diagnostic units or pressure sensors are connected to the electronic control unit of the brake pressure modulator. Thereby, it is possible to recognize a fault early, which is advantageous in particular in highly automated and / or driverless vehicles, in which a leak or a line break cannot be detected by the senses of a human driver. Alternatively or in addition to the first and second pressure sensors, an additional valve can also be provided, by means of which such a diagnosis can also be carried out.

[0014] In another preferred embodiment, it is provided that the brake actuator protection unit is connected on the one hand to the first and second brake pressure lines and on the other hand to the brake pressure actuator. This brake actuator protection unit is preferably connected between the brake pressure lines and the brake actuator instead of the above-mentioned reversing valve. The brake actuator protection unit can be constructed identically or similarly to the protection valve unit. In this way, the same component advantages can be achieved in the brake system.

[0015] In a first specific embodiment of the protection valve unit, which has a valve body with a protection valve inlet, a first protection valve outlet and a second protection valve outlet, and a working chamber in which a valve element is movably arranged between the first and the second protection valve outlet. Preferably, the valve element abuts in a first end position against a first valve seat assigned to the first protection valve outlet and in a second end position against a second valve seat assigned to the second protection valve outlet. Preferably, the protection valve unit also has a throttled first bypass connecting the protection valve inlet with the first protection valve outlet and a throttled second bypass connecting the protection valve inlet with the second protection valve outlet. Thus, if the pressure at the first protection valve outlet drops, for example, due to a break in the first brake pressure line, a pressure difference between the first and the second protection valve outlet results, the valve element is pressed in the direction of the first valve seat, so that the first protection valve outlet can be shut off. Compressed air can still flow via the throttled bypass in the direction of the first brake pressure line, but this is a small volume flow which hardly impairs the brake performance. On the other hand, in normal operation, the first and the second bypass serve to keep the valve element substantially in the middle of the working chamber, in order to achieve a uniform full utilization of the first and the second brake pressure line, or to bring it back into the middle if it has left it. Instead of or in addition to the bypass, one or more springs can also be provided, which load the valve element into the middle, i.e. into the neutral position.

[0016] It is also possible that the protection valve unit has a first pneumatically switchable valve and a second pneumatically switchable valve. The first pneumatically switchable valve is preferably assigned to the first brake pressure line and the second pneumatically switchable valve is assigned to the second brake pressure line. The first and the second pneumatically switchable valve are preferably designed in such a way that, in the event of a leak in the first brake pressure line, the first pneumatically switchable valve suppresses or prevents the brake pressure being regulated at the first protection valve outlet, and in the event of a leak in the second brake pressure line, the second pneumatically switchable valve suppresses or prevents the brake pressure being regulated at the second protection valve outlet. In this way, the same functionality as described above can be achieved, wherein the first and the second pneumatically switchable valve have a high fail-safe security and allow a large cross section and simple diagnosis.

[0017] Preferably, the pneumatically switchable first valve has a first switching position, a second switching position, a first control interface and a second control interface, wherein the pneumatically switchable first valve is loaded or switched into the first switching position when a first control pressure is regulated at the first control interface and the pneumatically switchable first valve is loaded or switched into the second switching position when a second control pressure is regulated at the second control interface. It can also be provided that the pneumatically switchable first valve has not only two defined end positions, but also intermediate positions between the first and second switching positions. Preferably, the pneumatically switchable second valve likewise has a third switching position, a fourth switching position, a third control interface and a fourth control interface. Preferably, the pneumatically switchable second valve is loaded or switched into the third switching position when a third control pressure is regulated at the third control interface and the pneumatically switchable second valve is loaded or switched into the second switching position when a fourth control pressure is regulated at the fourth control interface. The pneumatically switchable second valve can also have intermediate positions. In the fault-free normal operation, the first and second control pressures and the third and fourth control pressures are regulated approximately simultaneously, respectively, so that a symmetrical loading of the pneumatically switchable first and second valves is obtained. Only in the event of a line leak or breakage does an asymmetry occur which leads to a switching of the respective valve.

[0018] Preferably, in the first or third switching position of the pneumatically switchable first and second valves, the protection valve inlet is connected to the first or second protection valve outlet without throttling. In the second switching position or the fourth switching position of the pneumatically switchable first and second valves, the protection valve inlet is preferably connected to the first or second protection valve outlet with throttling. In this regard, it is preferred that in the second or fourth switching position of the pneumatically switchable first or second valve, the throttle is preferably integrated into the valve.

[0019] Preferably, it is provided that the first control pressure corresponds to the first brake pressure of the first brake pressure line or a pressure derived from the first brake pressure. The third control pressure likewise preferably corresponds to the second brake pressure of the second brake pressure line or a pressure derived from the second brake pressure. In this regard, the first control line can lead from the first brake pressure line to the first control interface, for example, and the third control line can lead from the second brake pressure line to the third control interface. These control lines can be embodied with little volume.

[0020] It is furthermore preferred to provide that the second control pressure corresponds to the second brake pressure in the second brake pressure line or a pressure derived from the second brake pressure. The fourth control pressure corresponds to the first brake pressure in the first brake pressure line or a pressure derived from the first brake pressure. To this end, the second control line can lead from the second brake pressure line to the second control interface and the fourth control line can lead from the first brake pressure line to the fourth control interface. They can also be embodied with a smaller cross section. Alternatively or additionally it can also be provided that the second and fourth control pressures correspond to the pressure present at the input of the protection valve or a pressure derived from this pressure. In this regard, the control lines branching off from the input of the protection valve can also lead to the respective second and fourth control interfaces.

[0021] It is preferred that the first and second pneumatically switchable valves are spring-loaded into the open, non-throttled switching position. If the electro-pneumatic device is functioning correctly and two brake pressure lines are applied to send the brake pressure from the brake pressure modulator to the brake actuators, all control lines in the aforementioned embodiments, i.e. the first, second, third and fourth control lines or all control interfaces, are supplied with the same pressure. In order to bring or keep the first and second pneumatically switchable valves in the open position, they are preferably spring-loaded into the open switching position. Alternatively, the control lines leading to the second and fourth control interfaces can also be embodied with a smaller cross section, so that the pressure is further suppressed. This can however also result in a reduction of the dynamics of the system. In another preferred embodiment, a throttle and / or an increased control volume is arranged between the input of the protection valve and the second and / or fourth control interface. The throttle serves to not regulate at the second and fourth control interfaces the pressure regulated directly at the input of the protection valve, but a suppressed pressure. Preferably, an increased control volume is provided, in particular downstream of the throttle, to provide a further reduction.

[0022] In one variant of the embodiment of the electro-pneumatic device, the brake pressure modulator is a vehicle axle modulator and the at least one brake actuator is a service brake actuator. The brake pressure modulator is for example designed as a front axle modulator, in particular as a single-channel front axle modulator, wherein a total of four brake pressure lines are coupled to the protection valve unit, two brake pressure lines leading to a left front axle brake actuator and two brake pressure lines leading to a right front axle brake actuator. Alternatively, the brake pressure modulator can also be designed as a parking brake modulator and the brake actuators are spring-energized actuators. Here again one, two, three, four or more spring-energized actuators can be coupled to the protection valve unit of the parking brake modulator. Alternatively, a separate protection valve unit can also be provided for each brake actuator.

[0023] In a second aspect the invention solves the aforementioned task by a method for regulating a brake pressure in a electronically controllable pneumatic brake system without a line rupture, the method having the steps of:

[0024] - receiving an electronic brake request signal at an electro-pneumatic brake pressure modulator;

[0025] - regulating a brake pressure by means of the brake pressure modulator;

[0026] - receiving the brake pressure at a protection valve unit;

[0027] - regulating the brake pressure by means of the protection valve unit in a first brake pressure line and a second brake pressure line, which connect the brake actuator redundantly to the protection valve unit;

[0028] wherein upon learning of a leak in the first brake pressure line, the protection valve unit inhibits or prevents the regulation of the brake pressure in the first brake pressure line, and upon learning of a leak in the second brake pressure line, the protection valve unit inhibits or prevents the regulation of the brake pressure in the second brake pressure line.

[0029] It is to be understood that the electro-pneumatic device according to the first aspect of the invention and the method according to the second aspect of the invention have identical or analogous sub-aspects. In this regard, reference is made to the above description of the first aspect of the invention.

[0030] It is conceivable, for example, that the method further has the steps of learning a first brake pressure in the first brake pressure line and learning a second brake pressure in the second brake pressure line, in particular by means of first and second pressure sensors, and providing corresponding first and second pressure signals to the electronic control unit. It is further conceivable that the method has the steps of a first control pressure being branched off from the first brake pressure line, which feeds an electro-pneumatically switchable first valve, and a second control pressure being branched off from the second brake pressure line, which feeds the electro-pneumatically switchable first valve.

[0031] In the third aspect, the aforementioned task is accomplished by a commercial vehicle having an electronically controlled pneumatic braking system, which has an electro-pneumatic device as described in one of the aforementioned preferred embodiments of the electro-pneumatic device according to the first aspect of the invention. It should be understood that the commercial vehicle according to the third aspect of the invention and the electro-pneumatic device according to the first aspect of the invention have the same and similar sub-aspects. For this purpose, reference is made in its entirety to the foregoing content of the first aspect of the invention. The electronically controlled pneumatic braking system of the commercial vehicle may also have other components, particularly, for example, a central module, a unit for autonomous driving, a brake value transmitter, and a parking brake module. The central module may also be designed as a rear axle modulator. Additionally, a front axle modulator is also preferably provided. The front axle module, the central module (which also functions as a rear axle modulator), and the parking brake module may also be designed as electro-pneumatic devices. It is also preferred that the electronically controlled pneumatic braking system has more than one of the aforementioned types of electro-pneumatic devices. For example, the front axle modulator, the central module (which is also designed as the rear axle modulator), the separate rear axle modulator, and the parking brake module are each equipped with their own protection valve unit or two or more protection valve units, so that all brake actuators of the braking system are redundantly wired.

[0032] Embodiments of the invention will now be described with reference to the accompanying drawings. These are not necessarily to scale; rather, the drawings are illustrated in a schematic and / or slightly distorted form to aid explanation. For supplementation to the teachings directly apparent from the drawings, refer to the relevant prior art. It should be understood that various modifications and changes to the form and details of the embodiments can be made without departing from the general spirit of the invention. Features of the invention disclosed in the specification and drawings, individually or in arbitrary combinations, are important for improvements to the invention. Furthermore, all combinations of at least two features disclosed in the specification and / or drawings fall within the scope of protection of the invention. The general spirit of the invention is not limited to the precise form or details of the preferred embodiments shown and described below. Where a measurement range is specified, values ​​within the mentioned boundaries should also be disclosed as boundary values ​​and can be used and claimed arbitrarily. For simplicity, the same reference numerals are used below for the same or similar components or components having the same or similar functions. Attached Figure Description

[0033] Other advantages, features, and details of the invention will become apparent from the preferred embodiments and the following description taken in conjunction with the accompanying drawings; in the drawings:

[0034] Figure 1 An electro-pneumatic device is shown in the first embodiment;

[0035] Figure 2An electro-pneumatic device is shown in a first embodiment;

[0036] Figure 3 An electro-pneumatic device is shown in a second embodiment;

[0037] Figure 4 An electro-pneumatic device is shown in a third embodiment;

[0038] Figure 5 A first embodiment of a protection valve unit;

[0039] Figure 6 A second embodiment of a protection valve unit;

[0040] Figure 7 A third embodiment of a protection valve unit;

[0041] Figure 8 A fourth embodiment of a protection valve unit; and

[0042] Figure 9 A commercial vehicle with an electro-pneumatic brake system. Specific embodiments

[0043] An electro-pneumatic device 1 which can be applied in the context of an electronically controllable pneumatic brake system 102 (cf. Figure 9 ) can also be used in a brake system which is purely pneumatically controlled. The electro-pneumatic device 1 has an electro-pneumatic brake pressure modulator 2 as a central element. The electro-pneumatic brake pressure modulator 2 can be designed, in particular, as an axle modulator, for example a front axle modulator 104, a rear axle modulator 106 or an additional axle modulator, or also as a parking brake modulator 108 or a trailer control valve (cf. Figure 9 ) respectively). The electro-pneumatic brake pressure modulator 2 is connected on the input side to a compressed air reservoir 4 and receives a reservoir pressure pVtherefrom. In addition, the compressed air reservoir 4 can be connected to further modules which are not shown here and supplied with a corresponding reservoir pressure.

[0044] The electro-pneumatic brake pressure modulator 2 has one or more valves which are not shown here, i.e. in particular and preferably pneumatic relay valves and one or more electromagnetically switchable valves, inside. Both the relay valves and the electromagnetically switchable valves receive the reservoir pressure pV. The electromagnetic valves are configured for providing a control pressure on the relay valves, so that the relay valves regulate a brake pressure pB at a brake pressure interface 6 of the electro-pneumatic brake pressure modulator 2 in dependence on the received control pressure.

[0045] Furthermore, the electro-pneumatic brake pressure modulator 2 has an electrical interface 8 via which it is connected, for example, with a vehicle bus, other bus or another electrical line. The electro-pneumatic brake pressure modulator 2 can receive an electrical or electronic brake signal SB via the electrical interface 8, which can be, for example, a brake request signal, a deceleration request signal, a parking brake signal or a direct electrical pulse, which directly acts on one or more electromagnetically switchable valves for the case that the electro-pneumatic brake pressure modulator 2 does not have its own intelligence. The brake pressure pB is then regulated at the brake pressure interface 6 in dependence on the brake signal SB.

[0046] Via the brake pressure interface 6, the brake pressure modulator 2 is connected with a protection valve unit 10, which likewise receives the regulated brake pressure pB. The protection valve unit 10 is connected with a brake actuator 16 via a first brake pressure line 12 and a second brake pressure line 14, which are configured redundantly to one another. The brake actuator 16 can be a usual service brake actuator or, for example, a spring-energized part of a spring-energized brake cylinder or of a combination cylinder. Even if only a service brake cylinder is explained in the present case, it is to be understood that analogous and similar embodiments are also applicable to spring-energized actuators.

[0047] The protection valve unit 10 has a protection valve inlet 10.1, a first protection valve outlet 10.2 and a second protection valve outlet 10.3. The protection valve inlet 10.1 is connected with the brake pressure interface 6 and receives the brake pressure pB regulated by the brake pressure modulator 2 therefrom. The first brake pressure line 12 is coupled with the first protection valve outlet 10.2 and the second brake pressure line 14 is coupled with the second protection valve outlet 10.3. In normal operation, the protection valve unit 10 continues to control the received brake pressure pB directly at the first and second protection valve outlets 10.2, 10.3, so that there is a brake pressure pB in the first and second brake pressure lines 12, 14 and, in the following, referred to as first brake pressure pB1 and second brake pressure pB2. Downstream of the first and second brake pressure lines 12, 14 and upstream of the brake actuator 16, a changeover valve 18 is provided, which combines the first and second brake pressures pB1, pB2 and regulates them as brake pressure pB on the brake actuator 16. The changeover valve 18 has a first changeover valve interface 18.1, which is connected with the first brake pressure line 12. The changeover valve has a second changeover valve interface 18.2, which is connected with the second brake pressure line 14. Furthermore, the changeover valve 18 has a third changeover valve interface 18.3, which is connected with the brake actuator 16. The changeover valve 18 is designed as a so-called high-select valve and regulates at the third changeover valve interface 18.3 the respective higher one of the pressures present at the first and second changeover valve interfaces 18.1, 18.2.

[0048] The protection valve unit 10 is configured in such a way that, in the event of a leak or a break in one of the first and second brake pressure lines 12, 14, the protection valve outlet 10.2, 10.3 assigned to the first or second brake pressure line 12, 14 is throttled. In particular, the protection valve unit 10 is configured for inhibiting or preventing the regulated out of the first brake pressure pB1 at the first protection valve outlet 10.2 in the event of a leak or a break in the first brake pressure line 12 and for inhibiting or preventing the regulated out of the second brake pressure pB2 at the second protection valve outlet 10.3 in the event of a leak or a break in the second brake pressure line 14. In this way it can be achieved that the brake actuator 16 is supplied with brake pressure pB also by the functionally intact brake pressure line of the first and second brake pressure lines 12, 14, on the other hand, it is also prevented that the compressed air reservoir 4 is idled. In this way it can also be ensured that the vehicle, in particular an autonomous or semi-autonomous vehicle, still functions completely normally in the event of a fault, i.e. in the event of a leak or a break in one of the two brake pressure lines 12, 14.

[0049] Figure 2 An embodiment is shown which is based on Figure 1 and identical and similar elements are provided with identical reference signs. In the following, in particular differences to the first embodiment of the Figure 1 are emphasized.

[0050] Unlike the first embodiment ( Figure 1 ), in the second embodiment a second brake actuator 20 is provided, which is likewise supplied via the first and second brake pressure lines 12, 14. For example, the first brake actuator 16 is a brake actuator for the right wheel of an axle, while the second brake actuator 20 is a brake actuator for the left wheel of the same axle. The protection valve unit 10 is implemented here as a single-channel, i.e. it feeds both brake pressure lines 12, 14. The same brake pressure pB is regulated in both brake pressure lines 12, 14, and here a wheel-specific regulation cannot be achieved. However, additional ABS valves can also be provided in order to achieve a wheel-specific and slip-controllable brake.

[0051] In order to supply the brake actuators 16, 20 with brake pressure pB, a branch 22 is provided in the first brake pressure line 12, which promotes a first section 12.1 of the first brake pressure line 12 and a second section 12.2 of the first brake pressure line 12. Likewise, a second branch point 24 is provided in the second brake pressure line 14, at which the second brake pressure line 14 is divided into a first section 14.1 of the second brake pressure line 14 and a second section 14.2 of the second brake pressure line 14. Thus, each of the first and second brake actuators 16, 20 is supplied not only with brake pressure pB1 from the first brake pressure line 12 but also with brake pressure pB2 from the second brake pressure line 14. Downstream of the first and second brake pressure lines 12, 14 and before the second brake actuator 20, a second directional valve 26 is arranged, which can likewise be embodied as the directional valve 18. The second directional valve 26 has a first directional valve connection 26.1 to the second section 12.2 of the first brake pressure line 12 and a second directional valve connection 26.2 to the second section 14.2 of the second brake pressure line 14. A third directional valve connection 26.3 of the second directional valve 26 is connected to the second brake actuator 20.

[0052] According to Figure 3 the third embodiment according to Figure 2 the second embodiment according to

[0053] First, in addition to the provision of the compressed-air reservoir 4, a second compressed-air reservoir 28 is also provided, which likewise provides a reservoir pressure pV. This second compressed-air reservoir 28 can be a compressed-air reservoir of the second brake circuit or of a backup circuit. The first compressed-air reservoir 4 and the second compressed-air reservoir 28 are connected to the electro-pneumatic brake pressure modulator 2 by means of a reservoir directional valve 30, which can also be designed as a selector valve. In this way, the respective higher one of the reservoir pressures pV delivered by the first and second compressed-air reservoirs 4, 28 is regulated at the electro-pneumatic brake pressure modulator 2 by means of the reservoir directional valve 30.

[0054] Furthermore, according to the third embodiment Figure 3The electro-pneumatic device 1 of the first embodiment shown comprises a first diagnostic unit 32 arranged for detecting a leak or a breakage of the first brake pressure line 12 and a second diagnostic unit 34 arranged for detecting a leak or a breakage of the second brake pressure line 14. The first diagnostic unit 32 provides a corresponding first diagnostic signal SD1 and the second diagnostic unit 34 provides a second diagnostic signal SD2. The first and second diagnostic signals SD1, SD2 are preferably provided on an electronic control unit, for example a central unit, a unit for autonomous driving or an electronic control unit of the electro-pneumatic brake pressure modulator 2. Preferably, the first and second diagnostic units 32, 34 are designed as pressure sensors and in this regard provide first and second pressure signals. For this purpose, the first and second diagnostic units 32, 34 are connected with the respective first and second brake pressure lines 12, 14. In the embodiment shown Figure 3 ), the first diagnostic unit 32 has a first diagnostic valve 33 in addition and the second diagnostic unit 34 has a second diagnostic valve 35. If the respective brake pressure line 12, 14 has a leak, these valves 33, 35 can be brought into an open switching position. Then, the respective brake pressure line 12, 14 can be completely vented, so that the valve unit 10 can completely block the respective brake pressure line 12, 14. In addition, the first and second diagnostic units 32, 34 serve to provide the autonomous unit with information about the state of the brake system in the case that the electro-pneumatic device 1 is installed in an autonomous or semi-autonomous vehicle, so that corresponding measures can be taken.

[0055] Figure 4 The embodiment shown is now again based on Figure 1 the first embodiment shown, in which identical and similar elements are provided with identical reference numerals, so that the above description applies in full.

[0056] Unlike the first embodiment Figure 1 , instead of the switching valve 18, a brake actuator protection unit 36 is provided, which has a first protection unit interface 36.1 connected with the brake actuator 16 and a second protection unit interface 36.2 connected with the first brake pressure line 12 and a third protection unit interface 36.3 connected with the second brake pressure line 14. In particular, the brake actuator protection unit 36 can be designed identically to the protection valve unit 10, however exactly reversed. In this regard, the first protection unit interface 36.1 corresponds to the protection valve inlet 10.1, the second protection unit interface 36.2 corresponds to the first protection valve outlet 10.2 and the third protection unit interface 36.3 corresponds to the second protection valve outlet 10.3. In this way, it is possible to combine the first and second brake pressures pB1, pB2 for the brake actuator 16.

[0057] Figure 5A first embodiment of a protection valve unit 10 is shown. The protection valve unit 10 has a valve body 40, which can also be referred to as protection valve housing and constitutes the base body of the protection valve unit 10. In the valve body 40 a working chamber 42 is formed, into which the protection valve inlet 10.1, the first protection valve outlet 10.2 and the second protection valve outlet 10.3 open. A valve element 44 is movably arranged within the working chamber 42. Figure 5 The valve element is shown in the right end position and abutting a first valve seat 46 which is assigned to the first protection valve outlet 10.2. A second valve seat 47 is assigned to the second protection valve outlet 10.3. The protection valve inlet 10.1 remains open. If, for example, a brake pressure pB is regulated at the protection valve inlet 10.1 and no counter pressure is present at the first protection valve outlet 10.2, the valve element 44 moves into the right end position towards the first valve seat 46 and blocks the first protection valve outlet 10.2. Compressed air can still flow from the protection valve inlet 10.1 via the working chamber 42 to the second protection valve outlet 10.3. Preferably and according to the embodiment shown here, a throttled first bypass 48 is also provided, which connects the working chamber 42 with the first protection valve outlet 10.2 by bypassing the first valve seat 46. Furthermore, a throttled second bypass 49 is provided in a similar manner, which connects the working chamber 42 with the second protection valve outlet 10.3 by bypassing the second valve seat 47. In this way, an overflow of the first and second valve seats 46, 47 is allowed, which leads to a higher stability in normal operation, when no leaks and breakages are present in the first and second brake pressure lines 12, 14, and in particular the valve element 44 is brought into an intermediate position between the first and second valve seats 46, 47. Basically, the protection valve unit 10 according to the first embodiment Figure 5 ) is based on a conventional changeover valve, however differs from the conventional changeover valve, among other things, in the first and second bypass 48, 49.

[0058] Figure 6 to Figure 8 Second to fourth embodiments of the protection valve unit 10 are shown, which are based on a provision of two pneumatically switchable valves.

[0059] The protection valve unit 10 according to the second embodiment Figure 6 ) is shown again in a valve body 40, which is not mandatory. In this embodiment, the wiring of the individual valve elements can also be realized in a conventional manner without a valve body 40.

[0060] The protection valve unit 10 according to this embodiment has a pneumatically switchable first valve 50 and a pneumatically switchable second valve 52. The pneumatically switchable first valve 50 has a first switch valve interface 50.1 which is connected with the protection valve inlet 10.1. Furthermore, the pneumatically switchable first valve 50 has a second switch valve interface 50.2 which is connected with the first protection valve outlet 10.2. In Figure 6In the shown first switching position, the first and second switching valve interfaces 50.1, 50.2 are connected without throttling. In Figure 6 In a second switching position, not shown, the first and second switching valve interfaces 50.1, 50.2 are connected with throttling. For this purpose, the first pneumatically switchable valve 50 has a first throttle 51. For switching the first pneumatically switchable valve 50, it has a first control interface 50.3 and a second control interface 50.4. The first control interface 50.3 is connected by a first control line 54 with the line downstream of the second switching valve interface 50.2 or with the first protection valve outlet 10.2 and thus regulates the first brake pressure pB1 at the first control interface 50.3 as a first control pressure pS1. A second control line 55 branches off from the line between the second pneumatically switchable valve 52 and the second protection valve outlet 10.3 or from the second protection valve outlet 10.3 and thus regulates the second brake pressure pB2 at the second control interface 50.4 as a second control pressure pS2. As soon as the first control pressure pS1 exceeds a first threshold value, the first pneumatically switchable valve 50 switches to Figure 6 the shown first switching position. However, as soon as this pressure falls, in particular below the first threshold value, and the second control pressure pS2 is above a second threshold value, the first pneumatically switchable valve 50 switches to Figure 6 the second switching position, not shown in the figure, so that a pressure is regulated with throttling at the first protection valve outlet 10.2.

[0061] In a corresponding manner, the second pneumatically switchable valve 52 has a third switching valve interface 52.1, a fourth switching valve interface 52.2, a third control interface 52.3 and a fourth control interface 52.4. The second pneumatically switchable valve 52 is connected in the shown first switching position without throttling, while Figure 6 the shown first switching position is again without throttling, while Figure 6 the second switching position, not shown, is with throttling. For this purpose, the second pneumatically switchable valve 52 has a second throttle 53. A third control line 56 branches off from the same location as the second control line 55, even if this is not necessary, but in any case regulates the second brake pressure pB2 at the third control interface 52.3 as a third control pressure pS3. A fourth control line 57 branches off from the same location as the first control line 54, even if this is not necessary, but in any case regulates the first brake pressure pB1 at the fourth control interface 52.4 as a fourth control pressure pS4. It also applies here that, if the third control pressure pS3 exceeds a third threshold value, the second pneumatically switchable valve 52 switches to Figure 6 the shown first switching position, while if the third control pressure pS3 is below the threshold value, but the fourth control pressure pS4 is above a fourth threshold value, it switches to Figure 6 the second switching position, not shown.

[0062] The third embodiment of the protection valve unit 10 is based on the second embodiment ( Figure 6 ), so that identical and similar elements are provided with identical reference numerals. In this regard, reference is made in general to the foregoing description relating to the second embodiment ( Figure 6 ) of the protection valve unit 10.

[0063] Unlike the second embodiment ( Figure 6 ), in the third embodiment ( Figure 7 ) a first spring 58 is additionally provided on the pneumatically switchable first valve 50, which spring loads the pneumatically switchable first valve 50 into the first switching position shown in Figure 7 . Likewise, a second spring 59 is provided on the pneumatically switchable second valve 52, which spring loads the pneumatically switchable second valve 52 into the first switching position shown in Figure 7 . In this way it can be ensured that an undefined state of the pneumatically switchable first and second valves 50, 52 does not occur when the first and second brake pressures pB1, pB2 are as high, but rather the first switching position is stably occupied.

[0064] The fourth embodiment of the protection valve unit 10 is based in principle on the second embodiment ( Figure 6 ), however additionally has the first and second springs 58, 59 as described in the third embodiment ( Figure 7 ). However, this is only optional in the fourth embodiment ( Figure 8 ).

[0065] The main difference of the fourth embodiment ( Figure 8 ) from the second and third embodiments ( Figure 6 , Figure 7 ) lies in the wiring of the second and fourth control interfaces 50.4, 52.4. While in the second and third embodiments ( Figure 6 , Figure 7 ) the second control interface 50.4 of the pneumatically switchable first valve 50 is supplied with the second brake pressure pB2 and the fourth control interface 52.4 of the pneumatically switchable second valve 52 is supplied with the first brake pressure pB1, these two control interfaces 50.4, 52.4 are in the fourth embodiment ( Figure 8 ) preferably throttled with the brake pressure regulated at the protection valve inlet 10.1. In the second and third embodiments ( Figure 6 , Figure 7 ) the pneumatically switchable first and second valves 50, 52 are in the second switching position in the event of a leak in both brake pressure lines 12, 14, while in the fourth embodiment ( Figure 8) the second switching position of the pneumatically switchable valves 50, 52 is not dependent on the brake pressure pB1, pB2 regulated by the protection valve unit 10, but on the brake pressure pB received by the protection valve unit 10, which is regulated at the protection valve inlet 10.1 by the brake pressure modulator 2.

[0066] For this purpose, in the fourth embodiment, the second control line 55 extends as a branch of the protection valve inlet 10.1, and the fourth control line 57 likewise extends as a branch of the protection valve inlet 10.1. Furthermore, between the protection valve inlet 10.1 and the second or fourth control line 55, 57, a third throttle 60 and an increased volume 62 are connected, it being non- mandatorily required that both are provided, it being possible that, if necessary, it is sufficient to provide one of the two, the third throttle 60 and the increased volume 62. In this way, too, a protection valve unit 10 according to the application can be realized.

[0067] It is to be understood that the protection valve unit 10 can also be claimed independently of the Figure 5 to Figure 8 electropneumatic arrangement shown in Figure 1 to Figure 4 . In this regard, the protection valve unit 10 is not dependent on the other elements shown in Figure 1 to Figure 4 , in particular the brake pressure modulator 2, the first and second brake pressure lines 12, 14, the reversing valve 18 and the brake actuator 16. It is also possible to claim the brake pressure modulator 2 and the protection valve unit 10, as well as the unit consisting of the protection valve unit 10 together with the first and second brake pressure lines 12, 14 and, if necessary, the brake pressure modulator 2.

[0068] Figure 9 An overview of a commercial vehicle 100 with an electronically controllable pneumatic brake system 102 is shown. The commercial vehicle has a front axle VA and a rear axle HA, it being understood, however, that it can also have further axles, for example additional axles not shown. Furthermore, a trailer control valve not shown for supplying a trailer not shown can also be provided.

[0069] The brake system 102 has a front axle modulator 104, a central module which at the same time acts as a rear axle modulator 106 and a parking brake modulator 108. These modules each constitute a brake pressure modulator 2 of the type described above, it being possible for only one or two such modules to be configured. A brake circuit with a separate compressed-air reservoir is assigned to each brake pressure modulator 2 not shown here for reasons of overview.

[0070] The front axle modulator 104 is designed to be two-channel and comprises a protection valve unit 10 for the left front wheel, to which a first brake actuator 16 in the form of a first service brake actuator 110.1 is assigned. Likewise, the right front wheel is assigned a second brake actuator 16 in the form of a second service brake actuator 110.2, which is likewise connected to the protection valve unit 10. The rear axle is supplied in the operating case by the rear axle modulator 106, which is likewise designed to be two-channel and supplies, by means of a first channel and the protection valve unit 10, a first combined service brake and spring-loaded energy store actuator 112.1 on the left rear wheel, and, by means of a second channel and the protection valve unit 10, a second combined service brake and spring-loaded energy store actuator 112.2 on the right rear wheel.

[0071] Furthermore, the parking brake modulator 108 is provided with a protection valve unit 10 and is designed to be single-channel. The parking brake modulator 108 actuates the spring-loaded energy store actuators of the combined service brake and spring-loaded energy store actuators 112.1, 112.2 on the rear axle HA.

[0072] In the case of the protection valve units 10 being equipped with diagnostic units 32, 34 as described with reference to Figure 3 they are preferably connected to the possible electronic control unit of the respective assigned brake pressure modulator 2 and / or to a central module.

[0073] List of reference signs (part of the description)

[0074] 1 electro-pneumatic device

[0075] 2 electro-pneumatic brake pressure modulator

[0076] 4 compressed air reservoir

[0077] 6 brake pressure interface

[0078] 8 electrical interface

[0079] 10 protection valve unit

[0080] 10.1 protection valve inlet

[0081] 10.2 first protection valve outlet

[0082] 10.3 second protection valve outlet

[0083] 12 first brake pressure line

[0084] 12.1 first section of the first brake pressure line

[0085] 12.2 second section of the first brake pressure line

[0086] 14 second brake pressure line

[0087] 14.1 first section of the second brake pressure line

[0088] 14.2 second section of the second brake pressure line

[0089] 16 brake actuator

[0090] 18 reversing valve

[0091] 18.1 first reversing valve interface

[0092] 18.2 second reversing valve interface

[0093] 18.3 third reversing valve interface

[0094] 20 second brake actuator

[0095] 22 first branch point

[0096] 24 second branch point

[0097] 26 second reversing valve

[0098] 26.1 first reversing valve interface

[0099] 26.2 second reversing valve interface

[0100] 26.3 third reversing valve interface

[0101] 28 second compressed-air reservoir

[0102] 30 reserve reversing valve

[0103] 32 first diagnostic unit

[0104] 33 first diagnostic valve

[0105] 34 second diagnostic unit

[0106] 35 second diagnostic valve

[0107] 36 brake actuator protection unit

[0108] 36.1 first protection unit interface

[0109] 36.2 second protection unit interface

[0110] 36.3 third protection unit interface

[0111] 40 valve body

[0112] 42 working chamber

[0113] 44 valve element

[0114] 46 first valve seat

[0115] 47 second valve seat

[0116] 48 throttled first bypass

[0117] 49 throttled second bypass

[0118] 50 first pneumatically switchable valve

[0119] 50.1 first switch valve interface

[0120] 50.2 second switch valve interface

[0121] 50.3 first control interface

[0122] 50.4 second control interface

[0123] 51 first throttling

[0124] 52 second pneumatically switchable valve

[0125] 52.1 third switch valve interface

[0126] 52.2 fourth switch valve interface

[0127] 52.3 third control interface

[0128] 52.4 fourth control interface

[0129] 53 second throttling

[0130] 54 first control line

[0131] 55 second control line

[0132] 56 third control line

[0133] 57 fourth control line

[0134] 58 first spring

[0135] 59 second spring

[0136] 60 third throttling

[0137] 62 enlarged volume

[0138] 100 utility vehicle

[0139] 102 electronically controllable pneumatic brake system

[0140] 104 front axle modulator

[0141] 106 rear axle modulator (central module)

[0142] 108 parking brake modulator

[0143] 110.1 First service brake actuator

[0144] 110.2 Second service brake actuator

[0145] 112.1 First service brake and spring-energized actuator

[0146] 112.2 Second service brake and spring-energized actuator

[0147] VA Front axle

[0148] HA Rear axle

[0149] pB Brake pressure

[0150] pB1 First brake pressure

[0151] pB2 Second brake pressure

[0152] pS1 First control pressure

[0153] pS2 Second control pressure

[0154] pS3 Third control pressure

[0155] pS4 Fourth control pressure

[0156] pV Reserve pressure

[0157] SB Brake signal

[0158] SD1 First diagnostic signal

[0159] SD2 Second diagnostic signal

Claims

1. Electropneumatic device (1) for an electronically controllable pneumatic brake system, comprising a compressed-air reservoir (4) for providing a reservoir pressure (pV); an electropneumatic brake-pressure modulator (2) which receives the reservoir pressure (pV) of the compressed-air reservoir (4) and which regulates a brake pressure (pB) at a brake-pressure interface (6) in dependence on an electronic brake request signal (SB); A protection valve unit (10) having a protection valve inlet (10.1), a first protection valve outlet (10.2) and a second protection valve outlet (10.3), wherein the protection-valve inlet (10.1) is connected to the brake-pressure interface (6) of the brake-pressure modulator (2), receives the brake pressure (pB) and can supply the brake pressure to the first and second protection-valve outlets (10.2, 10.3); a first brake-pressure line (12) which is connected to the first protection-valve outlet (10.2) and a second brake-pressure line (14) which is connected to the second protection-valve outlet (10.3); and at least one brake actuator (16) which is connected to the first and second brake-pressure lines (12, 14) to receive the brake pressure (pB), wherein the protection-valve unit (10) is designed to suppress or prevent the regulation of brake pressure at the first protection-valve outlet (10.2) in the event of a leak in the first brake-pressure line (12) and to suppress or prevent the regulation of brake pressure at the second protection-valve outlet (10.3) in the event of a leak in the second brake-pressure line (14).

2. Electropneumatic device according to claim 1, further having a reversing valve (18) which is connected on the one hand to the first and second brake-pressure lines (12, 14) and on the other hand to the brake actuator (16).

3. An electro-pneumatic device according to any of the preceding claims, wherein, The protection-valve unit (10) is arranged directly on the brake-pressure modulator (2) or is integrated with the brake-pressure modulator.

4. An electro-pneumatic device according to claim 1 or 2, having a second brake actuator (20) which is connected to the first and second brake pressure lines (12, 14) for receiving the brake pressure (pB), wherein A second reversing valve (26) is arranged between the second brake actuator (20) and the first and second brake-pressure lines (12, 14).

5. Electropneumatic device according to claim 1 or 2, having a second compressed-air reservoir (28) which is connected to the brake-pressure modulator (2) and which supplies a second reservoir pressure (pV) to the brake-pressure modulator.

6. An electro-pneumatic device according to claim 1 or 2, having a first diagnostic unit (32) for ascertaining a leak in the first brake pressure line (12) and a second diagnostic unit (34) for ascertaining a leak in the second brake pressure line (14), wherein First and second diagnostic units (32, 34) are connected to the same electronic control unit.

7. Electropneumatic device according to claim 1 or 2, having a brake-actuator protection unit (36) which is connected on the one hand to the first and second brake-pressure lines (12, 14) and on the other hand to the brake actuator (16).

8. An electro-pneumatic device according to claim 1 or 2, wherein, The protection valve unit (10) has a valve body (40) with the protection valve inlet (10.1), the first protection valve outlet (10.2) and the second protection valve outlet (10.3), and a working chamber (42) in which a valve element (44) is movably arranged between the first and second protection valve outlets (10.2, 10.3) and in a first end position abuts against a first valve seat (46) assigned to the first protection valve outlet (10.2) and in a second end position abuts against a second valve seat (47) assigned to the second protection valve outlet (10.3), wherein the protection valve unit (10) further has a throttled first bypass (48) connecting the protection valve inlet (10.1) with the first protection valve outlet (10.2) and a throttled second bypass (49) connecting the protection valve inlet (10.1) with the second protection valve outlet (10.3).

9. An electro-pneumatic device according to claim 1 or 2, wherein, The protection valve unit (10) has a first pneumatically switchable valve (50) and a second pneumatically switchable valve (52), wherein the first pneumatically switchable valve (50) is assigned to the first brake pressure line (12) and the second pneumatically switchable valve (52) is assigned to the second brake pressure line (14), and wherein the first pneumatically switchable valve (50) inhibits or prevents the regulated out of brake pressure at the first protection valve outlet (10.2) in the event of a leak in the first brake pressure line (12) and the second pneumatically switchable valve (52) inhibits or prevents the regulated out of brake pressure at the second protection valve outlet (10.3) in the event of a leak in the second brake pressure line (14).

10. The electro-pneumatic device according to claim 9, wherein The first pneumatically switchable valve (50) has a first switching position, a second switching position, a first control interface (50.3) and a second control interface (50.4), wherein the first pneumatically switchable valve (50) is loaded into the first switching position when a first control pressure (pS1) is regulated at the first control interface (50.3) and into the second switching position when a second control pressure (pS2) is regulated at the second control interface (50.4), and The second pneumatically switchable valve (52) has a third switching position, a fourth switching position, a third control interface (52.3) and a fourth control interface (52.4), wherein the second pneumatically switchable valve (52) is loaded into the third switching position when a third control pressure (pS3) is regulated at the third control interface (52.3) and into the second switching position when a fourth control pressure (pS4) is regulated at the fourth control interface (52.4).

11. An electro-pneumatic device according to claim 10, wherein, The first control pressure (pS1) corresponds to the first brake pressure (pB1) or a pressure derived from the first brake pressure, and the third control pressure (pS3) corresponds to the second brake pressure (pB2) or a pressure derived from the second brake pressure.

12. An electro-pneumatic device according to claim 10 or 11, wherein, The second control pressure (pS2) corresponds to the second brake pressure (pB2) or a pressure derived from the second brake pressure, and the fourth control pressure (pS4) corresponds to the first brake pressure (pB1) or a pressure derived from the first brake pressure, or wherein the second and fourth control pressures (pS2, pS4) correspond to a pressure (pB) present at the protection valve inlet (10.1) or a pressure derived from the pressure.

13. The electro-pneumatic device of claim 9, wherein, The first and second pneumatically switchable valves (50, 52) are spring-loaded into an open, non-throttled switching position.

14. The electro-pneumatic device of claim 12, wherein, A throttle (60) and / or an enlarged control volume (62) is configured between the protection valve inlet (10.1) and the second and / or fourth control interface (50.4, 52.4).

15. The electro-pneumatic device according to claim 1 or 2, wherein, The brake pressure modulator (2) is an axle modulator (104, 106) and the at least one brake actuator (16) is a service brake actuator (110.1, 110.2), or wherein the brake pressure modulator (2) is a parking brake modulator (108) and the at least one brake actuator (16) is a spring-energized actuator (112.1, 112.2).

16. Method for regulating an outgoing brake pressure (pB) in an electronically controllable pneumatic brake system (102) in a line-breakage-proof manner, the method having the steps of: - receiving an electronic brake request signal (SB) at an electro-pneumatic brake pressure modulator (2); - regulating a brake pressure (pB) by means of the brake pressure modulator (2); - receiving the brake pressure (pB) at a protection valve unit (10); - regulating the brake pressure (pB, pB1, pB2) in a first brake pressure line (12) and a second brake pressure line (14) connecting a brake actuator (2) redundantly to the protection valve unit (10) by means of the protection valve unit (10); wherein - upon knowledge of a leak in the first brake pressure line (12), the protection valve unit (10) inhibits or prevents the regulation of the brake pressure (pB, pB1) in the first brake pressure line (12), and upon knowledge of a leak in the second brake pressure line (14), the protection valve unit inhibits or prevents the regulation of the brake pressure (pB, pB2) in the second brake pressure line (14).

17. Commercial vehicle (100) having an electronically controllable pneumatic brake system (102), the commercial vehicle comprising an electro-pneumatic device (1) according to any one of claims 1 to 15.

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