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Title:
PNEUMATIC VEHICLE BRAKE ASSEMBLY
Document Type and Number:
WIPO Patent Application WO/2020/244793
Kind Code:
A1
Abstract:
The invention relates to a pneumatic vehicle brake assembly (1). The vehicle brake assembly (1) comprises a right and left pneumatic brake branch (2, 6) associated with different wheel ends of the vehicle axle and used for controlling the brake pressures biasing the brake actuators. The pneumatic brake branches (2, 6) comprise pivoting anchor valves (3, 7) allowing a fast aeration and de-aeration of the brake actuators. The invention proposes to connect the pneumatic brake branches (2, 6) by a connecting line (32) with an integrated valve device (33). The valve device (33) comprises an open position and a closed position. In the open position the brake pressures at the brake actuators are the same and can be alternatively controlled by the pivoting anchor valves (3, 7) so that also for a failure of one pivoting anchor valve (3, 7) the brake pressure can be provided. Instead, in the closed position of the valve device (33) a separate control in the brake lines (5, 9) is possible which e.g. allows the generation of a yaw moment and/or the consideration of different coefficients of friction at the two wheel ends. The inventive vehicle brake assembly (1) can be used for a commercial vehicle, in particular a tractor or a trailer.

Inventors:
MELLINGS CARL (GB)
HARRISON DUDLEY (GB)
HEER SIEGFRIED (DE)
NILSSON KRISTOFFER (SE)
Application Number:
PCT/EP2019/076097
Publication Date:
December 10, 2020
Filing Date:
September 26, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HALDEX BRAKE PROD AB (SE)
International Classes:
B60T13/26; B60T13/66; B60T13/68; B60T15/02
Domestic Patent References:
WO2016062542A12016-04-28
Foreign References:
EP1968831A12008-09-17
GB2535527A2016-08-24
US20050134109A12005-06-23
US20180022334A12018-01-25
US8651588B22014-02-18
GB201719309A2017-11-21
GB201904957A2019-04-08
GB201806527A2018-04-21
GB201719415A2017-11-22
GB201719344A2017-11-21
EP2567131A12013-03-13
EP1303719A12003-04-23
EP2756215A12014-07-23
EP2049373A12009-04-22
GB201820137A2018-12-11
EP3222897A12017-09-27
Attorney, Agent or Firm:
REHBERG HÜPPE + PARTNER PATENTANWÄLTE PARTG MBB (DE)
Download PDF:
Claims:
CLAIMS

1. Pneumatic vehicle brake assembly (1 ) comprising

a) a first pneumatic brake branch (2) associated with a first wheel end and used for controlling the brake pressure biasing a first brake actuator (51 ) of the first wheel end, the first pneumatic brake branch (2) comprising a first brake control valve (123), and

b) a second pneumatic brake branch (6) associated with a second wheel end and used for controlling the brake pressure biasing a second brake actuator (52) of the second wheel end, the second pneumatic brake branch (6) comprising a second brake control valve (124),

c) wherein the first pneumatic brake branch (2) is connected to the second pneumatic brake branch (6) by a valve device (33) which comprises

ca) an open position providing a connection of the first pneumatic brake branch (2) to the second brake actuator (52) and/or of the second pneumatic brake branch (6) to the first brake actuator (51 ) and

cb) a closed position wherein

the first pneumatic brake branch (2) is separated by the valve device (33) from the second brake actuator (52) and/or

the second pneumatic brake branch (6) is separated by the valve device (33) from the first brake actuator (51 ).

2. Pneumatic vehicle brake assembly (1 ) of claim 1 , characterized in that

a) the first pneumatic brake branch (2) is a right pneumatic brake branch (2) and the second pneumatic brake branch (6) is a left pneumatic brake branch (6),

b) the first wheel end is a right wheel end or associated with a right side of a vehicle axle and the second wheel end is a left wheel end or associated with a left side of another or the same vehicle axle,

c) the first brake actuator (51 ) is a right brake actuator (51 ) and the second brake actuator (52) is a left brake actuator (52) and

d) the first brake control valve (123) is a right brake control valve (123) and the second brake control valve (124) is a left brake control valve (124). 3. Pneumatic vehicle brake assembly (1 ) of claim 1 , characterized in that

a) the first pneumatic brake branch (2) is a front pneumatic brake branch (2) and the second pneumatic brake branch (6) is a rear pneumatic brake branch (6),

b) the first wheel end is a front wheel end of a front axle and the second wheel end is a rear wheel end of a rear axle, the front axle being arranged in front of the rear axle, c) the first brake actuator (51 ) is a front brake actuator (51 ) and the second brake actuator (52) is a rear brake actuator (52), the front brake actuator and the rear brake actuator being arranged on the same or different vehicle sides and

d) the first brake control valve (123) is a front brake control valve (123) and the second brake control valve (124) is a rear brake control valve (124).

4. Pneumatic vehicle brake assembly (1 ) of one of claims 1 to 3, characterized in that the valve device (33) comprises a 2/2-valve.

5. Pneumatic vehicle brake assembly (1 ) of one of claims 1 to 4, characterized in that the valve device (33) comprises a pivoting anchor valve (35).

6. Pneumatic vehicle brake assembly (1 ) of one of claims 1 to 5, comprising a control device

(33) with control logic, the control logic comprising

a) a first operational mode wherein the valve device (33) is controlled into the open position and the brake pressure biasing the first brake actuator (52) and the second brake actuator (51 ) is controlled by at least one of the brake control valves (123, 124) and

b) a second operational mode wherein the valve device (33) is controlled into the closed position and the brake pressure biasing the second brake actuator (52) is controlled by the second brake control valve (124) and/or the brake pressure biasing the first brake actuator (51 ) is controlled by the first brake control valve (123).

7. Pneumatic vehicle brake assembly (1 ) of claim 6, characterized in that the control logic a) determines an operational state and

b) switches from the first operational mode to the second operational mode and/or from the second operational mode to the first operational mode in dependence on the determined operational mode. 8. Pneumatic vehicle brake assembly (1 ) of claim 7, characterized in that the first operational mode is the normal operational mode and

a) the determined operational state is the need for a generation of a yaw moment and the operational mode is switched from the first operational mode to the second operational mode when the determined operational state is the detected need for a generation of a yaw moment and/or

b) the determined operational state is the detection of differing friction conditions at the wheel ends and the operational mode is switched from the first operational mode to the second operational mode when the determined operational state is the detection of differing friction conditions at the wheel ends.

9. Pneumatic vehicle brake assembly (1 ) of one of claims 6 to 8, characterized in that a) the first operational mode is the normal operational mode,

b) the operational mode is switched from the first operational mode to the second operational mode within a process of an application of the brake actuators (51 , 52).

10. Pneumatic vehicle brake assembly (1 ) of claim 9, characterized in that the operational mode is switched from the first operational mode to the second operational mode

a) when a given time span of the pressurization of the brake actuators by at least one of the brake control valves (123; 124) has elapsed or

b) when reaching a pressure criterion of the brake pressures in the brake actuators (51 , 52) or

c) when reaching a friction force value at at least one of the brake actuators (51 , 52) or d) when a slip control is initiated or a slip at at least one wheel is detected.

11. Pneumatic vehicle brake assembly (1 ) of claim 7, characterized in that

a) the second operational mode is the normal operational mode,

b) the determined operational state is the detection of differing friction conditions at the first wheel end and at the second wheel end and

c) the operational mode is switched from the second operational mode to the first operational mode when the determined operational state is the detection of differing friction conditions at the first wheel end and at the second wheel end. 12. Pneumatic vehicle brake assembly (1 ) of claim 7, characterized in that

a) the second operational mode is the normal operational mode,

b) the determined operational state is a defect or failure of a control of the first pneumatic brake branch (2) or of the second pneumatic brake branch (6) and

c) the operational mode is switched from the second operational mode to the first operational mode when the determined operational state is the detection of a defect of a control of the first pneumatic brake branch (2) or of the second pneumatic brake branch (6).

13. Pneumatic vehicle brake assembly (1 ) of one of claims 6 to 12, characterized in that for subsequent brake applications in the first operational mode the brake pressure is alternately controlled by the first brake control valve (123) and the second brake control valve (124).

14. Pneumatic vehicle brake assembly (1 ) of one of claims 6 to 13, characterized in that a) for a brake application process in the first operational mode in a first process part both brake control valves (123, 124) are controlled into the aerating position and

b) when one of the following criteria is fulfilled:

a given time span of the pressurization of the brake actuators by the brake control valves (123; 124) has elapsed or

a pressure criterion of the brake pressures in the brake actuators (51 , 52) is fulfilled or

a friction force value at at least one of the brake actuators (51 , 52) is reached or a slip control is initiated or a slip at at least one wheel is detected

within the same brake application process in the first operational mode in a second process part one brake control valve (123; 124) is controlled into the closed position and the pressures in the first brake actuator and in the second brake actuator are together controlled by the other brake control valve (123; 124).

15. Pneumatic vehicle brake assembly (1 ) of one of claims 6 to 14, characterized in that the control logic

a) in the first operational mode coordinates the control of the brake control valves (123; 124) and

b) in the second operational mode controls the brake control valves (123; 124) independently on each other. 16. Pneumatic vehicle brake assembly (1 ) of one of the preceding claims, characterized in that at least one of the brake control valves (123; 124) is integrated into a wheel end unit (53, 54).

17. Pneumatic vehicle brake assembly (1 ) of one of the preceding claims, characterized in that the valve device (33) or a valve (59; 60) of the valve device (33) is integrated into a or the wheel end unit (53; 54).

18. Pneumatic vehicle brake assembly (1 ) of one of the claims 1 to 17, characterized in that a) the first brake control valve (123) is integrated into a first wheel end unit (53) and the second brake control valve (124) is integrated into a second wheel end unit (54), b) a first valve (59) of the valve device (33) is integrated into the first wheel end unit (53) and a second valve (60) of the valve device (33) is integrated into the second wheel end unit (54) and

c) the first pneumatic brake branch (2) is connected to the second pneumatic brake branch (6) by a first connecting line (32) and a second connecting line (61 ), the first valve (59) being arranged in the first connecting line (32) and the second valve (60) being arranged in the second connecting line (61 ).

19. Pneumatic vehicle brake assembly (1 ) of one of the preceding claims, characterized in that the valve device (33) comprises a switching state wherein the valve device (33) connects a) a supply port (93) of the valve device (33) or

b) a brake control port (93) of the valve device (33)

to the pneumatic brake branches (2, 6).

20. Pneumatic vehicle brake assembly (1 ) of one of the preceding claims, characterized in that the valve device (33) comprises

a) a first switching state wherein the valve device (33) connects one of the brake control valves (123, 124) to the first brake actuator (51 ; 52) and

b) a second switching state wherein the valve device (33) closes the connection of the aforementioned brake control valve (123; 124) to the first brake actuator (51 ; 52) and provides a connection of the first brake actuator (51 ; 52) to the second brake actuator (52; 51 ). 21. Pneumatic vehicle brake assembly (1 ) of claim 20, characterized in that the valve device (33) comprises

b) a first valve (59) having

ba) a first switching state wherein the first valve (59) connects the first brake control valve (123) to the first brake actuator (51 ) and closes a connection of the first brake actuator (51 ) to the second brake actuator (52) and

bb) a second switching state wherein the first valve (59) closes the connection of the first brake control valve (123) to the first brake actuator (51 ) and provides a connection of the first brake actuator (51 ) to the second brake actuator (52) and a) a second valve (60) having

aa) a first switching state wherein the second valve (60) connects the second brake control valve (124) to the second brake actuator (52) and closes a connection of the second brake actuator (52) to the first brake actuator (51 ) and ab) a second switching state wherein second valve (60) closes the connection of the second brake control valve (124) to the second brake actuator (52) and provides a connection of the second brake actuator (52) to the first brake actuator (51 ).

22. Pneumatic vehicle brake assembly (1 ) of one of the preceding claims, characterized in that a control device (33) comprises control logic which performs a test procedure for testing the operation of the pneumatic vehicle brake assembly (1 ).

23. Pneumatic vehicle brake assembly (1 ) of claim 22, characterized in that in the test procedure the control logic

a) creates an electric control signal for increasing and/or decreasing the brake pressure in at least one of the brake actuators (51 , 52) and

b) analyses the resulting brake pressure in the pneumatic brake branches (2; 6).

24. Pneumatic vehicle brake assembly (1 ) of claim 22 or 23, characterized in that in cases where at the start of the test procedure at least one of the brake actuators (51 , 52) is biased by a brake pressure the control logic

a) creates an electric control signal for reducing the brake pressure of the brake actuators

(51 , 52) and

b) analyses the resulting brake pressure in the pneumatic brake branches (2; 6). 25. Pneumatic vehicle brake assembly (1 ) of one of claims 22 to 24, characterized in that in the test procedure the control logic switches the valves (59, 60) into the second switching states and aerates and/or de-aerates at least one of the brake actuators (51 ; 52) via the valve (59; 60) in the second switching state.

26. Pneumatic vehicle brake assembly (1 ) of one of claims 1 to 25, characterized in that a) two reservoirs (12a, 12b) are provided and the first brake control valve (123) is connected to a first reservoir (12a) and the second brake control valve (124) is connected to a second reservoir (12b) and/or

b) the first brake control valve (123) is supplied by a first supply line (100) with electric power and the second brake control valve (124) is supplied by a second supply line (101 ) with electric power and/or

c) the first brake control valve (123) or first wheel end unit (53) is connected to a first bus line (102) or first control line and the second brake control valve (124) or second wheel end (54) unit is connected to a second bus line (103) or second control line.

27. Pneumatic vehicle brake assembly (1 ) of one of claims 1 to 26, characterized by a) a third pneumatic brake branch (110) associated with a third wheel end and used for controlling the brake pressure biasing a third brake actuator (108), the third pneumatic brake branch (110) comprising a third brake control valve, and

b) a fourth pneumatic brake branch (11 1 ) associated with a fourth wheel end and used for controlling the brake pressure biasing a fourth brake actuator (109) , the fourth pneumatic brake branch (11 1 ) comprising a fourth brake control valve,

c) wherein the third pneumatic brake branch (110) is connected to the fourth pneumatic brake branch (1 11 ) by a valve device (33) which comprises

ca) an open position providing a connection of the third pneumatic brake branch (110) to the fourth brake actuator (109) and/or of the fourth pneumatic brake branch (1 11 ) to the third brake actuator (108) and

cb) a closed position wherein

the third pneumatic brake branch (110) is separated by the valve device (33) from the fourth brake actuator (109) and/or

the fourth pneumatic brake branch (1 11 ) is separated by the valve device (33) from the third brake actuator (108). 28. Pneumatic vehicle brake assembly (1 ) of claim 21 or one of claims 22 to 26 when directly or indirectly referring back to claim 21 , characterized by

a) a third pneumatic brake branch (110) associated with a third wheel end and used for controlling the brake pressure biasing a third brake actuator (108) of the third wheel end, the third pneumatic brake branch (1 10) comprising a third brake control valve (125), b) the valve device (33) comprising the first valve (59), the second valve (60) and a third valve (120),

c) the first valve (59)

ca) in a first switching state connecting the first brake control valve (123) to the first brake actuator (51 ) and

cb) in a second switching state connecting the first brake actuator (51 ) to the third brake actuator (108),

d) the second valve (60)

da) in a first switching state connecting the second brake control valve (124) to the second brake actuator (52) and

db) in a second switching state connecting the second brake actuator (52) to the first brake actuator (108) and

e) the third valve (120)

ea) in a first switching state connecting the third brake control valve (125) to the third brake actuator (108) and

eb) in a second switching state connecting the third brake actuator (108) to the second brake actuator (52).

29. Pneumatic vehicle brake assembly (1 ) of one of claims 1 to 28, characterized in that a) the first brake control valve (123) is a first pivoting anchor valve (3) and/or

b) the second brake control valve (124) is a second pivoting anchor valve (7) and/or c) the third brake control valve (125) is a third pivoting anchor valve (121 ).

Description:
PNEUMATIC VEHICLE BRAKE ASSEMBLY

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a pneumatic vehicle brake assembly that can be used in a commercial vehicle as a tractor or a trailer or an agricultural tractor. In the pneumatic vehicle brake assembly pivoting anchor valves can be used that for some embodiments are denoted as "fast acting brake valves" and which allow a fast aeration and/or de-aeration of the brake actuators in particular for an improved slip control and/or a fast application of a vehicle brake.

PRIOR ART

The patent application with the application number GB 1 719 309.5 discloses a pivoting anchor valve wherein the pivoting anchor does not comprise an actuating plunger cooperating with a valve body of the inlet valve or outlet valve. Instead, here the pivoting anchor has a beam-like flat configuration. In a closed operating state the surface of the pivoting anchor sealingly contacts a valve seat of the housing of the pivoting anchor valve that might comprise a seal member as a rubber O-ring. It is possible that the valve seat is supported by a packer which allows an automatic adjustment of the angle of the valve seat for providing a good seal between the pivoting anchor and the valve seat. The pivoting anchor valve might be a mono-stable valve which takes a defined switching state without energization. This switching state is also denoted as "failsafe mode". Furthermore, the patent application suggests to use additional solenoids instead of permanent magnets for securing a taken switching state of the pivoting anchor valve. The pivoting anchor valve might include a sensor, in particular a hall effect sensor for controlling the electrical power to the solenoid. Electric power might be provided by one or more batteries or one or more electrical generators forming part of the vehicle or the trailer. In the case of using permanent magnets for securing a taken switching position of the pivoting anchor valve one permanent magnet securing a first switching position might be weaker than another permanent magnet being responsible for securing another switching position. The weaker permanent magnet may be supplemented by an electromagnet. For providing the failsafe mode the flexible pivoting anchor might have a predetermined band or curvature towards the switching state forming the failsafe mode. The flexible pivoting anchor might include a laminated section with multiple layers wherein one of the layers might be stressed for providing the predetermined band or curvature.

The patent application with the application number GB 1 904 957.6 proposes to monitor the state of a pivoting anchor valve by use of a monitoring device on the basis of a signal from strain gauges or field effect transistors or a rate of change of current through the electromagnet biasing the pivoting anchor valve with a bending moment. The monitoring device determines whether the pivoting anchor is stuck. For the monitoring the electromagnet can be energized with a test- energization having a predetermined current profile. The monitoring might base on a comparison of the actual current through the electromagnet with an expected current through the electromagnet. It is also possible to analyze an expected variant in the strain gauge output or to compare an actual field effect transistor output with an expected field effect transistor output. It is also proposed to analyze a disturbance in the pulse width of the modulation pattern of the field effect transistor.

Another design of a pivoting anchor valve comprising three ports wherein in a first valve position the first port is open, in a second position the second port is open and in a third position the first port and the second port are closed is disclosed in the patent application GB 1 806 527.6. The patent application GB 1 719 415.0 discloses a vehicle brake system comprising wheel end units that include a brake torque control unit communicating with a central control unit for controlling an associated brake actuator to apply a braking torque. The wheel end units might also include diagnostics units. Furthermore, a sensor as e.g. a yaw sensor and/or a steering angle sensor can be provided. The wheel end units might comprise at least one pivoting anchor valve that might be controlled by a relay-based modulator. Furthermore, the wheel end units might comprise a wheel speed sensor the output of which is used for a slip control of the associated wheel. Furthermore, the patent application discloses a trailer control module comprising an emergency line restrictor valve being operable to control the flow of pressurized fluid from a reservoir to a supply line in the event of a drop in a pressure in the service line. The trailer control module might communicate with a CAN bus. Also here the use of pivoting anchor valves is proposed. Also the patent application GB 1 719 344.2 discloses possible designs of a vehicle braking system and a trailer control module including a pivoting anchor valve.

The patent publication EP 2 567 131 B1 discloses a possible design of a pivoting anchor valve, here in particular the design of the coil and a magnetic core of the coil used for providing the bending moment applied to the flexible pivoting anchor and the extension of different sections of the pivoting anchor into the magnetic core, a flexible material forming a section of the pivoting anchor, a magnetic flux container extending circumferentially around permanent magnets and the coil.

Other possible designs of a pivoting anchor valve can be taken from the patent publication EP 1 303 719 B1 and EP 2 756 215 B1.

OBJECT OF THE INVENTION

It is the object of the present invention to provide a pneumatic vehicle brake assembly which is in particular improved with respect to the control options,

- the options for generating a yaw moment,

the options for considering differing coefficients of friction at the wheels on different vehicle sides,

the options for assisting a steering action,

the options for considering a failure in a pneumatic brake branch and/or

- providing a redundant brake control or a failsafe brake control.

SOLUTION

According to the present invention, the object of the invention is solved by the features of the independent claim. Additional preferred embodiments according to the invention are to be seen in the dependent claims. DESCRIPTION OF THE INVENTION

The invention relates to a pneumatic vehicle brake assembly associated with brake actuators of at least one axle of the vehicle (e.g. a front, a middle and/or arear axle of a tractor or a trailer or a tandem axle). The inventive pneumatic vehicle brake assembly is responsible for providing the suitable brake pressures for (at least) two brake actuators which are in the following denoted as first brake actuator and second brake actuator. Here, the first brake actuator might be the right brake actuator of an axle, whereas the second brake actuator is the left brake actuator of the same axle. However, it is also possible that the first brake actuator and the second brake actuator are arranged on the same vehicle side so that the first brake actuator and the second brake actuator might be responsible for different wheels on the same side of a tandem axle. Furthermore, it is possible that the first brake actuator and the second brake actuator are arranged at wheels on the same vehicle side but of different axles. Finally, it is also possible that the first brake actuator is arranged at a right vehicle side at a first axle, whereas the second brake actuator is arranged on a left vehicle side at a second axle. In the inventive pneumatic vehicle brake assembly, there is a first pneumatic brake branch. The first pneumatic brake branch is used for controlling the brake pressure biasing the first brake actuator. The first pneumatic brake branch comprises a first brake control valve.

The inventive vehicle brake assembly also comprises a second pneumatic brake branch associated with the second brake actuator. The second pneumatic brake branch is used for controlling the brake pressure biasing the second brake actuator. The second pneumatic brake branch comprises a second brake control valve.

The first (and second) brake control valve serves for controlling the brake pressure in the associated pneumatic brake branch and in the associated brake actuator. Here, the brake control valve might be embodied as any singular valve or solenoid valve, valve device or valve group where the brake control valve is in particular directly electronically controlled or electro- pneumatically controlled by use of a pilot valve. The electronic control is here provided by a control device under consideration of the brake demand given by the driver (in particular by depressing a brake pedal), under consideration of a parking brake request, under consideration of a dynamic slip control and ABS function, under consideration of the dynamic vehicle driving stability (ASR, ESP) and/or under consideration of an autonomous vehicle driving system, to mention only some non-limiting examples. In the following for the sake of simplicity reference is made to the embodiment of the brake control valves as pivoting anchor valves. However, at any mention of a pivoting anchor valve also any other brake control valve might be used.

The invention proposes that the first pneumatic brake branch and the second pneumatic brake branch are (at least temporarily) not independent on each other. Instead, the first pneumatic brake branch can temporarily be connected to the second pneumatic brake branch by a valve device.

The valve device comprises two valve positions:

In an open position, the valve device provides a fluidic connection of the first pneumatic brake branch to the second brake actuator and/or of the second pneumatic brake branch to the first brake actuator. Accordingly, a kind of "cross control" or "bypass control" is possible wherein the first pneumatic brake branch (also) controls the second brake actuator and/or the second pneumatic brake branch (also) controls the first brake actuator. The open position of the valve device can in particular be used in the case that both brake actuators shall be biased with the same brake pressure. In this case, the brake pressure can be controlled by the pivoting anchor valves of both pneumatic brake branches or only by the pivoting anchor valve of one of the pneumatic brake branches. Accordingly, in the open position it is also possible to control the brake actuators by the pivoting anchor valve of one pneumatic brake branch in the case of the failure of the other pneumatic brake branch or its pivoting anchor valve.

Furthermore, the valve device comprises a closed position. In the closed position, the first pneumatic brake branch is separated by the valve device from the second brake actuator and/or the second pneumatic brake branch is separated by the valve device from the first brake actuator. Accordingly, the closed position of the valve device allows an independent control of the brake pressures for the second brake actuator and the first brake actuator. This might e.g. be advantageous in the case that the first brake actuator is a right brake actuator and the second brake actuator is a left brake actuator, the aforementioned brake actuators being arranged at the same axle. In this case, a generation of different friction forces at the two wheels of the axle might be advantageous in order to generate a yaw moment or in order to assist a steering action. Furthermore, in the closed position it is possible to individually control the brake pressures and so also the friction forces at the different wheel ends so that it is also possible to consider different coefficients of friction at the different wheel end. The valve device used within the frame of the invention might be any single valve or combination of valves that might be integrated into a constructional unit or might be arranged separately and also remote from each other. For one embodiment of the invention, the valve device comprises a 2/2-valve. The 2/2-valve might be a 2/2-solenoid valve which is directly controlled by an electric control signal. However, it is also possible that the 2/2-valve is a pilot controlled valve which is pneumatically controlled by a separate solenoid valve. The use of a 2/2-valve as the valve device provides the aforementioned open position and the closed position so that by use of a simple valve design the aforementioned functionality can be provided.

For another proposal of the invention, the valve device comprises a pivoting anchor valve which might also be used for improving the control characteristics and for allowing large flows of pressurized air.

For one inventive pneumatic vehicle brake assembly a control device is provided. The control device comprises control logic which comprises two different operational modes:

In a first operational mode, the valve device is controlled by the control device into the open position. In the first operational mode the brake pressure biasing the first brake actuator and the second brake actuator is controlled by at least one of the pivoting anchor valves.

In the second operational mode, the control device controls the valve device into the closed position. In the second operational mode the brake pressure biasing the second brake actuator is controlled by the second pivoting anchor valve whereas the brake pressure biasing the first brake actuator is controlled by the first pivoting anchor valve.

There are different options for the at least one criterion for determining when the control logic has to be in the first operational mode and when it has to be in the second operational mode. For example, the criterion might depend on any operational state of the vehicle, on an environmental parameter or also on a demand or input by the driver or a demand of an autonomous driving system. For one proposal of the invention, the control logic determines an operational state. In this case, the control logic switches from the first operational mode to the second operational mode and/or vice versa in dependence on the determined operational mode.

Here, there are a lot of options for the type of the determined operational mode. For one exemplary embodiment, the first brake actuator is a right brake actuator and the second brake actuator is a second brake actuator. Here, the first operational mode might be a "normal operational mode". In this case, the determined operational state might be the need for a generation of a yaw moment. The need for the generation of a yaw moment might e.g. be indicated by a driving stability system which asks for a correcting yaw moment for dynamically stabilizing the vehicle. It might also be possible that the need for a generation of a yaw moment might be indicated by a steering action for assisting the steering. For this proposal, when detecting a need for a generation of a yaw moment, the operational mode is switched from the first operational mode to the second operational mode. In the second operational mode, it is possible to generate differing friction forces at the different wheel ends for generating the yaw moment.

For another proposal, the determined operational state is the detection of differing friction conditions at the right wheel and at the left wheel or at the different wheel ends. For example, one of the wheels might run on ice or a wet road leading to a small coefficient of friction, whereas the wheel at the other wheel end runs on a perfect road with a high coefficient of friction. It is also possible that the differing friction conditions occur because the wheels at different wheel end (in particular at the same axle but different sides of the vehicle) are pressed against the road by different normal forces which might be caused by dynamic changes (e. g. because of driving through a curve) or by a lateral offset of the load on the chassis. In these cases in the first operational mode the brake pressure and so the friction forces are the same at both wheel ends. The required slip control leads to the result that the smaller of the applicable friction force is generated so that no benefit is taken from the possible higher friction level at the other wheel. Accordingly, for this embodiment the operational mode is switched from the first operational mode to the second operational mode when differing friction conditions at the different wheel ends or wheel sides are detected. For another variant of the invention, the first operational mode is the normal operational mode. In this normal operational mode at the beginning of a brake application the brake actuators are pressurized by the same brake pressures due to their connection via the open valve device. This can be achieved by an aeration by only one of the pivoting anchor valves whereas the other pivoting anchor valve is closed. However, it is also possible that the brake actuators are aerated via both pivoting anchor valves. For this embodiment of the invention the operational mode of the valve device might be switched from the first operational mode to the second operational mode during a process of an application of the brake actuators. Accordingly, for this embodiment the process of the application of the brake actuators at the wheel ends is split to a first process part in the first operational mode with opened valve device and a second process part wherein the valve device is in the second operational mode with closed valve device. In these two process parts, differing control schemes and/or differing control paths and/or pressurization paths can be used.

For a first embodiment, the operational mode is switched from the first operational mode to the second operational mode after a given time span of the pressurization of the brake actuators by at least one of the pivoting anchor valves has elapsed. Accordingly, within the given time span and in the first process part there is a kind of "in-shot" into the brake chambers of the two brake actuators. This "in-shot" can be used for reaching the so called kissing point meaning that the brake pads have closed the gap between the brake pad surfaces and the brake discs and/or contact the brake discs with a minimum contact force. However, the given time span might e.g. also correlate to a threshold brake pressure for achieving a threshold friction force at the wheel ends. It is also possible that the time span is calculated dependent on operating positions (as e.g. dependent on the load of the vehicle or on the load of the axle; dependent on the coefficient of friction between the wheel and the road) or taken from a characteristic map.

For another embodiment, the operational mode is switched from the first operational mode to the second operational mode when a pressure criterion of the brake pressures in the brake actuators has been reached. To mention only some examples, the pressure criterion might be a threshold of the brake pressure correlating with the kissing point or a predetermined friction level.

It is also possible that the switching from the first operational mode to the second operational mode takes place when a threshold friction force value at at least one of the brake actuators has been reached.

For a specific embodiment, the given time span, the pressure criterion and/or the threshold friction force value as described above are chosen such that before the expiration of the time span or before reaching the pressure criterion or before reaching a threshold friction force value there is no closed loop control of the friction force but an un-modulated brake application with a continuous increase of the brake pressure. This might apply for a "normal" brake application assuming a minimum friction level of the wheels with the road. Another possible criterion for switching the first operational mode to the second operational mode is the initiation of a slip control, so the indication of a slip at at least one of the wheels (e.g. on the basis of a wheel speed sensor) or the initiation of a modulating action of the control of the pivoting anchor valves. However, it is also possible that the second operational mode is the normal operational mode. In this case, the determined operational state might be the detection of differing friction conditions at the first wheel and at the second wheel. For this embodiment, the operational mode is switched from the second operational mode to the first operational mode when the determined operational state is the detection of differing friction conditions at the first wheel and at the second wheel. For another embodiment, the determined operational state is a defect or failure of a control of the first pneumatic brake branch or of the second pneumatic brake branch. Such a failure might e.g. be based upon a faulty control signal from a control unit in the pneumatic brake branch, pressure losses in the pneumatic brake branch, a missing supply pressure in the pneumatic brake branch, a clogged aeration in the pneumatic brake branch or a mechanical defect in the pivoting anchor valve of the pneumatic brake branch. When detecting a defect or a failure in one of the pneumatic brake branches, the operational mode of this pneumatic brake branch is switched from the second operational mode to the first operational mode so that it is possible to control the same brake pressure for the two wheel ends by the remaining pneumatic brake branch which does not have the failure. The provision of the first operational mode with the bypass connection opened by the valve device might also be used for alternately controlling the brake applications of the two brake actuators by the first pivoting anchor valve and the second pivoting anchor valve. Accordingly, for a first brake application the brake pressure is controlled by the first pivoting anchor valve whereas for a subsequent brake application the brake pressure is controlled by the second pivoting anchor valve and vice versa. It is e.g. possible that by alternately controlling the brake pressure via the two different control paths (namely the first pivoting anchor valve and the second pivoting anchor valve) subsequent characteristics of the performance of the brake applications can be compared to each other so that on the basis of the alternating control it is possible to detect a failure in one of the control branches or pneumatic brake branches. For another proposal of the invention, a brake application process is (normally or in a failsafe mode) performed in the first operational mode. Here, the process of the brake application is split into a first process part and a second process part. Upon a request for braking, in the first process part both pivoting anchor valves are controlled into the aerating position. This might be the case on the basis of an open-loop control or also in a closed-loop control. This leads to a fast pressurization of the brake chambers of the brake actuators. Also in the case that the bypass or connecting line between the two brake actuators is quite long, the pressurization by the two pivoting anchor valves leads to the consequence that both brake actuators have (approximately) the same pressure increases. The switch from the first process part to the second process part takes place when one of the following criteria is fulfilled: a given time span of the pressurization of the brake actuators by the pivoting anchor valves has expired,

a pressure criterion of the brake pressures in the brake actuators is fulfilled (e.g. a pressure threshold has been reached),

- a threshold friction force value at at least one of the brake actuators is reached or

a slip control is initiated or a slip at one wheel is detected.

When changing to the second process part one of the pivoting anchor valves is controlled into the closed position, whereas the other pivoting anchor valve controls the brake pressure for both brake actuators. In this way, it is possible to avoid an unintended interference of the action of the two pivoting anchor valves.

Furthermore, the invention suggests that in the first operational mode the control logic coordinates the control of the pivoting anchor valves. In particular, this coordination involves that an interference of the pivoting anchor valves (e.g. such that one of the pivoting anchor valves de aerates the brake lines whereas at the same time the other pivoting anchor valve aerates the brake lines) is avoided. It is also possible that by the coordination the control is switched from one pivoting anchor valve to the other pivoting anchor valve and vice versa. Furthermore, it is possible that the coordination by the control logic uses only one single pivoting anchor valve in the case that only small volumetric flows are required for aerating or de-aerating the brake lines, whereas the control logic uses both pivoting anchor valves in the case that higher volumetric flows are required for aerating or de-aerating the brake lines. Generally, the brake system of the vehicle might have any known design. Preferably, the brake system is modular wherein at a wheel end (or each wheel end) there is a wheel end unit that comprises the brake actuator and/or related electronics, sensors and/or valves. An inventive pneumatic vehicle brake assembly might also be a constructional unit, a modular unit or might be formed by separate components that might also be arranged remote from each other. For one proposal of the invention, parts of the vehicle brake assembly, in particular at least one of the pivoting anchor valves, are/is integrated into a wheel end unit. Within the frame of the invention a wheel end unit might be arranged adjacent the wheel (preferably with a distance from the wheel center axis of less than 2,0 m or less than 1 ,0 m or less than 0,5 m) or at the wheel end and fixed to an axle body or to the chassis.

Furthermore, the invention suggests that the valve device or a valve of the same is integrated into the wheel end unit.

It is possible that the valve device comprises two valves. In this case, one of the valves might be integrated into the first wheel end unit, whereas the other valve is integrated into the second wheel end unit.

For a particular embodiment, the first pivoting anchor valve is integrated into a first wheel end unit. The second pivoting anchor valve is integrated into a second wheel end unit. A first valve of the valve device is integrated into the first wheel end unit and a second valve of the valve device is integrated into the second wheel end unit. In this case, the first pneumatic brake branch is connected to the second pneumatic brake branch by a first connecting line and a second connecting line. The first valve is arranged in the first connecting line, whereas the second valve is arranged in the second connecting line. Preferably, the first valve is controlled by a first control unit which might also be integrated into the first wheel end unit, whereas the second valve is controlled by a second control unit which might be integrated into the second wheel end unit. In this case, in particular for a failure of one of the control units it is possible to control the brake application by the other control unit and the related wheel end unit by switching the associated valve into the open position for interconnecting the two pneumatic brake branches.

As explained above, the valves of the valve device might have any design and number of switching positions. For a particular proposal of the invention, the valve device comprises a switching state wherein the valve device connects a supply port of the valve device (which is connected to a source of pressurized air or a supply reservoir) to the pneumatic brake branches. For this embodiment, when controlling the valve device into the switching state the brake lines are connected to the supply port. Accordingly, in the switching state the brake lines and so the brake actuators are biased with the supply pressure so that the brake actuators are applied. This might be used for an emergency brake action triggered by a switching of the valve device into the switching state.

However, it is also possible that in one switching state the valve device connects a brake control port of the valve device to the pneumatic brake branches. The brake control port is connected to another brake line with a pneumatic brake pressure. Accordingly, by switching the valve device into the switching state it is possible that the brake line with a redundant brake pressure "takes over".

It is possible within the frame of the invention that a pivoting anchor valve is permanently connected to the associated brake actuator. In this case when using the connecting line or bypass with the integrated valve device for connecting the two brake actuators to each other and when controlling both brake actuators by one and the same pivoting anchor valve it is required that the other pivoting anchor valve which is (also or directly) connected to the associated brake actuator comprises a closed position. This closed position is in particular automatically taken in the case of a failure of the electric power supply of this pivoting anchor valve. Alternatively or cumulatively, the pivoting anchor valve is controlled into this closed position in the case of a detection of a malfunction of this pneumatic brake branch. In particular the pivoting anchor valve is controlled into the closed position when not energizing the control port of the pivoting anchor valve.

However, for a different embodiment of the invention the valve device comprises at least one valve which is interposed between the pivoting anchor valve and the associated brake actuator. This will in the following be explained on the basis of the right pivoting anchor valve and the associated right brake actuator. However, the same might (alternatively or cumulatively) apply to any configurations of brake actuators associated with the same and/or different wheel axes and/or the same or different vehicle sides:

The right valve of the valve device comprises a first switching state. In the first switching state the right valve connects the right pivoting anchor valve to the right brake actuator (whereas at the same time a connection of the right brake actuator to the left brake actuator is closed by the valve device or right valve). The right valve also comprises a second switching state. In the second switching state the right valve closes the connection of the right pivoting anchor valve to the associated right brake actuator, whereas the valve device or right valve provides a connection of the first brake actuator to the second brake actuator. Accordingly, in the second switching state (irrespective on the switching state of the right pivoting anchor valve) the right pivoting anchor valve is "deactivated" so that the switching state of the right pivoting anchor valve does not influence the pressurization of the right brake actuator (and also of the left brake actuator). Instead, in the second switching state, the right valve allows a control of the right brake actuator and of the left brake actuator by the left pivoting anchor valve only. The use of the valve device or valve interposed between a pivoting anchor valve and the associated brake actuator might be limited to the integration of the valve into only one of the pneumatic brake branches. However, the invention also proposes that a second or left valve is integrated into the second or left pneumatic brake branch and a first or right valve is integrated into the first or right pneumatic brake branch. In this case, by the transfer of one of the valves into the second switching state it is possible to deactivate the related pivoting anchor valve and to control both brake actuators by the other pivoting anchor valve.

In the case that a valve is integrated between the pivoting anchor valve and the associated brake actuator the port of the valve providing the connection of the brake actuator to the other pneumatic brake branch might be connected to the other pneumatic brake branch downstream or upstream from the valve integrated into the other pneumatic brake branch.

For one embodiment, the pneumatic vehicle brake assembly (here an electronic control device or electronic control unit) comprises control logic which performs a test procedure. The test procedure might e.g. be triggered by the start of an engine (e.g. by the actuation of the ignition). The test procedure tests the operation of the components of the vehicle brake assembly, in particular the electric power supply, the function of the pivoting anchor valves and/or of the valve device according to the specifications. If the test procedure leads to the result that the vehicle brake assembly does not work properly or has a malfunction it is possible that a corresponding signal or warning is given to the driver and/or that the vehicle brake assembly is run in a failsafe mode or a redundancy mode and/or that the start of the driving mode is disabled (e.g. by activation a parking brake and/or by keeping a transmission in a neutral gear). Within the frame of the invention, generally any test procedure might be used. For one particular test procedure control logic of the electronic control device creates an electric control signal (e.g. at the standstill of the vehicle). The electric control signal then biases the related control port of the pivoting anchor valve and/or the valve device. The control logic analyses the brake pressures in the pneumatic brake branches and brake actuators resulting from the created control signal. The sensing of a brake pressure by a sensor might e.g. be used as follows for deciding if the vehicle brake assembly works properly: If the created brake pressure correlates with a given dependency on the control signal, the vehicle brake assembly works properly. Also the curvature of the resulting brake pressure can be compared to a given curvature for a control test signal for detecting a malfunction of the vehicle brake assembly. This test procedure is in particular used at standstill of the vehicle where the creation of a brake pressure during the test performance (in some cases additional to a parking brake or other brakes guaranteeing the desired standstill) does not interfere with the vehicle safety.

Another test procedure can be run in the case that when performing the test procedure the brake actuators are already biased by a brake pressure, in particular for providing a parking brake function. In this case the control logic creates an electric control signal for reducing the brake pressure of the brake actuator. The brake pressure is in particular only reduced in the case that the brake pressure is by a difference X above the threshold brake pressure Y that guarantees that the vehicle cannot move. The reduction of the brake pressure (and the corresponding electric control signal) is dimensioned such that after the reduction the brake pressure still equals or is still higher than the required brake pressure Y for keeping the vehicle at standstill. So, the reduction is smaller than X. Alternatively or cumulatively, it is possible that during the reduction of the brake pressure a vehicle speed signal or a wheel speed signal is monitored. In the case that the wheel speed signal indicates that the vehicle or the wheel starts to move the brake pressure reduction is stopped and the brake pressure is increased for again stopping the vehicle and for keeping the vehicle at rest.

In the case that valves of the valve device are only actuated in the case of a malfunction or a failure of the vehicle brake assembly it might be possible that the valves of the valve device are not switched for a longer period into the redundancy states or second switching states. In this case, another embodiment of the invention proposes that in the test procedure the control logic switches the valves of the valve device into the second switching states and aerates and/or de aerates at least one of the brake actuators via the valve in the second switching state. During the aeration and/or de-aeration the resulting pressure change is monitored. On the one hand, this embodiment guarantees that the valves of the valve device are regularly switched between the different states. On the other hand, also the valves of the valve device are integrated into the test procedure.

For another embodiment of the invention, the vehicle safety is increased by providing an additional redundancy. It is proposed to provide two reservoirs for pressurized air. In this case, the first pivoting anchor valve is connected to a first reservoir, whereas the second pivoting anchor valve is connected to a second pivoting anchor valve.

Alternatively or cumulatively, it is possible that also a redundant electric power supply is provided and/or at least one electric power supply is connected by two redundant supply lines to the pivoting anchor valves.

Alternatively or cumulatively, it is possible that there are two redundant bus lines (as e.g. a CAN line) connected to the two pivoting anchor valves or to the two wheel end units. The redundant bus lines can on the one hand be used for transmitting operational data as e.g. measured pressures or switching states from the pivoting anchor valves or the wheel end units to other control units. On the other hand, the bus lines might be used for transmitting control signals to the pivoting anchor valves.

The invention also proposes that the pneumatic vehicle brake assembly comprises a third pneumatic brake branch and a fourth pneumatic brake branch. The third pneumatic brake branch is associated with a third wheel end. The third pneumatic brake branch serves for controlling the brake pressure biasing a third brake actuator. The third pneumatic brake branch comprises a third pivoting anchor valve. The corresponding applies for the fourth pneumatic brake branch. The third pneumatic brake branch is connected to the fourth pneumatic brake branch by a valve device. Also this valve device comprises an open position and a closed position. In the open position the valve device provides a connection of the third pneumatic brake branch to the fourth brake actuator and/or of the fourth pneumatic brake branch to the third brake actuator. Instead, in the closed position the third pneumatic brake branch is separated by the valve device from the fourth brake actuator. Alternatively or cumulatively, the fourth pneumatic brake branch is separated by the valve device from the third brake actuator. To mention only one example for this embodiment, the first and second brake actuators might be arranged on different sides of a first vehicle axle, whereas the third and fourth brake actuators are arranged on different sides of a second vehicle axle.

For another embodiment of the invention, besides the first pneumatic brake branch and the second pneumatic brake branch the pneumatic vehicle brake assembly also comprises a third pneumatic brake branch. The third pneumatic brake branch is associated with a third wheel end and used for controlling the brake pressure biasing a third brake actuator of the third wheel end. In this case, the third pneumatic brake branch comprises a third pivoting anchor valve. Here, the valve device comprises a first valve, a second valve and a third valve. The first valve in a first switching state connects the first pivoting anchor valve to the first brake actuator (and closes the connection of the first brake actuator to the third brake actuator). Instead, in the second switching state the first valve connects the first brake actuator to the third brake actuator (whereas the connection to the first pivoting anchor valve is closed). The second valve (and the third valve) have corresponding first switching states. However, the second valve (the third valve) in the first switching state connects the second (third) pivoting anchor valve to the second (third) brake actuator. In the second switching state, the second valve (third valve) connects the second (third) brake actuator to the first brake actuator (second brake actuator). This design allows that each of the brake actuators is able to receive the pressure from another pneumatic brake branch controlled by another pivoting anchor valve in a failure mode. Furthermore, this embodiment might additionally allow that one remaining pivoting anchor valve in the case of a failure in two other pneumatic brake branches controls the first, second and third brake actuator so that also in the case of a failure of two pneumatic brake branches a full brake performance or reduced brake performance can be maintained. It is e.g. possible that the remaining pivoting anchor valve allows an ABS control with a common brake pressure for the first, second and third brake actuator.

DEFINITION OF A "PIVOTING ANCHOR VALVE"

A "pivoting anchor valve" in the sense of the present invention in particular is a valve which fulfills one of the following conditions, a plurality or any number of the following conditions or all of the following conditions:

The pivoting anchor valve comprises a pivoting anchor which forms the valve body or is coupled to the valve body, the valve body moving relatively to a valve seat between a closed position and at least one open position. The pivoting anchor can be pivoted by an electro-magnetic actuation into different pivoting positions which correlate with different valve positions (at least two valve positions). Alternatively or cumulatively, it is possible that by the electro-magnetic actuation the pivoting anchor and/or the valve body can be held in at least one of the different valve positions. It is possible that the pivoting anchor is biased with a bending moment due to the electro-magnetic actuation. The pivoting anchor or a holding device of the same comprises a flexible element or flexible section being flexible with respect to a bending by the bending moment applied by the electromagnet. A changed pivoting position or operating position of the pivoting anchor valve correlates with a changed bending of the pivoting anchor or the holding device achieved by the electro magnetic actuation. With respect to possible exemplary embodiments of a pivoting anchor valve of this type comprising a flexible bending element reference is e.g. made to the patent publications EP 2 756 215 B1 , EP 2 049 373 B1 , EP 2 567 131 B1 and EP 1 303 719 B1 and the patent applications with the application numbers GB 1 719 309.5, GB 1 904 957.6, GB 1 820 137.6, GB 1 806 527.6, GB 1 719 415.0 and GB 1 719 344.2. The disclosure of these patent publications and patent applications is incorporated by reference into the disclosure of the present patent application, in particular with respect to design options for a pivoting anchor valve and/or

the provision of a different number of stable and/or unstable valve positions and/or the design of the flexible element being bent by the bending moment and/or the integration of the flexible element into the pivoting anchor or its linkage thereto and/or

the use and arrangement of permanent magnets for providing stable valve positions and/or

the design of at least one electromagnet applying the bending moment for pivoting the pivoting anchor and/or

the control of the pivoting anchor valve.

However, it is also possible that the pivoting anchor valve comprises a pivoting anchor which is supported for being pivoted by a bearing. The pivoting anchor can be pivoted by electromagnets into different operating positions or held in the same. The different operating positions correlate with different valve positions of the pivoting anchor valve. With respect to embodiments of this type, exemplary reference is made to the publications WO 2016/062542 A1 and EP 3 222 897 A1 . The disclosure of these publications is incorporated by reference into the present patent application, in particular with respect to the design of the pivoting anchor valve, the provided valve positions and/or the control and the electro-magnetic actuation of the pivoting anchor valve.

An inventive pivoting anchor valve might also be denoted as "fast acting brake valve" (abbreviated "FABV"). An FABV allows a fast actuation with a fast change of the operating position wherein a change of the operating position might e.g. be achieved within a time span of less than 25 ms, less than 20 ms, less than 10 ms, less than 7 ms, less than 5 ms, less than 3 ms, less than 2 ms or even less than 1 ms.

By use of an inventive pivoting anchor valve in an open position a large flow rate and/or a large valve cross-section or transitional cross-section can be provided.

Preferably, the transitional cross-section of the pivoting anchor valve in an open position at least equals the inner cross-section of the supply tube connected to the supply port of the pivoting anchor valve. Accordingly, if the supply tube has an inner cross-section with a diameter of 5 mm, the transitional cross-section of the pivoting anchor valve in the open position is at least 0.2 cm 2 .

Preferably, in an open position the transitional cross-section or valve cross-section is at least 0,3 cm 2 , at least 0,4 cm 2 , at least 0,5 cm 2 , at least 0,6 cm 2 or even at least 0,8 cm 2 .

Due to the pivoting of the pivot anchor the valve body closing the valve seat is pivoted between the closed position and the open position. Accordingly, the transitional cross- section in the open position corresponds to the outer circumference of a cylinder cut in two non-parallel planes wherein these planes form an angle that corresponds to the pivot angle of the pivot anchor between the open position and the closed position. In particular the pivot angle and the angle between these planes is in the range of 1 ° to 5° or 2° to 4°.

The (averaged) movement of the valve body formed by the pivoting anchor or connected thereto between one valve position and the adjacent valve position is in the range of 0.5 to 5 mm, in particular 1.0 to 4 mm. When controlling a pivoting anchor valve of this type, there might be only a short delay due to the inertial mass of the moved valve elements, in particular a delay or dead time being smaller than 4 ms, smaller than 2 ms or even less than 1 ms.

It is possible that the pivoting anchor valve comprises more than one stable operating position. The pivoting anchor valve might e.g. be bi-stable or multi-stable. This might e.g. be provided in the way that in two or more operating positions the pivoting anchor or a component connected therewith contacts a permanent magnet (cp. the patent publications EP 2 756 215 B1 , EP 2 049 373 B1 , EP 2 567 131 B1 and EP 1 303 719 B1 and the patent applications with the application numbers GB 1 719 309.5, GB 1 904 957.6, GB 1 820 137.6, GB 1 806 527.6, GB 1 719 415.0 and GB 1 719 344.2). However, it is also possible that bi-stable operating positions are provided by a mechanical spring element which e.g. biases the pivoting anchor or a valve element connected therewith from an unstable middle equilibrium position in both directions towards stable operating positions as disclosed in the publications WO 2016/062542 A1 or EP 3 222 897 A1. Furthermore, it is possible that a stable position is provided by the bending stiffness of the flexible element or pivoting anchor.

The pivoting anchor valve might be an electrically controlled pneumatic valve without pneumatic pilot having a single stable state, two or more stable states when not being electrically energized.

For the pivoting anchor valve the pneumatic control bandwidth is primarily determined by the mechatronic design and actuator size or control volume

Within the frame of the invention, the pivoting anchor valve might be embodied as a 2/2-way valve, 3/2-way valve, 3/3-way valve or any other valve. It is also possible that a plurality of redundant pivoting anchor valves are arranged in one constructional unit and/or a combination of a plurality of pivoting anchor valves that are arranged in pneumatical parallel connection or in series connection are arranged in a constructional unit (e.g. a combination of a 3/2-way valve and a 2/2-way valve; e.g. a connection of a pressurized inlet line to the outlet for the service brake cylinder via a first 2/2-way valve as well as a connection of a de-aerating port to the outlet for the service brake cylinder via a second 2/2-way valve). It is possible that a pivoting anchor valve which is pivoted into different operating positions due to the bending of the pivoting anchor or an associated holding element is partially transferred from one operating position of the pivoting anchor valve into another operating position of the pivoting anchor valve by energy which is stored by the bending of the pivoting anchor or the associated holding element. In this way, then for achieving the desired operating positions by means of at least one electromagnet only the required additional energy for arriving at the other operating position has to be provided.

GENERAL

Advantageous developments of the invention result from the claims, the description and the drawings. The advantages of features and of combinations of a plurality of features mentioned at the beginning of the description only serve as examples and may be used alternatively or cumulatively without the necessity of embodiments according to the invention having to obtain these advantages. Without changing the scope of protection as defined by the enclosed claims, the following applies with respect to the disclosure of the original application and the patent: further features may be taken from the drawings, in particular from the illustrated designs and the dimensions of a plurality of components with respect to one another as well as from their relative arrangement and their operative connection. The combination of features of different embodiments of the invention or of features of different claims independent of the chosen references of the claims is also possible, and it is motivated herewith. This also relates to features which are illustrated in separate drawings, or which are mentioned when describing them. These features may also be combined with features of different claims. Furthermore, it is possible that further embodiments of the invention do not have the features mentioned in the claims.

The number of the features mentioned in the claims and in the description is to be understood to cover this exact number and a greater number than the mentioned number without having to explicitly use the adverb "at least". For example, if an element is mentioned, this is to be understood such that there is exactly one element or there are two elements or more elements. Additional features may be added to these features, or these features may be the only features of the respective product.

The reference signs contained in the claims are not limiting the extent of the matter protected by the claims. Their sole function is to make the claims easier to understand. BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention is further explained and described with respect to preferred exemplary embodiments illustrated in the drawings.

Figs. 1 and 2 schematically show a pneumatic vehicle brake assembly comprising a left and a right pneumatic brake branch connected to each other by a valve device.

Figs. 3 and 4 schematically show a method for operating a pneumatic vehicle brake assembly executed by control logic of a control unit.

Fig. 5 schematically shows a brake system of a commercial vehicle or trailer comprising a pneumatic vehicle brake assembly. Fig. 6 schematically shows a pneumatic vehicle brake assembly comprising a left and a right pneumatic brake branch connected to each other by a valve device.

Fig. 7 schematically shows a pneumatic vehicle brake assembly wherein valves of a valve device are interposed between a pivoting anchor valve and an associated brake actuator, the valves allowing a closure of the connection between the pivoting anchor valve and the associated brake actuator and a connection of the brake actuator to another brake actuator.

Fig. 8 schematically shows a pneumatic vehicle brake assembly corresponding to Fig. 7 with a redundant supply of electric power, supply of pressure and control.

Fig. 9 schematically shows a pneumatic vehicle brake assembly comprising wheel end units associated with a rear axle and a front axle with steered wheels.

Fig. 10 schematically shows a pneumatic vehicle brake assembly comprising wheel end units associated with a tandem rear axle and a front axle with steered wheels.

Fig. 11 schematically shows a pneumatic vehicle brake assembly comprising three wheel end units associated with the same vehicle side and three axles. DESCRIPTION OF THE DRAWINGS

Fig. 1 schematically shows a pneumatic vehicle brake assembly 1. The vehicle brake assembly 1 is associated with any axle of a commercial vehicle (in particular a tractor or a trailer) and responsible for controlling the brake pressure in the brake actuators at a right wheel and a left wheel of the axle.

The vehicle brake assembly 1 comprises a first pneumatic brake branch 2 which here is a right pneumatic brake branch 2. The right pneumatic brake branch 2 comprises a first (here right) pivoting anchor valve 3 having a first (here right) brake port 4 which is connected via a first (here right) brake line 5 to a first (here right) pneumatic brake actuator (not shown in Fig. 1 ). Dependent on the electronic control of the right pivoting anchor valve 3 by a control device 31 and the operating position of the right pivoting anchor valve 3 it is possible to aerate the right brake line 5 and so the right brake actuator,

to de-aerate the right brake line 5 and so the right brake actuator and

to hold the brake pressure in the right brake line 5 and the right brake actuator. The vehicle brake assembly 1 further comprises a second (here left) pneumatic brake branch 6. The left pneumatic brake branch 6 comprises a second (here left) pivoting anchor valve 7 having a second (here left) brake port 8 which is connected via a second (here left) brake line 9 to a second (here left) pneumatic brake actuator (not shown in Fig. 1 ). Dependent on the electronic control of the right pivoting anchor valve 7 by the control device 31 and the operating position of the right pivoting anchor valve 7 it is possible to aerate the left brake line 9 and so the left brake actuator,

to de-aerate the left brake line 9 and so the left brake actuator and

to hold the brake pressure in the left brake line 9 and the left brake actuator.

Accordingly, the pivoting anchor valves 3, 7 have three different switching positions or valve positions. Preferably, all of the three valve positions are stable valve positions that can be upheld without an electronic control action by the control device 33 but can be changed due to the control by the control device 33. Additional to the brake ports 4, 8 the pivoting anchor valves 3, 7 also comprise an associated supply port 10, 1 1 which is connected to a supply reservoir 12. Furthermore, the pivoting anchor valves 3, 7 each comprise a de-aerating port 13, 14.

For the shown embodiment, the pivoting anchor valves 3, 7 have the same designs which in the following is explained on the basis of the pivoting anchor valve 3:

The pivoting anchor valve 3 comprises a valve chamber 15 which is permanently connected to the brake port 4. The valve chamber 15 is connected by an inlet valve 16 to the supply port 10 and by an outlet valve 17 to the de-aerating port 13.

The inlet valve 16 comprises an inlet valve seat 18 formed by a housing 19 of the pivoting anchor valve 3. An inlet valve body 20 is pressed by an inlet valve spring 21 against the inlet valve seat 18 for closing the connection between the valve chamber 15 and the supply port 10. The inlet valve body 20 is additionally pressed by the supply pressure against the inlet valve seat 18, whereas the pressure in the valve chamber 15 biases the inlet valve body 20 away from the inlet valve seat 18. The inlet valve spring 21 is dimensioned and pre-tensioned such that also for a zero supply pressure any existing pressure in the valve chamber 15 is not able to open the inlet valve 16.

The outlet valve 17 comprises an outlet valve seat 22 formed by the housing 19 of the pivoting anchor valve 3. An outlet valve body 23 is pressed by an outlet valve spring 24 against the outlet valve seat 22 for closing the connection between the valve chamber 15 and the de-aerating port 13. The pressure in the valve chamber 15 biases the outlet valve body 23 away from the outlet valve seat 22. The outlet valve spring 24 is dimensioned and pre-tensioned such that any existing pressure in the valve chamber 15 is not able to open the outlet valve 17.

The pivoting anchor valve 3 comprises an actuation element 25. By the control of at least one electromagnet 26 by the control device 31 it is possible to pivot the actuation element 25 in one direction towards the inlet valve body 20 and to apply an opening force upon the inlet valve body 20 so that the inlet valve 16 can be opened. Furthermore, by an opposite control it is possible to pivot the actuation element 25 into the opposite direction towards the outlet valve body 23 and to apply an opening force upon the outlet valve body 23 for opening the outlet valve 17. Accordingly, the pivoting anchor valve 3 comprises three operating positions, namely the closed position as shown in Fig. 1 without an energization of the electromagnet 26 wherein both the inlet valve 16 and the outlet valve 17 are closed,

an aerating position wherein the outlet valve 17 is closed and the actuation element 25 is pressed against the inlet valve body 20, the inlet valve 16 is opened and the supply reservoir is fluidically connected to the brake port 4 and

a de-aerating position wherein the inlet valve 16 is closed and the actuation element 25 is pressed against the outlet valve body 23, the outlet valve 17 is opened and the brake port 4 is fluidically connected to the de-aerating port 13.

For the shown embodiment, the actuation element 25 has a specific design (without this necessarily being the case):

The actuation element 25 comprises a flexible anchor 27. The electromagnet 26 applies a bending moment upon the flexible anchor 27 when energized by the control device 31. Due to the bending moment, the flexible anchor 27 is deflected with a bending curve. The flexible anchor 27 carries an actuation plunger 28 having an orientation transverse to the longitudinal axis of the flexible anchor 27. Opposing front faces of the actuation plunger 28 contact in the respective valve positions the inlet valve body 20 respectively the outlet valve body 23.

It is possible that for holding the pivoting anchor valve 3 in the aerating position or the de-aerating position it is required to permanently energize the electromagnet 26. However, as shown for the preferred embodiment of the pivoting anchor valve 3 in Fig. 1 , the pivoting anchor valve 3 might comprise a permanent inlet magnet 29 and a permanent outlet magnet 30. In the aerating position the flexible anchor 27 contacts the permanent inlet magnet 29. By the magnetic force applied by the permanent inlet magnet 29 upon the flexible anchor 27 the flexible anchor 27 can be held in position also when at least reducing the energization of the electromagnet 26. In the same way, the flexible anchor 27 contacts the permanent outlet magnet 30 in the de-aerating position of the pivoting anchor valve.

It is possible that without an energization of the electromagnet 26 the pivoting anchor valve 3 comprises three stable operating positions wherein in the closed position of the pivoting anchor valve 3 correlating with the centered position of the flexible anchor 27 in Fig. 1 the stable operating position is upheld by the bending stiffness of the flexible anchor 27 and in the other operating positions the stable operating positions are upheld by the permanent inlet magnet 29, respectively the permanent outlet magnet 30.

For leaving the stable aerating position or de-aerating position, the electromagnet 26 can be energized with a control signal created or controlled by the control device 31. If due to the energization the flexible anchor 27 has established a gap to the permanent magnet 29, 30, the magnetic force of the permanent magnet 29, 30 reduces. Also when reducing or removing the energization of the electromagnet 26, the flexible anchor 27 will then be moved further away from the former stable position due to the bending stiffness of the flexible anchor 27. With a decay of the resulting oscillations of the actuation plunger 28 (that might also be additionally dampened or dampened by a dampening control of the electromagnet 26) the actuation plunger 28 returns into the stable centered position correlating with the closed pivoting anchor valve 3. However, without any additional damping the resulting oscillation and the bending stiffness of the flexible anchor 27 lead to the result that the flexible anchor 27 oscillates through the centered position towards the other stable operating position. Accordingly, for changing the valve position from the aerating position to the de-aerating position (and vice versa) the minimum energy that has to be provided by the electromagnet 26 is the energy required for overcoming the existing damping. Furthermore, the energy provided by the electromagnet 26 has to guarantee that also the pneumatic forces applied upon the valve bodies 20, 23 can be overcome for opening the related valve 16, 17.

The pneumatic brake branches 2, 6 are connected to each other by a connecting line 32. In the connecting line 32 a valve device 33 is arranged. For the embodiment shown in Fig. 1 , the valve device 33 is a 2/2-solenoid valve 34. The 2/2-solenoid valve 34 is controlled by the control device 31. The 2/2-solenoid valve 34 comprises an open position and a closed position.

The embodiment of Fig. 2 generally corresponds to the embodiment of Fig. 1 . However, here the valve device 33 arranged in the connecting line 32 is a pivoting anchor valve 35. The pivoting anchor valve 35 generally has the same design as the pivoting anchor valves 3, 7. However, here the port being the brake port 4 for the pivoting anchor valve 3 is a first (here right) connecting port 36 connected via the connecting line 32 to the right brake line 5 and the right brake actuator. The port being the right supply port 10 of the pivoting anchor valve 3 here is a second or left connecting port 37 connected via the connecting line 32 to the left brake line 9 and the left brake actuator. The centered operating position of the pivoting anchor valve 35 of Fig. 2 corresponds to the closed position of the 2/2-solenoid valve 34 in Fig. 1 so that in this closed position of the pivoting anchor valve 35 the connection of the pneumatic brake branches 2, 6 is closed. Instead, the aerating position of the pivoting anchor valve 3 corresponds to an open position of the pivoting anchor valve 35 and to the open position of the 2/2-solenoid valve 34 in Fig. 1. In this open operating position, the pivoting anchor valve 35 connects the pneumatic brake branches 2, 6 with each other. Furthermore, the pivoting anchor valve 35 comprises a de-aerating position. In the de aerating position, it is possible to de-aerate the right brake actuator and the right brake line 5 via the pivoting anchor valve 35, whereas the left brake actuator and the left brake line 9 are closed against the right pneumatic brake branch 2 (whereas the pressurization of the right pneumatic brake branch 2 can still be controlled by the pivoting anchor valve 7). The control device 31 might be a single control unit or might comprise a plurality of control units that also might be linked to each other by connecting lines or a data bus system.

The control device 31 comprises control logic for controlling the pivoting anchor valves 3, 7 as well as the valve device 33 for executing the following functions:

For a method for operating a pneumatic vehicle brake assembly 1 as schematically shown in Fig. 3, the vehicle brake assembly 1 in a method step 38 is operated in a normal operational mode. In this normal operational mode, the valve device 33 is controlled into the open position for connecting the pneumatic brake branches 2, 6. In this normal operational mode, the brake lines 5, 9 and the right brake actuator and the left brake actuator are biased by the same brake pressures for generating the same brake forces at the right wheel and the left wheel of the axle. Within the normal operational mode in a method step 39 it is possible to aerate the brake lines 5, 9 and the associated brake actuators for increasing the brake friction or in a method step 40 it is possible to de-aerate the pressure in the brake lines 5, 9 with the associated brake actuators for reducing the brake force. It is also possible that there is a slip control with an intermittent switching between a de-aeration, a blocking and an aeration of the brake lines 5, 9 for a modulated brake action.

For at least temporarily keeping the brake pressure constant, the control device 31 controls the pivoting anchor valves 3, 7 into the closed positions.

For at least temporarily aerating the brake lines 5, 9 the control device choses one of the following options: a) It is possible that the pivoting anchor valve 3 is kept in the closed position, whereas the pivoting anchor valve 7 is controlled into the aerating position. b) It is also possible that the pivoting anchor valve 3 is controlled into the aerating position, whereas the pivoting anchor valve 7 is controlled into the closed position. c) Finally, it is possible that both the pivoting anchor valve 3 as well as the pivoting anchor valve 7 are controlled into the aerating position which is in particular the case if an aeration with an increased flow of pressurized air, so a steep increase of the brake pressure in the brake actuators, is of interest.

The control device 31 comprises control logic which guarantees that it is avoided that one of the pivoting anchor valves 3, 7 is in aerating position, whereas the other one of the pivoting anchor valves 3, 7 is in the de-aerating position for avoiding that the pivoting anchor valves 3, 7 have counteracting effects leading to pressure losses and a decrease of the velocity of the aeration and/or de-aeration.

In a method step 41 , the control device 31 determines an operational state. For the determination of the operational state the control device 31 e. g. considers available sensor signals, signals from other control units, inputs of the driver, inputs from an autonomous driving system, environmental parameters and the like. In the method step 41 , the operational state is determined for deciding if the normal operational mode can be upheld as a first operational mode wherein the valve device 33 is in the open position or

- if it is required to switch to a second operational mode wherein the valve device 33 is controlled into the closed position.

For a first embodiment of the invention, the determined operational state is the determination if there is a (actual or estimated) need for a yaw moment. Such a yaw moment can for example be requested by a driving stability system that indicates that the vehicle tends to enter into an unstable driving mode requiring a correcting yaw moment. Another example for an indicated or actual need for a generation of a yaw moment might be the detection of a need for a steering action achieved by an applied yaw moment. In the case that in the method step 41 it is detected that there is a need for a yaw moment the yaw moment can be achieved by generating differing brake forces at the right wheel and at the left wheel. In this case in the method step 42 the second operational mode is entered and the valve device 33 is switched into the closed position. In the closed position of the valve device 33 it is possible to control a brake pressure via the pivoting anchor valve 3 in the brake line 5 and the right brake actuator that is different from the brake pressure controlled by the pivoting anchor valve 7 in the brake line 9 and the left brake actuator.

In a method step 43, again the operational state is determined. If there is still the need for a generation of a yaw moment, the second operational mode is upheld and the generation of a yaw moment is continued by producing differing brake pressures at the different wheel sides. Otherwise, the method returns back to the method step 38 and into the first operational mode (i.e. the normal operational mode).

For an alternative or cumulative embodiment in the method steps 41 , 43 the determined operational state is the detection of differing friction conditions at the right wheel and at the left wheel. If the coefficients of friction differ on the different wheel sides (one wheel on wet ground or ice; the other wheel on dry ground), the open position of the valve device 33 in the first operational mode and the requirement to avoid slippage at both wheels lead to the consequence that the brake pressure applied to both brake actuators considers the lower one of the two coefficients of friction so that it is not possible to use the maximum of the possible friction force. Accordingly, when detecting in the method steps 41 , 43 that there are different friction conditions at the right wheel and at the left wheel the valve device 33 can be switched into the closed position so that the brake pressures at the brake lines 5, 9 and at the associated brake actuators can be controlled individually so that on both wheel sides the optimum of the friction force can be achieved.

As an alternative or cumulative determined operational state leading to different friction conditions at the right wheel and at the left wheel also differing wheel loads on the left wheel and on the right wheel (due to driving through a curve or due to an offset of the load arranged on the vehicle platform) can be used. Accordingly, when detecting a higher normal load at one wheel end than at the other wheel end it is possible to switch the valve device 33 into the closed position and to individually control the brake pressures in the brake lines 5, 9 under consideration of the differing normal loads with the result of optimal and differing brake forces at the right wheel and at the left wheel. Fig. 4 shows another method for operating the pneumatic vehicle brake assembly 1 under the control by the control logic of the control device 31. Here, in a method step 44 the pneumatic vehicle brake assembly 1 is in a second operational mode which here forms the "normal operational mode". The valve device 33 is controlled in a method step 45 into the closed position so that the pneumatic brake branches 2, 6 are separated. This allows an independent control of the brake pressures in the brake lines 5, 9 and the brake actuators in method steps 46, 47 which includes a de-aerating, an aerating or a blocking as well as a modulated brake action.

In a method step 48, an operational state is determined. On the basis of the determined operational state it is decided if the second operational mode is upheld with an independent control of the two pneumatic brake branches 2, 6. Otherwise, the method continues with method step 49, wherein the operational mode is switched to the first operational mode 49 by switching the valve device 33 from the closed position into the open position.

The operational state considered for this decision is in particular the detection of a failure of a control of the right pneumatic brake branch 2 or of the left pneumatic brake branch 6. This might e. g. be a defect in the control device 31 for one of the pivoting anchor valves 3, 7, a failure as a pressure leakage in one of the supply lines to the supply ports 10, 1 1 , a failure of one of the sensors associated with the control of one of the pneumatic brake branches 2, 6 (as e.g. a wheel speed sensor or a brake pressure sensor) or a failure of the pivoting anchor valve 3, 7 itself. In this case, by a switch to the first operational mode in method step 49 it is possible to use the remaining control path not having the failure for controlling the brake pressure for both brake lines 5, 9 and so for the right brake actuator and the left brake actuator. Accordingly, if e.g. the supply line to the supply port 1 1 , the control for the pivoting anchor valve 7 or the pivoting anchor valve 7 itself has the failure, the control branch via the pivoting anchor valve 7 is deactivated, the valve device 33 is switched into the open position and both brake lines 5, 9 are controlled by the pivoting anchor valve 3 (whereas the pivoting anchor valve 7 takes the closed position so that there is no interference of the pivoting anchor valve 7 with the control actions of the pivoting anchor valve 3).

Fig. 5 shows a (part of a) brake system 50 comprising the pneumatic vehicle brake assembly 1 , a right brake actuator 51 and a left brake actuator 52 (here embodied as combination brake cylinder comprising a spring brake part and a service brake part). The brake actuators 51 , 52 are connected to the associated brake lines 5, 9. In Fig. 5 the pivoting anchor valves 3, 7 are shown in a schematic representation with the inlet valve 16 and the outlet valve 17 being represented by 2/2-solenoid valves. The pivoting anchor valve 3 (respectively the pivoting anchor valve 7) is integrated into a right wheel end unit 53 (respectively a left wheel end unit 54). The wheel end units 53, 54 are here schematically represented by the boxes drawn with dotted and dashed lines.

For the shown embodiment, also a control unit 55 (respectively 56) and a pressure sensor 57 (respectively 58) is integrated into the right wheel end unit 53 (respectively the left wheel end unit 54). The pressure sensors 57, 58 measure the brake pressure in the brake lines 5, 9.

For the embodiment shown in Fig. 5, the valve device 33 comprises a valve 59 integrated into the connecting line 32 which connects the right pneumatic brake branch 2 to the left pneumatic brake branch 6. The valve 59 is also integrated into the right wheel end unit 53. On the basis of this valve 59 and the connecting line 32 the functionality described on the basis of Figs. 1 to 4 can be provided.

Optionally, the valve device 33 might comprise an additional valve 60 which is integrated into an additional connecting line 61 which also connects the pneumatic brake branches 2, 6. The valve 60 is integrated into the left wheel end unit 54. The valves 59, 60 are here embodied by 2/2-solenoid valves 34. The connecting lines 32, 61 can be connected at any point to the brake lines 5, 9, so within the wheel end units 53, 54 or outside from the wheel end units 53, 54. For the embodiment shown in Fig. 5 connecting line 32 branches from the brake line 5 within the right wheel end unit 53 but branches from the left brake line 9 outside from the left wheel end unit 54. The corresponding applies for the connecting line 61. The brake system 50 shown in Fig. 5 comprises a foot brake pedal 62 wherein two redundant sensors 63, 64 provide redundant brake signal via redundant signal lines 65, 66 to a control unit 67.

The control unit 67 is part of an air processing unit 68 of common design. Compressed air is supplied to the air processing unit 68 via a compressor 69 which is here controlled by the air processing unit 68. The air processing unit 68 comprises an air dryer 70, pressure sensors 71a, 71 b, 71 c, a pressure controller 72, a central line 73 comprising a check valve 74, a bypass line 75 bypassing the check valve 74, a regeneration valve 76 integrated into the bypass line 75, circuit protection valves 77a, 77b, 77c, 77d, 77e and/or control valves 78a, 78b controlled by the control unit 67 and controlling the functions of the air processing unit 68 (here e. g. controlling the regeneration valve 76, the pressure controller 72 and the compressor 69). The air processing unit 68 serves for providing different consumer circuits 79a, 79b, 79c, 79d, 79e, 79f with pressurized air. Here, by the control of the air processing unit 68 and the circuit protection valves 77 it is provided that the consumer circuits 79 are supplied with pressurized air at the desired pressures and/or a minimum pressure is provided and/or

it is possible that one consumer circuit 79 can be supplied with pressurized air by a transverse flow of pressurized air from another consumer circuit and/or

- the consumer circuits 79 are filled with pressurized air in a given sequence.

For the embodiments shown, the consumer circuit 79b comprises the right pivoting anchor valve 3, the right pneumatic brake branch 2 and the right wheel end unit 53 with the right brake actuator 51. As shown in Fig. 5, in this consumer circuit 79b a supply reservoir 80b can be arranged.

The consumer circuit 79c comprises the left pivoting anchor valve 7, the left pneumatic brake branch 6 and the left wheel end unit 54 with the left brake actuator 52. A supply reservoir 80c is integrated into the consumer circuit 79c.

The control unit 67 is connected via signal lines 81 , 82 to another control unit 83. The signal lines 81 , 82 transmit (possibly besides other data) redundant signals at least correlating to the signals of the sensors 63, 64, so a brake demand by the driver, from the control unit 67 to the control unit 83. Via a control line 84 (respectively control line 85) the control unit 83 is connected to a control port 86 (respectively 87) of the right wheel end unit 53 (respectively left wheel end unit 54) and transmits a brake demand. On the basis of this brake demand the control units 55, 56 of the wheel end units 53, 54 control the pivoting anchor valves 3, 7 for generating the desired brake pressure.

In the case that e.g. one of the control units 67, 83, 55, 56 detects that one of the wheel end units 53 , 54 does not work properly, the control unit 55, 56 correlated to the wheel end unit 53, 54 having the failure controls the respective pivoting anchor valve 3, 7 into the closed position or the pivoting anchor valve 3, 7 takes the closed position. The valve 59, 60 associated with the wheel end unit 53, 54 having the failure will then be opened which leads to the desired effect that both brake actuators 51 , 52 can be controlled by the control unit 55, 56 and the associated pivoting anchor valve 3, 7 of the wheel end unit 53, 54 which does not have the failure.

In the case that there are two connecting lines 32, 61 with integrated valves 59, 60 of the valve device 33 this functionality can also be provided in the case that the failure effects or is caused by one of the control units 55, 56.

To mention only one example for the way of detecting a failure, it is possible that the control unit 55 compares the brake demand submitted to the control port 86 with the pressure signal sensed by the pressure sensor 57. In the case that the control by the control unit 55 and/or the pivoting anchor valve 3 does not work properly, the sensed pressure differs from the desired pressure signal which can be taken as an indicator that the wheel end unit 53 has a failure. Accordingly, the wheel end unit 53 can be "deactivated" and control of the brake actuator 51 is taken over by the wheel end unit 54.

In Fig. 6 the pneumatic vehicle brake assembly 1 has a valve device 33 being a pivoting anchor valve 35 having a differing design: In the valve position shown in Fig. 6 (which is the centered stable switching position upheld by the bending stiffness of the flexible anchor 27) the pivoting anchor valve connects the ports 36, 37 so that the pneumatic brake branches 2, 6 are connected with each other. By an energizing of the electromagnet 26 in a first direction the pivoting anchor 27 is pivoted in clockwise direction. The pivoting anchor 27 closes a valve seat 88 formed by a sealing or O-ring so that the connection of the ports 36, 37 is closed. The two described valve positions of the pivoting anchor valve 35 generally correspond to the two positions described for the 2/2-solenoid valve 34 in Fig. 1 so that the above-described functionality can be provided. Additionally, by an energization of the electromagnet 26 in a second direction it is possible to pivot the flexible anchor 27 in counter-clockwise direction in Fig. 6. A plunger 89 of the flexible anchor 27 moves a valve body 90 against the bias by a valve spring 91 away from a valve seat 92. Accordingly, a connection between a port 93 and the valve chamber 94 is established. Due to the fact that the flexible anchor 27 has moved away from the valve seat 88 the ports 93, 36 and 37 are connected to each other.

For one embodiment, the port 93 is connected to a pressurized air source, as e.g. a supply reservoir. In the case that the pivoting anchor valve 35 is controlled into the position wherein the valve body 90 does not close the valve seat 88 the pressurized air from the pressure source or reservoir approaches ports 36, 37 so that the brake lines 5, 9 as well as the brake actuators 51 , 52 are biased by the pressure of the pressurized air source or reservoir. This leads to an emergency brake action with the full application of the service brake of the brake actuators 51 , 52.

For another embodiment of the invention, the port 93 is connected to a brake line providing a brake pressure. This brake pressure can be generated by a separate brake path, on the basis of an autonomous driving system, on the basis of the demand of the driver, via an electro- pneumatical control path or via a mechanical-pneumatical control path (e.g. the direct control of the brake pressure by the brake pedal linked to the valve generating the brake pressure). In this case, the control of the pivoting anchor valve 35 into the position wherein the valve body 90 does not close the valve seat 92 leads to the transfer of the brake pressure at port 93 to the brake lines 5, 9 and so to the brake actuators 51 , 52 so that the wheels on both sides are braked with the brake force correlating with the brake pressure at port 93.

For the embodiment shown in Fig. 7, the valve device 33 comprises valves 59, 60. The valves 59, 60 are here both embodied as 3/2-solenoid valves 95, 96. The first valve 59 is integrated into the first (here right) pneumatic brake branch 2, whereas the second valve 60 is integrated into the second (here left) pneumatic brake branch 6. The first valve 59 is interposed between the first (here right) brake port 4 of the first (here right) pivoting anchor valve 3 and the first (here right) brake actuator 51 , whereas the second valve 60 is interposed between the second (here left) brake port 8 of the second (here left) pivoting anchor valve 7 and the second (here left) brake actuator 52.

The first valve 59 comprises a first switching state (not effective in Fig. 7), wherein the first valve 59 connects the first pivoting anchor valve 3 to the first brake actuator 51. This first switching state is preferably taken against the bias by a spring when energizing a control port 97 of the first valve 59. In the second switching state (effective in Fig. 7) the first valve 59 connects the first brake actuator 51 to the second pneumatic brake branch 6. Here, the connection is established by a first connecting line 32a which connects the first valve 59 to the second pneumatic brake branch 6 at a position between the second valve 60 and the second brake actuator 52. However, for a differing embodiment the connecting line 32a might also be connected to the second pneumatic brake branch 6 at a position between the second valve 60 and the second pivoting anchor valve 7. The corresponding applies for the second valve 60, where here in the second switching state the second valve 60 connects the second brake actuator 52 via a second connecting line 32b to the first brake actuator 51.

Pressure sensors 57, 58 sense the pressure in the pneumatic brake branches 2, 6. The vehicle brake assembly 1 of Fig. 7 is operated as follows:

In a normal operational mode (wherein in particular the electric power supply is according to the specifications and the components of the vehicle brake assembly 1 do not comprise any failure) the valves 59, 60 are in the first switching states. Accordingly, in the normal operational mode the pneumatic brake branches 2, 6 are separated from each other with closed connecting lines 32a, b. In the normal operational mode it is possible that the control device 31 individually controls the brake pressures in the brake actuators 51 , 52 by an individual control of the pivoting anchor valves 3, 7.

Another mode (which might be a power saving mode, a mode with a simplified control, a mode with a common control of both brake actuators 51 , 52, a failure mode or a redundancy mode) will be explained on the basis of a failure in the first pneumatic brake branch 2 (e. g. a failure of the first pivoting anchor valve 3, a failure of the electric control of the first pivoting anchor valve 3, a failure of the supply of the first pivoting anchor valve3 with compressed air and/or a failure in the line between the first pivoting anchor valve 3 and the first valve 59; where the corresponding might apply for the second pneumatic brake branch 6): In the other mode the first valve 59 is transferred into the second switching state. Accordingly, the connecting line 32a connects via the first valve 59 the first brake actuator 51 to the second brake actuator 52. The second switching state of the first valve 59 is in particular achieved by removing the energization of the control port 97 which might be provided by a suitable control strategy of the control device 31 or due to a power failure at the control port 97. In this other mode the second valve 60 is kept by the control device 31 in the first switching state. Accordingly, the second pivoting anchor valve controls the pressurization of both brake actuators 51 , 52.

It is possible that in the case of a complete failure or a failsafe mode both valves 59, 60 are transferred into the second switching states. This means that the brake actuators 51 , 52 are connected to each other by both connecting lines 32a, 32b and that the pressurization of the brake actuators 51 , 52 does not change. If e.g. before the transfer of the valves 59, 60 into the second switching states a parking brake pressure or an emergency brake pressure has been created by the pivoting anchor valves 3, 7, the achieved brake pressures are upheld. For the embodiments shown in Figs. 1 , 2, 6 and 7 the valve device 33 or the valves 59, 60 is/are arranged separately and remote from the wheel end units 53, 54. However, also for these embodiments it is possible that the brake device 33 or valves 59, 60 of the same are integrated into at least one of the wheel end units 53, 54 as shown in Fig. 5. For the embodiment shown in Fig. 6, for one option this means that the port 93 can be connected to the supply line of the related consumer circuit 97b, 97c within the wheel end unit 53, 54.

The embodiment of Fig. 8 generally corresponds to the embodiment of Fig. 7. Here, the wheel end units 53, 54 include control units 55, 56, the pivoting anchor valves 3, 7, the valves 59, 60 of the valve device 33 and pressure sensors 98, 99 which sense the pressures at the supply ports 10, 11 and the sensors 57, 58. Here, two separate reservoirs 12a, 12b are provided for a redundant supply of compressed air. The reservoir 12a is connected to the supply port 10 of the wheel end unit 53, whereas the reservoir 12b is connected to the supply port 1 1 of the wheel end unit 54. Furthermore, the wheel end units 53, 54 are supplied with electric power by separate and redundant electric power supply lines 100, 101. Finally, here the wheel end units 53, 54 or the control units 55, 56 are connected separately and in a redundant way to associated bus lines 102, 103.

For the embodiments shown in Figs. 1 , 2, 5, 6, 7, 8, the wheel end units 53, 54 were associated with one and the same axle and different vehicle sides. However, these embodiments of the vehicle brake assembly 1 are not limited to this way of integration into a vehicle. Instead, the wheel end units, the associated pneumatic brake branches, the brake actuators and the pivoting anchor valves and the related ports and sensors and the like might also be associated with any other wheel end unit, so e.g. wheel end units on the same vehicle side but different axles or a tandem axle, wheel end units of different vehicles sides and different axles. Furthermore, it is possible that the wheel ends are associated with the same vehicle side but different axles. This will be shown for some examples in the following figures: Fig. 9 shows a first axle 104 (here a front axle with steered wheels) and a second axle 105 (here a rear axle). Wheel end units 53, 54 embodied as shown in Figs. 1 , 2 or 5 to 8 are associated with the two wheel ends of the axle 104. In this case, the pneumatic vehicle brake assembly 1 comprises a third wheel end unit 106 and a fourth wheel end unit 107 and an associated third brake actuator 108, an associated fourth brake actuator 109, associated third and fourth pivoting anchor valves and associated third and fourth valves of the valve device 33 and an associated third pneumatic brake branch 1 10 and an associated fourth pneumatic brake branch 1 11. Here, the pneumatic brake branches 1 10, 1 11 can have the same construction, design and/or functionality as the pneumatic brake branches 2, 6 of the embodiments of Figs. 1 , 2 or 5 to 8. The pneumatic brake branches 6, 110 (here associated with the front left wheel end and the rear right wheel end) are supplied with compressed air by the reservoir 12b, whereas the pneumatic brake branches 2, 1 11 (here associated with the right front wheel end and the left rear wheel end) are connected to the reservoir 12a.

The vehicle brake assembly 1 in particular allows the following functionality: A failure of one of the wheel end units 53, 54, 106, 107 is for an example described for a failure of the wheel end unit 107: In this case, it is possible to switch the fourth valve of the valve device 33 into a switching position, wherein the fourth brake actuator 109 is separated from the fourth pivoting anchor valve of the fourth pneumatic brake branch 11 1. Instead, the brake chamber of the fourth brake actuator 109 is connected via the fourth valve and the connecting line 32 to the third brake actuator 108 so that it is possible to control the fourth brake actuator 109 by the third pneumatic brake branch 110.

In this way, for the embodiment shown in Fig. 9 any failure of one of the pneumatic brake branches 2, 6, 1 10, 1 11 can be compensated by the fact that another pneumatic brake branch is able to take over the control of the brake actuator associated with the failing pneumatic brake branch. Also in the case of the failure, a full brake performance can be maintained. An ABS control and/or slip control is still possible, where in the case of the failure one pneumatic brake branch then controls the brake pressure for both associated wheel ends. Also for this embodiment, a redundant supply of electric power and/or a redundant connection to a bus line 102, 103 is possible. Fig. 9 in particular relates to a truck 4x2.

Fig. 10 shows another embodiment of a vehicle brake assembly 1 , which might e.g. be used for a truck 6x4. The vehicle brake assembly 1 of Fig. 10 generally corresponds to the vehicle brake assembly 1 of Fig. 9. However, here a third axle 1 12 is provided. Preferably, the axles 105, 112 build a tandem axle 1 19. The third axle 1 12 comprises a fifth wheel end unit 113 and a sixth wheel end unit 114 with associated fifth and sixth brake actuators 1 15, 1 16, fifth and sixth pneumatic brake branches 117, 118 and associated fifth and sixth pivoting anchor valves and other components. Also here, the pneumatic brake branches 117, 118 can be embodied and provide the functionality as described for the pneumatic brake branches 2, 6. Here, the pneumatic brake branches 1 10, 117, respectively 11 1 , 1 18, of different axles 105, 1 12 on the same side of the vehicle are connected to each other by respective connective lines 32. Also here, control of the brake pressure in one brake actuator 108, 109, 115, 116 in the case of a failure of an associated pneumatic brake branch 1 10, 11 1 , 117, 1 18 can be taken over by another pneumatic brake branch as follows: If e.g. a failure occurs in the pneumatic brake branch 110, the third valve of the valve device 33 closes the connection between the third pivoting anchor valve and the third brake actuator 108 but opens a connection of the third brake actuator 108 via the connecting line 32 to the fifth brake actuator 115 and the fifth pneumatic brake branch 1 17. Accordingly, the fifth pivoting anchor valve controls the pressurization of the third brake actuator 108 as well as of the fifth brake actuator 115.

Fig. 11 shows an embodiment where the first wheel end unit 53, the second wheel end unit 54 and the third wheel end unit 106 are responsible for controlling the brake actuators 51 , 52, 108 on the same vehicle side and associated with the axles 104, 105, 1 12. The wheel end units 53, 54, 106 each comprise a valve 59, 60, 120, a pivoting anchor valve 3, 7, 121 , pneumatic brake branches 2, 6, 110 formed therewith and control units 55, 56, 122.

The wheel end unit 53, here the valve 59, is connected via the connecting line 32a to the third brake actuator 108. Accordingly, in the second switching state the first valve 59 is connected to the third pneumatic brake branch 1 10, so that in the case of a failure of the first wheel end unit 53 it is possible to control the brake pressure of the first brake actuator 51 by the third pneumatic brake branch 1 10.

In a corresponding way, the second wheel end unit 54, here the second valve 60, is connected by the connecting line 32b to the first brake actuator 51 and the third wheel end unit 106, here the third valve 120, is connected to the second brake actuator 52.

In this way, it is possible that in the case of a failure in any one of the wheel end units 53, 54, 106 another wheel end unit is able to take over the control of the brake actuator associated with the failing wheel end unit.

It is also possible that in the case of a failure of two of the wheel end units, e.g. a failure of the wheel end units 53, 54, the remaining wheel end unit 106 is able to control the first, second and third brake actuators 51 , 52, 108: For the mentioned example of failing wheel end units 53, 54, the wheel end unit 106 controls the pressure in the third brake actuator 108. Due to the fact that the first valve 59 is switched by its spring (also in the case of a power failure) into the second switching position, the brake pressure in the brake actuator 108 is also transmitted to the first brake actuator 51. Due to the fact that by the spring (also in the case of a power failure) the second valve 60 is switched into the second switching position, the brake pressure in the first brake actuator 51 is also transferred to the second brake actuator 52.

In the shown and described embodiments, pivoting anchor valves 3, 7, 121 were used as brake control valves 123, 124, 125. Within the frame of the invention, any brake control valves 123, 124, 125 having a different design an functionality than pivoting anchor valves might be used.

Accordingly, at any position within the drawings and the specification any mention of a pivoting anchor valve 3, 7, 121 might be replaced by a brake control valve 123, 124, 125 of a differing design. LIST OF REFERENCE NUMERALS pneumatic vehicle brake assembly

pneumatic brake branch

pivoting anchor valve

brake port

brake line

pneumatic brake branch

pivoting anchor valve

brake port

brake line

supply port

supply port

supply reservoir

de-aerating port

de-aerating port

valve chamber

inlet valve

outlet valve

inlet valve seat

housing

inlet valve body

inlet valve spring

outlet valve seat

outlet valve body

outlet valve spring

actuation element

electromagnet

flexible anchor

actuation plunger

permanent inlet magnet

permanent outlet magnet

control device

connecting line valve device 2/2-solenoid valve pivoting anchor valve connecting port connecting port method step method step method step method step method step method step method step method step method step method step method step method step brake system brake actuator brake actuator wheel end unit wheel end unit control unit control unit pressure sensor pressure sensor valve

valve

connecting line foot brake pedal sensor

sensor

signal line signal line control unit

air processing unit compressor

air dryer

pressure sensor pressure controller central line

check valve

bypass line

regeneration valve circuit protection valve control valve

consumer circuit supply reservoir signal line

signal line

control unit

control line

control line

control port

control port

valve seat

plunger

valve body

valve spring

valve seat

port

valve chamber

3/2-solenoid valve 3/2-solenoid valve control port

pressure sensor pressure sensor electric power supply line electric power supply line bus line

bus line

axle

axle

wheel end unit wheel end unit brake actuator brake actuator pneumatic brake branch pneumatic brake branch axle

wheel end unit wheel end unit brake actuator brake actuator pneumatic brake branch pneumatic brake branch tandem axle

valve

pivoting anchor valve control unit

brake control valve brake control valve brake control valve