Brake system of vehicle having redundant parking brake function

Abstract

The invention relates to a brake system for a vehicle, comprising an electropneumatic parking brake device having a parking brake module and a parking brake function, an electropneumatic service brake device having an electropneumatic service brake circuit, and a redundant parking brake function carried out in a control device, a holding force for holding the vehicle in a stationary state is generated by means of the parking brake function and the redundant parking brake function. The redundant parking brake function is designed to actuate the first solenoid valve device in order to press the first service brake cylinder or to hold the first service brake cylinder in a pressed state when a fault or defect in the vehicle stationary state and in the parking brake circuit that results in a non-energized state of the parking brake module is detected, and to actuate the second solenoid valve device in order to hold the first service brake cylinder in the pressed state, and to actuate the second solenoid valve device in order to hold the second service brake cylinder in the pressed state. In order to control the pressure air from the reserve pressure vessel into the second service brake cylinder and to control the pressure air from the second service brake cylinder into the pressure reduction unit, the reserve pressure in the reserve pressure vessel is reduced and the spring accumulator brake cylinder is pressed.

Description

Technical Field

[0001] The present invention relates to a brake system of a vehicle according to claim 1, the brake system having an electropneumatic parking brake, an electropneumatic service brake and a redundant parking brake function implemented in a control device, the electropneumatic parking brake having a parking brake function, the electropneumatic service brake having at least one electropneumatic service brake circuit, wherein a holding force for holding the vehicle in a stationary state can be generated by means of the parking brake function and the redundant parking brake function, respectively. In addition, the present invention also relates to a vehicle having at least one such brake system according to claim 25. Background Art

[0002] In particular, vehicles with autonomous driving systems that support driverless driving are often equipped with redundant electropneumatic service brakes, wherein the redundancy takes effect when the electropneumatic service brake fails. If such a vehicle is also braked to a standstill by means of the (redundant) electropneumatic service brake and then held in a standstill by means of the (redundant) electropneumatic service brake, a safe standstill is therefore not ensured. Since the braking effect of the electropneumatic service brake decreases after a certain time due to leakage, this is also caused by the fact that after the engine is shut down, the compressor no longer delivers additional reserve pressure air to the at least one reserve pressure container.

[0003] It is therefore desirable to provide redundancy for the parking brake function even when the parking brake function fails, for example due to a power failure or due to an electrical fault or defect in the parking brake device. Because in particular in vehicles with autonomous driving systems, the driver usually does not intervene to ensure, for example, that the vehicle is securely parked. Therefore, it should be ensured in particular that the vehicle can be held in a stationary state via the spring accumulator brake cylinder in any case. The redundant parking brake function should function properly, in particular, independently of the high performance of the electronic parking brake control device. Summary of the invention

[0004] Therefore, the task of the present invention is to construct a brake system in such a way that a vehicle can be safely parked by means of a parking brake device. In addition, a vehicle having such a brake system should also be provided.

[0005] This object is achieved by the features of claims 1 and 25 .

[0006] The present invention discloses a braking device of a vehicle, wherein the braking device comprises an electro-pneumatic parking brake device, an electro-pneumatic service brake device and a redundant parking brake function implemented in at least one control device, wherein the electro-pneumatic parking brake device has a parking brake function, and the electro-pneumatic service brake device has at least one electro-pneumatic service brake circuit, and in particular when the parking brake function fails, the redundant parking brake function is implemented, wherein holding forces for keeping the vehicle in a stationary state can be generated respectively by means of the parking brake function and the redundant parking brake function.

[0007] “Electropneumatics” means that the control of the corresponding device takes place electrically or electronically, but the working medium is compressed air.

[0008] A “redundant parking brake function” means in particular that the normal parking brake function used in normal operation subsequently no longer functions properly and is then replaced by the redundant parking brake function. Both in the case of the parking brake function and in the case of the redundant parking brake function, the parking brake is applied by bleeding at least one spring-accumulator brake cylinder to at least the application pressure of the spring-accumulator brake cylinder.

[0009] In particular, at least one electropneumatic service brake circuit is provided in the service brake device, preferably two service brake circuits are provided, namely a first service brake circuit for a front axle of the vehicle and a second service brake circuit for a rear axle, wherein a common reserve pressure vessel can be provided for the two brake circuits or each brake circuit can be provided with its own reserve pressure vessel.

[0010] The electropneumatic service brake device comprises at least one first service brake cylinder assigned to a first wheel of the vehicle, at least one electronic service brake control device, at least one reserve pressure container and a first solenoid valve device which can be controlled by the at least one electronic service brake control device and by a redundant parking brake function.

[0011] The first solenoid valve device is (in principle) designed and arranged to control compressed air from the at least one storage pressure container into the at least one first service brake cylinder and simultaneously or overlappingly in time to control compressed air from the at least one first service brake cylinder into the pressure reduction.

[0012] The parking brake device includes an electro-pneumatic parking brake circuit, which is supplied with compressed air only by at least one reserve pressure container. The parking brake circuit has at least one pneumatically controlled spring accumulator brake cylinder, an electronic parking brake control device and an intake / exhaust solenoid valve combination controlled by the electronic parking brake control device, the intake / exhaust solenoid valve combination is used at least for charging and discharging at least one spring accumulator brake cylinder, and the intake / exhaust solenoid valve combination is constructed so that the intake / exhaust solenoid valve combination connects the at least one spring accumulator brake cylinder to the at least one reserve pressure container in a non-energized state.

[0013] The redundant parking brake function is designed such that, at least when a fault or defect in the parking brake circuit is detected, which results in a de-energized state of the inlet / exhaust solenoid valve combination, the redundant parking brake function controls the first solenoid valve device in the sense of a pressure reduction mode in order to control compressed air from the at least one reserve pressure container into the first service brake cylinder and simultaneously or overlapping in time control compressed air from the first service brake cylinder into the pressure reduction. In the pressure reduction mode, the reserve pressure in the at least one reserve pressure container is thus reduced or decreased such that the at least one spring accumulator brake cylinder is compressed.

[0014] The service brake device or at least one electro-pneumatic service brake circuit comprises in particular at least one first service brake cylinder assigned to a first wheel of the vehicle and optionally at least one second service brake cylinder assigned to a second wheel of the vehicle, at least one electronic service brake control device, at least one reserve pressure vessel and a first solenoid valve device controlled by the at least one electronic service brake control device and optionally also a second solenoid valve device.

[0015] The first solenoid valve device is designed so that compressed air can be controlled from the at least one reserve pressure container into the at least one first service brake cylinder by means of the first solenoid valve device and compressed air can be controlled from the at least one first service brake cylinder into the pressure reduction unit simultaneously or overlapping in time. The optional second solenoid valve device is designed so that a second service brake pressure in the at least one second service brake cylinder can be maintained, increased or reduced by means of the second solenoid valve device.

[0016] The first service brake cylinder and the second service brake cylinder can be arranged, for example, on different axles or on the same axle and on the vehicle side on the same vehicle side or on different vehicle sides. In this regard, the first service brake cylinder and the second service brake cylinder can both belong to a common electropneumatic service brake circuit, but can also belong to only one electropneumatic service brake circuit.

[0017] The first solenoid valve device and / or the second solenoid valve device can, for example, include at least one intake valve and at least one exhaust valve. The terms "intake valve" and "exhaust valve" can be interpreted in a broad sense. Therefore, an "intake valve" refers to any valve with the help of which compressed air can enter the first or second service brake cylinder from a reserve pressure container. The term "exhaust valve" also refers to any valve with the help of which compressed air can be guided from the first or second service brake cylinder to the pressure reduction section. In particular, the "intake valve" and / or the "exhaust valve" can have at least two attachment ends and at least two switching positions.

[0018] The first solenoid valve device and / or the second solenoid valve device can in particular include at least one ABS pressure control valve and / or an inlet valve and an outlet valve of a pressure control module.

[0019] For example, a first electropneumatic service brake circuit may include a first solenoid valve device, at least one first service brake cylinder, optionally a first reserve pressure container and at least one first wheel, and a second electropneumatic service brake circuit may include a second solenoid valve device, at least one second service brake cylinder, optionally a second reserve pressure container and at least one second wheel. Preferably, the first electropneumatic service brake circuit is a rear axle service brake circuit with, for example, two first wheels, each of which has an associated first service brake cylinder, and the second electropneumatic service brake circuit is a front axle service brake circuit with, for example, two second wheels, each of which has an associated second service brake cylinder. In particular, there may be two reserve pressure containers, here a first and a second reserve pressure container, from which only the parking brake circuit is fed. Alternatively, the parking brake circuit may also be fed only from the first reserve pressure container or the second reserve pressure container.

[0020] Furthermore, the parking brake device of the brake system comprises an electropneumatic parking brake circuit which is supplied with compressed air only by at least one reserve pressure vessel of the service brake device or at least one electropneumatic service brake circuit of the service brake device, the parking brake circuit having at least one passively pneumatically controlled spring accumulator brake cylinder, an electronic parking brake control device and having an inlet / exhaust solenoid valve combination controlled by the electronic parking brake control device, the inlet / exhaust solenoid valve combination being used at least for charging and discharging the at least one spring accumulator brake cylinder. Thus, the at least one reserve pressure vessel is a common reserve pressure vessel which feeds the parking brake circuit and simultaneously feeds the electropneumatic service brake device or at least one service brake circuit of the electropneumatic service brake device. It is also possible that the first service brake circuit comprises a first reserve pressure vessel, the second service brake circuit comprises a second reserve pressure vessel, and that the parking brake circuit is supplied with compressed air by the first reserve pressure vessel and / or by the second reserve pressure vessel.

[0021] The intake / exhaust solenoid valve combination of the parking brake circuit is designed such that in the de-energized state it connects at least one spring accumulator brake cylinder to at least one reserve pressure vessel of an electropneumatic service brake device or of at least one electropneumatic service brake circuit.

[0022] Thus, in the de-energized state of the inlet / exhaust solenoid valve combination, at least one spring-accumulator brake cylinder is charged and deflation of the at least one spring-accumulator brake cylinder is prevented. In particular, the at least one spring-accumulator brake cylinder is provided for safety reasons, because it is thereby prevented that, in the event of a power failure or a fault or defect in the electronic parking brake control device, the at least one spring-accumulator brake cylinder suddenly deflates in the electrical connection between the electronic parking brake control device and the inlet / exhaust solenoid valve combination when the vehicle is in motion, and thus leads to an unstable driving situation. The present invention then advantageously utilizes the maintenance of the charge by the de-energized inlet / exhaust solenoid valve combination, which is preferably provided for safety reasons, for a redundant parking brake function in the manner further described below.

[0023] Furthermore, according to a preferred embodiment, at least one first sensor is provided, by means of which it is possible to determine whether the vehicle is at rest (or whether it is moving), wherein the first sensor controls the input of a corresponding first sensor signal into at least one electronic control device for evaluation by a redundant parking brake function. Thus, the electronic control device can determine, by means of the first sensor signal, whether the vehicle is at rest (or whether it is traveling). The at least one first sensor comprises, in particular, at least one wheel speed sensor. Since a stationary state of the vehicle cannot be distinguished from traveling at a very low speed (approximately 0-5 km / h) by means of a simple wheel speed sensor, a "stationary state of the vehicle" is to be understood as a range of approximately 0 km / h to 5 km / h.

[0024] In addition, the redundant parking brake function implemented in the electronic control unit is constructed so that when a fault or defect in the parking brake circuit that leads to a de-energized state of the intake / exhaust solenoid valve combination is detected and optionally additionally when a stationary state of the vehicle is detected based on the first sensor signal, the redundant parking brake function optionally controls the second solenoid valve device to clamp at least one second service brake cylinder or maintain at least one second service brake cylinder in a clamped state, and optionally simultaneously or thereafter, the redundant parking brake function controls the first solenoid valve device in the sense of a pressure reduction mode to control compressed air from at least one reserve pressure container into the first service brake cylinder and simultaneously or overlapping in time to control compressed air from the first service brake cylinder to the pressure reduction unit in order to reduce the reserve pressure in the at least one reserve pressure container and compress at least one spring accumulator brake cylinder.

[0025] Therefore, within the framework of a redundant parking brake function, at least one second service brake cylinder is optionally (in particular first) pressed or, if it has already been pressed beforehand, is kept pressed in order to generate a (in particular temporary) holding force, and the at least one second service brake cylinder is controlled with compressed air via a second solenoid valve device.

[0026] In normal operation, the reserve pressure in the at least one reserve pressure container is greater than the application pressure of the at least one spring-accumulator brake cylinder, to which the at least one spring-accumulator brake cylinder is connected via an inlet-exhaust solenoid valve combination. The application pressure is a relatively low pressure in the brake chamber of the at least one spring-accumulator brake cylinder, which then works against the spring force of the at least one accumulator spring of the at least one spring-accumulator brake cylinder.

[0027] Then, according to one embodiment, if at least one control device controls the first solenoid valve device within the framework of a redundant parking brake function in order to control compressed air from at least one reserve pressure container into the first service brake cylinder and simultaneously or overlapping in time controls compressed air from the first service brake cylinder into the pressure reduction unit, then due to the resulting compressed air consumption, the pressure in the at least one reserve pressure container drops to a compression pressure or below the compression pressure, so that at least one spring accumulator brake cylinder, which is thus only supplied with compressed air from the at least one reserve pressure container, is compressed and generates the necessary holding force, which can then keep the vehicle in a stationary state.

[0028] Therefore, within the framework of a redundant parking brake function, a first solenoid valve device assigned to at least one first wheel and at least one first service brake cylinder controlled by the first solenoid valve device with compressed air are used to vent at least one reserve pressure vessel. A first service brake pressure generated by the first solenoid valve device and controlled to be fed into the at least one service brake cylinder then substantially corresponds to the parking brake pressure in the at least one spring accumulator brake cylinder.

[0029] In other words, within the framework of a redundant parking brake function, when a fault or defect in the parking brake circuit is detected or optionally when the vehicle is stationary, the second service brake cylinder is optionally initially pressed or kept pressed by the second service brake pressure at at least one second wheel, whereby the vehicle can be held in a stationary state by the at least one second service brake cylinder being pressed (in particular initially). Preferably, this process is performed at a plurality of second wheels of the vehicle or at a plurality of second service brake cylinders of the vehicle in order to generate a compensated braking force distribution and / or a high holding braking force.

[0030] Optionally, simultaneously or thereafter, the reserve pressure in at least one reserve pressure container, which supplies compressed air to the parking brake device not only by means of the parking brake circuit of the parking brake device but also by means of at least one service brake circuit of the electro-pneumatic service brake device, is preferably reduced at least to the pressing pressure of at least one spring-accumulator brake cylinder in order to press the spring-accumulator brake cylinder. Thus, the process simulates, for example, a "consumption" of compressed air in a service brake circuit or in a plurality of service brake circuits and is preferably carried out on a plurality of first service brake cylinders in order to achieve the fastest possible venting of the common reserve pressure container, so that the at least one spring-accumulator brake cylinder can be pressed as quickly as possible. Thus, the redundant parking brake function in particular includes a single pressing of the at least one spring-accumulator brake cylinder, or is preferably limited to such a single pressing.

[0031] Here, the above-described property of the intake / exhaust solenoid valve combination of the parking brake circuit, which is actually provided for safety reasons, comes into play, according to which the intake / exhaust solenoid valve combination connects at least one spring accumulator brake cylinder to a common reserve pressure container when not energized, i.e. in this case, for example, in the event of an electrical or electronic defect or fault in the parking brake circuit.

[0032] Preferably, the control device is designed such that it prevents the additional supply of compressed air into the common storage pressure container, for example by a compressor of the brake system driven by the drive engine. This can be achieved, for example, in that the control device activates, starts using or implements the redundant parking brake function only when the ignition switch of the drive engine is switched off. The control device implementing the redundant parking brake function can be supplied with current in particular by a (own) current supply device, which supplies current to the control device independently of the actuation of the ignition switch.

[0033] The venting of at least one common reserve pressure vessel for the service brake device or at least one service brake circuit and the parking brake circuit is therefore accompanied on the one hand by the compression of at least one spring-accumulator brake cylinder and the gradual release of at least one second service brake cylinder, by which the vehicle is optionally initially held in a stationary state. Thus, by means of the redundant parking brake function, preferably a time transition occurs from holding the vehicle by means of at least one compressed second service brake cylinder to holding by means of at least one compressed spring-accumulator brake cylinder. Thus, in the transition period, the holding force generated by means of the at least one second service brake cylinder decreases, while the holding force generated by means of the at least one spring-accumulator brake cylinder increases. However, the at least one first service brake cylinder cannot or can only contribute insignificantly to the generation of the holding force, since it is supplied by means of the common reserve pressure vessel and is therefore also vented.

[0034] Alternatively, the optional temporary holding of the vehicle by at least one pressed second service brake cylinder can also be omitted, since, due to the consumption of compressed air in at least one common reserve pressure container for at least one service brake circuit and a parking brake circuit, on the one hand, although the first service brake pressure drops, on the other hand, the parking brake pressure in the parking brake also increases to approximately the same extent, so that the vehicle can be braked to a standstill and / or can be held in a standstill by the resulting reduction in the service brake force and the increase in the parking brake force.

[0035] It is clear that the redundant parking brake function implemented in the control device includes software, by which the above-mentioned control function is implemented. Likewise, there are corresponding line connections and signal connections between the control device on the one hand and the actuators and sensors on the other hand.

[0036] In order to achieve independence between the control device and the parking brake control electronics, the control device is preferably supplied with current by a second voltage supply device which is independent of a first voltage supply device of the parking brake control electronics.

[0037] It is also advantageous that a first reserve pressure container is associated with the first service brake circuit and is separate and independent of a second reserve pressure container, wherein the first reserve pressure container feeds a first solenoid valve device in order to generate a first service brake pressure in at least one first service brake cylinder based on the reserve pressure in the first reserve pressure container, and the second reserve pressure container feeds a second solenoid valve device in order to generate a second service brake pressure in at least one second service brake cylinder based on the reserve pressure in the second reserve pressure container.

[0038] All in all, the redundant parking brake function described above leads to an improvement in the safety of the brake system.

[0039] At least one second sensor may also be provided in the brake system, which directly or indirectly determines or measures the reserve pressure present in at least one reserve pressure container and controls the input of a corresponding reserve pressure signal into the electronic control device for evaluation by the redundant parking brake function. This may be understood to mean, for example, that the reserve pressure present in a common reserve pressure container for at least one service brake circuit and a parking brake circuit is measured by means of a pressure sensor, which then forms the second sensor.

[0040] The redundant parking brake function implemented in the control device can then be constructed such that it controls the first solenoid valve device at least for such a long time / solangly so as to control compressed air from at least one reserve pressure container into the first service brake cylinder and simultaneously or temporally overlappingly controls compressed air from the first service brake cylinder into the pressure reduction part until the redundant parking brake function can determine based on the reserve pressure signal that the reserve pressure in the at least one reserve pressure container is reduced to a pressure that is less than or equal to the compression pressure of the at least one spring accumulator brake cylinder.

[0041] Furthermore, the redundant parking brake function implemented in the control device can be designed such that after the redundant parking brake function determines that the reserve pressure in the reserve pressure container has dropped to a pressure that is less than or equal to the pressure of the at least one spring-accumulator brake cylinder, the redundant parking brake function actuates the second solenoid valve device in order to release the at least one second service brake cylinder. This is because the vehicle is then held in a stationary state by the at least one spring-accumulator brake cylinder with sufficient holding force, so that it is no longer necessary to keep the at least one second service brake cylinder pressed. Alternatively, however, for safety reasons, the at least one second service brake cylinder can also continue to be pressed even if the at least one spring-accumulator brake cylinder is already pressed.

[0042] The redundant parking brake function implemented in the control device can also be designed so that the redundant parking brake function only controls the second solenoid valve device to release the at least one second service brake cylinder when the redundant parking brake function can determine that the vehicle is at a standstill based on the first sensor signal. Therefore, the at least one second service brake cylinder is only released by this measure when it is ensured that the vehicle is actually at a standstill.

[0043] According to another embodiment, the redundant parking brake function implemented in the control device can be constructed so that the redundant parking brake function controls the second solenoid valve device at least for so long or only for so long in order to clamp at least one second service brake cylinder or keep at least one second service brake cylinder in a clamped state until the redundant parking brake function can determine based on the first sensor signal that the vehicle is actually in a stationary state.

[0044] At least one third sensor may also be provided in the brake system, which directly or indirectly determines or measures a second service brake pressure present in at least one second service brake cylinder and controls the input of a corresponding third sensor signal into the electronic control device.

[0045] The redundant parking brake function implemented in the electronic control device can also be designed such that it controls the second solenoid valve device so that the second service brake pressure in the at least one second service brake cylinder is increased at least for such a long time that the second service brake pressure exceeds a minimum value. The minimum value for the second service brake pressure can be predetermined such that, based on the minimum value, a holding force is applied to the vehicle, which holding force at least corresponds to the parking brake force applied to the vehicle via the at least one stressed spring accumulator brake cylinder.

[0046] According to an extended scheme, in a parking brake device, the intake / exhaust solenoid valve combination may include an intake solenoid valve and an exhaust solenoid valve, wherein the intake solenoid valve is connected to at least one reserve pressure container on the one hand and to a pneumatic control input of a relay valve on the other hand, and the exhaust solenoid valve is connected to a pressure reduction unit on the one hand and to a pneumatic control input of a relay valve on the other hand, the working output of the relay valve is connected to at least one spring accumulator brake cylinder, and the reserve input of the relay valve is connected to at least one reserve pressure container.

[0047] Preferably, the intake / exhaust solenoid valve combination of the parking brake device may include at least one 2 / 2-way valve and / or at least one 2 / 3-way valve, and the valve is monostable or bistable.

[0048] According to a preferred embodiment, the second solenoid valve device can include at least one second inlet valve and at least one second outlet valve of the second pressure regulating module or the second channel of the pressure regulating module. Then, the redundant parking brake function implemented in the electronic control device can be configured so that the redundant parking brake function controls the second inlet valve and the second outlet valve to increase or maintain the second service brake pressure in the at least one second service brake cylinder to press the at least one second service brake cylinder or keep the at least one second service brake cylinder in a pressed state.

[0049] Likewise preferably, the first solenoid valve device may include at least one first inlet valve and at least one first exhaust valve of a first pressure regulating module or a first channel of a pressure regulating module, wherein the redundant parking brake function implemented in the electronic control device is constructed so that the redundant parking brake function opens or keeps open the first inlet valve and the first exhaust valve in a temporally overlapping manner in order to compress at least one spring accumulator brake cylinder.

[0050] "Overlapping in time" can mean that the opening times are the same for the first intake valve and the first exhaust valve, respectively, but can also mean that, although the opening times of the first intake valve and the first exhaust valve are different, there is a duration during which both the first intake valve and the first exhaust valve are open.

[0051] This ensures that compressed air is withdrawn from the common reserve pressure container of the parking brake circuit and the at least one service brake circuit via the opened first inlet valve and the first brake cylinder at the at least one first wheel is charged therewith. However, since the first outlet valve of the first solenoid valve device is opened or opened simultaneously or in a staggered manner, the compressed air supplied to the first brake cylinder is discharged into the pressure reduction device in a controlled manner. By means of the temporally overlapping and in particular simultaneous charging and discharging processes of the at least one first service brake cylinder, the reserve pressure in the common reserve pressure container drops, in particular, to the pressure pressure of the at least one spring accumulator brake cylinder.

[0052] As is known, such a pressure regulating module includes, in addition to a backup valve for conducting a redundant control pressure through the pressure regulating module, a combination of an inlet valve and an outlet valve, which then inflates or deflates a relay valve with control pressure air, the relay valve being attached to at least one service brake cylinder at its working output and to at least one reserve pressure container at its reserve input. In addition, such a pressure regulating module includes a pressure sensor, by means of which the actual service brake pressure outputted by the control is determined and adjusted to a target service brake pressure in the sense of brake pressure regulation. The target service brake pressure is represented by a target service brake pressure signal, which is controlled by the electronic service brake control device and input into the integrated control electronics of the pressure regulating module, which then controls the inlet valve and the outlet valve accordingly. Thus, in a single-channel pressure regulating module, for example, one brake pressure is adjusted for one or more service brake cylinders, and in a dual-channel pressure regulating module, two brake pressures are adjusted for at least two service brake cylinders. Thus, two single-channel pressure regulating modules are structurally combined in a two-channel pressure regulating module. The brake system can then be, for example, an EBS (electronically controlled brake system) with a brake pressure regulating device, which also includes at least one driving dynamics control device, such as ABS, ASR and / or ESP.

[0053] The first inlet valve and / or the first exhaust valve and / or the second inlet valve and / or the second exhaust valve can also be formed by a 2 / 2-way valve or a 2 / 3-way valve, which is monostable or bistable. Monostable means that the valve is prestressed into a certain switching position and assumes this certain switching position when the valve is not energized or is de-energized. Bistable means that the valve maintains the position it last assumed, in particular the switching position, when de-energized.

[0054] Alternatively or additionally, the second solenoid valve device can include a holding valve and an exhaust valve of an ABS pressure control valve. The redundant parking brake function implemented in the control device can then be configured so that it closes the holding valve and the exhaust valve or keeps the holding valve and the exhaust valve closed in order to maintain the service brake pressure in the at least one first service brake cylinder. Alternatively or additionally, the first solenoid valve device can also include such a holding valve and an exhaust valve of an ABS pressure control valve.

[0055] Such an ABS pressure control valve usually contains two diaphragm valves, which are controlled by solenoid valves, one of which constitutes a holding valve for pressure maintenance and one of which constitutes an exhaust valve for pressure reduction. If the holding valve is open and the exhaust valve is closed, the brake pressure controlled to be input into the ABS pressure control valve is controlled to be conducted to the service brake cylinder. If the exhaust valve is open and the holding valve is closed, the service brake pressure in the service brake cylinder is reduced. Then, by alternately opening and closing the holding valve and the exhaust valve, the service brake pressure in the first service brake cylinder can be adjusted in the sense of brake slip regulation. In the framework of the redundant parking brake function, the exhaust valve and the holding valve are closed to maintain the first service brake pressure in the first service brake cylinder. Then, the ABS pressure control valve thus has an advantageous dual function in that it is controlled on the one hand in the sense of brake slip regulation and on the other hand in the sense of redundant parking brake function. The ABS pressure control valve can be arranged in the brake pressure line between the pressure regulating module or the foot brake valve or the foot brake module.

[0056] The above-described example—pressure regulating module and ABS pressure control valve—shows that no additional valves are required to realize a redundant parking brake function and that the existing valve arrangement of the service brake system can usually be used.

[0057] The at least one electronic control unit implementing the redundant parking brake function can also be designed as a single electronic control unit or a stand-alone control unit in the sense of a separate structural unit, or the at least one electronic control unit can be distributed over a plurality of electronic control units or can be at least partially integrated into another electronic control unit, for example preferably into an electronic service brake control unit. Preferably, the redundant parking brake function is implemented in an electronic control unit different from the electronic parking brake control unit.

[0058] As described above, two electromagnetic service brake circuits may preferably be provided in the brake system, wherein the first solenoid valve device and the second solenoid valve device may be components of different electromagnetic service brake circuits or also components of a single electromagnetic service brake circuit.

[0059] The invention also relates to a vehicle, in particular a commercial vehicle equipped for trailer operation, which comprises a brake system as described above.

[0060] Therefore, if at least one spring-accumulator brake cylinder is no longer pressed by the parking brake control electronics or the intake / exhaust solenoid valve combination controlled by the parking brake control electronics (for example due to an electronic defect), the electronic control unit is designed so that it presses the at least one spring-accumulator brake cylinder by bleeding at least one service brake circuit, which includes at least one reserve pressure vessel, which also feeds the parking brake circuit.

[0061] Preferably, the bleeding is carried out by controlling at least one service brake circuit of the service brake device by means of an electronic control device, in that, for example, at least one pressure regulating module is controlled by the control device in such a way that the service brake pressure output by the at least one pressure regulating module and measured, for example, by an integrated pressure regulating module reaches or is less than the pressure of the at least one spring accumulator brake cylinder. As a result, the at least one spring accumulator brake cylinder is compressed and the vehicle can be parked in a safe state even if the normal parking brake function no longer functions properly. Another advantage is that no additional components are required for release.

[0062] At least one pressure regulating module can be part of a primary or redundant service brake device. In normal conditions, the primary service brake device is used, and when the primary service brake device fails, the redundant service brake device is used. In addition, at least one pressure regulating module can be controlled by a primary control device of the primary service brake device or by a redundant control device of the redundant service brake device. Defects or faults in the parking brake circuit or in the parking brake function can also be detected by the primary control device or by the redundant control device. The control device can be designed so that it detects defects or faults in the parking brake circuit or in the parking brake function based on sensor signals of at least one sensor, data bus signals and / or based on, for example, a missing CAN communication of the parking brake control electronics.

[0063] The at least one ABS pressure control valve can also be controlled by the electronic control device in such a way that the service brake pressure in the at least one second service brake cylinder is maintained in order to hold the vehicle in a stationary state by the service brake device or by the second service brake circuit. The at least one ABS pressure control valve can then include a second solenoid valve device in the above-mentioned sense.

[0064] The control device can also control at least one ABS pressure control valve in such a way that the holding valve and the venting valve are opened simultaneously or overlapping in time in order to vent at least one reserve pressure vessel, which then also feeds the parking brake circuit, preferably until the service brake pressure at least reaches the application pressure of the at least one spring accumulator brake cylinder. The at least one ABS pressure control valve can then include a second solenoid valve device in the above sense.

[0065] At least one ABS pressure control valve may be part of a primary or redundant service brake system. The primary service brake system is used in normal conditions, and the redundant service brake system is used when the primary service brake system fails. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In the following description, embodiments of the present invention are described in more detail with reference to the accompanying drawings. The accompanying drawings show:

[0067] Figure 1 A brake device according to a preferred embodiment of the present invention is shown;

[0068] Figure 2 Show Figure 1 Fragments in the pressure control module of the brake system and in the parking brake module. DETAILED DESCRIPTION

[0069] exist Figure 1 Schematically shows a preferred embodiment of a brake system 1 of a tractor vehicle equipped for trailer operation, which includes an electropneumatic service brake device and an electropneumatic parking brake device, the electropneumatic service brake device being in the form of an electronic brake pressure regulating service brake system (EBS) in this case, for example. In the present case, the tractor vehicle is configured, for example, for towing a double-axle trailer, which is not shown here, but it can also tow a drawbar trailer or a plurality of drawbar trailers.

[0070] In the case of an electronically controlled brake system (EBS), for example, two single-channel pressure regulating modules 36, 38 are provided on the front axle, wherein one single-channel pressure regulating module respectively regulates the brake pressure in the pneumatic service brake cylinder 59 of a front wheel of the front axle, and a two-channel pressure regulating module 16 is provided on the rear axle, in which in principle the two single-channel pressure regulating modules are combined, each channel of the two single-channel pressure regulating modules regulating the brake pressure in a rear wheel of the rear axle. The design and function of such pressure regulating modules 16, 36, 38 are well known.

[0071] Figure 2 The construction of a channel of a dual-channel pressure regulating module 16 on the rear axle is drawn, which is constructed in the above-described manner and, in addition to a first backup valve not shown here, also includes a first intake valve 108', a first exhaust valve 109', a first relay valve 110', a first pressure sensor 111', an integrated first control electronic device 112', a first reserve attachment end 113', a first working attachment end 115' and a first signal attachment end 116'.

[0072] The first reserve attachment end 113' is connected to the rear axle reserve pressure container 6 via the supply line 10, and the first working attachment end 115' is connected to one of the two second service brake cylinders 50 on the rear axle on each vehicle side. The other channel is constructed as the channel described above, but in which the first working attachment end 115' is connected to the other second service brake cylinder 50 on the other vehicle side of the rear axle. As a result, the service brake pressure can be adjusted independently of each other in the two channels.

[0073] Here, the first relay valve 110' modulates the first actual service brake pressure at the first working connection 115' from the reserve pressure of the rear axle reserve pressure container 6 acting on the first reserve connection 113' according to the first pneumatic control pressure formed by the first solenoid valves 108', 109'. The first pressure sensor 111' is also connected to the first working connection 115', which then measures the first actual service brake pressure output by the relevant channel control of the two-channel pressure control module 16 and controls the input of the corresponding sensor signal into the first control electronics 112', which receives a signal corresponding to the first target service brake pressure from the central EBS brake controller 14 at the first signal connection 116'. Then, with the help of the control algorithm implemented in the integrated first control electronics 112', the first actual service brake pressure is matched to the first target service brake pressure by correspondingly actuating the first inlet valve 108' and the first outlet valve 109'.

[0074] exist Figure 1The single-channel pressure control modules 36, 38 on the front axle are also designed as an example according to Figure 2 , because the structure corresponds to the structure of one channel of the dual-channel pressure regulating module 16. In addition to the second backup valve not shown here, the single-channel pressure regulating module 36 also includes a second intake valve 108, a second exhaust valve 109, a second relay valve 110, a second pressure sensor 111 and an integrated second control electronic device 112, which electrically controls the second intake valve 108 and the second exhaust valve 109, the second intake valve is implemented as a 2 / 2-way solenoid valve, for example, and the second exhaust valve is also implemented as a 2 / 2-way solenoid valve, for example. The second intake valve 108 and the second exhaust valve 109 have a closed position and an open position, respectively, wherein in Figure 2 In the embodiment, the second intake valve 108 is controlled to an open position, and the second exhaust valve 109 is controlled to a closed position.

[0075] The second intake valve 108 is connected on the input side to the second reserve attachment end 113 of the single-channel pressure regulating module 36, which is attached to the front axle reserve pressure container 4 via the supply line 20, and is connected on the output side to the second pneumatic control attachment end 114 of the second relay valve 110, which is attached on the input side to the second reserve attachment end 113 and on the output side to the second working attachment end 115 of the single-channel pressure regulating module 36. The second exhaust valve 109 is connected on the input side to the second pneumatic control attachment end 114 of the second relay valve 110, and is connected on the output side to the second pressure reducing unit 117.

[0076] Here, the second relay valve 110 modulates the actual service brake pressure at the second working connection 115 from the reserve pressure of the front axle reserve pressure container 4 acting on the second reserve connection 113 according to the second control pressure formed by the second solenoid valves 108 and 109. The second pressure sensor 111 is also connected to the second working connection 115, which then measures the second actual service brake pressure output by the single-channel pressure control module 36 and controls the input of the corresponding sensor signal into the second control electronics 112, which receives a signal corresponding to the second target service brake pressure from the central EBS brake controller 14 at the second signal connection 116. Then, with the help of the control algorithm implemented in the integrated second control electronics 112, the second actual service brake pressure is matched to the second target service brake pressure by correspondingly actuating the second inlet valve 108 and the second outlet valve 109.

[0077] If the primary electrical control of the pressure regulating modules 16, 36 and / or 38 respectively fails, the de-energized integrated backup valve is then connected and the corresponding pneumatic control input 114, 114' of the corresponding relay valve 110, 110' is controlled by the pneumatic control pressure of the purely pneumatic front axle or rear axle brake circuit respectively conducted in the control lines 24, 32.

[0078] Furthermore, the electronically controlled brake system (EBS) of the towing vehicle includes a brake slip control system (ABS), the ABS control routine of which is preferably integrated into the central electronic EBS brake controller 14. In addition, in the case of the electronically controlled brake system (EBS), a drive slip control system (ASR) and an electronic stability program (ESP) are preferably present, wherein the control routines associated therewith are preferably also implemented in the central brake controller 14.

[0079] According to the electro-pneumatic brake device 1 of the towing vehicle Figure 1 In the circuit diagram shown in FIG. 1 , there is a foot brake value transmitter or foot brake module 2, a front axle reserve pressure container 4, and a rear axle reserve pressure container 6, the foot brake value transmitter or the foot brake module having a foot brake pedal as a service brake actuating mechanism 3, the front axle reserve pressure container for supplying the front axle service brake circuit, and the rear axle reserve pressure container for supplying the rear axle service brake circuit and the parking brake circuit at the same time. Here, for example, the rear axle reserve pressure container 6 alone constitutes a common reserve pressure container for the rear axle service brake circuit and the parking brake circuit. The air supply device, the air preparation device and the protection device are implemented as required by law by an air preparation module 8, which is not described in more detail here.

[0080] The rear axle reserve pressure container 6 is connected via pneumatic supply lines 10, 12 to the two first reserve attachment ends 113' of the two-channel pressure regulating module 16 for the first service brake cylinder 50 of the rear axle and to the rear axle channel 26 of the foot brake module 2. Similarly, the front axle reserve pressure container 4 is connected via pneumatic supply lines 20, 22 to the second reserve attachment ends 113 of two single-channel pressure regulating modules 36, 38, each of which is assigned to a second service brake cylinder 48 of a front wheel, and to the front axle channel 18 of the foot brake module 2.

[0081] Therefore, the foot brake module 2 includes two pneumatic channels 18, 26, which generate pneumatic standby pressure or control pressure at the output of the channels 18, 26 respectively, depending on the braking request predefined by the driver's foot at the foot brake pedal 3. In parallel with this, the front axle electric channel and the rear axle electric channel are configured in the foot brake module 2 in such a way that they are combined in the electric channel 28, which control the input of the electric brake request signal into the electric connection preferably configured as a data bus 30 between the electric channel 28 of the foot brake module 2 and the central electronic EBS brake controller 14 according to the braking request, and the central electronic EBS brake controller can distinguish between two brake request signals for the front axle and the rear axle, which are different, for example, due to load distribution.

[0082] In addition, the front axle channel 18 and the rear axle channel 26 of the foot brake module 2 are connected to the assigned, not shown, standby attachment ends of the dual-channel pressure regulating module 16 or the single-channel pressure regulating modules 36, 38 via pneumatic control lines 24, 32. In addition, the first and second pneumatic brake lines 40, 42 lead from the two first working attachment ends 115' of the dual-channel pressure regulating module 16 or from the two second working attachment ends 115 of the two single-channel pressure regulating modules 36, 38 to the first and second pneumatic service brake cylinders 48, 50 of the front axle or the rear axle, wheel by wheel.

[0083] The rotation speed sensor 56 reports the wheel rotation speed of the wheels of the dual-axle vehicle to the central brake controller 14 via an electrical signal line 58. Likewise, preferably, each wheel brake is provided with a wear sensor 60, which reports a signal to the central brake controller 14 via an electrical signal line 62 according to the current brake wear.

[0084] Furthermore, a trailer control module 64 is provided, which is supplied with compressed air via the supply line 46 by means of the trailer reserve pressure container 44 on the towing vehicle side and which is pneumatically controlled by the reserve pressure via the control line 52 by means of the pneumatic control pressure of the foot brake module 2, for example, the front axle channel 18. Furthermore, the trailer control module 64 also receives electrical signals from the central brake controller 14 via the electrical control line 54. Finally, the trailer control module 64 is pneumatically actuated by the parking brake module 66 of the parking brake circuit.

[0085] and Figure 2Similarly to the single-channel pressure regulating module 36 of the trailer control module 64, the trailer control module 64 also contains, in addition to the backup solenoid valve for redundant pressure control, an inlet valve, an outlet valve and a relay valve fed with compressed air from the trailer reserve pressure container 44, so that the control pressure for the coupling head "brake" 70 is controlled and output via these solenoid valves and the relay valve according to the control signal brought via the electrical control line 54. Here, the relay valve modulates the control pressure for the coupling head "brake" 70 from the reserve pressure of the trailer reserve pressure container 44 acting on its reserve attachment end according to the control pressure formed by the solenoid valve. With the help of an integrated pressure sensor, this control pressure for the coupling head "brake" 70 is measured and reported to the central brake controller 14. If the primary electrical control device fails, the integrated backup valve is switched on and the relay valve is controlled by the pneumatic control pressure of the front axle brake circuit guided in the control line 52. Finally, the trailer control module 64 circulates compressed air from the trailer reserve pressure container 44 at the reserve pressure acting on the towing vehicle's coupling "reserve" 68. The design and function of such an electropneumatic trailer control module 64 are sufficiently known and therefore do not need to be explained in detail here.

[0086] Preferably, the brake application device of the rear axle is constructed as a known combination cylinder, that is, as a combination (combination cylinder) of an active second service brake cylinder 50 and a passive spring accumulator brake cylinder 94. In this context, "active" means that the second service brake cylinder 50 is pressed when inflated and released when deflated, while "passive" means that the spring accumulator brake cylinder 94 is pressed when deflated and released when inflated. In contrast, only the active first service brake cylinder 48 is provided on the wheels of the front axle. The spring accumulator brake cylinder 94 is a passive brake cylinder and is released by inflating and pressed by deflation.

[0087] The electro-pneumatic two-channel pressure regulating module 16 on the rear axle, which is implemented as a structural unit, has two separately adjustable pressure regulating channels, wherein for each pressure regulating channel, based on the reserve air from the rear axle reserve pressure container 6, according to the service brake request signal generated in the electrical channel 28 of the foot brake module 2 and modified as required in the central brake control, a pressure sensor 111 ′ ( Figure 2 ) measures the regulated working pressure of the second brake cylinder 50 for the rear axle, so as to match the measured actual brake pressure to the first target brake pressure or adjust the measured actual brake pressure according to the brake request signal. Similarly, in each single-channel pressure regulation module 36, 38 of the front axle, the second brake pressure is individually regulated for the two first service brake cylinders 48 of the wheels of the front axle.

[0088] Therefore, in order to construct a pressure regulating channel with a pneumatically separated circuit (for example, here: a front axle pressure regulating channel or a rear axle pressure regulating channel), each pressure regulating channel is assigned its own reserve pressure container 4, 6, wherein the pneumatic flow path of each pressure regulating channel is constructed to be pneumatically separated from the pneumatic flow path of the corresponding other pressure regulating channel, starting from the assigned reserve pressure container 4, 6 via the assigned pressure regulating module 16, 36, 38 to the assigned first and second service brake cylinders 48, 50.

[0089] Particularly preferably, in order to construct an electronic pneumatic service brake device with a primary electrically-actuated pressure regulating channel (front axle pressure regulating channel or rear axle pressure regulating channel), and in order to construct a secondary pneumatic backup level in the event of an electrical system failure, each pressure regulating module 16, 36, 38 is assigned its own purely pneumatic backup circuit, which has its own backup valve for controlling the input of a pneumatic backup pressure derived from the reserve pressure of the reserve pressure container 4, 6 of the corresponding pressure regulating circuit assigned to the rear axle or the front axle and formed by the foot brake module 2, and in the event of an electrical component failure, the pneumatic backup pressure is supplied to the first and second working pressure attachment ends 115', 115( Figure 2 ) forms corresponding braking pressure.

[0090] The brake device 1 of the towing vehicle and the brake device of the trailer are coupled to each other, as is customary in such brake systems, by means of a respective coupling head “reserve” 68 and respectively by means of a coupling head “brake” 70. Since the trailer control module 64 does not have its own electronic control unit, if the trailer has an electropneumatic brake system, electric brake control signals need to be transmitted from the central brake control unit 14 to the trailer via the CAN bus “trailer” 78 and the electronic trailer interface 76. The trailer control module 64 as well as the two-channel pressure regulating module 16 and the two single-channel pressure regulating modules 36, 38 are controlled by the central brake control unit 14 via electrical control lines 54, 88, 90, 92, respectively.

[0091] Instead of a purely pneumatic brake system, the trailer can also be provided with an electro-pneumatic brake system with ABS functionality. In this case, the electrical interface 76 of the towing vehicle is connected to an interface in the trailer that is complementary to the electrical interface via a data connection, such as a cable, which leads to an ABS controller in the trailer so that data can be exchanged. Therefore, brake slip regulation is performed for all axles of the trailer. However, if, as is preferred, the wheel brake slip determination is performed on, for example, only one axle of a double-axle saddle semitrailer by means of a wheel speed sensor, then the brake slip on the other axle that is not provided with a wheel speed sensor is adjusted after the axle with the wheel speed sensor. Then, the disadvantages described at the beginning in terms of brake blocking of the other axle without wheel speed sensing and the lack of lateral guidance of the wheels of the other axle that accompanies this can occur.

[0092] The parking brake module 66 is at least partially configured as Figure 2 The parking brake control electronics 96 is constructed like the pressure regulating module 36 of the electric parking brake actuator 98 and includes an integrated parking brake control electronics 96, which receives a parking brake request signal from the electric parking brake actuator 98, and the parking brake request signal is controlled to be input into the parking brake module 66 via the electric control line 100 via the third signal attachment terminal 116'. Here, the parking brake request signal is generated electrically according to the operation of the parking brake actuator 102. Typically, the parking brake actuator 102 is a rocker, a rocker button or a button, and is usually operated by the driver by hand. The parking brake control electronics 96 communicates with the central EBS brake controller 14 via the data bus 30. In addition to the parking brake control electronics 96, the parking brake module 66 also includes a third inlet valve 108'', a third outlet valve 109'', a third relay valve 110'' and a third pressure sensor 111'', which are pneumatically controlled by the third inlet valve and the third outlet valve at the third control attachment 114''. The third working attachment 115'' of the parking brake module 66 is then connected to the spring accumulator brake cylinder 94 of the rear axle via the pneumatic line 104. Figure 2 The third working attachment end (not shown) pneumatically controls the trailer control module 64 via a further pneumatic line 106. The parking brake circuit does not have its own reserve pressure container, so that the parking brake module 66 is supplied with reserve pressure, for example, from the rear axle reserve pressure container 6 via the third reserve attachment end 113" and the supply line 10. The parking brake module 66 is Figure 2The illustrated configuration is exemplary only. In addition, the parking brake module 66 may have other valves or solenoid valves to implement other functions, such as a test function or an auxiliary brake function. At least one integrated proportional valve and / or at least one holding valve may also be provided in the parking brake module 66.

[0093] The third inlet valve 108" is "normally open", i.e. it switches to the open position due to the spring prestressing when not energized, while the third outlet valve 109"' is "normally closed", i.e. it switches to the closed position due to the spring prestressing when not energized. This has the result that in the event of a fault during control via the integrated parking brake control electronics 96, when, for example, the entire parking brake module 66 is de-energized, the spring accumulator brake cylinder 94 is connected to the rear axle reservoir 6 via the open third inlet valve 108" and is thus charged. This prevents the spring accumulator brake cylinder 94 from being suddenly deflated and then creating a critical situation with regard to driving stability if, for example, a current failure or interference occurs while the vehicle is being driven.

[0094] A parking brake function for normal operation is implemented by software in the parking brake control electronics 96 , and a redundant parking brake function is also implemented by software, for example in the central brake control unit 14 , wherein the parking brake function for normal operation and the redundant parking brake function are described further below.

[0095] Furthermore, a pressure sensor 107 is attached to the supply line 10, via which the third reserve attachment 113″ of the parking brake module 66 is supplied with compressed air from the rear axle reserve pressure container 6, the pressure sensor measuring the pressure in the rear axle reserve pressure container 6 and, for example, controlling the input of a corresponding reserve pressure signal into the central brake controller 14 in order to use the reserve pressure signal, for example, within the framework of a redundant parking brake function implemented there.

[0096] The front axle reserve pressure vessel 4 feeds a front axle service brake circuit, which comprises at least two pressure regulating modules 36, 38 and two second service brake cylinders 48 on the front axle, and the rear axle reserve pressure vessel 6 feeds a rear axle service brake circuit, which comprises at least a two-channel pressure regulating module 16 and two first service brake cylinders 50 on the rear axle. Due to the circuit separation, the front axle reserve pressure vessel 4 is independent of the rear axle reserve pressure vessel 6, which here forms, for example, a common reserve pressure vessel for the parking brake circuit and the rear axle service brake circuit.

[0097] In this context, the operating principle of the braking device 1 is as follows:

[0098] During normal driving braking, the driver operates the brake pedal and thus the foot brake module 2, thereby generating an electric brake request signal in the electrical channel 28 similar to the desired target deceleration or the driver's braking desire and controlling the input of the electric brake request signal into the central brake controller 14. In turn, the central brake controller controls the input of the target brake pressure into the trailer control module 64, the dual-channel pressure regulation module 16 of the rear axle and the two single-channel pressure regulation modules 36 and 38 of the front axle via electrical control lines 54, 88, 90, 92 in accordance with the brake request signal and possibly according to other parameters, such as the corresponding load distribution.

[0099] Here, in the pressure regulating modules 16, 36, 38 and also in the trailer control module 64, the first and second integrated inlet valves 108, 108' and exhaust valves 109, 109' are switched in accordance with the braking request, which valves are respectively designed as 2 / 2-way solenoid valves, for example, so that the valves pneumatically control the first and second integrated relay valves 110, 110', so that the corresponding actual service brake pressure is controlled to be input into the first and second service brake cylinders 48, 50 of the towing vehicle or into the brake cylinders of the trailer via the coupling head "brake" 70 according to the braking request. Then, the first and second pressure sensors 111, 111' ( Figure 2 ) and the pressure sensor integrated in the trailer control module 64 report the actual service brake pressure to the integrated first and second control electronic devices 112, 112' in the pressure regulation modules 16, 36 and 38 or to the integrated control electronic device in the trailer control module 64, and then the integrated control electronic device adjusts the corresponding target brake pressure by controlling the integrated solenoid valve.

[0100] If the brake request signal for the central brake controller 14 is not generated by the foot brake module 2, but by a driver assistance system, such as ESP (Electronic Stability Program) or ACC (Adaptive Cruise Control) or by an autopilot for autonomous driving, the same function is implemented in the manner described above.

[0101] If the brake slip of one or more wheels of the tractor vehicle exceeds a predefined brake slip limit of, for example, 12% to 14%, which can be determined via wheel speed sensors 56, the brake slip control device or ABS of the tractor vehicle responds. In this case, by correspondingly actuating the integrated first and second inlet and outlet valves 108, 108', 109, 109', in the pressure control modules 36, 38 assigned to the wheel in which brake slip respectively occurs or in the pressure control modules 16 assigned to the wheels in which brake slip respectively occurs, the brake pressure for the tractor vehicle is set by the ABS routine implemented in the central brake control unit 14 in such a way that the brake slip control difference is adjusted.

[0102] A compatibility band is stored in the central brake control 14, which defines the ratio between the respectively desired braking value z of the tractor-trailer combination and the braking force of the trailer resulting therefrom or / and the pressure at the coupling head "brake" 70 of the tractor. Optionally, the brake pressure for the brake system of the trailer resulting from the compatibility band can then also be modified by the coupling force control device. The trailer control module 64 is then controlled by the central brake control 14 in order to set the pneumatic control pressure in the coupling head "brake" 70 for the trailer in accordance with these specifications. The brake pressure in the trailer is thus formed in accordance with the brake pressure in the tractor that is influenced by the brake slip control device.

[0103] In summary, the brake pressure of the brake system of the trailer then forms a reference brake pressure for the brake system of the trailer, which in its absolute magnitude depends on the brake request signal or on a predefined target deceleration of the tractor-trailer combination or on a corresponding brake slip control (friction value of the road surface) of the tractor, on the tractor-trailer compatibility band and possibly also on an existing coupling force control. Instead of a reference brake pressure, a reference braking force of the trailer or a reference braking value of the trailer can also be considered, which relates to the same situation as described above.

[0104] If, in normal operation, the parking brake operating mechanism 102 is operated to the position "parking" after the vehicle is braked to a standstill by means of the service brake device within the framework of the parking brake function, the corresponding electric parking brake application signal is input into the parking brake control electronic device 96 via the third signal attachment terminal 116", and the parking brake control electronic device further controls the integrated air inlet / air outlet solenoid valve combination, i.e., the third air inlet valve 108" and the third air outlet valve 109" (such as Figure 2As shown, the third intake valve 108" is controlled to a closed position, and the third exhaust valve 109" is controlled to an open position) in order to deflate the third working attachment end 115" and therefore the pneumatic line 104 and the spring accumulator brake cylinder 94, which are then compressed. The other third working attachment end connected to the pneumatic line 106 is also deflated. Therefore, the pneumatic control attachment end of the trailer control module 64 attached to the pneumatic line 106 is also deflated, wherein the trailer control module 66 then inflates the coupling head "brake" 70 according to its reversal characteristics in order to compress the trailer brake.

[0105] In order to release the parking brake, the parking brake operating mechanism 102 is operated to the position "driving" so that the corresponding parking brake release signal is input into the integrated parking brake control electronic device 96 via the third signal attachment end 116", and the parking brake control electronic device further controls the third inlet valve 108" and the third exhaust valve 109", so as to inflate the third working attachment end 115" and thus the third pneumatic line 104 and the spring accumulator brake cylinder 94 (such as Figure 2 As shown, the third inlet valve 108" is controlled to the open position, and the third exhaust valve 109" is controlled to the closed position), and the spring accumulator brake cylinder is then released. The other third working attachment end connected to the pneumatic line 106 is also inflated. Therefore, the pneumatic control attachment end of the trailer control module 64 attached to the pneumatic line 106 is also inflated, wherein the trailer control module 66 then deflates the coupling head "brake" 70 according to its reversal characteristics in order to release the trailer brake.

[0106] In addition, further functions can be implemented in the parking brake module 66, such as a test function, by means of which it is tested whether a towing vehicle with an applied parking brake is able to hold an unbraked trailer in a stationary state, or an auxiliary braking function, in which the parking brake supports or redundantly replaces the service brake. For this purpose, the parking brake actuator 102 then has a plurality of continuously adjustable positions for the degree of auxiliary braking and a position for the test function.

[0107] For example, the parking brake control electronics 96 integrated into the parking brake module 66 are externally monitored by the central brake controller 14 as to whether at least the parking brake function "parking brake applied" operates properly and without errors in normal operation. This external monitoring is carried out, for example, via the data bus 30, to which both the third signal connection terminal 116" of the parking brake module 66 and the central brake controller 14 are connected.

[0108] Here, if it is determined, for example, by the central brake controller 14 that the parking brake module 66 is unable to perform at least the parking brake function "parking brake applied" because the parking brake control device 96, the current supply to the parking brake module 66, the signal connection within the parking brake module 66 and / or the third inlet valve 108" and / or the third outlet valve 109" have a fault or defect, then the redundant parking brake function comes into play, and the parking brake function "parking brake applied" can then be redundantly implemented with the help of this redundant parking brake function, so that the towing vehicle and, if necessary, a trailer coupled to the towing vehicle can be braked and / or can be safely held in a stationary state.

[0109] It is assumed here that due to a fault or defect, not only the third intake valve 108" but also the third exhaust valve 108" is de-energized or is de-energized. Since, as mentioned above, the third intake valve 108" is "normally open", that is, the third intake valve is switched to the open position due to spring prestress when not energized, and the third exhaust valve 109" is "normally closed", that is, the third exhaust valve is switched to the closed position due to spring prestress when not energized, the spring accumulator brake cylinder 94 is automatically connected to the rear axle reserve pressure container.

[0110] The redundant parking brake function is implemented as software, for example, in the central brake controller 14 , wherein, in order to then achieve independence between the central brake controller 14 and the parking brake control electronics 96 , the central brake controller 14 is preferably supplied with current by a second voltage supply device that is independent of the first voltage supply device of the parking brake control electronics 96 .

[0111] Then, within the framework of a redundant parking brake function, for example, the central brake control unit 14 optionally controls the two single-channel pressure regulating modules 36, 38 on the front axle, thereby braking the second service brake cylinder 48 on the front axle and then braking and / or holding the towing vehicle, if necessary together with the coupled trailer, at a standstill. To this end, the second inlet valve 108 is switched to the open position and the second outlet valve 109 is switched to the closed position, so that compressed air can flow from the front axle reserve pressure container 4 into the second service brake cylinder 48 on the front axle. This control of the two single-channel pressure regulating modules 36, 38 on the front axle is optional and can also be omitted.

[0112] Preferably, simultaneously or after the optional control of the two single-channel pressure regulating modules 36, 38 on the front axle described above, the central brake control 14 controls the two-channel pressure regulating module 16 on the rear axle in such a way that, for example, in each of the two channels, both the first inlet valve 108' and the first outlet valve 109' are opened. This results in compressed air flowing from the rear axle reserve pressure vessel 6 into the first service brake cylinder 50 on the rear wheel, but from there outwardly via the opened first outlet valve 109' into the first pressure reduction 117. Within the framework of a redundant parking brake function, the open switching position of the first outlet valve 109' and the first inlet valve 108' of the two-channel pressure regulating module 16 is maintained by the central brake control 14 in particular for such a long time that the reserve pressure present in the rear axle reserve pressure vessel 6 drops to the compression pressure of the spring accumulator brake cylinder 9 on the rear axle and the spring accumulator brake cylinder 94 is thereby compressed. Since the reserve pressure present in the rear axle reserve pressure container 6 is preferably measured by means of a pressure sensor 107 and is controlled as a corresponding reserve pressure signal to be input into the central brake controller 14, a value for the application pressure of the spring accumulator brake cylinder 94, for example determined by experiments, can then be saved in the memory of the central brake controller 14 and then compared with the current actual value of the reserve pressure provided by the pressure sensor 107.

[0113] The open position of both first inlet valve 108 ′ and first outlet valve 109 ′ of dual-channel pressure control module 16 therefore ensures that rear axle compressed air reservoir 6 , which supplies compressed air to both the rear axle service brake circuit and the parking brake circuit, is vented over time.

[0114] The bleeding of the rear axle pressure air reservoir 6 then also ensures that the other third working attachment end of the parking brake module 66, which is also attached to the rear axle pressure air reservoir and is connected to the pneumatic line 106, is also bleeding. Thus, the pneumatic control attachment end of the trailer control module 64, which is attached to the pneumatic line 106, is also bleeding, wherein the trailer control module 66 then charges the coupling head "brake" 70 according to its reversing characteristic in order to apply the trailer brake.

[0115] Preferably, the supply of compressed air to the rear axle reserve pressure container 6 by a compressor of the brake system 1 driven by the drive engine is prevented in that, for example, the central brake controller 14 is designed so that it activates, starts using or implements the redundant parking brake function only when the ignition switch of the drive engine is turned off.

[0116] As in the normal case of a parking brake function, the pressed spring-accumulator brake cylinder 94 of the towing vehicle and the pressed brake cylinder of a possibly coupled trailer then generate sufficient holding force to hold the towing vehicle, possibly with the coupled trailer, at a standstill.

[0117] However, if the first vent valve 109' of the two-channel pressure regulating module 16 remains switched to the open position, then with the release of the rear axle reserve pressure vessel 6, not only the spring accumulator brake cylinder 94 of the towing vehicle and possibly the brake cylinder of the trailer are compressed, but also the first service brake cylinder 50 on the rear axle is released. The braking effect exerted by the first service brake cylinder 50 on the rear axle is then reduced, but this does not lead to an impairment of safety, because the necessary holding force is applied by the compressed spring accumulator brake cylinder 96 within the framework of the redundant parking brake function.

[0118] Then, it is preferably no longer necessary to keep the second service brake cylinder 48 on the front axle pressed, so that the central brake control 14 closes the second inlet valve 108 and opens the second outlet valve 109 in each of the two single-channel pressure control modules 36, 38 on the front wheels within the scope of the redundant parking brake function, in order to release the second service brake cylinder 48 on the front axle. Preferably, this measure can only be performed if the central brake control 14 determines within the scope of the redundant parking brake function based on the wheel speed signal input by the speed sensor 56 that the towing vehicle with a possibly coupled trailer is at a standstill.

[0119] Furthermore, within the framework of a redundant parking brake function, it can be provided that a second pressure sensor 111 integrated into the single-channel pressure regulating module 36, 38 measures the service brake pressure present in the (still initially) pressed second service brake cylinder 48 of the front wheel and controls the input of a corresponding service brake pressure sensor signal into the central brake control 14. The central brake control 14 can then, for example, open or keep open the second inlet valve 108 of the single-channel pressure regulating module 36, 38 on the front axle and close or keep closed the second outlet valve 109 until it can determine from the service brake pressure sensor signal that the service brake pressure controlled into the second service brake cylinder 48 of the front wheel exceeds a minimum value in each case. Here, the minimum value for the service brake pressure can be predetermined in each case so that, based on the minimum value for the service brake pressure, a holding force is applied to the towing vehicle and to a possibly coupled trailer, which holding force at least corresponds to the parking brake force, which is applied via the pressed spring accumulator brake cylinder 94 and possibly via the pressed brake cylinder of the trailer.

[0120] In addition to or as an alternative to the pressure regulating modules 16, 36 and 38, the brake system 1 may include at least one ABS pressure control valve (not shown here), which is usually used for brake slip control (ABS control). Such an ABS pressure control valve usually contains two diaphragm valves, which are controlled by solenoid valves, one of which forms a holding valve for pressure holding and one of which forms an exhaust valve for pressure reduction. If the holding valve is open and the exhaust valve is closed, the brake pressure controlled to be input into the ABS pressure control valve is controlled to be conducted to the service brake cylinder. If the exhaust valve is open and the holding valve is closed, the service brake pressure in the service brake cylinder is reduced. Then, by alternately opening and closing the holding valve and the exhaust valve, the service brake pressure in the service brake cylinder is adjusted in the sense of brake slip control. Then, one such ABS pressure control valve can be arranged in the brake line 40 on the front axle and / or in the brake line 42 on the rear axle in order to perform wheel-by-wheel ABS control.

[0121] Then, within the framework of a redundant parking brake function, the ABS pressure control valve can be controlled, for example by the central brake controller 14, so that if the service brake device has been operated by the driver or automatically, then the holding valve and the exhaust valve are closed at the ABS pressure control valve on the front axle, for example, so that the first service brake pressure in the second service brake cylinder 48 of the front axle is maintained and the second service brake cylinder 48 remains pressed.

[0122] The above-described example—pressure regulating module and ABS pressure control valve—shows that no additional valves are required to realize a redundant parking brake function and that existing valves of the service brake system can usually be used.

[0123] The control device that implements the redundant parking brake function can also be designed as an independently operated control device, or it can be distributed over multiple control devices or can be at least partially integrated in another control device, for example in the central brake controller 15. Preferably, the redundant parking brake function is implemented in a control device that is different from the electronic parking brake control electronics 96.

[0124] Reference numerals list

[0125] 1 Braking equipment

[0126] 2-foot brake module

[0127] 3 Service brake operating mechanism

[0128] 4 Front axle reserve pressure vessel

[0129] 6 Rear axle reserve pressure vessel

[0130] 8 Air preparation module

[0131] 10 Supply lines

[0132] 12 Supply lines

[0133] 14 Central brake controller

[0134] 16 Dual channel pressure regulator module

[0135] 18 Front axle tunnel

[0136] 20 Supply lines

[0137] 22 Supply lines

[0138] 24 Control lines

[0139] 26 Rear axle channel

[0140] 28 electrical channels

[0141] 30 Data bus

[0142] 32 Control lines

[0143] 36 First pressure regulating module

[0144] 38 First pressure regulating module

[0145] 40 Pneumatic brake circuit

[0146] 42 Pneumatic brake circuit

[0147] 44 Trailer Reserve Pressure Vessel

[0148] 46 Supply lines

[0149] 48 First service brake cylinder

[0150] 50 Second service brake cylinder

[0151] 52 Control Line

[0152] 54 Electric control circuit

[0153] 56 Speed ​​sensor

[0154] 58 Electrical signal lines

[0155] 60 Wear sensor

[0156] 62 Electrical signal lines

[0157] 64 Trailer Control Module

[0158] 66 Parking brake module

[0159] 68 Connector "Reservoir"

[0160] 70 Coupling "Brake"

[0161] 76 Trailer interface

[0162] 78 Trailer data bus

[0163] 88 Electric control circuit

[0164] 90 Electric control circuit

[0165] 92 Electric control circuit

[0166] 94 Spring accumulator brake cylinder

[0167] 96 Parking brake control electronics

[0168] 98 Parking brake control device

[0169] 100 Electric control circuit

[0170] 102 Parking brake operating mechanism

[0171] 104 Pneumatic lines

[0172] 106 Pneumatic lines

[0173] 107 Pressure Sensor

[0174] 108, 108', 108" 1st, 2nd, 3rd intake valve

[0175] 109, 109', 109" 1st, 2nd, 3rd exhaust valve

[0176] 110, 110', 110" 1st, 2nd, 3rd relay valve

[0177] 111, 111', 111" First, second, third pressure sensors

[0178] 112, 112' first and second control electronic devices

[0179] 113, 113', 113" 1st, 2nd, 3rd reserve attachment end

[0180] 114, 114', 114" First, second, third control attachment end

[0181] 115, 115', 115" 1st, 2nd, 3rd working attachment end

[0182] 116, 116', 116" First, second, third signal attachment terminals

[0183] 117, 117', 117" are the first, second and third pressure reducing parts.

Claims

1. A braking system (1) for a vehicle, the braking system comprising an electropneumatic parking brake, an electropneumatic service brake and a redundant parking brake function implemented in at least one control device, the electropneumatic parking brake having a parking brake function, the electropneumatic service brake having at least one electropneumatic service brake circuit, in particular when the parking brake function fails, the redundant parking brake function is implemented, wherein: By means of the parking brake function and the redundant parking brake function, a holding force for holding the vehicle in a stationary state can be generated in each case, wherein: a) The electropneumatic service brake device comprises at least one first service brake cylinder (50) assigned to a first wheel of the vehicle, at least one electronic service brake control device (14), at least one reserve pressure container (4, 6) and a first solenoid valve device (16), the first solenoid valve device being controllable by the at least one electronic service brake control device (14) and by the redundant parking brake function, wherein: b) the first solenoid valve device (16) is designed and arranged to control compressed air from the at least one reserve pressure container (6) into the at least one first service brake cylinder (50) and to control compressed air from the at least one first service brake cylinder (50) into the pressure reduction unit simultaneously or overlapping in time, and wherein: c) The parking brake device comprises an electro-pneumatic parking brake circuit, which is supplied with compressed air only by the at least one reserve pressure container (4, 6), the parking brake circuit has at least one pneumatically controlled spring accumulator brake cylinder (94), an electronic parking brake control device (96) and an intake / exhaust solenoid valve combination (108", 109") controlled by the electronic parking brake control device (96), the intake / exhaust solenoid valve combination being used at least for charging and discharging the at least one spring accumulator brake cylinder (94), the intake / exhaust solenoid valve combination being designed such that the intake / exhaust solenoid valve combination connects the at least one spring accumulator brake cylinder (94) to the at least one reserve pressure container (4, 6) in a non-energized state, and wherein d) The redundant parking brake function is constructed so that, at least when a fault or defect in the parking brake circuit is detected, which leads to a non-energized state of the intake / exhaust solenoid valve combination (108", 109"), the redundant parking brake function controls the first solenoid valve device (16) in a pressure reduction mode in order to control compressed air from the at least one reserve pressure container (4, 6) into the first service brake cylinder (50) and simultaneously or overlapping in time to control compressed air from the first service brake cylinder (50) into the pressure reduction section.

2. The brake device according to claim 1, characterized in that At least one first sensor (56) is provided, by which it is possible to determine whether the vehicle is in a stationary state and whether the first sensor (56) controls the input of a first sensor signal representing the stationary state of the vehicle into the at least one control device for analysis by the redundant parking brake function, wherein the redundant parking brake function is designed so that when the redundant parking brake function additionally recognizes the stationary state of the vehicle based on the first sensor signal, the redundant parking brake function controls the second solenoid valve device (16) in the sense of the pressure reduction mode.

3. The brake system according to claim 1 or 2, characterized in that: At least one second sensor (107) is provided, which directly or indirectly determines or measures the reserve pressure present in the at least one reserve pressure container (4, 6) and controls the input of a corresponding reserve pressure signal into the at least one control device for evaluation by the redundant parking brake function.

4. The brake device according to claim 3, characterized in that The redundant parking brake function is designed such that it controls the first solenoid valve device (16) at least for such a long time that compressed air is controlled from the at least one reserve pressure container (4, 6) into the second service brake cylinder (50) and simultaneously or overlappingly controls compressed air from the second service brake cylinder (50) into the pressure reduction unit until the redundant parking brake function can determine based on the reserve pressure signal that the reserve pressure in the at least one reserve pressure container (4, 6) is reduced to a pressure that is less than or equal to the application pressure of the at least one spring accumulator brake cylinder (94).

5. The brake system according to any one of the preceding claims, characterized in that The electro-pneumatic service brake device comprises at least one second service brake cylinder (48) assigned to a second wheel of the vehicle and a second solenoid valve device (36, 38), the second solenoid valve device being controlled by the at least one electronic service brake control device (14), wherein the second solenoid valve device (36, 38) is designed so that a second service brake pressure in the at least one second service brake cylinder (48) can be maintained, increased or reduced by means of the second solenoid valve device (36, 38).

6. The brake device according to claim 5, characterized in that The second solenoid valve device (36, 38) can be controlled by the redundant parking brake function, and the redundant parking brake function is designed so that the redundant parking brake function is activated at least when a fault or defect in the parking brake circuit is detected, which leads to a non-energized state of the intake / exhaust solenoid valve combination (108", 109"). a) actuating the second solenoid valve device (36, 38) in order to apply the at least one second service brake cylinder (48) or to keep the at least one second service brake cylinder in a applied state, and simultaneously or thereafter, b) actuating the first solenoid valve device (16) in the sense of the pressure reduction mode.

7. The brake system according to any one of claims 5 or 6, characterized in that: The second solenoid valve device (36, 38) comprises at least one second intake valve (108) and at least one second exhaust valve (109) of at least one second pressure regulating module (36, 38).

8. The brake device according to claim 7, characterized in that The redundant parking brake function implemented in the at least one control device is designed so that the redundant parking brake function controls the second inlet valve (108) and the second outlet valve (109) in order to increase or maintain a second service brake pressure in the at least one second service brake cylinder (48) in order to press the at least one second service brake cylinder (48) or to maintain the at least one second service brake cylinder in a pressed state.

9. The brake system according to claim 7 or 8, characterized in that: The second intake valve (108) and / or the second exhaust valve (109) include a 2 / 2-way valve and / or a 2 / 3-way valve, and the 2 / 2-way valve and / or the 2 / 3-way valve are monostable or bistable.

10. The brake system according to any one of claims 5 to 9, characterized in that The second solenoid valve device includes a holding valve and an exhaust valve of an ABS pressure control valve.

11. The brake device according to claim 10, characterized in that The redundant parking brake function implemented in the control device is designed such that it closes the holding valve and the exhaust valve or keeps them closed in order to maintain a second service brake pressure in the at least one second service brake cylinder (48).

12. The brake system according to claim 3 and any one of claims 5 to 11, characterized in that The redundant parking brake function implemented in the at least one control device is designed so that after the redundant parking brake function determines based on the reserve pressure signal that the reserve pressure in the at least one reserve pressure container (4, 6) has decreased to a pressure that is less than or equal to the pressure of the at least one spring accumulator brake cylinder (94), the redundant parking brake function controls the second solenoid valve device (36, 38) to release the at least one second service brake cylinder (48).

13. The brake system according to claim 2 and any one of claims 5 to 12, characterized in that The redundant parking brake function implemented in the control device is designed so that the redundant parking brake function only activates the second solenoid valve device (36, 38) to release the at least one second service brake cylinder (48) when the redundant parking brake function can determine that the vehicle is stationary based on the first sensor signal.

14. The brake system according to claim 2 and any one of claims 5 to 13, characterized in that The redundant parking brake function implemented in the at least one control device is designed so that the redundant parking brake function controls the second solenoid valve device (36, 38) at least for so long or only for so long as to apply pressure to the at least one second service brake cylinder (48) or to keep the at least one second service brake cylinder in a applied state until the redundant parking brake function can determine based on the first sensor signal that the vehicle is actually at a standstill.

15. The brake system according to any one of claims 5 to 14, characterized in that At least one third sensor (111) is provided, which directly or indirectly determines or measures a second service brake pressure present in the at least one second service brake cylinder (48) and controls the input of a corresponding third sensor signal into the at least one control device.

16. The brake device according to claim 15, characterized in that The redundant parking brake function implemented in the control device is designed so that the redundant parking brake function controls the second solenoid valve device (36, 38) so that the second service brake pressure in the at least one second service brake cylinder (48) is increased at least for a long time until the redundant parking brake function can determine that the second service brake pressure exceeds a minimum value based on the third sensor signal.

17. The brake device according to claim 16, characterized in that A minimum value for the second service brake pressure is predetermined such that, based on the minimum value, a holding force is applied to the vehicle which at least corresponds to a parking brake force which is applied to the vehicle by means of the at least one spring-accumulator brake cylinder (94) being pressed.

18. Braking system according to any one of the preceding claims, characterized in that The intake / exhaust solenoid valve combination (108", 109") comprises an intake solenoid valve (108") and an exhaust solenoid valve (109"), wherein the intake solenoid valve (108") is connected to the at least one reserve pressure container (4, 6) on the one hand and to the pneumatic control input (114") of the relay valve (110") on the other hand, and the exhaust solenoid valve (109") is connected to the pressure reducing unit (117") on the one hand and to the pneumatic control input (114") of the relay valve (110") on the other hand, the working output of the relay valve is connected to the at least one spring accumulator brake cylinder (94), and the reserve input (113") of the relay valve is connected to the at least one reserve pressure container (6).

19. The brake device according to claim 18, characterized in that The air intake solenoid valve (108") and / or the air exhaust solenoid valve (109") include a 2-position 2-way valve and / or a 2-position 3-way valve, and the 2-position 2-way valve and / or the 2-position 3-way valve are monostable or bistable.

20. The brake system according to any one of the preceding claims, characterized in that The first solenoid valve device (16) comprises at least one first inlet valve (109') and at least one first outlet valve (108') of a first pressure regulating module, wherein a redundant parking brake function implemented in the at least one control device is configured such that the redundant parking brake function opens or keeps open the first inlet valve (108') and the first outlet valve (109') in a temporally overlapping manner in order to reduce the reserve pressure in the at least one reserve pressure container (4, 6) and thereby compress the at least one spring accumulator brake cylinder (94).

21. The brake device according to claim 20, characterized in that The first intake valve (108') and / or the first exhaust valve (109') include a 2 / 2-way valve and / or a 2 / 3-way valve, and the 2 / 2-way valve and / or the 2 / 3-way valve are monostable or bistable.

22. The brake system according to any one of the preceding claims, characterized in that The first solenoid valve device comprises a holding valve and a vent valve of an ABS pressure control valve, wherein a redundant parking brake function implemented in the at least one control device is configured such that the redundant parking brake function opens or keeps the holding valve and the vent valve open in a temporally overlapping manner in order to reduce the reserve pressure in the at least one reserve pressure container (4, 6) and thereby compress the at least one spring accumulator brake cylinder (94).

23. The brake system according to any one of the preceding claims, characterized in that The at least one control device implementing the redundant parking brake function is the only control device or is distributed over a plurality of control devices or is at least partially integrated in another control device, such as, in particular, the electronic service brake control device (14).

24. The brake system according to any one of the preceding claims, characterized in that At least two electromagnetic service brake circuits are provided, each of which has a reserve pressure container (4, 6), and the first solenoid valve device (16) and the second solenoid valve device (36, 38) are components of different electromagnetic service brake circuits or components of a single electromagnetic service brake circuit.

25. A vehicle having a brake system according to any one of the preceding claims.

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