Electropneumatic parking brake device with emergency brake function

Abstract

The invention relates to an electropneumatic parking brake device (1) comprising an electropneumatic parking brake valve unit (2), said parking brake valve unit (2) being designed to provide a parking brake pressure (pFS) at at least one working connection (8), and an electropneumatic parking brake redundancy unit (10). A redundancy supply connection (16) of the parking brake redundancy unit (10) is connected to the working connection (8) of the electropneumatic parking brake valve unit (2), and the electropneumatic parking brake redundancy unit (10) has at least one operating position (20) and at least one ventilation position (22), wherein the electropneumatic parking brake redundancy unit (10) can be actuated by at least one first control unit (36) in order to be switched from the ventilation position (22) to the operating position (20), and the electropneumatic parking brake redundancy unit (10) is designed to be switched to the ventilation position (22) in order to provide an emergency brake function (50).

Description

[0001] Electropneumatic parking brake system with emergency braking function

[0002] The invention relates to an electropneumatic parking brake device for pressurizing and venting one or more spring-loaded brake cylinders of an at least partially electronically controllable pneumatic braking system for a vehicle, comprising an electropneumatic parking brake valve unit with a supply connection for receiving supply pressure from a compressed air supply, and a parking brake control unit, wherein the parking brake valve unit is configured to control a parking pressure at at least one working connection depending on a parking brake signal. The invention further relates to an electronically controllable pneumatic braking system and a vehicle comprising such a braking system.

[0003] Modern commercial vehicles often feature an electronically controlled pneumatic braking system. The braking system typically includes spring-loaded parking brakes, also known as parking brakes. These parking brakes operate under spring force and can be released or engaged by applying a parking pressure to the spring-loaded brake cylinders. The parking brake is typically used to secure a commercial vehicle when stationary.

[0004] To regulate service brake pressure, valves within a service brake system are electronically controlled. The valves can be located in so-called axle modulators or outside of them. The axle modulators can be automated or semi-automated and / or electronically controlled by an autonomous unit. The parking brakes are also electronically controlled. For example, the actuation of a solenoid valve can control the pressurization or venting of the spring brake cylinders. The spring brake cylinders can be combined with service brake cylinders so that the spring brake and service brake act on the same brake pistons. Suitable design measures can be taken to prevent mechanical overloading of the brake pistons due to the addition of braking forces from the service brakes and the spring brakes.If the service brakes are applied while the parking brakes are engaged, the spring-loaded brake cylinders are simultaneously ventilated to prevent the braking forces from accumulating. This function is also known as the "anti-compound function."

[0005] Safety concepts are highly relevant for electropneumatic braking systems in modern vehicles. Particularly in vehicles with automated or partially automated driving functions, braking functions must remain available, at least to a limited extent, even in the event of a fault or power failure of a control unit. This is the only way to guarantee the safety of the vehicle, its occupants, and other road users. For this purpose, it is known to provide redundancy levels that can still provide at least a limited braking function even in the event of a primary system failure. One way to increase reliability is to make the service braking system at least partially redundant. The parking brake can also be used to decelerate the vehicle in emergencies.For example, if the service brake system fails, the vehicle's spring brake cylinders can be vented to brake the vehicle.

[0006] Partially redundant systems and methods that provide redundancy are part of the state of the art in various forms. For example, DE 10 2021 122 497 A1 discloses a method for operating an electropneumatic braking system for a vehicle, wherein the braking system comprises a service braking system and a parking braking system, wherein the parking braking system comprises at least one spring-loaded brake cylinder.The method is characterized by the following steps: providing a control signal for maintaining a spring-loaded brake pressure that vents the at least one spring-loaded brake cylinder by a control unit; interrupting the provision of the control signal in the event of a fault and / or a power failure and / or a diagnostic event of the control unit, thereby automatically terminating the maintenance of the spring-loaded brake pressure to vent the at least one spring-loaded brake cylinder; thereby triggering a spring-loaded brake failure of the vehicle by the parking brake system, wherein the venting of the spring-loaded brake pressure is performed by a service brake venting function of the service brake system. The service brake venting function enables at least one venting path, in particular one that is open continuously or intermittently, in the service brake system for venting the at least one spring-loaded brake cylinder.The service brake venting function is implemented in particular by a valve in the service brake system, preferably an outlet valve and / or another outlet valve.

[0007] Further partially redundant systems are known from DE 102022 101 142 A1 , DE 10 2021 122498 A1 , DE 102021 122 499 A1 , DE 10 2020 132 875 A1 and EP 3 145 769 B1.

[0008] Even though existing systems already provide a partially redundant option for engaging or releasing a parking brake, there is a need for options for implementing an emergency braking function. In particular, with the aforementioned known options, emergency braking of the vehicle may not be possible or may only be possible to a limited extent if one or more technical systems fail.

[0009] It is therefore desirable to improve the provision of an emergency braking function. In particular, this should be achieved with little or no disruption to normal operation.

[0010] This is where the invention comes in, the object of which is to provide an improved electropneumatic parking brake device which allows the provision of an emergency braking function.

[0011] In a first aspect, the invention solves this problem with an electropneumatic parking brake device according to claim 1. Starting from an electropneumatic parking brake device of the type mentioned above, an electropneumatic parking brake redundancy unit is further provided with a redundancy supply connection, a spring-loaded connection for at least indirect connection to a spring-loaded brake cylinder, and at least one redundancy vent. The redundancy supply connection of the parking brake redundancy unit is connected to the working connection of the electropneumatic parking brake valve unit to receive the parking pressure. The electropneumatic parking brake redundancy unit has at least one operating position in which the redundancy supply connection is connected to the spring-loaded connection, and at least one venting position in which the spring-loaded connection is connected to the at least one redundancy vent.The electropneumatic parking brake redundancy unit can be controlled by at least one first control unit to switch from the venting position to the operating position, wherein the electropneumatic parking brake redundancy unit is designed to connect the spring-loaded brake connection to the redundancy venting independently of the electropneumatic parking brake valve unit for venting a spring-loaded brake cylinder connected to the spring-loaded brake connection in order to provide an emergency braking function.

[0012] In known parking brake systems, the working port of an electropneumatic parking brake valve unit is directly connected to a spring brake cylinder in order to pressurize the spring brake cylinder with the parking pressure applied at the working port. Known parking brake valve units are typically electrically switchable to either pressurize or vent the spring brake cylinder depending on the situation. A problem with known systems is that the parking brake valve unit may not be able to provide this functionality in the event of a fault. This is where the invention comes in by additionally providing the electropneumatic parking brake redundancy unit. The redundancy supply port of the electropneumatic parking brake redundancy unit is connected to the working port of the electropneumatic parking brake valve unit and can thus receive the parking pressure applied at the working port.The spring-loaded connection of the electropneumatic parking brake redundancy unit can be connected at least indirectly to a spring-loaded brake cylinder. A direct connection is established without the interposition of additional functional units between the spring-loaded connection and the spring-loaded brake cylinder, whereas an indirect connection can comprise additional functional units, such as valves in particular. A direct connection can, however, comprise lines, for example. In the electropneumatic parking brake device according to the invention, the electropneumatic parking brake redundancy unit is therefore also provided between the electropneumatic parking brake valve unit and the spring-loaded connection, which is provided for connection to at least one spring-loaded brake cylinder. The electropneumatic parking brake redundancy unit comprises at least one operating position and one venting position.In the operating position, the redundancy supply connection is connected to the spring-loaded connection. The parking pressure controlled by the electropneumatic parking brake valve unit and the parking pressure applied to the redundancy supply connection can thus be passed through to the spring-loaded connection when the electropneumatic parking brake redundancy unit is in the operating position. Preferably, the electropneumatic parking brake redundancy unit is designed to pass the parking pressure, essentially unchanged, to the spring-loaded connection in the operating position. This is preferably the case when the electropneumatic parking brake redundancy unit is designed to apply a pressure at the spring-loaded connection that has a value corresponding to 90% or more, preferably 95% or more, of the parking pressure.Preferably, a minimum flow cross-section of the electropneumatic parking brake redundancy unit in the operating position between the redundancy supply connection and the spring-loaded brake connection is greater than or equal to the flow cross-section of the working connection. In the venting position, the spring-loaded brake connection is connected to at least one redundancy vent of the electropneumatic parking brake redundancy unit. In the venting position, the electropneumatic parking brake redundancy unit can therefore vent a spring-loaded brake cylinder connected to the spring-loaded brake connection.

[0013] The electropneumatic parking brake redundancy unit is configured to switch to the venting position independently of the electropneumatic parking brake valve unit to provide an emergency braking function, in order to vent a spring-loaded brake cylinder connected to the spring-loaded brake connection via the redundancy venting. The electropneumatic parking brake redundancy unit is preferably configured to switch to the venting position passively to provide the emergency braking function, i.e., without providing a corresponding emergency braking signal for the electropneumatic parking brake redundancy unit.Because the electropneumatic parking brake redundancy unit can provide the emergency braking function independently of the electropneumatic parking brake valve unit, venting a spring-loaded brake cylinder connected to the spring-loaded brake port is also possible if the parking brake control unit fails. The parking brake can then be used particularly reliably to provide emergency braking, increasing safety.

[0014] In a first preferred development of the electropneumatic parking brake device, the electropneumatic parking brake redundancy unit is designed to provide the emergency braking function if the first control unit exhibits a fault. This achieves additional fault tolerance, since the emergency braking function can be provided even without a functional first control unit. The electropneumatic parking brake redundancy unit is preferably designed to assume the venting position when de-energized. In other words, the electropneumatic parking brake redundancy unit is preferably preloaded into the venting position.

[0015] The electropneumatic parking brake redundancy unit preferably has at least one first electrically switchable redundancy valve, which, in a first redundancy valve operating position, releases the redundancy supply connection to the first working path connecting the spring-loaded connection, so that the electropneumatic parking brake redundancy unit is in the operating position. Preferably, the first electrically switchable redundancy valve, in a first redundancy valve venting position, connects the spring-loaded connection to a redundancy vent, so that the electropneumatic parking brake redundancy unit is in the venting position. Preferably, the first electrically switchable redundancy valve can be controlled by the first control unit to switch from the first redundancy valve venting position to the first redundancy valve operating position.The electropneumatic parking brake redundancy unit can thus be switched to the working position by switching the first electrically switchable redundancy valve to the first redundancy valve operating position. However, it can also be provided that at least one further valve must be switched to switch the electropneumatic parking brake redundancy unit to the operating position. The electropneumatic parking brake redundancy unit can therefore also be designed such that switching the first electrically switchable redundancy valve to the redundancy valve operating position is a partial prerequisite for moving the electropneumatic parking brake redundancy unit to the operating position.In variants, it can also be provided that the electropneumatic parking brake redundancy unit can be brought into the operating position and / or the venting position by switching at least one valve different from the first electrically switchable redundancy valve. For example, the electropneumatic parking brake redundancy unit can have multiple paths. The first electrically switchable valve can then be arranged, for example, in a first path, wherein a connection between the redundancy supply connection and the spring-loaded connection can then preferably also be established via an alternative second path.

[0016] In a preferred development, the electropneumatic parking brake redundancy unit further comprises a second electrically switchable redundancy valve, which, in a second redundancy valve operating position, releases the redundancy supply connection to the second working path connecting the spring-loaded connection, so that the electropneumatic parking brake redundancy unit is in the operating position. Preferably, the second electrically switchable redundancy valve can also comprise a second redundancy valve venting position, in which it connects the spring-loaded connection to a redundancy vent, so that the electropneumatic parking brake redundancy unit is in the venting position. The second electrically switchable redundancy valve can be designed essentially analogously to the first electrically switchable redundancy valve.In particular, it can also be provided that switching the second electrically switchable redundancy valve into the redundancy valve operating position is only a partial condition for switching the electropneumatic parking brake redundancy unit into the operating position and / or that switching the second electrically switchable redundancy valve into the redundancy venting position is only a partial condition for switching the electropneumatic parking brake redundancy unit into the venting position. For example, the first electrically switchable redundancy valve and the second electrically switchable redundancy valve can be connected in series, wherein the electropneumatic parking brake redundancy unit is in the operating position if the first electrically switchable redundancy valve is in the first redundancy valve operating position and the second electrically switchable redundancy valve is in the second redundancy valve operating position.The first work path and the second work path can therefore also be sections of a common work path.

[0017] Preferably, however, the first electrically switchable redundancy valve and the second electrically switchable redundancy valve are arranged in parallel paths of the electropneumatic parking brake redundancy unit. Particularly preferably, the first working path and the second working path of the electropneumatic parking brake redundancy unit are parallel working paths. The first working path and the second working path are then preferably parallel working paths, each forming at least partial sections of a compressed air path between the redundancy supply connection and the spring-loaded connection. It should be understood that the first working path and the second working path can be connected to the same redundancy supply connection. In alternative embodiments, however, each working path can also be connected to its own redundancy supply connection or to multiple redundancy supply connections.Furthermore, the working path and the second working path can be connected to the same spring-loaded connection or to different spring-loaded connections.

[0018] In a further development of the variant with a parallel first working path and a second working path, the first working path and the second working path are connected via a selector valve, preferably adjacent to the spring-loaded connection. Working paths connected adjacent to the spring-loaded connection are connected to one another in particular at sections that are directly connected to the spring-loaded connection, in particular are not separated from the spring-loaded connection by switchable valves. The selector valve is preferably designed to connect the working path from the first working path and the second working path that carries a higher pressure to the spring-loaded connection. The selector valve is therefore preferably designed as a so-called "select-high valve."

[0019] Preferably, the electropneumatic parking brake redundancy unit can be controlled by a second control unit to switch from the venting position to the operating position. The electropneumatic parking brake redundancy unit can then be controlled by the first control unit and the second control unit to switch from the venting position to the operating position. Preferably, the electropneumatic parking brake redundancy unit can then be switched from the venting position to the operating position if it is controlled simultaneously by the first control unit and the second control unit. In other embodiments, in particular in embodiments with a parallel first operating path and a second operating path, it can also be provided that the electropneumatic parking brake redundancy unit can be switched from the venting position to the operating position by the first control unit alone and / or by the second control unit alone.

[0020] Preferably, the second electrically switchable redundancy valve can be controlled by the second control unit to switch from the second redundancy valve venting position to the second redundancy valve operating position.

[0021] Preferably, the first electrically switchable redundancy valve can be controlled by the first control unit to switch from the first redundancy valve venting position to the first redundancy valve operating position. For example, and preferably, the first control unit can be provided to control the first working path, and the second control unit can be provided to control the second working path.

[0022] In a preferred embodiment, the electropneumatic parking brake redundancy unit is designed to provide the emergency braking function if the first control unit has a fault or if the second control unit has a fault. Alternatively or additionally, the electropneumatic parking brake redundancy unit can be designed to provide the emergency braking function if the first control unit and the second control unit have a fault. In the event of a fault in the first control unit and / or the second control unit, the electropneumatic parking brake redundancy unit can provide the emergency braking function or switch to the venting position, thus connecting the spring-loaded connection to at least one redundancy vent.

[0023] The electropneumatic parking brake valve unit and the electropneumatic parking brake redundancy unit are preferably connected in series along a parking compressed air path. The parking compressed air path is preferably provided for pressurizing and venting at least one spring brake cylinder. The series connection of the electropneumatic parking brake valve unit and the electropneumatic parking brake redundancy unit allows for high operational reliability. Thus, the electropneumatic parking brake redundancy unit can prevent a spring brake cylinder from being pressurized by a faulty electropneumatic parking brake valve unit. The electropneumatic parking brake redundancy unit is preferably arranged downstream of the electropneumatic parking brake valve unit, i.e., closer to the spring brake cylinder.

[0024] In a preferred embodiment, the electropneumatic parking brake device comprises a protective device with a first parking pressure connection, an operating pressure connection, and a working connection. The parking pressure connection is connected to the spring-loaded connection of the electropneumatic parking brake redundancy unit for receiving the parking pressure. The operating pressure connection is connectable to a service brake circuit for receiving a service brake pressure. The protective device is designed to control the higher pressure from the parking pressure and the service brake pressure at the working connection. The protective device can prevent both an operating pressure and a parking pressure from being passed to a brake actuator connected to the electropneumatic parking brake device.

[0025] In a second aspect, the invention achieves the aforementioned object with an electronically controllable pneumatic braking system for a vehicle, in particular a commercial vehicle. The electronically controllable pneumatic braking system comprises at least one parking brake actuator with a spring-loaded brake cylinder, a first compressed air reservoir for providing reservoir pressure, and an electropneumatic parking brake device according to one of the above-described preferred embodiments according to the first aspect of the invention. The reservoir connection of the electropneumatic parking brake valve unit is connected to the first compressed air reservoir, and the spring-loaded connection of the electropneumatic parking brake redundancy unit is connected to the spring-loaded brake cylinder.To pressurize the spring brake cylinder, compressed air from the compressed air reservoir can be supplied to the spring brake cylinder via the electropneumatic parking brake system. The electropneumatic parking brake system can pass the reservoir pressure unchanged or modulate its pressure level and / or flow rate.

[0026] In a first preferred development, the electronically controllable pneumatic brake system comprises an electropneumatic parking brake device that can be controlled by a second control unit to switch from the venting position to the operating position. The electropneumatic parking brake redundancy unit is designed to provide the emergency braking function only if the first control unit and the second control unit are faulty. According to the preferred development, the spring-loaded brake cylinder connected to the spring-loaded brake connection is thus only connected to at least one redundancy venting device by the electropneumatic parking brake redundancy unit if both the first control unit and the second control unit are faulty.A control unit may be faulty, for example, if it is not supplied with electrical power, if it has a software error and / or if it has a hardware error, such as a broken cable.

[0027] The electronically controllable braking system preferably further comprises a first voltage source and a second voltage source, wherein the first voltage source is provided for supplying the first control unit with electrical voltage. Particularly preferably, the second voltage source is provided for supplying the second control unit with electrical voltage. The first voltage source and the second voltage source are preferably independent voltage sources. Providing independent voltage sources can further increase the reliability of the braking system, since a failure of a single voltage source does not cause a total failure of the parking brake system.

[0028] In a preferred variant of the electronically controllable braking system, the first control unit can only switch the electropneumatic parking brake redundancy unit from the venting position to the operating position when the first voltage source and the second voltage source provide electrical energy. It should be understood that the first control unit does not have to be supplied with electrical energy from both the first voltage source and the second voltage source for this purpose. For example, the first control unit can also be supplied only from the first voltage source. However, even in such embodiments, it can be advantageous for the first control unit to only switch the electropneumatic parking brake redundancy unit from the venting position to the operating position when both voltage sources provide electrical energy.This means that the first control unit can still be operational even if the second voltage source fails, while system safety is already reduced and venting the spring brakes is therefore undesirable.

[0029] Preferably, the electronically controllable pneumatic braking system further comprises a unit for autonomous driving, wherein the unit for autonomous driving is the first control unit. A unit for autonomous driving can, in particular, be a so-called virtual driver, which generates driving commands based on sensor data, operating data, route data, target data, and the like and provides them to the vehicle. Driving commands can include steering commands, acceleration commands, and braking commands, in particular a braking request AB.

[0030] In alternative embodiments, the electronically controllable pneumatic brake system comprises at least one service brake actuator and a service brake system with a service brake control unit for controlling at least the at least one service brake actuator, wherein the service brake control unit is the first control unit. The service brake control unit is typically independent of the parking brake control unit.

[0031] Preferably, the electronically controllable pneumatic brake system further comprises, in addition to the service brake system, a secondary system with a secondary control unit, wherein the secondary system is designed to control the at least one service brake actuator if a fault is detected in the service brake system. The secondary system can also be referred to as a service brake redundancy system. In variants in which the electronically controllable pneumatic brake system

[0032] Secondary system and in which the electropneumatic

[0033] If the parking brake redundancy unit of the electropneumatic parking brake device of the electronically controllable pneumatic brake system is controlled by a second control unit to switch from the venting position to the operating position, the secondary control unit can be or include the second control unit. In this variant, an existing control unit can then be used to control the electropneumatic parking brake redundancy unit.

[0034] In variants in which a unit for autonomous driving of the electronically controllable pneumatic brake system is or comprises the first control unit, the electronically controllable pneumatic brake system can have at least one service brake actuator and a service brake system with a service brake control unit at least for controlling the at least one service brake actuator. The service brake control unit is then preferably the second control unit. Thus, two units already present in the brake system can be used to control the electropneumatic locking redundancy unit for switching from the venting position to the operating position. The electropneumatic locking redundancy unit is preferably designed to automatically switch to the venting position if the unit for autonomous driving (the first control unit) or the service brake control unit (the second control unit) has a fault.In alternative preferred embodiments, the electropneumatic locking redundancy unit is designed to automatically switch to the venting position if the unit for autonomous driving (the first control unit) and the service brake control unit (the second control unit) have a fault.

[0035] According to a third aspect of the invention, the object mentioned above is achieved by a commercial vehicle having at least one front axle, at least one first rear axle and an electronically controllable pneumatic braking system according to one of the above-described preferred embodiments of an electronically controllable pneumatic braking system according to the second aspect of the invention. In a fourth aspect, the invention achieves the object mentioned above by a method for operating an electronically controllable pneumatic braking system for a vehicle, which comprises a first control unit and a parking brake system with at least one spring brake cylinder and an electropneumatic parking brake device. In particular, the method is a method for operating an electronically controllable pneumatic braking system according to one of the above-described preferred embodiments of an electronically controllable pneumaticBraking system according to the second aspect of the invention. The method according to the fourth aspect of the invention comprises the following steps: Providing at least one redundancy switching signal to an electropneumatic parking brake redundancy unit of the electropneumatic parking brake device; Switching the parking brake redundancy unit to an operating position in response to the provision of the at least one redundancy switching signal; Providing a parking brake signal to a parking brake control unit of an electropneumatic parking brake valve unit of the electropneumatic parking brake device; Controlling a parking pressure by the electropneumatic parking brake valve unit at a working connection of the electropneumatic parking brake valve unit as a function of the parking brake signal provided at the parking brake control unit; Passing the parking pressure controlled at the working connection from aRedundancy supply connection of the parking brake redundancy unit to a spring-loaded connection of the parking brake redundancy unit, venting a spring-loaded brake cylinder connected to the spring-loaded connection of the parking brake redundancy unit; and Automatic switching of the parking brake redundancy unit, independent of the electropneumatic parking brake valve unit, from the operating position to a venting position in which the spring-loaded connection is connected to a redundancy vent of the parking brake redundancy unit in order to vent the spring-loaded brake cylinder to provide an emergency braking function. By switching the parking brake redundancy unit from the operating position to the venting position, the spring-loaded connection is connected to the redundancy vent, and the spring-loaded brake cylinder connected to the spring-loaded connection is vented. This applies the parking brake and brakes the vehicle.The parking brake redundancy unit is preferably switched on to provide the emergency braking function if the supply of electrical energy and / or redundancy switching signals to the parking brake redundancy unit is interrupted and / or if the provision of the at least one redundancy switching signal is omitted. Preferably, the parking brake valve unit switches automatically from the operating position to the venting position to provide the emergency braking function if a first control unit for controlling the electropneumatic parking brake redundancy unit and / or a second control unit for controlling the electropneumatic parking brake redundancy unit has a fault. Alternatively or additionally, the automatic switching can also occur if a first voltage source and / or a second voltage source of the braking system fails.

[0036] When passing the locking pressure, the locking pressure can also be varied in terms of pressure level and / or flow rate. However, it is particularly preferred that the locking pressure be passed without significantly influencing the locking pressure beyond the usual pressure losses in line components.

[0037] It should be understood that the electronically controllable pneumatic braking system according to the second aspect of the invention, the commercial vehicle according to the third aspect of the invention and the method for operating an electronically controllable pneumatic braking system according to the fourth aspect of the invention have the same and similar sub-aspects as particularly set out in the dependent claims to the first aspect of the invention and to the second aspect of the invention.

[0038] Embodiments of the invention will now be described below with reference to the drawings. These are not necessarily intended to represent the embodiments to scale; rather, the drawings are schematic and / or slightly distorted where this is useful for explanation. With regard to additions to the teachings immediately apparent from the drawings, reference is made to the relevant prior art. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, in the drawings and in the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of ​​the invention is not limited to the exact form or detail of the preferred embodiments shown and described below, or limited to an object that would be more limited than the object claimed in the claims. For specified dimensioning ranges, values ​​within the stated limits are also intended to be disclosed as limit values ​​and to be used and claimed as desired. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions.

[0039] Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawings, which show:

[0040] Fig. 1 is a schematic representation of a commercial vehicle with an electronically controllable pneumatic braking system;

[0041] Fig. 2 shows a first embodiment of an electropneumatic parking brake device,

[0042] Fig. 3 shows a second embodiment of an electropneumatic parking brake device; and in

[0043] Fig. 4 is a block diagram illustrating a method for operating an electronically controllable pneumatic braking system.

[0044] Fig. 1 shows an electronically controllable pneumatic braking system 200 with an electropneumatic parking brake device 1. The electronically controllable pneumatic braking system 200 is used in a vehicle 300 designed as a commercial vehicle 302, which is shown here highly schematically, in particular with a front axle VA, a first rear axle HA1 and a second rear axle HA2.

[0045] The electronically controllable pneumatic braking system 200 has first, second, third, fourth, fifth, and sixth service brake actuators 208a-208f, each for a wheel of the vehicle 300. A rear axle brake circuit 202 and a front axle brake circuit 204 are provided to supply the first to sixth service brake actuators 208a-208f with brake pressures. The service brake actuators 208a, 208b are assigned to the front axle VA and are therefore also referred to as front axle brake actuators 208a, 208b. Similarly, the service brake actuators 208c-208f assigned to the rear axles HA1, HA2 are also referred to as rear axle brake actuators 208c-208f. The rear axle brake circuit 202 is supplied by a first compressed air supply 206 and the front axle brake circuit 204 is supplied by a second compressed air supply 210.The commercial vehicle 300 is designed here as a towing vehicle and comprises a trailer brake circuit 207 with a trailer module 209, which is provided for supplying a trailer (not shown) connected to the commercial vehicle 300 with compressed air.

[0046] The electronically controllable pneumatic braking system 200 has an operating level and a first redundancy level. At the operating level, the electronically controllable pneumatic braking system 200 comprises a service brake system 212 with an electronic service brake control unit 214, which controls the electronically controllable pneumatic braking system 200 at the operating level. The electronic service brake control unit 214 is connected to an autonomous driving unit 218 via a vehicle bus 216 and receives braking request signals therefrom.

[0047] SA. Furthermore, the electronic service brake control unit 214 is connected to a first voltage source 222 via a first supply line 220 and is supplied with electrical energy by the first voltage source 222. The electronic service brake control unit 214 converts the brake request signals SA and, based thereon, controls service brake signals SB at a first service axle modulator 224.

[0048] The first service axle modulator 224 here is a front axle modulator 228 provided for the front axle VA. Alternatively or additionally, brake request signals SA can also be provided by an electronic foot brake pedal 264 on the service brake control unit 214.

[0049] The first operating axle modulator 224 is connected to the second compressed air supply 210 and receives supply pressure pV therefrom. The first operating axle modulator 224 controls, based on the received operating brake signals

[0050] SB, a first service brake pressure pB1 at a first service brake pressure connection 232.1 and a second service brake connection 232.2. At the first and second service brake pressure connections 232.1, 232.2, the first service brake pressure pB1 is preferably controlled in a wheel-specific manner, and the first service axle modulator 224 is designed as a two-channel modulator. In other embodiments, however, the first service brake pressure connection 232.1 and the second service brake pressure connection 232.2 can also be combined, and the first service axle modulator 224 can thus be designed as a single-channel axle modulator that controls the first service brake pressure pB1 in a wheel-specific manner.

[0051] A first wheel speed sensor 234 is also provided on the front axle VA, which provides first wheel speed signals SD to the service brake control unit 214. The service brake control unit 214 is configured to process the first wheel speed signals SD and provide ABS switching signals to ABS valves 238 of the front axle VA in order to achieve slip control or ABS modulation of the first service brake pressure pB1 and prevent locking of the front wheels of the vehicle 300.

[0052] Furthermore, the electronically controllable pneumatic brake system 200 comprises, at the operating level, a second service axle modulator 236, which is provided for the first and second rear axles HA1, HA2 and can thus also be referred to as a rear axle modulator 237. In the exemplary embodiment shown in Fig. 1, the rear axle modulator 237 is installed with the electronic service brake control unit 214 to form a module, which is referred to here as the central module 240. However, it should be understood that the rear axle modulator 237 and the service brake control unit 214 can also be separate or structurally separated. The service brake control unit 214 and the rear axle modulator 237 can then be connected to one another, for example, via a signal line or a bus line.Internally, the electronic service brake control unit 214 controls the rear axle modulator 237 in accordance with the brake request signals SA that the service brake control unit 214 has received from the autonomous driving unit 218.

[0053] An operating supply connection 230 of the second operating axle modulator 236 is connected to the first compressed air supply 206 and receives supply pressure pV therefrom. Depending on its control by the service brake control unit 214, the rear axle modulator 237 controls at least a second service brake pressure pB2; in the exemplary embodiment shown here, however, it also controls a third service brake pressure pB3. In the exemplary embodiment shown in Fig. 1, the second service brake pressure pB2 is provided for the right side of the vehicle, and the third service brake pressure pB3 is provided for the left side of the vehicle. The rear axle modulator 237 is thus designed here as a two-channel axle modulator. The second service brake pressure pB2 is intended for a fourth and sixth service brake actuator 208d, 208f, while the third service brake pressure pB3 is provided for a third and fifth service brake actuator 208c, 208e.In other variants, the first operating axis modulator 236 can also be designed as a single-channel modulator or as a multi-channel modulator with more than two outputs.

[0054] In the redundancy level, the electronically controllable pneumatic braking system 200 includes a secondary control unit 242 of a secondary system 241, which is designed to control the electronically controllable pneumatic braking system 200 in the event of one or more errors at the operating level. The secondary control unit 242 can thus control the electronically controllable pneumatic braking system 200, for example, in the event of a power failure in the first voltage source 222, an electronic error in the service brake control unit 214, or the like.

[0055] The electronic secondary control unit 242 is also connected to the autonomous driving unit 218 via the vehicle bus 216 and also receives braking request signals SA from it. Unlike the service brake control unit 214, the secondary control unit 242 is connected to a second voltage source 246 via a second supply line 244 and is supplied with electrical energy from it. The first and second voltage sources 222, 246 are independent of one another, so that a failure in the first voltage source 222 does not lead to a loss of the second voltage source 246, and vice versa. The electronic service brake control unit 214 and the electronic secondary control unit 242 are therefore electrically independent of one another.

[0056] In order to exchange signals, the service brake control unit 214 and the secondary control unit 242 are connected to one another via a redundancy bus 248. In this way, the secondary control unit 242 can determine the availability of the service brake control unit 214 and only assume control of the electronically controllable pneumatic brake system 200 when the service brake control unit 214 is not available or is no longer available correctly. However, in variants, communication between the service brake control unit 214 and the secondary control unit 242 can also take place, for example, via the vehicle bus 216. A redundancy axle modulator 250 is provided in the redundancy level, which is connected to the secondary control unit 242 and receives redundancy brake signals SR from it. In the exemplary embodiment according to Fig. 1, the secondary control unit 242 is integrated into the redundancy axle modulator 250.In other variants, the secondary control unit 242 and the redundant axis modulator 250 may also be physically separate units.

[0057] The redundant axis modulator 250 is connected to the second compressed air supply 210, which is independent of the first compressed air supply 206, so that the second compressed air supply 210 can provide supply pressure pV even if the first compressed air supply 206 fails. In other embodiments, the redundant axis modulator 250 can also be connected to the second compressed air supply 210 or to the first compressed air supply 206 and the second compressed air supply 210.

[0058] The redundancy axle modulator 250 controls a redundancy brake pressure pBR1 at a redundancy brake pressure connection 252 depending on the redundancy brake signals SR. The redundancy brake pressure pBR1 controlled at the redundancy brake pressure connection 252 is provided to the front axle modulator 228. The redundancy axle modulator 250 is shown in Fig. 1 as a single-channel axle modulator with only one redundancy brake pressure connection 252, but can also be designed as a multi-channel axle modulator, which can, for example, implement a side-by-side control of redundancy brake pressures.

[0059] The secondary control unit 242 can control the redundant axle modulator 250 such that, in the event of a fault in the service brake control unit 214, a brake pressure, namely the redundant brake pressure pBR1, is still provided to the front axle brake actuators 208a, 208b. Unlike what is shown in Fig. 1, the redundancy level can also be provided for braking the first and second rear axles HA1, HA2. This can be implemented using the redundant axle modulator 250 or using a second redundant axle modulator. The secondary control unit 242 can then preferably also be provided for controlling such a second redundant axle modulator. In the embodiment of the electronically controllable pneumatic brake system 200 shown in Fig. 1, the brake actuators assigned to the wheels of the rear axles HA1, HA2 are designed as double-acting brake actuators, which are also referred to as tri-stop cylinders.In addition to the service brake actuators 208c-208f, each of these also includes a spring brake cylinder 254c-254f. The spring brake cylinders 254c-254f are designed to apply the brakes of the vehicle 300 when they are depressurized or vented. The spring brake cylinders 254c-254f can thus be advantageously used as a parking brake, which does not require compressed air to brake the rear axles HA1, HA2. To release the rear wheels, the spring brake cylinders 254c-254f must be pressurized with a parking pressure pFS. This parking pressure pFS counteracts the spring brake and releases the brakes of the vehicle 300. The spring brake cylinders 254c-254f are part of a parking brake system 203.

[0060] To provide the parking brake function, the electronically controllable pneumatic brake system 200 comprises the electropneumatic parking brake device 1. This comprises an electropneumatic parking brake valve unit 2, which is supplied with supply pressure pV via a supply connection 4. In the illustrated embodiment, the supply connection 4 is connected to the first compressed air supply 206. However, the parking brake valve unit 2 could also be supplied with supply pressure pV from the second compressed air supply 210.

[0061] The electropneumatic parking brake valve unit 2 comprises a parking brake control unit 6, which is connected to the autonomous driving unit 218 via the vehicle bus 216. To engage the parking brake, the autonomous driving unit 218 provides a parking brake signal SFS to the parking brake control unit 6 via the vehicle bus 216, which then provides the parking pressure pFS at a working port 8.

[0062] The working port 8 of the electropneumatic parking brake valve unit 2 is connected in Fig. 1 to a redundancy supply port 16 of an electropneumatic parking brake redundancy unit 10 of the electropneumatic parking brake device 1. In response to the parking brake signals SFS, the electropneumatic parking brake valve unit 2 controls the parking pressure pFS at its working port 8 and thus makes it available at the redundancy supply port 16. The electropneumatic parking brake redundancy unit 10 further comprises a spring-loaded port 18, which in Fig. 1 is directly connected to the spring-loaded brake cylinders 208c, 208d, 208e, 208f of the electronically controllable pneumatic brake system 200.

[0063] In the embodiment shown, the electropneumatic parking brake valve unit 2 and the electropneumatic parking brake redundancy unit 10 are connected in series along a parking compressed air path 12, which is provided here to supply the spring brake cylinders 208c, 208d, 208e, 208f with parking pressure pFS. In particular, the electropneumatic

[0064] In the embodiment shown in Fig. 1, the parking brake valve unit 2 is only connected to the spring brake cylinders 208c, 208d, 208e, 208f via the electropneumatic parking brake redundancy unit 10. The electropneumatic parking brake valve unit 2 cannot therefore supply the spring brake cylinders 208c, 208d, 208e, 208f with parking pressure pFS bypassing the electropneumatic parking brake redundancy unit 10.

[0065] The electropneumatic parking brake redundancy unit 10 can be switched between an operating position 20 and a venting position 22.

[0066] In the operating position 20, the electropneumatic parking brake redundancy unit 10 connects the redundancy supply connection 16 to the spring-loaded connection 18. Here, the electropneumatic parking brake redundancy unit 10 controls the parking pressure pFS provided at the redundancy supply connection 16 essentially unchanged from the

[0067] Spring brake connection 18 when it is in the operating position 20. In this case, the parking pressure pFS is also present at the spring brake connection 18 and can thus be provided to the spring brake cylinders 208c, 208d, 208e, 208f.

[0068] In the venting position 22, however, the spring-loaded connection 18 is connected to a redundancy vent 24 of the electropneumatic parking brake redundancy unit 10. In the venting position 22, the electropneumatic parking brake redundancy unit 10 vents the spring-loaded brake cylinders 208c, 208d, 208e, 208f connected to the spring-loaded connection 18 directly into the environment. If the electropneumatic parking brake redundancy unit 10 is in the venting position 22, the parking brake of the vehicle 300 is engaged, or the wheels of the rear axles HA1 and HA2 of the vehicle 300 are braked.

[0069] Also indicated in Fig. 1 are a first electrically switchable redundancy valve 26 and a second electrically switchable redundancy valve 28 of the electropneumatic parking brake redundancy unit 10. The structure of the electropneumatic parking brake redundancy unit 10 will be explained in more detail later with reference to Fig. 2 and Fig. 3.

[0070] The electropneumatic parking brake redundancy unit 10 can be controlled by at least one control unit of the electronically controllable pneumatic brake system 200 to switch from the venting position 22 to the operating position 20. For this purpose, the electropneumatic parking brake redundancy unit 10 in Fig. 1 is connected, for example, via a first redundancy signal line 256 to the secondary control unit 242. This provides a first redundancy switching signal SR1 to the electropneumatic parking brake redundancy unit 10 via the redundancy signal line 256.

[0071] In Fig. 1, the spring brake cylinders 254c-254f are connected directly to the spring brake connection 18. In a preferred variant, however, the electropneumatic parking brake device 1 can additionally comprise a protective device 30 (Fig. 3), which is arranged between the spring brake connection 18 and the spring brake cylinders 254c-254f or between the working connection 8 and the redundancy supply connection 16.

[0072] Preferably, the electropneumatic parking redundancy unit 10 is switched from the venting position 22 to the operating position 20 when the vehicle 300 is started up, in particular when the ignition of the vehicle 300 is activated. The electropneumatic parking brake valve unit 2 can then vent the spring brake cylinders 254c, 254d, 254e, 254f via the electropneumatic parking redundancy unit 10 and thus release the parking brake of the vehicle 300. The vehicle 300 is then ready to drive. Preferably, the electropneumatic parking redundancy unit 10 is permanently held in the operating position 20 during normal operation. Any necessary venting of the spring brake cylinders 254c, 254d, 254e, 254f can then also be performed via the electropneumatic parking brake valve unit 2.The electropneumatic locking redundancy unit 10 preferably only switches to the venting position 22 to provide an emergency braking function if a fault occurs, in particular in the event of a total electrical failure of the electronically controllable pneumatic braking system 200 or in the event of a failure of several control units 6, 214, 218, 242 of the electronically controllable pneumatic braking system 200.

[0073] Although in the exemplary embodiment shown in Fig. 1, only the secondary control unit 242 is shown for controlling the electropneumatic locking redundancy unit 10, it should be understood that the electropneumatic locking redundancy unit 10 can also be controlled individually or in combination by further control units of the electronically controllable pneumatic brake system 200 in order to switch from the venting position 22 to the operating position 20. In particular, the electropneumatic locking redundancy unit 10 can also be controlled by the autonomous driving unit 218 and / or the service brake control unit 214.

[0074] Fig. 2 now schematically shows a first exemplary embodiment of the electropneumatic parking brake device 1. The electropneumatic parking brake valve unit 2 is shown only schematically. Furthermore, Fig. 2 shows only one spring-loaded brake cylinder 254 as an example. In the first exemplary embodiment, the electropneumatic parking brake redundancy unit 10 comprises only a first electrically switchable redundancy valve 32. The working port 8 of the electropneumatic parking brake valve unit 2 is connected here to a first redundancy valve supply port 32.1 of the redundancy valve 32, which here forms the redundancy supply port 16. The first redundancy valve 32 is an electrically switchable 3 / 2-way valve. In addition to the first redundancy valve supply port 32.1, the first redundancy valve 32 comprises a first redundancy valve working port 32.2, which in the first embodiment of the electropneumatic parking brake device 1 forms the spring-loaded connection 18 of the electropneumatic parking redundancy unit 10, and a first redundancy valve vent connection 32.3, which here forms the redundancy vent 24. The first electrically switchable redundancy valve 32 has two switching positions. A first redundancy valve vent position 32.4 shown in Fig. 2 is also the vent position 22 of the electropneumatic locking redundancy unit 10. The first electrically switchable redundancy valve 32 is preloaded into this redundancy valve vent position 32.4 or the vent position 22 and automatically returns to this redundancy valve vent position 32.4, provided a first electromagnet 32.6 of the first electrically switchable redundancy valve 32 is not supplied with electrical energy or energized. In the redundancy valve vent position 32.4, the first redundancy valve working port 32.2 is conductively connected to the first redundancy valve venting port 32.3, and a first working path 34 of the electropneumatic locking redundancy unit 10 is blocked or interrupted. The spring brake port 18 is then connected to the redundancy venting 24 via the first electrically switchable redundancy valve 32, so that the spring brake cylinder 254 is vented via the electropneumatic locking redundancy unit 10.

[0075] In a first redundancy valve operating position 32.5, which here is also the operating position 20 of the electropneumatic parking redundancy unit 10, the first redundancy valve supply port 32.1 and the first redundancy valve working port 32.2 are fluidly connected. In the first redundancy valve operating position 32.5, the first electrically switchable redundancy valve 32 releases the first working path 34. The parking pressure pFS controlled by the electropneumatic parking brake valve unit 2 thus reaches the parking brake cylinder 254 via the redundancy supply port 16 and the spring-loaded port 18.

[0076] The electropneumatic locking redundancy unit 10 can be controlled by a first control unit 36 ​​to switch between the venting position 22 and the operating position 20. As explained with reference to Fig. 1, the first control unit 36 ​​can be the secondary control unit 242. In other variants, however, the first control unit 36 ​​can preferably also be formed by the unit for autonomous driving 218 or the service brake control unit 214. The first control unit 36 ​​provides the first redundancy control signals SR1 to the first electrically switchable redundancy valve 32. Here, the first redundancy control signal SR1 is in the form of electrical energy, which is provided to the first magnet 32.6, which then switches the first electrically switchable redundancy valve 32 to the redundancy valve operating position 32.5 and holds it there. For energization, the first electrically switchable redundancy valve 32 comprises first redundancy valve signal connections 32.7.One or more of the redundancy valve signal terminals 32.7 are connected to the first control unit 36.

[0077] However, it can also be provided that, in addition to the first control unit 36, a second control unit 38 for switching the electropneumatic locking redundancy unit 10 is connected to the first electrically switchable redundancy valve 32. In such variants, the first electrically switchable redundancy valve 32 can then be switched by only one control unit from the first control unit 36 ​​and the second control unit 38, or only by the first control unit 36 ​​and the second control unit 38 together.

[0078] The first control unit 36 ​​can be the autonomous driving unit 218, the service brake control unit 214, the secondary control unit 242, or the parking brake control unit 6. The second control unit 38 can be the autonomous driving unit 218, the service brake control unit 214, the secondary control unit 242, or the parking brake control unit 6, wherein the second control unit 38 is preferably a different control unit 36 ​​from the first control unit 36.

[0079] In the first exemplary embodiment according to FIG. 2, the electropneumatic parking brake device 1 further comprises the protection device 30. This comprises a first protection connection 30.1 which is connected to the spring-loaded connection 18. A second protection connection 30.2 of the protection device 30 is provided for receiving a service brake pressure pB1, pB2, pB3. The first protection connection 30.1 is also referred to as the parking pressure connection 30.1. The second protection connection 30.2 is also referred to as the operating pressure connection 30.2. A third protection connection 30.3 of the protection device 30, which is also referred to as the protection device working connection 30.3, is connected to the spring-loaded brake cylinder 254. The protection device comprises a first shuttle valve 40 which transfers the higher of the pressures present at the first protection connection 30.1 and the second protection connection 30.2 to a second shuttle valve 42.The first shuttle valve 40 is a so-called select-high valve. This ensures that a parking pressure pFS and a service brake pressure pB1, pB2, pB3 are not applied to the spring brake cylinder at the same time.

[0080] Fig. 3 shows a second embodiment of the electropneumatic parking brake device 1. According to the second embodiment, the electropneumatic parking redundancy unit 10 comprises a second working path 44, which runs parallel to the first working path 34 from the redundancy supply connection 16 to the spring-loaded actuator connection 18. Here, the redundancy supply connection 16 and the spring-loaded actuator connection 18 are therefore not formed by connections 32.1, 32.2 of the first electrically switchable redundancy valve 32. The first redundancy valve vent connection 32.3 is connected here to a first redundancy vent 24.1.

[0081] A second electrically switchable redundancy valve 46 is arranged in the second working path 44. This is designed essentially identically to the first electrically switchable redundancy valve 32. The second electrically switchable redundancy valve 46 comprises a second redundancy valve supply connection 46.1, a second redundancy valve working connection 46.2, and a second redundancy valve vent connection 46.3. The second redundancy valve vent connection 46.3 is connected to a second redundancy vent 24.2. The first redundancy valve vent connection 32.3 and the second redundancy valve vent connection 46.3 could also be connected to a common redundancy vent 24. The second electrically switchable redundancy valve 46 is preloaded into a second redundancy valve vent position 46.4 by supplying a second magnet 46.6 of the second electrically switchable redundancy valve 46, the second electrically switchable redundancy valve 46 can be switched into a second redundancy valve operating position 46.5. A second control unit 38 is preferably provided to control the second electrically switchable redundancy valve 46. Particularly preferably, the first control unit 36 ​​is designed to control the first electrically switchable redundancy valve 32, and the second control unit 38 is provided to control the second electrically switchable redundancy valve 46.

[0082] In the second exemplary embodiment, the electropneumatic locking redundancy unit 10 is controlled either by switching the first electrically switchable redundancy valve 32 from the first redundancy valve venting position 32.4 to the first redundancy valve operating position 32.5 and / or by switching the second electrically switchable redundancy valve 46 from the second redundancy valve venting position 46.4 to the second redundancy valve operating position 46.5 from the venting position 22 to the operating position 20, in which the locking pressure pFS provided at the redundancy supply connection 16 is passed through to the spring-loaded connection 18.

[0083] In the second exemplary embodiment of the electropneumatic parking brake device 1, the electropneumatic parking redundancy unit 10 comprises a selector valve 48 adjacent to the spring-loaded connection 18. The selector valve 48 comprises a first selector valve connection 48.1 connected to the first redundancy valve working connection 32.2 and a second selector valve connection 48.2 connected to the second redundancy valve working connection 46.2. The selector valve 48 is here a select-high valve and controls the higher of the pressures provided at the first selector valve connection 48.1 and the second selector valve connection 48.2 at the spring-loaded connection 18. This can, for example, prevent a parking pressure pFS provided via the first working path 34 from being vented via the second electrically switchable redundancy valve 46 if this is in the second

[0084] Redundancy valve venting position 46.4 and vice versa. Thus, the spring brake cylinder 254 can still be vented with the locking pressure pFS even if the second control unit 38, which controls the second electrically switchable redundancy valve 46, is faulty.

[0085] In the event of a total electrical failure of the electronically controllable pneumatic brake system 200, both the first control unit 36, which in the second exemplary embodiment is provided for controlling the first electrically switchable redundancy valve 32, and the second control unit 38, which in the second exemplary embodiment is provided for controlling the second electrically switchable redundancy valve 46, exhibit a fault. The first electrically switchable redundancy valve 32 and the second electrically switchable redundancy valve 46 then each switch automatically and independently of the electropneumatic parking brake valve unit 2 to their respective redundancy valve venting positions 32.4, 46.4. In the event of a total electrical failure of the electronically controllable pneumatic brake system 200, the spring brake cylinder 254 is then vented via the first redundancy vent 24.1 and / or the second redundancy vent 24.2.The spring brake of the spring brake cylinder 254 then applies the parking brake and brakes the vehicle 300. Thus, even in the event of a total failure of the electronically controllable pneumatic brake system 200, an emergency braking function 50 can still be provided.

[0086] Fig. 4 illustrates, using a block diagram, a method 400 for operating an electronically controllable pneumatic braking system 200 of a vehicle 300. The method is described here with reference to the braking system 200 shown in Fig. 1 and comprises a total of seven steps S1-S7, wherein more steps or intermediate steps may also be provided and / or wherein the steps S1-S7 may also comprise sub-steps.

[0087] In a step S1 of the method 400, at least one redundancy switching signal SR1 is provided to the electropneumatic parking brake redundancy unit 10 of the electropneumatic parking brake device 1. As shown in Fig. 1, for example, the secondary control unit 242 can act as the first control unit 36 ​​and provide the first redundancy switching signal SR1 to the electropneumatic parking brake redundancy unit 10. In a second step S2, the electropneumatic parking brake redundancy unit 10 switches to the operating position 20 in response to the provision (step S1) of the at least one redundancy switching signal SR1.In a third step S3, which can also take place before the first step S2, before the second step S2 or simultaneously with the first step S1 and / or the second step S2, a parking brake signal SFB is provided to the parking brake control unit 6 of the electropneumatic parking brake valve unit 2 of the electropneumatic parking brake device 1. In the embodiment according to Fig. 1, this is done by the unit for autonomous driving 218. This causes a control (step S4) of a parking pressure pFS by the electropneumatic parking brake valve unit 2 at its working connection 8, wherein the control takes place as a function of the parking brake signals SFB provided to the electropneumatic parking brake valve unit 2.The parking brake redundancy unit 10 passes the parking pressure pFS, which is output at the working port 8 of the electropneumatic parking brake valve unit 2, from its redundancy supply port 16 to its spring-loaded brake port 18 (step S5), since it was previously switched to the operating position 20. As a result, in a sixth step S6, a spring-loaded brake cylinder 254c, 254d, 254e, 254f of the electronically switchable pneumatic brake system 200, which is connected to the spring-loaded brake port of the electropneumatic parking brake redundancy unit 10, is ventilated. This releases the spring-loaded brakes of the vehicle 300, and the vehicle 300 is ready to drive.

[0088] In the event of a fault, in particular a combined fault 402 of the service brake control unit 214 and the secondary control unit 242, the service brake actuators 208a-208f may no longer be able to brake the vehicle 300. In this fault case, however, neither the service brake control unit 214 nor the secondary control unit 242 can hold the electropneumatic parking brake redundancy unit 10 in the operating position 20. The electropneumatic parking brake redundancy unit 10 then switches to the venting position 22 independently of the electropneumatic parking brake valve unit 2 and in particular automatically (for example, due to spring preload), thus connecting the spring-loaded connection 18 to the redundancy venting 24 (step S7).As a result, the spring brake cylinders 254c-254f of the electronically switchable pneumatic brake system 200 connected to the spring brake connection 18 are vented and applied, whereby an emergency braking function 50 is realized and the vehicle 300 is braked.

[0089] Reference symbol (part of the description)

[0090] Parking brake device

[0091] Parking brake valve unit

[0092] Storage connection

[0093] Parking brake control unit

[0094] Work connection

[0095] Parking brake redundancy unit

[0096] Locking compressed air path

[0097] Redundancy supply connection

[0098] Spring-loaded connection

[0099] Operating position

[0100] Venting position

[0101] Redundancy venting first redundancy venting second redundancy venting first electrically switchable redundancy valve second electrically switchable redundancy valve

[0102] Protective device first protective connection, locking pressure connection second protective connection, operating pressure connection third protective connection,

[0103] Protective device working connection first redundancy valve first redundancy valve supply connection first redundancy valve working connection first redundancy valve vent connection first redundancy valve vent position first redundancy valve operating position first solenoid first redundancy valve signal connections first working path first control unit second control unit first shuttle valve second shuttle valve second working path second redundancy valve second redundancy valve supply connection second redundancy valve working connection second redundancy valve vent connection second redundancy valve vent position second redundancy valve operating position second solenoid

[0104] Selection valve first selection valve connection second selection valve connection

[0105] Emergency braking function

[0106] braking system

[0107] Rear axle brake circuit

[0108] Parking brake system

[0109] Front axle brake circuit first compressed air supply

[0110] Trailer brake circuit a-208f service brake actuators

[0111] Trailer module second compressed air supply

[0112] Service brake system

[0113] Service brake control unit

[0114] Vehicle-BUS

[0115] Autonomous driving unit first supply line first voltage source first operating axle modulator

[0116] Front axle modulator

[0117] Service supply connection .1 first service brake pressure connection .2 second service brake connection

[0118] Wheel speed sensor second operating axle modulator 237 rear axle modulator

[0119] 238 ABS valve

[0120] 240 central module

[0121] 241 Secondary system

[0122] 242 Secondary control unit

[0123] 244 second supply line

[0124] 246 second voltage source

[0125] 248 Redundancy BUS

[0126] 250 Redundancy Axis Modulator

[0127] 252 Redundancy brake pressure connection

[0128] 254, 254c-254f spring brake cylinder

[0129] 256 second redundancy signal line

[0130] 264 Foot brake pedal

[0131] 300 vehicles

[0132] 302 commercial vehicles

[0133] 400 procedures

[0134] 402 Error

[0135] HA1 first rear axle

[0136] HA2 second rear axle pB1 , pB2, pB3 service brake pressures pFS parking pressure

[0137] SA brake request signals

[0138] SB operating brake signals

[0139] SD wheel speed signals

[0140] SFB parking brake signal

[0141] SFS parking brake signal

[0142] SR redundancy brake signals

[0143] SR1 redundancy switching signal

[0144] VA front axle

[0145] S1-S7 steps of the procedure

Claims

Patent claims 1. Electropneumatic parking brake device (1) for ventilating and venting one or more spring brake cylinders (254c, 254d, 254e, 254f) of an at least partially electronically controllable pneumatic brake system (200) for a vehicle (300), comprising an electropneumatic parking brake valve unit (2) with a supply connection (4) for receiving supply pressure (pV) from a compressed air supply (210), and a parking brake control unit (6), wherein the parking brake valve unit (2) is designed to control a parking pressure (pFS) at at least one working connection (8) of the electropneumatic parking brake valve unit (2) as a function of a parking brake signal (SP), and an electropneumatic parking brake redundancy unit (10) with a redundancy supply connection (16), a spring brake connection (18) for at least indirectly connecting to a spring brake cylinder (254c, 254d, 254e,254f) and at least one redundancy vent (24), wherein the redundancy supply connection (16) of the parking brake redundancy unit (10) is connected to the working connection (8) of the electropneumatic parking brake valve unit (2) for receiving the parking pressure (pFS), wherein the electropneumatic parking brake redundancy unit (10) has at least one operating position (20), in which the redundancy supply connection (16) is connected to the spring-loaded connection (18), and at least one venting position (22), in which the spring-loaded connection (18) is connected to the at least one redundancy vent (24), wherein the electropneumatic parking brake redundancy unit (10) is controllable by at least one first control unit (36) for switching from the venting position (22) to the operating position (20), wherein the electropneumatic parking brake redundancy unit (10) is designed to is,to provide an emergency braking function (50) independently of the electropneumatic parking brake valve unit (2) in the venting position (22).

2. Electropneumatic parking brake device (1) according to claim 1, wherein the electropneumatic parking brake redundancy unit (10) is designed to provide the emergency braking function (50) if the first control unit (36) has a fault.

3. Electropneumatic parking brake device (1) according to claim 1 or 2, wherein the electropneumatic parking brake redundancy unit (10) has at least one first electrically switchable redundancy valve (32) which, in a first redundancy valve operating position (32.5), releases the first working path (34) connecting the redundancy supply connection (16) to the spring-loaded connection (18), so that the electropneumatic parking brake redundancy unit (10) is in the operating position (20); and which, in a first redundancy valve venting position (32.4), connects the spring-loaded connection (18) to a redundancy vent (24, 24.1), so that the electropneumatic parking brake redundancy unit (10) is in the venting position (22), wherein the first electrically switchable redundancy valve (32) can be controlled by the first control unit (36) to switch from the first redundancy valve venting position (32.4) to the first redundancy valve operating position (32.5).

4. Electropneumatic parking brake device (1) according to claim 3, wherein the electropneumatic parking brake redundancy unit (10) further comprises a second electrically switchable redundancy valve (46) which, in a second redundancy valve operating position (46.5), releases the second working path (44) connecting the redundancy supply connection (16) to the spring-loaded connection (18), so that the electropneumatic parking brake redundancy unit (10) is in the operating position (20); and which, in a second redundancy valve venting position (46.4), connects the spring-loaded connection (18) to a redundancy vent (24, 24.2), so that the electropneumatic parking brake redundancy unit (10) is in the venting position (22).

5. Electropneumatic parking brake device (1) according to claim 4, wherein the first working path (34) and the second working path (44) of the electropneumatic parking brake redundancy unit (10) are parallel working paths (34, 44).

6. Electropneumatic parking brake device (1) according to claim 5, wherein the first working path (34) and the second working path (44) adjacent to the spring-loaded connection (18) are connected via a selector valve (48), wherein the selector valve (48) is designed to connect that working path (34, 44) from the first working path (34) and the second working path (44) which carries a higher pressure to the spring-loaded connection (48).

7. Electropneumatic parking brake device (1) according to one of claims 1 to 6, wherein the electropneumatic parking brake redundancy unit (10) can be controlled by a second control unit (38) to switch from the venting position (22) to the operating position (22).

8. The electropneumatic parking brake device (1) according to claim 7, wherein the electropneumatic parking brake redundancy unit (10) is configured to provide the emergency braking function (50) when the first control unit (36) has a fault or when the second control unit (38) has a fault; and / or wherein the electropneumatic parking brake redundancy unit (10) is configured to provide the emergency braking function (50) when the first control unit (36) and the second control unit (38) have a fault.

9. Electropneumatic parking brake device (1) according to one of claims 1 to 8, wherein the electropneumatic parking brake valve unit (2) and the electropneumatic parking brake redundancy unit (10) are connected in series along a parking compressed air path (12).

10. Electropneumatic parking brake device (1) according to one of claims 1 to 9, further comprising a protective device (30) with a first parking pressure connection (30.1), an operating pressure connection (30.2) and a protective device working connection (30.3), wherein the parking pressure connection (30.1) for receiving the parking pressure (pFS) is connected to the spring-loaded connection (18) of the electropneumatic parking brake redundancy unit (10), wherein the operating pressure connection (30.2) for receiving a service brake pressure (pB1, pB2, pB3) is connectable to a service brake circuit, and wherein the protective device (30) is designed to control the higher pressure from the parking pressure (pFS) and the service brake pressure (pB1, pB2, pB3) at the protective device working connection (30.3).

11. An electronically controllable pneumatic braking system (200) for a vehicle (300), comprising at least one parking brake actuator with a spring-loaded brake cylinder (254c, 254d, 254e, 254f), a first compressed air supply (206, 210) for providing supply pressure (pV), and an electropneumatic parking brake device (1) according to one of claims 1 to 10, wherein the supply connection (4) of the electropneumatic parking brake valve unit (2) is connected to the first compressed air supply (206, 210) and wherein the spring-loaded connection (18) of the electropneumatic parking brake redundancy unit (10) is connected to the spring-loaded brake cylinder (254c, 254d, 254e, 254f).

12. Electronically controllable pneumatic braking system (200) according to claim 11, comprising an electropneumatic parking brake device (1) according to claim 7, wherein the electropneumatic parking brake redundancy unit (10) is designed to provide the emergency braking function (50) only if the first control unit (36) and the second control unit (38) have a fault.

13. Electronically controllable pneumatic brake system (200) according to claim 11 or 12, further comprising a first voltage source (222) and a second voltage source (246), wherein the first voltage source (222) is provided for supplying the first control unit (26) with electrical voltage.

14. Electronically controllable pneumatic brake system (200) according to claim 13, wherein the first control unit (36) only moves the electropneumatic parking brake redundancy unit (10) from the venting position (22) to the operating position (20) when the first voltage source (222) and the second voltage source (246) provide electrical energy.

15. The electronically controllable pneumatic braking system (200) of any one of claims 11 to 14, further comprising an autonomous driving unit (218), wherein the autonomous driving unit (218) is the first control unit (36).

16. Electronically controllable pneumatic brake system (200) according to one of claims 11 to 14, further comprising at least one service brake actuator (208a, 208b, 208c, 208d, 208e, 208f) and a service brake system (212) with a service brake control unit (214) at least for controlling the at least one service brake actuator (208a, 208b, 208c, 208d, 208e, 208f), wherein the service brake control unit (214) is the first control unit (36).

17. Electronically controllable pneumatic brake system (200) according to claim 16, further comprising a secondary system (241) with a secondary control unit (242), wherein the secondary system (241) is designed to control the at least one service brake actuator (208a, 208b) if a fault is detected in the service brake system (212).

18. Electronically controllable pneumatic braking system (200) according to claim 17, comprising an electropneumatic parking brake device (1) according to claim 7, wherein the secondary control unit (242) is the second control unit (38).

19. Electronically controllable pneumatic brake system (200) according to claim 15, comprising an electropneumatic parking brake device (1) according to claim 7, further comprising at least one service brake actuator (208a, 208b, 208c, 208d, 208e, 208f) and a service brake system (212) with a service brake control unit (214) at least for controlling the at least one service brake actuator (208a, 208b), wherein the service brake control unit (214) is the second control unit (38).

20. Vehicle (300), in particular commercial vehicle (302), with at least one front axle (VA), at least one first rear axle (HA1) and an electronically controllable pneumatic braking system (1) according to one of the preceding claims 11 to 19.

21. A method (400) for operating an electronically controllable pneumatic braking system (200) for a vehicle (300), comprising a first control unit (36) and a parking brake system (203) with at least one spring brake cylinder (254c, 254d, 254e, 254f) and an electropneumatic parking brake device (1), the method (400) comprising the steps: - Providing (S1) at least one redundancy switching signal (SR1) to an electropneumatic parking brake redundancy unit (10) of the electropneumatic parking brake device (1); - switching (S2) the parking brake redundancy unit (10) into an operating position (20) in response to the provision of the at least one redundancy switching signal (SR1); - Providing (S3) a parking brake signal (SFB) to a parking brake control unit (6) of an electropneumatic parking brake valve unit (2) of the electropneumatic parking brake device (1); - Control (S4) of a parking pressure (pFS) by the electropneumatic parking brake valve unit (2) at a working connection (8) of the electropneumatic parking brake valve unit (2) as a function of the parking brake signal provided at the parking brake control unit (6); - passing (S5) the parking pressure (pFS) output at the working connection (8a, 8b) from a redundancy supply connection (16) of the parking brake redundancy unit (10) to a spring-loaded connection (18) of the parking brake redundancy unit (10), - venting (S6) a spring brake cylinder (254c, 254d, 254e, 254f) connected to the spring brake connection (18) of the parking brake redundancy unit (10); and - Automatic switching (S7) of the parking brake redundancy unit (10) from the operating position (20) to a venting position (22) independent of the electropneumatic parking brake valve unit (2), in which the spring-loaded brake connection (18) is connected to a redundancy vent (24) of the parking brake redundancy unit (10) in order to vent the spring-loaded brake cylinder (254c, 254d, 254e, 254f) to provide an emergency braking function (50).

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