DE102020130261A1 - Method for operating an electropneumatic parking brake module, electropneumatic parking brake module, electronically controllable pneumatic braking system, vehicle - Google Patents

Abstract

The invention relates to a method for operating an electropneumatic parking brake module (10, 10', 10") for an electronically controllable pneumatic brake system (204) for a vehicle (200), in particular a commercial vehicle (202), with a supply connection (20) for receiving a supply pressure (pV), at least one parking brake connection (21) for connecting at least one parking brake cylinder (24), a main valve unit (50) receiving the reservoir pressure (pV), which is designed to apply a spring accumulator pressure (pF) as a function of a control pressure (pS). the parking brake connection (21), and a pilot valve arrangement (70) receiving the reservoir pressure (pV) to provide the control pressure (pS), the pilot valve arrangement (70) having a bistable valve (72) which is positioned between a first venting position (72A) and a second vent position (72B) is switchable, and a control unit (300) for providing first and second Switching signals (S1, S2) to the pilot valve assembly (70).

Description

In modern electronically controllable pneumatic brake systems, which are used in particular in commercial vehicles that are intended for autonomous driving, it is important to provide measures that nevertheless allow the commercial vehicle to be safely decelerated in the event of a fault in the brake system.

DE 10 2017 001 409 A1 describes a method for controlling an autonomous vehicle with a vehicle control unit for controlling autonomous driving functions of the vehicle and with a brake control unit for controlling braking functions of an in particular pneumatic braking system of the vehicle with at least one braking device, in particular a parking brake. The brake device can be activated by the brake control unit and/or the vehicle control unit for braking and can be deactivated for driving, in that at least one switching element is activated. In the DE 10 2017 001 409 A1 The solution shown is characterized in that the switching element, preferably a solenoid valve, has two electrical conductors for activation, one of the two conductors being switched by the brake control unit and the other of the two conductors being switched by the vehicle control unit.

In the DE 10 2017 001 409 A1 The electrical interconnection of the brake valve shown with both the brake control unit and the vehicle control unit allows failsafe operation. In the event of a failure or malfunction of one of the two control units, the braking device is activated via the brake valve, since the electromagnet is then switched off. Each of the control units switches only the two conductors of the supply line of the electromagnet.

DE 10 2015 008 377 A1 shows a parking brake module of a parking brake device, with an electronic control device, at least one solenoid valve that can be actuated by the control device, and a pressure medium-increasing valve for pressurizing at least one brake actuator with pressure medium. The parking brake module also has an emergency release pressure medium connection and a double check valve, with which an emergency release function of the parking brake device can be provided, for which purpose the emergency release pressure medium connection is connected to the supply input of the pressure medium quantity-boosting valve by means of a first pressure medium line via a check valve and by means of a second pressure medium line to an input of the double check valve connected is.

The concepts presented are still in need of improvement—despite the generally advantageous failsafe device implemented electrically in the present case. This relates in particular to a simple structure of the system, ie to keep the expenditure on equipment for an electronically controllable pneumatic brake system as low as possible in order to save installation space and weight and to keep the complexity of the brake system low.

It would therefore be desirable to provide a method for operating an electronically controllable pneumatic brake system in which the disadvantages of the prior art are at least partially eliminated.

This is where the invention comes in, the object of which is to provide a method for operating an electronically controllable pneumatic brake system in which the disadvantages of the prior art are at least partially eliminated.

The object relating to the electropneumatic parking brake module is solved by the invention with a method for operating an electronically controllable pneumatic brake system of claim 1. The invention is based on a method for operating an electropneumatic parking brake module for an electronically controllable pneumatic braking system for a vehicle, in particular a commercial vehicle, with a supply connection for receiving a supply pressure, at least one parking brake connection for connecting at least one parking brake cylinder, a main valve unit receiving the supply pressure, is designed to modulate a spring-loaded pressure at the parking brake connection as a function of a control pressure, and a pilot valve arrangement receiving the reservoir pressure for providing the control pressure, the pilot valve arrangement having a bistable valve which can be switched between a first venting position and a second venting position, and a control unit for providing of first and second switching signals to the pilot valve assembly, wherein the pilot valve assembly with the bistable valve pneumatically connected in series and arranged in a control line of the main valve unit, monostable holding valve, wherein the holding valve is open in an open position without current, and the control unit is designed to hold the holding valve in the holding position to hold the control pressure by means of the first switching signal, and in an additional input port is arranged on the control line for receiving an additional control pressure provided at an additional brake pressure connection, having the step: filling the parking brake cylinder by applying pressure to the control connection of the main valve arrangement for modulating the spring-loaded pressure at the parking brake connection as a function of the control pressure, wherein the control port is acted upon by means of an additional control pressure which is provided at the additional brake pressure port and is accepted via the additional input port.

According to the invention, the method provides that in the event of a fault in an electronic component, in particular in a control unit of the brake system, and/or in the event of a power failure, the holding valve automatically switches to an open position for venting the control port, the control port of the main valve arrangement for venting the parking brake port is vented.

The invention is based on the consideration that it is advantageous to expand a braking system with little effort in such a way that safe operation is also possible in an autonomous operating mode. Safe operation includes a fail-safe system, by means of which the vehicle can still be decelerated and transferred to a safe state in the event of a fault in the brakes or a serious fault in the overall system or a power failure.

The invention includes the knowledge that it is advantageous to keep the expenditure on equipment for such a fail-safe device as low as possible in order to save weight and installation space and increase the complexity of the brake system only as little as necessary. In particular, a failsafe is to be achieved while largely retaining the current service brake and vehicle on-board network architecture.

Because the pilot valve arrangement has a holding valve, the control pressure at the control port of the main valve unit can be held when the holding valve for holding the control pressure is held in the holding position by the control unit using the first switching signal.

Due to the fact that an additional control port is arranged in the control line for receiving an additional control pressure provided at an additional brake pressure connection, the control connection can - independently of a manual operating mode in which the main valve unit is pressurized via the supply connection and the pilot valve arrangement - in another , In particular automatic operating mode are operated. In such a further, in particular automatic, operating mode, the control connection is pressurized via an additional brake pressure connection, and in particular vented via the holding valve of the pilot valve arrangement. In both operating modes, manual and automatic, the brake pressure can be made available via a supply connection; however, the actuation of the main valve unit via the control port changes. Within the scope of the application, a pneumatic connection or a similar pneumatic connection option is referred to as the control port.

The holding valve makes it possible to keep the control port of the main valve unit under pressure, even when the bistable valve is in a venting position. The holding valve thus achieves fail-safety, since it is not actuated in the event of a fault or power failure and is therefore automatically switched to its open position, in particular by the spring force of a holding valve return spring, for venting the control connection and thus for braking the parking brake cylinder.

Thus, with the method according to the invention, independent control for releasing one or more parking brake cylinders can be achieved in that the additional brake pressure connection is pneumatically connected to a pressure source, for example an axle modulator, in particular a front or rear axle modulator, to provide the additional control pressure, and at the same time via the de-energized holding valve can be provided a failsafe.

Due to the fact that the control pressure at the control connection of the main valve unit can be maintained independently of the bistable valve, a method according to the invention also enables failsafe operation during the period in which the parking brake is released. In a parking brake module according to the prior art, in which the parking brake is released by switching the bistable valve, this fail-safety would not exist, since in the event of a fault or power failure during the period in which the bistable valve - to release the parking brake - in a venting position, venting for the purpose of emergency braking would not be possible - and a venting position would also not be automatically achievable due to the bistable character of the bistable valve, which remains in its switching position without current. The inventive electropneumatic parking brake module with holding valve ensures failsafe operation, ie the possibility of failsafe braking in the event of a fault and/or power failure, since the main valve unit can be activated independently of the bistable valve.

Automatic venting advantageously achieves fail-safety in the event of a fault and/or power failure in the brake system, in particular in a central control unit or control unit of the brake system and/or the electropneumatic mechanical parking brake module is present. Due to the fact that the holding valve is designed to be open, in particular without current, the control connection of the main valve unit is vented in the event of a failure of the control of the holding valve in such a fault case and/or power failure, which means that the parking brake connection and thus the parking brake cylinders are also vented, causing the vehicle to come to a standstill to be led.

In the context of the invention, a service brake system is a brake system that can usually be actuated via a brake signal transmitter and that can be used for braking during operation of the vehicle by actuating the service brake cylinder via one or more axle modulators by applying compressed air. In contrast to this, a parking brake is usually used to lock the vehicle in the idle state by means of one or more parking brake cylinders, which are designed in particular as spring-loaded brake cylinders and can be released by applying compressed air to move the vehicle. In an automatic operating mode, in which, in particular, relatively low speeds below 10 km/h are to be expected, the parking brake is used in an electropneumatic parking brake module according to the invention for failsafety, i.e. to ensure emergency braking in the event of an error and/or power failure.

The control unit can be a control module integrated in the electropneumatic parking brake module, or a hardware or software module integrated in a central module of the vehicle control or the brake control, which is assigned to the electropneumatic parking brake module.

Advantageous developments of the invention can be found in the subclaims and specify advantageous possibilities in detail for realizing the concept explained above within the scope of the task and with regard to further advantages.

In a further development of the method, it is provided that in order to apply the additional control pressure to the control connection, the holding valve is switched to the open position and/or is held in the open position. Such a development of the method is particularly advantageous if the additional control port is arranged in the control line between the bistable valve and the holding valve or is formed as a bistable valve connection of the bistable valve, because in these cases the additional control pressure is routed from the additional brake pressure connection to the control connection of the main valve arrangement can.

In a development of the method, it is provided that the holding valve is held in the holding position in order to hold the additional control pressure at the control port. The holding valve is held in the holding position, in particular after an additional control pressure has been applied to the control connection. In particular, if the additional control pressure is still being provided by the additional brake pressure connection, the holding valve is switched to the holding position, and in particular only then is the provision of the additional control pressure at the additional brake pressure connection ended. In this way, the auxiliary control pressure is held or captured by the hold valve at the control port of the main valve assembly. In such a development of the method, the parking brake can advantageously be kept released, specifically independently of the bistable valve.

In a further development of the method, it is provided that in order to apply the additional control pressure to the control connection, the bistable valve is switched to the venting position and/or remains in the venting position. Such a development of the method is particularly advantageous if the additional control port is formed as a bistable valve port, in particular as the third bistable valve port, of the bistable valve, because in these cases the additional control pressure can be routed from the additional brake pressure port to the control port of the main valve assembly. In particular, the bistable valve always remains in its venting position. Constantly remaining the bistable valve in its venting position advantageously allows the parking brake to be operated independently of the bistable valve, in particular that the holding valve can vent the control port of the main valve arrangement independently of the bistable valve in order to allow the parking brake to apply to trigger emergency braking.

In a development of the method, it is provided that before the additional control pressure is applied to the control connection, the holding valve is switched to its holding position. A further development of this type is particularly advantageous if the additional control port is arranged in the control line between the holding valve and the control connection of the main valve arrangement.

In a development of the method, it is provided that the additional control port is formed as a first selection valve connection of a selection valve unit for receiving the additional control pressure. In a further development of the method it is provided that the selection valve unit is arranged between the holding valve and a control connection of the main valve unit. In a further development of the method it is provided that the off selector valve unit is arranged between the bistable valve and the holding valve. In a development of the method, it is provided that the additional control port is formed by a bistable valve connection of the bistable valve, in particular a third bistable valve connection, which is pneumatically connected to the holding valve in the venting position and is blocked in particular in the ventilation position.

In a development of the method, it is provided that the venting of the control connection continues via the bistable valve, with the bistable valve being constantly in the venting position during automatic operation. Because the bistable valve is constantly in the venting position during automatic operation, the availability of the fail-safe device is advantageously guaranteed at all times during automatic operation, because venting of the control port of the main valve unit, which would result in braking, depends only on the holding valve.

A development of the method provides that the additional control pressure is provided by an additional brake component and/or by an axle modulator, in particular by a front axle modulator, by a rear axle modulator or by a trailer control valve. In such a development of the method, the additional control pressure can advantageously be provided by an existing compressed air source of the brake system, in particular an axle modulator of the service brake system.

In a further development of the method it is provided that the additional control pressure is formed by a front axle brake pressure or a rear axle brake pressure or a trailer brake pressure or is derived from one of these brake pressures. In such a development, the respective brake pressure, which is provided in particular by an axle modulator of the service brake system, can be used to control the main valve unit in order to release the parking brake cylinder of the brake system.

In a development of the method, it is provided that the loading of the control connection by means of the additional control pressure is terminated when a desired spring-loaded pressure is reached for the spring-loaded pressure provided at the parking brake connection. In such a development of the method, the spring accumulator pressure controlled by the main valve unit is measured, in particular with a pressure sensor. With the knowledge of the modulated spring-loaded pressure, the main valve unit can be closed when the target spring-loaded pressure is reached. In this way, a suitable spring accumulator pressure can always be provided at the parking brake connection in the sense of a control loop.

In a further development of the method, it is provided that the control connection is acted upon by means of the additional control pressure during an actuation period, with the actuation period having a duration of between 0.5 and 1 second. Such a period of time usually gives enough time to build up sufficient control pressure at the control port of the main valve unit.

In a development of the method, it is provided that the additional control pressure is applied to the control connection again when the spring-loaded pressure has dropped to a value below the setpoint spring-loaded pressure. A drop in the spring-loaded pressure to a value below the target spring-loaded pressure can occur, for example, when the pressure present at the control port of the main valve unit drops to a value below a target value for the additional control pressure. A pressure drop at the control port can occur, for example, due to leaks in the control line between the holding valve and the control port of the main valve unit, in particular at the selector valve. As a consequence of a drop in pressure at the control port, the modulated spring-loaded pressure falls to a value below the target spring-loaded pressure. The presence of such leaks can thus be compensated for by applying pressure to the control connection again. In particular, a drop in the modulated spring accumulator pressure can be detected by a pressure sensor that is pneumatically connected to the third main valve connection. The target spring accumulator pressure is preferably between 4 and 8 bar, most preferably 6 bar.

In a further development of the method, it is provided that in order to apply the additional control pressure to the control connection, the holding valve is switched to the open position, and in particular after the application or shortly before the end of the application, the holding valve is switched back to the holding position.

In particular, the method provides for the holding valve to be held in the holding position in order to hold the additional control pressure at the control connection, in particular after the additional control pressure has been applied.

In a second aspect, the invention to achieve the object also specifies an electropneumatic parking brake module for an electronically controllable pneumatic brake system a vehicle, in particular a commercial vehicle, with a reservoir connection for receiving a reservoir pressure, at least one parking brake connection for connecting at least one parking brake cylinder, a main valve unit receiving the reservoir pressure, which is designed to modulate a spring-loaded pressure at the parking brake connection as a function of a control pressure, and one the reservoir pressure receiving pilot valve arrangement for providing the control pressure, the pilot valve arrangement having a bistable valve which can be switched between a first ventilation position and a second venting position, and a control unit for providing first and second switching signals to the pilot valve arrangement, the pilot valve arrangement being connected pneumatically in series with the bistable valve switched and arranged in a control line of the main valve unit, monostable holding valve, wherein the holding valve is de-energized in e is open in the open position, and the control unit is designed to hold the holding valve in the holding position for holding the control pressure by means of the first switching signal, and an additional control port is arranged in the control line for receiving an additional control pressure provided at an additional brake pressure connection.

In the electropneumatic parking brake module according to the second aspect, it is provided that the holding valve automatically switches to an open position for venting the control port in the event of a fault in an electronic component, in particular in a control unit of the brake system, and/or in the event of a power failure, the control port of the main valve arrangement to bleed the parking brake port.

In the case of the electropneumatic parking brake module according to the second aspect of the invention, the advantages of the method according to the first aspect of the invention are used accordingly.

The electropneumatic parking brake module can be further developed in that the additional control port is formed as a first selection valve port of a selection valve unit for receiving the additional control pressure, the selection valve unit having a non-return characteristic at the first selection valve port such that the first selection valve port in a flow direction from the additional brake pressure port via a third selector valve port opens to the control port and blocks against the direction of flow. The non-return characteristic of the selector valve advantageously ensures that the additional control pressure continues to be held at the control port even after the pressure at the additional brake pressure port has dropped. As a result, the main valve unit is actuated in such a way that a spring accumulator pressure for releasing the parking brake cylinders is made available at the parking brake connection. In particular, a selector valve advantageously allows that port of a first and second selector valve port at which the higher pressure is present to open and connect this opened selector valve port to a third selector valve port.

An additional control port, in particular a selection valve unit, can be formed within the scope of the invention in the simplest case by an additional pneumatic connection for the additional brake pressure connection to the control line, which in particular has a reverse locking characteristic.

It is advantageously provided that the selection valve unit is arranged between the holding valve and a control connection of the main valve unit. In such a development, an additional control pressure can advantageously be introduced without the holding valve having to be open.

In particular, it is provided that the selection valve unit is arranged between the bistable valve and the holding valve. In a further development of this type, it is advantageously possible to hold the pressure routed as additional control pressure to the control port of the main valve unit by the holding valve, in particular without requiring a non-return characteristic of the additional control port.

The electropneumatic parking brake module can be further developed in that the additional control port is formed by a bistable valve connection of the bistable valve, in particular a third bistable valve connection, which is pneumatically connected to the holding valve in the venting position and is blocked in particular in the venting position. In such a development, the existing bistable valve can advantageously be used to conduct the additional control pressure into the control line, and an additional valve can be dispensed with.

A trailer valve is advantageously provided, which is preferably designed as a 3/2-way valve, particularly preferably as a 3/2-way solenoid valve. The trailer valve is designed in particular to pneumatically connect the supply port to a trailer port in a first, storage position and to pneumatically connect the third main valve port to the trailer port in a second, control position. A trailer connected to the vehicle can advantageously be supplied with compressed air by means of a trailer valve be provided, in particular optionally with a reservoir pressure or with a spring-loaded pressure. In particular, a parking brake of the trailer can be supplied with spring-loaded pressure by means of a trailer valve.

The electropneumatic parking brake module can be further developed in that the holding valve is arranged between the bistable valve and the control connection of the main valve unit. Such an arrangement of the holding valve has proven to be advantageous, in particular because the volume of the control pressure to be held is advantageously kept low due to the proximity to the control connection.

It is advantageously provided that the holding valve is designed as a 2/2-way solenoid valve. In such a development, the holding valve automatically moves into its open position when the magnet armature of the magnet valve is not energized.

It is advantageously provided that the bistable valve is designed as a 3/2-way bistable solenoid valve.

The electropneumatic parking brake module can be further developed in that the main valve unit has a throttle designed to produce a pneumatic connection between a third main valve port connected to the parking brake port and the control port of the main valve unit.
The pneumatic connection created by the throttle and possibly by a main valve bypass line is such that if the control pressure at the control port drops due to a leak, the control pressure is adjusted to a value of the spring-loaded pressure applied at the third main valve port. Due to the smaller line cross-section of the throttle, such an adjustment takes place slowly in comparison to a compressed air flow—caused by a switching of the holding valve or bistable valve. Such a throttle can advantageously be used to compensate for leaks, in particular in the control line, which lead to a drop in the control pressure at the control connection.

In particular, it is provided that the selector valve unit has a shuttle valve which is designed to connect the first or a second selector valve port to the third selector valve port, with the first and second selector valve port being opened at which the higher pressure is present. In such a development, the non-return characteristic is realized via a valve body that can be moved within the shuttle valve and can be pressed in a sealing manner against both the first selection valve connection and the second selection valve connection. In this way, that one of the first or second selector valve port at which the higher pressure is present is always pneumatically connected to the third selector valve port, and the other of the two is blocked. With such a shuttle valve it is advantageously achieved that a pressure present at the first selector valve port and additionally a pressure present at the second selector valve port do not add up, since the port at which the lower pressure is present is always blocked by the valve body. This reduces the risk of too high and possibly harmful pressure at the control port.

The electropneumatic parking brake module can be further developed in that the shuttle valve has a pretensioning spring for spring-loaded setting of a valve position, in particular for spring-loaded setting of the first valve position. In the first valve position, the first selector valve port leading to the additional brake pressure port is blocked and, in particular, the pilot valve arrangement is connected to the control port (or the bistable valve to the holding valve). By means of such a prestressing spring, the valve body of the shuttle valve can be pressed in a sealing manner against a selector valve connection, in particular the first selector valve connection, by selecting a suitable spring constant with a defined restoring force. The compressed air provided at the additional brake pressure connection must therefore first overcome this restoring force before the first selector valve connection opens. In this way, it is advantageously possible to prevent the first selection valve connection from opening even when there is only a small amount of compressed air applied to the additional brake pressure connection. The valve body is held stably in its valve position, which is defined as the rest position, by the prestressing spring.

The electropneumatic parking brake module can be further developed in that the additional control port and/or the selection valve unit has a check valve that blocks against the flow direction at the first selection valve connection. In such a development, an air flow counter to the direction of flow can be prevented by a valve body that is placed in place in a sealing manner. This advantageously means that a quantity of compressed air provided with an additional control pressure at the additional brake pressure connection can flow to the control connection of the main valve unit, but if the pressure at the additional brake pressure connection drops, the compressed air cannot escape via this. In this way, a non-return characteristic of the selector valve is realized and it can be closed at the control pressure at the control connection must be maintained with its holding valve. In particular, the check valve can have a check valve biasing spring.

The electropneumatic parking brake module can be further developed in that the selection valve unit has a bypass line, the bypass line pneumatically connecting the second and third selection valve ports and having a throttle and/or a bypass check valve. By means of a bypass line, a restoring force can be generated by pressure equalization between the second and third selection valve connection, which restoring force presses a valve body in a sealing manner against the first selection valve connection in order to produce the non-return characteristic. By creating a targeted leakage through the bypass line, when the first selector valve port is pressurized—when the valve body is pressed against the second selector valve port—despite this position of the valve body, the additional control pressure present at the first selector valve port can also be set at the second selector valve port, viz via the bypass line. As a result, after the pressure at the first selection valve connection has dropped, a restoring force is generated by a pressure difference between the first and second selection valve connection, which restoring force presses the valve body sealingly against the first selection valve connection. In a bypass line with a throttle, the restoring force FR is generated in particular because the compressed air flows back through the bypass line much more slowly through the throttle than the air flows back through the first selection valve connection. In the case of a bypass line with a bypass check valve, the additional control pressure for generating the restoring force - which has reached the second selector valve port via the bypass line - is maintained at the second selector valve port, even after the pressure at the first selector valve port has dropped, because a backflow through the bypass check valve is prevented.

In particular, it is provided that the additional control pressure is formed by a front axle brake pressure or a rear axle brake pressure or a trailer brake pressure or is derived from one of these brake pressures. In a further development of this type, an already existing brake pressure—in particular in a service brake system—can advantageously be used as an additional control pressure for actuating the parking brake cylinder. In particular, it is provided that the additional brake pressure connection can be pneumatically connected to a front axle modulator and/or rear axle modulator and/or trailer control valve. In the case of a pneumatic connection of the additional brake pressure connection to a front axle modulator, a front axle brake pressure can advantageously be used as additional control pressure. In the case of a pneumatic connection of the additional brake pressure connection to a rear axle modulator, a rear axle brake pressure can advantageously be used as additional control pressure. When the additional brake pressure connection is pneumatically connected to a trailer control valve, a trailer brake pressure can advantageously be used as the additional control pressure.

In a third aspect of solving the problem, the invention also leads to an electronically controllable pneumatic brake system with a central control unit, at least one axle modulator, a brake value transmitter and at least one spring-loaded brake cylinder, having an electropneumatic parking brake module according to the first aspect of the invention, designed to carry out a Method according to the second aspect of the invention. The advantages of the electropneumatic parking brake module and/or the method are advantageously used in the braking system.

In a development of the electronically controllable pneumatic brake system, the additional brake pressure connection of the electropneumatic parking brake module can be pneumatically connected to a front axle modulator or a rear axle modulator or to a trailer control valve to provide an additional control pressure. In particular, the additional brake pressure connection of the electropneumatic parking brake module is pneumatically connected to the rear axle modulator via an additional control line. In particular, the additional brake pressure connection of the electropneumatic parking brake module is pneumatically connected to the front axle modulator via a further additional control line. In particular, the additional brake pressure connection of the electropneumatic parking brake module is pneumatically connected to the trailer control valve via yet another additional control line.

In a fourth aspect, the invention also specifies a vehicle, in particular a commercial vehicle, for solving the problem, with an electropneumatic parking brake module according to the first aspect of the invention, in particular with a brake system according to the third aspect of the invention. In the vehicle, the advantages of the electropneumatic parking brake module and/or the method and/or the electronically controllable pneumatic brake system are advantageously used.

• einem Vorratsanschluss zum Empfangen eines Vorratsdrucks,
• wenigstens einem Feststellbremsanschluss zum Anschließen wenigstens eines Feststellbremszylinders,
• einer den Vorratsdruck empfangenden Hauptventileinheit, die dazu ausgebildet ist, in Abhängigkeit von einem Steuerdruck einen Federspeicherdruck an dem Feststellbremsanschluss auszusteuern, und
• einer den Vorratsdruck empfangenden Vorsteuerventilanordnung zum Bereitstellen des Steuerdrucks, wobei die Vorsteuerventilanordnung ein Bistabilventil aufweist, das zwischen einer ersten Belüftungsstellung und einer zweiten Entlüftungsstellung umschaltbar ist,
• und einer Steuereinheit zum Bereitstellen von ersten und zweiten Schaltsignalen (S1, S2) an der Vorsteuerventilanordnung,
• dadurch gekennzeichnet, dass
• die Vorsteuerventilanordnung ein mit dem Bistabilventil pneumatisch in Reihe geschaltetes und in einer Steuerleitung der Hauptventileinheit angeordnetes, monostabiles Halteventil aufweist, wobei das Halteventil stromlos in einer Öffnungsstellung geöffnet ist, und
• die Steuereinheit ausgebildet ist, das Halteventil zum Halten des Steuerdrucks mittels des ersten Schaltsignals in der Haltestellung zu halten, und
• in der Steuerleitung zwischen dem Halteventil und einem Steueranschluss der Hauptventileinheit eine Auswahlventileinheit angeordnet ist mit einem ersten Auswahlventilanschluss zum Empfangen eines an einem Zusatz-Bremsdruckanschluss bereitgestellten Zusatzsteuerdrucks, wobei
  • - die Auswahlventileinheit am ersten Auswahlventilanschluss eine Rücksperrcharakteristik aufweist derart, dass der erste Auswahlventilanschluss in einer Strömungsrichtung vom Zusatz-Bremsdruckanschluss über einen dritten Auswahlventilanschluss zum Steueranschluss öffnet und entgegen der Strömungsrichtung sperrt.

Also in a fifth aspect of the invention is an electropneumatic parking brake module intended for an electronically controllable pneumatic brake system for a vehicle, in particular a commercial vehicle

• a reservoir port for receiving a reservoir pressure,
• at least one parking brake connection for connecting at least one parking brake cylinder,
• a main valve unit which receives the reservoir pressure and is designed to modulate a spring accumulator pressure at the parking brake connection as a function of a control pressure, and
• a pilot valve arrangement receiving the reservoir pressure for providing the control pressure, the pilot valve arrangement having a bistable valve which can be switched between a first ventilation position and a second ventilation position,
• and a control unit for providing first and second switching signals (S1, S2) to the pilot valve arrangement,
• characterized in that
• the pilot valve arrangement has a monostable holding valve which is pneumatically connected in series with the bistable valve and is arranged in a control line of the main valve unit, the holding valve being open when de-energized in an open position, and
• the control unit is designed to hold the holding valve in the holding position for holding the control pressure by means of the first switching signal, and
• A selector valve unit is arranged in the control line between the holding valve and a control port of the main valve unit, with a first selector valve port for receiving an additional control pressure provided at an additional brake pressure port, wherein
  • - The selector valve unit at the first selector valve port has a non-return characteristic such that the first selector valve port opens in a flow direction from the additional brake pressure port via a third selector valve port to the control port and blocks against the flow direction.

• - Befüllen des Feststellbremszylinders durch Beaufschlagen des Steueranschlusses der Hauptventilanordnung zum Aussteuern des Federspeicherdrucks an dem Feststellbremsanschluss in Abhängigkeit des Steuerdrucks,

dadurch gekennzeichnet, dass

• - das Beaufschlagen des Steueranschlusses mittels eines Zusatzsteuerdrucks erfolgt, der an dem Zusatz-Bremsdruckanschluss bereitgestellt wird und über die Auswahlventileinheit angenommen wird, wobei
• - zum Beaufschlagen und zum anschließenden Halten des Zusatzsteuerdrucks am Steueranschluss das Halteventil in der Haltestellung gehalten wird.

In a sixth aspect of the invention, a method is also provided for operating an electropneumatic parking brake module according to the fifth aspect of the invention, having the step:

• - Filling of the parking brake cylinder by applying pressure to the control port of the main valve arrangement to modulate the spring-loaded pressure at the parking brake port depending on the control pressure,

characterized in that

• - The control port is acted upon by means of an additional control pressure which is provided at the additional brake pressure port and is accepted via the selection valve unit, wherein
• - the holding valve is held in the holding position for applying and then holding the additional control pressure at the control port.

It should be understood that the method according to the first aspect of the invention, the electro-pneumatic parking brake module according to the second aspect of the invention, the braking system according to the third aspect of the invention, the vehicle according to the fourth aspect of the invention, the electro-pneumatic parking brake module according to the fifth aspect of the invention and the method according to the sixth aspect of the invention have the same and similar sub-aspects as particularly laid down in the dependent claims. In this respect, for the development of one aspect of the invention, reference is also made to the developments of the other aspects of the invention.

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, where helpful in explanation, the drawings are presented in schematic and/or slightly distorted form. With regard to additions to the teachings that can be seen directly from the drawings, reference is made to the relevant state of the art. In this context, it must be taken into account that a wide variety of modifications and changes relating 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. In addition, 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 any subject matter which would be limited in the Comparison to the subject-matter claimed in the claims. In the case of specified design ranges, values within the specified limits should also be disclosed as limit values and be usable and stressable as desired. For the sake of simplicity, the same reference numbers are used below for identical or similar parts or parts with an identical or similar function.

• 1 ein elektropneumatisches Feststellbremsmodul gemäß der Erfindung,
• 2A-D verschiedene Weiterbildungen einer Auswahlventileinheit,
• 3 ein schematischer zeitlicher Verlauf mit unterschiedlichen Schaltstellungen von Feststellbremse, Bistabilventil und Halteventil,
• 4 ein Bremssystem mit einem elektropneumatischen Feststellbremsmodul gemäß der Erfindung,
• 5 eine weitere bevorzugte Weiterbildung eines elektropneumatischen Feststellbremsmoduls gemäß der Erfindung,
• 6 eine noch weitere bevorzugte Weiterbildung eines elektropneumatischen Feststellbremsmoduls gemäß der Erfindung.

Further advantages, features and details of the invention result from the following description of the preferred embodiments and from the drawings; these show in:

• 1 an electropneumatic parking brake module according to the invention,
• 2A-D various developments of a selector valve unit,
• 3 a schematic time course with different switching positions of the parking brake, bistable valve and holding valve,
• 4 a braking system with an electropneumatic parking brake module according to the invention,
• 5 a further preferred development of an electropneumatic parking brake module according to the invention,
• 6 yet another preferred development of an electropneumatic parking brake module according to the invention.

1 shows an electropneumatic parking brake module 10 according to a development of the invention. A supply connection 20, to which a first main line section 80.1 of a main line 80 is connected, is designed to receive compressed air for the electropneumatic parking brake module 10. Further along the main line 80, between a second main line section 80.2 and a third main line section 80.3, there is a main line check valve 86 which is designed to open and open in the filling direction, i.e. in the direction of a filling flow SB flowing from the supply port 20 into the main line 80 to block in the opposite direction.

A relay valve 52 of a main valve unit 50 is connected to the third main line section 80.3, the relay valve 52 being connected to the third main line section 80.3 via a second main valve connection 52.2. The relay valve 52 is designed to pneumatically connect the second main valve connection 52.2 and a third main valve connection 52.3 via appropriate pressurization of a control connection 52.4 in order to modulate a spring accumulator pressure pF at the third main valve connection 52.3. The third main valve connection 52.3 is in turn connected to a fourth main line section 80.4. Via a second main line branch 81.2, the fourth main line section 80.4 is connected to a pressure sensor 92 via a sixth main line section 80.6, and to a parking brake connection 21 via a fifth main line section 80.5 to provide the spring-loaded pressure pF.

The main line 80 has a first main line branch 81.1 between its first main line section 80.1 and the second main line section 80.2, from which a fourth control line section 82.4 of a control line 82 leads to a first bistable valve connection 72.1 of a bistable valve 72 of a pilot valve arrangement 70.

The bistable valve 72 of the pilot valve arrangement 70 is designed as a bistable 3/2-way solenoid valve, which is shown here in a venting position 72B. The bistable valve 72 is designed to produce a pneumatic connection between the first bistable valve connection 72.1 and a third bistable valve connection 72.3 in a ventilation position 72A—not shown here.

The pilot valve assembly 70 includes a hold valve 76 . The third bistable valve connection 72.3 is connected to a first holding valve connection 76.1 of the holding valve 76 via a third control line section 82.3 of the control line 82 . The pilot valve arrangement 70 can be designed as a structural unit, but it is also possible for the bistable valve 72 and the holding valve 76 to be designed as independent components.

The holding valve 76 is designed here as a normally open, 2/2-way solenoid valve and is shown here in its holding position 76A. In the holding position 76A, which is present in particular when the holding valve 76 is energized, the pneumatic connection between the first holding valve port 76.1 and a second holding valve port 76.2 is disconnected.

A second control line section 82.2 is connected to the second holding valve connection 76.2. The second control line section 82.2 is in turn pneumatically connected to a second selection valve connection 54.2 of a selection valve unit 54—in the present case designed as a shuttle valve 56. The shuttle valve 56 has a prestressing spring 56.4, which presses a valve body 56.5 with a spring force against a first selector valve connection 54.1 and thus the shuttle valve 54 is spring-prestressed in a first valve position 54A (see Fig. 2 B ) holds. In the valve position 54A is the second selector valve port 54.2 is pneumatically connected to the third selector valve port 54.3.

A first control line section 82.1 is connected to the third selection valve connection 54.3, which in turn is pneumatically connected to the control connection 52.4 of the relay valve 52. The relay valve 52 can be actuated by actuating the control port 52.4 in order to modulate the spring accumulator pressure pF at the third main valve port 52.3.

A further, alternative compressed air source can be connected to the control connection 52.4 by the selection valve unit 54 for the purpose of actuating the relay valve 52. For this purpose, an additional brake pressure connection 41 is pneumatically connected to the first selector valve connection 54.1 via a fifth control line section 82.5. The first selection valve connection 54.1 is an additional control port 60, via which an additional control pressure pZ provided at the additional brake pressure connection 41 is received.

With the shuttle valve 54 in the embodiment shown here, that one of the first and second selector valve ports 54.1, 54.2 at which the higher pressure prevails is always pneumatically connected to the third selector valve port 54.3. Depending on how a shuttle valve works, the other selector valve port 54.1, 54.2 is always blocked by the valve body 54.5, so that the two pressures present at the two selector valve ports 54.1, 54.2 do not add up, and therefore not one that could be damaging , pressure increase at the control port 52.4.

In further developments of the invention, the additional control port 60, in particular the selection valve 54, can be designed differently, for example as in FIGS 3A until 3D shown.

A first vent line section 84.1 of a vent line 84 is connected to a second bistable valve connection 72.2 of the bistable valve 72. In a venting position 72B of the bistable valve, the third bistable valve connection 72.3 is pneumatically connected to the second bistable valve connection 72.2. In this venting position 72B, the third control line section 82.3 of the control line 82 is therefore pneumatically connected to the first venting line section 84.1.

The first vent line section 84.1 is followed by the second vent line section 84.2, which in turn is connected to a vent port 3 of the electropneumatic parking brake module 10. A third vent line section 84.3 extends from a first main valve connection 52.1 of the relay valve 52 to a vent line junction 85.1, the vent line junction 85.1 being arranged in the vent line 84 between the first vent line section 84.1 and the second vent line section 84.2.

The relay valve 52 also has a throttle 52.5 in a main valve bypass line 52.6, the main valve bypass line 52.6 being designed to produce a pneumatic connection between the third main valve port 54.3 facing the parking brake port 21 and a control port 54.4. The pneumatic connection is formed by the restrictor 52.5 with a relatively small nominal size, so that if the pressure at the control port 54.4 drops due to a leak, in particular the control pressure pS provided in the form of the additional control pressure pZ, this is adjusted again to the level of the triggered spring-loaded accumulator pressure pF by a relatively slow follow-up flow .

with a inside 1 The system shown makes it possible to provide emergency braking functionality, ie functionality for braking a vehicle if there is a power failure or an error signal from a control unit 300 . The emergency brake functionality is provided by maintaining a control pressure pS at the control port 52.4 of the relay valve, by means of which at least one parking brake cylinder 24 is pressurized to release the parking brake. When a failure braking situation occurs, in particular if there is a power failure or an error signal from control unit 300, the parking brake cylinders 24 are correspondingly bled by venting the control connection 52.4 in order to activate the parking brake. The control pressure pS is provided in particular in the form of the additional control pressure pZ via the additional brake pressure connection.

According to the concept of the invention, the control port 52.4 can be vented via the holding valve 76, which automatically becomes de-energized and opens in the event of a power failure FS or an error FA in the control unit 300.

Because an additional control port 60, in particular a selection valve unit 54, is provided according to the invention, the control port 52.4 of the relay valve 52 can also be pressurized, i.e. pressurized with compressed air, when the bistable valve 72 is switched to the venting position 72B.

A combination of holding valve 76 and an additional control port 60, in particular a selection valve unit 54, can thus be pressurized and vented from control port 52.4 of relay valve 52, in particular without having to switch bistable valve 72 to venting position 72A.

This combination advantageously avoids a situation in which a power failure or an error signal from the control unit 300 occurs at a time when the bistable valve 72 is still in the ventilation position 72A and it would therefore not be possible to vent the control port 52.4 to generate contingency braking , because in this case no pneumatic connection could be established between the control port 52.4 and the exhaust port 3.

Emergency braking generated by the parking brake is particularly suitable for operating the vehicle at low speeds, for example around 10 km/h, which occur, for example, when a vehicle is being driven automatically.

In the 2A , 2 B , 2C and 2D different developments of a selector valve unit 54 are shown. In 2A a first development of a selector valve unit 54 is shown, which has a check valve 55 . The check valve 55 is arranged on the first selection valve connection 54.1 in such a way that an air flow flowing in the flow direction SR, ie an air flow flowing from the first selection valve connection 54.1 into the selection valve unit 54, can pass, but an air flow in the opposite direction is prevented by the sealing placement of a valve body 55.5 . The valve body 55.5 is pressed in a sealing manner against the first selector valve connection 54.1 by a check valve pretensioning spring 55.4 with a restoring force FR. In the present case, the check valve 55 implements a non-return characteristic RC, which ensures that even if no pressure is present at the first selector valve port 54.1 or the pressure is lower than that at a second selector valve port 54.2, the control pressure pS present at the control port 52.4 at this point in time is maintained can be.

In 2 B the selector valve unit 54 has a shuttle valve 56 . Analogous to in 2A The further development shown also has this selection valve unit 54 with a non-return characteristic RC by means of a valve body 55.5, which is pressed by means of a further pretensioning spring 56.4 under a restoring force FR to form a seal against the first selection valve connection 54.1. In the 2 B However, the further development shown is further designed such that the valve body 55.5 can be pressed against the second selection valve connection 54.2 by an additional control pressure pZ present at the first selection valve connection 54.1, and thus closes it in a sealing manner. If the additional control pressure pZ present at the first selector valve port 54.1 is higher than a pressure present at the second selector valve port 54.2 and the restoring force FR of the prestressing spring 56.4 is also overcome, then the valve body 55.5 is pressed against the second selector valve port 54.2 in a correspondingly sealing manner.

With a shuttle valve 56, it is advantageously achieved that a pressure present at the first selector valve port 54.1 and additionally a pressure present at the second selector valve port 54.2 do not add up, since the port at which the lower pressure is present is always blocked by the valve body 55.5. In this way, the risk of an excessive and potentially harmful pressure at the control port 52.4 can be reduced.

In the 2C The development of a selection valve unit 54 shown has a further shuttle valve 57, which has a bypass line 57.1 for generating a restoring force FR. The bypass line 57.1 connects the second and third selection valve connection 54.2, 54.3 pneumatically to generate a targeted leakage. As a result, during pressurization via the first selection valve connection 54.1, in which the valve body 55.5 is pressed against the second selection valve connection 54.2, the additional control pressure pZ present at the first selection valve connection 54.1 can also be set at the second selection valve connection 54.2 via the bypass line 57.1. By further providing a throttle 57.2 in the bypass line 57.1, it can advantageously be ensured that after the pressure, in particular the additional control pressure pZ, has dropped at the first selector valve port 54.1, a restoring force FR due to the now at the second selector valve port 54.2 is approximately at the level of the previously applied - Additional control pressure pZ presses the valve body 55.5 sealingly against the first selector valve connection 54.1. The restoring force FR is generated in particular because the compressed air flows back through the bypass line 57.1 much more slowly through the throttle 57.2 than the air flows back through the first selection valve connection 54.1.

At the in 2D shown development with an even further shuttle valve 58 is also generated by a - the second and third selection valve connection 54.2, 54.3 connecting - additional bypass line 58.1 a targeted leakage to generate a restoring force FR. However, here - instead of a throttle - a bypass return check valve 58.2 is provided in the additional bypass line 58.1. The bypass check valve 58.2 ensures that when the selection valve unit 54 is pressurized via the first selection valve connection 54.1—despite the valve body 55.5 being seated in a sealed manner on the second selection valve connection 54.2—compressed air can flow via the additional bypass line 58.1 to the second selection valve connection 54.2, the additional bypass line 58.1 blocks in the opposite direction of flow, however. This ensures that when the pressure drops at the first selector valve port 54.1, which had previously reached the second selector valve port 54.2 via the additional bypass line 58.1 and the additional control pressure pZ held there via the bypass check valve 58.2, the valve body 55.5 is again sealingly pressed against the first selector valve port 54.1 , wherein a restoring force FR is generated by the pressure difference generated between the first and second selector valve port 54.1, 54.2.

In 3 a schematic time sequence of different switching positions 72A, 72B of a bistable valve 72 and switching positions 76A, 76B of a holding valve 76 of an electropneumatic parking brake module 10 is shown. At an initial point in time T0, a vehicle (not shown here) is in a manual operating mode MM, in which a parking brake of the vehicle is generally actuated by a bistable valve 72 and the holding valve 76 is correspondingly constantly in an open position 76B. In the manual operating mode MM, the holding valve 76 is therefore not actuated, ie a first switching signal S1 is 0 and the holding valve 76 is not activated, in particular de-energized, open. At the initial point in time T0, the bistable valve 72 is in a venting position 72B, in which, correspondingly, the control port 52.4 of the relay valve 52 is vented via the vent port 3, and thus no spring-loaded pressure pF is provided at the parking brake port 21, as a result of which the vehicle is in a braking position 24B (see 4 ) - is braked. Due to the braking effect of the venting position 72B on the parking brake, the venting position 72B is also referred to as the parking brake position.

As an example of the manual operating mode MM, it is shown how at a first point in time T1 the bistable valve is switched from the venting position 72B to a venting position 72A by a one-time actuation using a second switching signal S2. After time T1, the parking brake is thus released and the parking brake cylinder 24 is in a release position 24A. Accordingly, the vehicle can be moved normally in manual mode, in particular by a human driver, and braked during operation, in particular by means of a service brake system 206 . At a second point in time T2, the journey is complete and the bistable valve 72 is returned to its venting position 72B by means of a one-time actuation by the second control signal S2, as a result of which the at least one parking brake cylinder 24 is actuated and the vehicle is braked. According to its mode of operation, the bistable valve 72 is only ever actuated for switching and then remains in its switched state without being actuated.

At a third point in time T3, an automatic operating mode MA is initiated, in which emergency braking functionality is provided according to the concept of the invention. The automatic operating mode MA can be used in particular when a vehicle is driving autonomously or automatically at a lower speed, for example when maneuvering on a defined area or the like.

For this purpose, the bistable valve 72 is in its venting position 72B--venting the parking brake cylinder 24--and does not have to be switched during the automatic operating mode MA. The holding valve 76, on the other hand, is switched from its open position 76B to its holding position 76A at the third point in time T3 by activation using the first switching signal S1 and is held in the holding position 76A by corresponding continuous activation using the first switching signal S1.

At a fourth point in time T4, an additional control pressure pZ is now provided at the control port 52.4 via an additional brake pressure port 41 and a selection valve unit 54, as a result of which the relay valve 52 modulates a corresponding spring-loaded pressure pF to release the at least one parking brake cylinder 24 and thus releases the parking brake FB.

Even after the pressure at the additional brake pressure connection 41 has dropped, the additional control pressure pZ is maintained—by the non-return characteristic RC of the selection valve unit 54 and the holding valve 76 located in its holding position 76A.

In the holding position 76A, the holding valve 76 thus assumes the function of the bistable valve 72 in that it holds a control pressure pS at the control port 52.4 of the relay valve 52 in the automatic operating mode MA in order to hold the parking brake cylinder 24 in a release position 24A.

At a fifth point in time T5, an error FA or a power failure FS of the control unit 300 occurs during the automatic operating mode MA. According to the concept of the invention, the first switching signal S1 is omitted at this moment, as a result of which the holding valve 76 automatically jumps back from its holding position 76A to its open position 76B and the parking brake cylinder 24 is vented and thus moved to its braking position 24B to carry out emergency braking.

4 shows an electronically controllable pneumatic brake system 204. The electronically controllable pneumatic brake system 204 is used in the present case in a vehicle 200 designed as a commercial vehicle 202, which is shown here in a highly schematic manner, in particular with two front wheels 212 on a front axle 210 and four rear wheels 222 on a rear axle 220.

A central control unit 700 is connected to a control unit 300 of the electropneumatic parking brake module 10 by means of a central control line 310 in a signal-carrying manner. The control unit 300 is also supplied with power from a power supply 710 via a supply line 320 .

Two service brake cylinders 26, each assigned to a front wheel 212 of front axle 210, can be actuated by means of a brake signal transmitter 718 for braking operation, service brake cylinders 26 being pressurized via a front axle modulator 720 with compressed air from a second compressed air reservoir 752, in that front axle modulator 720 generates a front axle brake pressure pBV provides.

In an analogous manner, two parking brake cylinders 24, each of which is assigned to the rear wheels 222 of the rear axle 220, can have a service brake chamber 28, which, controlled by the brake value sensor 718, can be pressurized with compressed air from a first compressed air reservoir 750 via a rear axle modulator 722 for the purpose of braking. For this purpose, rear axle modulator 722 provides a rear axle brake pressure pBH.

Furthermore, the brake system 204 has a trailer control valve 724 for providing a trailer brake pressure pBA, which can be pneumatically connected to a trailer of the vehicle 200 (not shown here)—to supply a brake system of the trailer.

The two parking brake cylinders 24 each have a spring-loaded brake and are pneumatically connected to a parking brake connection 21 of the electropneumatic parking brake module 10 by means of a parking brake line 760 .

A spring-loaded pressure pF can be provided to the parking brake cylinders 24 by means of the electropneumatic parking brake module 10 in order to pressurize the parking brake cylinder 24 in each case and thus to move it from a braking position 24B into a release position 24A.

Compressed air is made available to the electropneumatic parking brake module 10 from a third compressed air reservoir 754 via a compressed air supply line 762 and a supply connection 20 . Both in the manual operating mode MM and in the automatic operating mode MA, the parking brake cylinders 24 are supplied with compressed air from the third compressed air reservoir 754 via the supply connection 20 in order to switch them to the release position 24A. However, the relay valve 52 is actuated to control the spring-loaded pressure pF in the manual operating mode MM, in that the bistable valve 72 is switched in order to apply pressure from the third compressed air reservoir 754 to the control connection 52.4 of the relay valve 52. In the automatic operating mode MA, on the other hand, the control connection 52.4 is pressurized to activate the relay valve 52 via an additional brake pressure connection 41, which in the present case is fed via an additional control line 764 from the first compressed air reservoir 750. The rear axle brake pressure pBH can be provided via the rear axle modulator 722 via the additional control line 764 as an additional control pressure pZ at the additional brake pressure connection 41, with the rear axle modulator 722 being able to be activated by the central control unit 700 in the automatic operating mode MA - for the selective provision of the rear axle brake pressure pBH as an additional control pressure pZ .

Additionally or alternatively, another additional control line 766 can be provided, which pneumatically connects front axle modulator 720 to additional brake pressure port 41 in order to provide front axle brake pressure pBV as additional control pressure pZ at additional brake pressure port 41 .

Additionally or alternatively, another additional control line 768 can be provided, which pneumatically connects trailer control valve 724 to additional brake pressure port 41 in order to provide trailer brake pressure pBA as additional brake pressure pZ at additional brake pressure port 41 .

The control unit 300 is supplied with power from a power supply 710 via a supply line 320 .

A power failure FS can occur in the control unit 300 if an error in the Energy supply 710 and / or in the supply line 320 is present. Furthermore, an error FA can occur in the control unit 300 if the safety of the vehicle can no longer be guaranteed by the control unit 300 and/or the central control unit 700 . Such a case can exist, for example, when there is a lack of sensor information relevant to driving operation, or when there is conflicting sensor information, or when a state based on sensor information cannot be processed by the control logic.

5 Figure 1 shows another preferred embodiment of an electropneumatic parking brake module 10' according to the invention. In the case of the electropneumatic parking brake module 10′, the additional control port 60′ is formed as a first selection valve connection 54.1 of a further selection valve arrangement 54′ designed as a shuttle valve 56. In contrast to the in 1 The embodiment shown is the further selector valve arrangement 54' in the third control line section 82.3', namely between the bistable valve 72 and the holding valve 76. Accordingly, a first control line section 82.1′ and a second control line section 82.2′ are designed as a common control line section which pneumatically connects the holding valve 76 to the control port 52.4 of the relay valve 52 of the main valve arrangement 50 . In the present case, the parking brake connection 21 has a first parking brake connection 21.1 and a second parking brake connection 21.2. In all embodiments, the parking brake connection 21 can also be designed as a simple parking brake connection 21, such as, for. Am 1 shown.

6 shows another preferred embodiment of an electropneumatic parking brake module 10" according to the invention. In the electropneumatic parking brake module 10", the additional control port 60" is designed as a third bistable valve connection 72.3 of the bistable valve 72. In this development, the third bistable valve connection 72.3 is not or not exclusively used for venting, but is pneumatically connected to the additional control port 41 by means of a fifth control line section 82.5" to receive an additional control pressure pZ. Analogous to the in 5 A first control line section 82.1" and a second control line section 82.2" are configured here as a common control line section.

In the 5 shown development of the electropneumatic parking brake module 10 'and in 6 The development of the electropneumatic parking brake module 10" shown can optionally have a trailer valve 90, which is preferably designed as a 3/2-way valve, particularly preferably as a 3/2-way solenoid valve. The trailer valve is designed in particular, in a first, storage position 90A the supply connection 1 to be connected pneumatically to a trailer connection 22 and, in a second, control position 90B, to be connected pneumatically to the third main valve connection 52.3 to the trailer connection 22. A trailer valve 90 can advantageously be used to supply compressed air to a trailer connected to a vehicle 200, in particular optionally with a reservoir pressure pV or with a spring-loaded pressure pF A trailer valve 90 can be used in particular to supply a parking brake of the trailer with a spring-loaded pressure pF.

Reference List

3

vent port

10

electropneumatic parking brake module

20

supply connection

21

parking brake connector

21.1, 21.2

first, second parking brake connection

22

trailer connection

24

parking brake cylinder

24A

release position

24B

brake position

26

service brake cylinder

28

service brake chamber

41

Auxiliary brake pressure connection

50

main valve unit

52

relay valve

52.1

first main valve port

52.2

second main valve port

52.3

third main valve port

52.4

control port

52.5

throttle

52.6

Main valve bypass line

54

selector valve unit

54.1

first selector valve port

54.2

second selector valve port

54.3

third selector valve port

54.4

control port

54.5

valve body

54A, 54B

Valve position of the selector valve unit

55

check valve

55.4

Check valve bias spring

55.5

valve body

56

shuttle valve

56.4

bias spring

56.5

valve body

57

another shuttle valve

57.1

bypass line

57.2

throttle

58

another changeover valve

58.2

Bypass check valve

60

Auxiliary insertion port

70

pilot valve arrangement

72

bistable valve

72.1

first bistable valve connection

72.2

second bistable valve connection

72.3

third bistable valve connection

72A

Ventilation position of the bistable valve

72B

Venting position of the bistable valve

76

holding valve

76.1

first hold valve port

76.2

second holding valve port

76A

holding position

76B

open position

80

main line

80.1

first main line section

80.2

second main line section

80.3

third main line section

80.4

fourth main line section

80.5

fifth main line section

80.6

sixth main line section

81.1

first main branch

81.2

second main branch

82

control line

82.1

first control line section

82.2

second control line section

82.3

third control line section

82.4

fourth control line section

82.5

fifth control line section

84

vent line

84.1

first vent line section

84.2

second vent line section

84.3

third vent line section

85.1

vent line junction

86

Main line check valve

90

trailer valve

90.1

first trailer valve port

90.2

second trailer valve connection

90.3

third trailer valve port

90A

Trailer valve reserve position

90B

Control position of the trailer valve

92

pressure sensor

200

vehicle

202

commercial vehicle

204

braking system

206

service braking system

210

front axle

212

front wheels

220

rear axle

222

rear wheels

300

control unit

310

central control line

320

supply line

700

central control unit

710

power supply

718

brake signal transmitter

720

front axle modulator

722

rear axle modulator

724

trailer control valve

750

first compressed air supply

752

second compressed air supply

754

third compressed air supply

760

parking brake line

762

compressed air supply line

764

Additional control line

766

further additional control line

768

another additional control line

820

compressed air storage

BEF

filling status

FA

error case

FB

parking brake

FR

restoring force

FS

Power failure

MA

automatic mode of operation

mm

manual mode of operation

pBA

trailer brake pressure

pBH

rear brake pressure

pBV

front axle brake pressure

pF

spring pressure

pFS

Target spring pressure

pHA

rear axle brake pressure

p.s

control pressure

pv

reservoir pressure

pZ

auxiliary control pressure

RC

reverse blocking characteristic

S1

first switching signal

S2

second switching signal

SB

filling flow

SR

flow direction

T0

initial time

T1

first time

T2

second point in time

T3

third point in time

T4

fourth point in time

T5

fifth point in time

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102017001409 A1 [0002, 0003]
• DE 102015008377 A1 [0004]

Claims (24)

Method for operating an electropneumatic parking brake module (10, 10', 10") for an electronically controllable pneumatic brake system (204) for a vehicle (200), in particular a commercial vehicle (202), with a supply connection (20) for receiving a supply pressure (pV) , at least one parking brake connection (21) for connecting at least one parking brake cylinder (24), a main valve unit (50) receiving the reservoir pressure (pV), which is designed to apply a spring-loaded pressure (pF) to the parking brake connection ( 21), and a pilot valve arrangement (70) receiving the reservoir pressure (pV) to provide the control pressure (pS), the pilot valve arrangement (70) having a bistable valve (72) which is positioned between a first ventilation position (72A) and a second ventilation position ( 72B) can be switched over, and a control unit (300) for providing first and second switching signals (S1, S2 ) on the pilot valve arrangement (70), the pilot valve arrangement (70) having a monostable holding valve (76) which is pneumatically connected in series with the bistable valve (72) and is arranged in a control line (82) of the main valve unit (50), the holding valve ( 76) is normally open in an open position (76B), and the control unit (300) is designed to hold the holding valve (76) for holding the control pressure (pS) in the holding position (76A) by means of the first switching signal (S1), and an additional control port (60) is arranged in the control line (82) for receiving an additional control pressure (pZ) provided at an additional brake pressure connection (41), having the step: - filling the parking brake cylinder (24) by pressurizing the control connection (52.4) the main valve arrangement (50) for modulating the spring-loaded pressure (pF) at the parking brake port (21) as a function of the control pressure (pS), wherein - the loading of the control port hlusses (52.4) by means of an additional control pressure (pZ), which is provided at the additional brake pressure connection (41) and is accepted via the additional control port (60), characterized in that - the holding valve (76) in the event of a fault in one electronic component, in particular in a control unit (300) of the brake system (204), and/or automatically switches to an open position (76B) for venting the control port (52.4) in the event of a power failure, with the control port (52.4) of the main valve arrangement (50) for Bleeding the parking brake connection (21) is bled. procedure after claim 1 , characterized in that - to apply the additional control pressure (pZ) to the control connection (52.4), the holding valve (76) is switched to the open position (76B). procedure after claim 1 or 2 , characterized in that - to hold the additional control pressure (pZ) at the control port (52.4), in particular after the control port (52.4) has been acted upon by the additional control pressure (pZ), the holding valve (76) is held in the holding position (76A). . Procedure according to one of Claims 1 until 3 , characterized in that to apply the additional control pressure (pZ) to the control connection (52.4), the bistable valve (72) is switched to the venting position (72B) and/or remains in the venting position (72B). Procedure according to one of Claims 1 until 4 , characterized in that the control port (52.4) is vented further via the bistable valve (72), the bistable valve (72) being constantly in the vent position (72B) in an automatic operating mode (MA). Procedure according to one of Claims 1 until 5 , characterized in that the additional control pressure (pZ) from an additional brake component and/or from an axle modulator (720, 722, 724), in particular from a front axle modulator (720), from a rear axle modulator (722) or from a trailer control valve (724 ), provided. Procedure according to one of Claims 1 until 6 , characterized in that the additional control pressure (pZ) is formed by a front axle brake pressure (pBV) or a rear axle brake pressure (pBH) or a trailer brake pressure (pBA) or from one of these brake pressures (pBV, pBH, pBA) is derived. Procedure according to one of Claims 1 until 7 , characterized in that the loading of the control connection (52.4) by means of the additional control pressure (pZ) is terminated when a desired spring-loaded pressure (pFS) for the spring-loaded pressure (pF) provided at the parking brake connection (21) is reached. Procedure according to one of Claims 1 until 8th , characterized in that the loading of the control connection (52.4) by means of the additional control pressure (pZ) during a loading period (TB) takes place, the loading period (TB) having a duration between 0.5 and 1 second. Procedure according to one of Claims 1 until 9 , characterized in that the control connection (52.4) is acted upon again by means of the additional control pressure (pZ) when the spring-loaded pressure (pF) has dropped to a value below the setpoint spring-loaded pressure (pFS). Procedure according to one of Claims 1 until 10 , characterized in that before the additional control pressure (pZ) is applied to the control connection (52.4), the holding valve (76) is switched to its holding position (76A). Electropneumatic parking brake module (10, 10', 10") for an electronically controllable pneumatic brake system (204) for a vehicle (200), in particular a commercial vehicle (202), with a supply connection (20) for receiving a supply pressure (pV), at least one parking brake connection (21) for connecting at least one parking brake cylinder (24), a main valve unit (50) receiving the supply pressure (pV), which is designed to modulate a spring-loaded pressure (pF) at the parking brake connection (21) as a function of a control pressure (pS), and a pilot valve arrangement (70) receiving the reservoir pressure (pV) for providing the control pressure (pS), the pilot valve arrangement (70) having a bistable valve (72) which can be switched over between a first ventilation position (72A) and a second ventilation position (72B). , and a control unit (300) for providing first and second switching signals (S1, S2) to the pilot valve arrangement ng (70), wherein the pilot valve arrangement (70) has a monostable holding valve (76) which is pneumatically connected in series with the bistable valve (72) and is arranged in a control line (82) of the main valve unit (50), the holding valve (76) being currentless is open in an open position (76B), and the control unit (300) is designed to hold the holding valve (76) for holding the control pressure (pS) in the holding position (76A) by means of the first switching signal (S1), and in the control line (82) an additional control port (60) is arranged to receive an additional control pressure (pZ) provided at an additional brake pressure connection (41), characterized in that - the holding valve (76) in the event of a fault in an electronic component, in particular in a Control unit (300) of the brake system (204) and/or automatically switches to an open position (76B) for venting the control connection (52.4) in the event of a power failure, the control connection (52.4) of the Main valve assembly (50) for venting the parking brake port (21) is vented. Electropneumatic parking brake module (10, 10', 10") claim 12 , characterized in that the additional control port (60) is formed as a first selection valve connection (54.1) of a selection valve unit (54) for receiving the additional control pressure (pZ), wherein - the selection valve unit (54) at the first selection valve connection (54.1) has a non-return characteristic ( RC) in such a way that the first selector valve port (54.1) opens in a flow direction (SR) from the additional brake pressure port (41) via a third selector valve port (54.3) to the control port (52.4) and blocks against the flow direction (SR). Electropneumatic parking brake module (10, 10', 10") Claim 13 , characterized in that the selection valve unit (54) between the holding valve (76) and a control port (52.4) of the main valve unit (50) is arranged. Electropneumatic parking brake module (10, 10', 10") Claim 13 , characterized in that the selection valve unit (54) is arranged between the bistable valve (72) and the holding valve (76). Electropneumatic parking brake module (10, 10', 10") claim 12 , characterized in that the additional control port (60) is formed by a third bistable valve connection (72.3) of the bistable valve (72) which is pneumatically connected to the holding valve (76) in the venting position (72B). Electropneumatic parking brake module (10, 10', 10") according to one of Claims 12 until 16 , characterized in that the selector valve unit (54) has a shuttle valve (56) which is designed to connect the first or a second selector valve port (54.1, 54.2) to the third selector valve port (54.3), wherein from the first and second selector valve port ( 54.1, 54.2) the one to which the higher pressure is applied is opened. Electropneumatic parking brake module (10, 10', 10") Claim 17 , characterized in that the shuttle valve (54) has a prestressing spring (54.4) for spring-loaded fixing of a valve position (54A, 54B), in particular for spring-loaded fixing of the first selection valve connection (54.1) leading to the additional brake pressure connection (41) blocking, valve position (54A). Electropneumatic parking brake module (10, 10', 10") according to one of Claims 12 until 18 , characterized in that the additional control port (60) and/or the selection valve unit (54, 54') at the first selection valve connection (54.1) has a check valve (55) blocking against the direction of flow (SR). Electropneumatic parking brake module (10, 10', 10") according to one of Claims 12 until 19 , characterized in that the selection valve unit (54, 54') has a bypass line (57.1, 58.1), the bypass line (57.1, 58.1) connecting the second and third selection valve connection (54.2, 54.3) pneumatically and a throttle (57.2) and/or or has a bypass check valve (58.2). Electropneumatic parking brake module (10, 10', 10") according to one of Claims 12 until 20 , characterized in that the additional control pressure (pZ) is formed by a front axle brake pressure (pBV) or a rear axle brake pressure (pBH) or a trailer brake pressure (pBA) or from one of these brake pressures (pBV, pBH, pBA) is derived. Electronically controllable pneumatic brake system (204) with a central control unit (700), at least one axle modulator (720, 722, 724), a brake signal transmitter (730) and at least one spring-loaded brake cylinder (24), having an electropneumatic parking brake module (10, 10', 10") after one of the Claims 11 until 20 , designed to carry out a method according to one of Claims 1 until 11 . Electronically controllable pneumatic braking system (204). Claim 22 , characterized in that the additional brake pressure connection (41) of the electropneumatic parking brake module (10, 10', 10") with a front axle modulator (720) or a rear axle modulator (722) or with a trailer control valve (724) for providing an additional control pressure ( pZ) can be connected pneumatically. Vehicle (200), in particular commercial vehicle (202), with an electropneumatic parking brake module claim 12 until 21 , In particular with an electronically controllable pneumatic brake system (204). Claim 22 or 23 .

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