DE102024111771B3 - ELECTROPNEUMATIC BRAKE SYSTEM - Google Patents

Abstract

The invention relates to an electropneumatic braking device for a guided vehicle (B) that can be coupled into a train set with at least one leading vehicle (A), comprising a main air line (1) that can be coupled air-tight between adjacent vehicles of the train set and that controls the compressed air brakes of the vehicles of the train set, the pressure of which main air line can be influenced in each guided vehicle (B) by means of at least one electrically switchable brake valve (2) and at least one electrically switchable release valve (3). This is intended to enable an increase in the braked weight of a train set led by a traction vehicle. This is achieved in that the braking device further comprises an electrical transmission means (4) comprising at least one first wire (41) and a second wire (42) for energizing the at least one electrically controllable brake valve (2) and the at least one electrically controllable release valve (3) by means of a control voltage, wherein both wires (41, 42) can each be electrically coupled between adjacent vehicles of the train set.
wherein each brake valve (2) is designed to close when a control voltage is applied and each release valve (3) is designed to open when a control voltage is applied, wherein the at least one brake valve (2) and the at least one release valve (3) are connected in parallel to one another in the electrical transmission means (4), and wherein each brake valve (2) is connected in a current-direction-independent manner and each release valve (3) is connected in a current-direction-dependent manner in the electrical transmission means (4).

Description

The invention relates to an electropneumatic braking device of a guided vehicle which can be coupled into a train with at least one leading vehicle, with a main air line which can be coupled air-tight between adjacent vehicles of the train and which controls the compressed air brakes of the vehicles of the train, the pressure of which main air line can be influenced in each guided vehicle by means of at least one electrically switchable brake valve and at least one electrically switchable release valve.

Braking of moving rail vehicles is usually achieved using pneumatically controlled indirect air brakes. For this purpose, all vehicles in a train are connected to one another via a continuous air line (the so-called "main air line"). A drop in pressure in the main air line controls the braking system of each individual vehicle into a braking state. Even in the event of an unintentional drop in pressure in the main air line, for example due to a leak or a separation of the train between two vehicles, the brakes are activated in all vehicles, especially in vehicles separated from the train. A disadvantage, however, is the time delay in the propagation of the pressure drop in the main air line from a leading vehicle, which controls the pressure in the main air line, towards the other vehicles in the train. This means that the braking effect on each vehicle controlled by the pressure drop in the main air line begins later the further away from the leading vehicle. This can cause unbraked vehicles at the end of the train, particularly in long trains, to push against already braked vehicles in the front section of the train in front.

To remedy this problem, generic electropneumatic braking systems have long been known from the state of the art. These enable electrically transmitted brake request signals to be applied simultaneously to all brakes in the entire train. In this way, a braking effect is achieved on all brakes in the entire train at the same time, and dynamic longitudinal forces in the train caused by the delayed response of brakes in the train can be reduced to a minimum. While in a direct-acting electropneumatic basic system, the brake cylinders are directly pressurized and vented via electric brake and release valves, in an indirect-acting electropneumatic basic system, the pressure in the main air line is influenced via the brake and release valves, which are combined in an electropneumatic control unit located on each vehicle in a train. The brake and release valves are usually designed as electrically controllable solenoid valves. To initiate a braking operation, the brake valve is activated, which vents the main air line to the atmosphere. To release the brake, the release valve increases the pressure in the main air line from a supply air reservoir, with the supply air reservoir being refilled from a main air reservoir line separate from the main air line. As a fallback, the brake remains purely pneumatically controlled via the main air line.

This so-called "indirect electropneumatic brake" has become established in Europe as the standard for trainsets hauled by a leading traction unit. The electrical braking and release signals are generated in the leading vehicle in parallel with the control of the pressure in the main air line and transmitted via electrical lines to all vehicles in the trainset. This ensures simultaneous control of the relevant braking and release valves throughout the entire trainset.

However, the brake valve of such an indirect electropneumatic brake must be energized to assist in venting the main brake line. If energization is missing, for example, in the event of a train separation, no venting support is available and thus—if the affected vehicle is sufficiently far away from the leading vehicle in the train formation—no rapid brake activation is possible, which in turn causes the aforementioned problems due to longitudinal dynamic forces within the train formation. Thus, according to current regulations, the positive effects of an indirect electropneumatic brake, particularly in trains hauled by a traction unit, may not be considered operationally, and thus the permissible braked weight of such a train may not be increased despite electropneumatic brake activation.

Out of DE 32 09 157 A1 A system for monitoring the safety status of a train consisting of several track-bound vehicles is known, in which two monitoring devices each performing a monitoring function (e.g. door closure, train completeness) are connected by means of separate monitoring lines which are fed at opposite ends of the train from a common power supply loop running through the entire train.

Out of CH 474 931 A is a device for automatically controlling and recording processes within a train set, which is based on an electrical transmission of commands between the vehicles of the train set by means of appropriately designed transmitters and receivers on the vehicles and represents an early precursor to later train bus transmission systems.

Out of WO 2006/027165 Finally, a method for forming a train from individual wagons without traction equipment is known, which provides for a first autonomously operated individual wagon which is equipped to transmit energy and/or information to other non-autonomously operated individual wagons of the train set.

The invention is therefore based on the technical object of providing a generic electropneumatic braking device which overcomes this aforementioned disadvantage and in particular enables the braked weight of a train set driven by a traction vehicle, in particular a freight train, to be increased.

• ▪ die Bremseinrichtung ferner ein mindestens eine erste Ader sowie eine zweite Ader umfassendes elektrisches Übertragungsmittel zur Bestromung des mindestens einen elektrisch ansteuerbaren Bremsventils sowie des mindestens einen elektrisch ansteuerbaren Löseventils mittels einer Steuerspannung aufweist, wobei beide Adern zwischen benachbarten Fahrzeugen des Zugverbandes jeweils elektrisch koppelbar sind,
• ▪ wobei jedes Bremsventil bei Anliegen einer Steuerspannung schließend und jedes Löseventil bei Anlegen einer Steuerspannung öffnend ausgeführt ist,
• ▪ wobei das mindestens eine Bremsventil und das mindestens eine Löseventil in Parallelschaltung zueinander im elektrischen Übertragungsmittel verschaltet sind,
• ▪ und wobei jedes Bremsventil stromrichtungsunabhängig sowie jedes Löseventil stromrichtungsabhängig im elektrischen Übertragungsmittel verschaltet sind.

This is achieved according to the invention in that

• ▪ the braking device further comprises an electrical transmission means comprising at least one first wire and a second wire for supplying current to the at least one electrically controllable brake valve and the at least one electrically controllable release valve by means of a control voltage, wherein both wires can be electrically coupled between adjacent vehicles of the train set,
• ▪ each brake valve is designed to close when a control voltage is applied and each release valve is designed to open when a control voltage is applied,
• ▪ wherein the at least one brake valve and the at least one release valve are connected in parallel to one another in the electrical transmission means,
• ▪ and each brake valve is connected in the electrical transmission medium independently of the current direction and each release valve is connected in the electrical transmission medium dependent on the current direction.

• 1) erster Betriebszustand: bei Bestromung des elektrischen Übertragungsmittels mit einer Steuerspannung erster Polarität ist das Bremsventil bestromt und somit in geschlossener Stellung, während das Löseventil unbestromt und somit in ebenfalls geschlossener Stellung ist. In einem solchen ersten Betriebszustand wird die Hauptluftleitung weder über das Bremsventil ins Freie entlüftet noch über das Löseventil aus dem Vorratsbehälter nachgespeist. Somit wird der Druck in der Hauptluftleitung auf einem zuvor erreichten Druckniveau gehalten, was eine ungebremste Fahrt des zur Bremse zugehörigen Fahrzeugs ermöglicht.
• 2) zweiter Betriebszustand: bei Bestromung des elektrischen Übertragungsmittels mit einer zur Steuerspannung erster Polarität entgegengesetzten zweiten Polarität ist das Bremsventil dennoch bestromt und somit in geschlossener Stellung, während das Löseventil ebenfalls bestromt, aber in geöffneter Stellung ist. In einem solchen zweiten Betriebszustand wird die Hauptluftleitung nicht über das Bremsventil ins Freie entlüftet, jedoch über das Löseventil aus dem Vorratsbehälter nachgespeist. Somit wird der Druck in der Hauptluftleitung gegenüber einem vorherigen Druckniveau erhöht, was ein Füllen der Hauptluftleitung bzw. Lösen der Bremse, beispielsweise nach einer vorangegangenen Druck-Absenkung bzw. Bremsung, ermöglicht.
• 3) dritter Betriebszustand: bei Unterbrechung der Bestromung bzw. Steuerspannung des elektrischen Übertragungsmittels sind sowohl das Bremsventil als auch das Löseventil unbestromt. Somit sind das Bremsventil in geöffneter Stellung und das Löseventil in geschlossener Stellung. In einem solchen dritten Betriebszustand wird die Hauptluftleitung über das Bremsventil ins Freie entlüftet, ohne einer Nachspeisung aus dem Vorratsbehälter. Somit wird der Druck in der Hauptluftleitung gegenüber einem vorherigen Druckniveau abgesenkt, was ein Bremsen des Fahrzeugs ermöglicht.

This creates an electropneumatic braking system that eliminates the need for energizing the brake valve to assist in venting the main air line. This is achieved by switching the electropneumatic braking system between three operating states by interrupting or reversing the polarity of the control voltage in the electrical transmission medium, as follows:

• 1) First operating state: When the electrical transmission medium is energized with a first-polarity control voltage, the brake valve is energized and thus in the closed position, while the release valve is de-energized and thus also in the closed position. In this first operating state, the main air line is neither vented to the atmosphere via the brake valve nor replenished from the reservoir via the release valve. Thus, the pressure in the main air line is maintained at a previously reached pressure level, allowing the vehicle associated with the brake to travel without braking.
• 2) Second operating state: When the electrical transmission medium is energized with a second polarity opposite to the control voltage of the first polarity, the brake valve is still energized and thus in the closed position, while the release valve is also energized but in the open position. In such a second operating state, the main air line is not vented to the atmosphere via the brake valve, but is replenished from the reservoir via the release valve. Thus, the pressure in the main air line is increased compared to a previous pressure level, which enables the main air line to be filled or the brake to be released, for example, after a previous pressure reduction or braking.
• 3) Third operating state: When the power supply or control voltage of the electrical transmission medium is interrupted, both the brake valve and the release valve are de-energized. Thus, the brake valve is in the open position and the release valve is in the closed position. In this third operating state, the main air line is vented to the atmosphere via the brake valve without replenishment from the reservoir. This reduces the pressure in the main air line compared to a previous pressure level, enabling the vehicle to brake.

Thus, in the aforementioned third operating state of the electropneumatic braking system, the main air line is vented when the brake valve is de-energized. This represents a significant advantage over the previous state of the art, as the brake support provided by the electropneumatic braking system can be used to decelerate the vehicle or train even in the event of an interrupted power supply to the electrical transmission system, for example, due to a train separation.

To set these three aforementioned operating states, a DC voltage source can be provided on the vehicle or traction unit leading the train set, which can be interrupted by means of a first switching means, the polarity of which can be switched or reversed by means of a second switching means. To trigger the brake during a service, full, or emergency braking of the train set initiated by the brake control, the supply voltage on the leading vehicle of the train set is interrupted by means of the first aforementioned switching means, so that the at least one brake valve in each vehicle of the train set opens and in this way synchronizes and accelerates the drop in pressure in the main air line in all vehicles of the train set. Furthermore, the at least one brake valve of each vehicle can be connected by means of an upstream rectifier in the electrical transmission means, so that a control voltage polarity is applied to each brake valve that is independent of the switching state of the aforementioned second switching means. In contrast, the at least one release valve is connected in series with a blocking diode and can therefore only be energized during the aforementioned second operating state and is therefore in the open position.

The inventive idea further provides that the braking device comprises a first pressure switch which can be actuated by means of the pressure in the main air line and which is designed to interrupt the second wire of the electrical transmission means as soon as the pressure in the main air line falls below a first switching pressure below the pressure value set during full braking of the train set.

This enables the transmission device in all following vehicles in the same trainset to be immediately de-energized, thus enabling the immediate activation of the brake valves of each subsequent vehicle in the trainset. However, the pressure drop in the main air line propagating toward the leading vehicle in the same trainset causes a delayed response of the first pressure switches of each leading vehicle in the trainset, thus resulting in a delayed or successive response of the brake valves of the leading vehicles in the trainset. The resulting stretching of the braked trainset is unproblematic with regard to the force dynamics within the trainset.

It is particularly advantageous if the braking device comprises a second pressure switch which can be actuated by means of the pressure in the main air line and which is designed to energize an electrically controllable relay for switching an electrical bridging of the aforementioned interruption in the second wire of the electrical transmission means and for energizing the at least one brake valve. The switching pressure of the second pressure switch is lower than the switching pressure of the first pressure switch. Thus, the switching pressure of the first pressure switch represents an upper switching point and the switching pressure of the second pressure switch represents a lower switching point of the braking device. The switching contact of the second pressure switch is closed as long as the pressure in the main air line is below the lower switching point and opens when this point is exceeded.

The electrical control of the aforementioned relay enables the electrical conductivity of the electrical transmission medium to be restored by closing the aforementioned interruption in the second wire, thus restoring the power supply to the vehicles following in the train, and re-energizing its own brake valve as soon as the polarity of the DC voltage source on the leading vehicle or the current direction in the electrical transmission medium is switched according to the aforementioned second operating state. To ensure the current direction dependency of the current supply to the brake valve, appropriately oriented blocking diodes can also be provided in all lines of the transmission medium connecting the respective brake valve to the DC voltage source. This switching state of the second pressure switch is maintained as long as the pressure in the main air line is below the switching pressure of the second pressure switch or the lower switching point.

Furthermore, the second pressure switch is designed to switch a third electrical connection which is dependent on the current direction and is connected in parallel to the at least one brake valve and release valve in the electrical transmission means in order to energize the relay.

Additionally, the first pressure switch is configured to open or close the third electrical connection that energizes the relay. In this way, the relay goes into self-holding mode by closing a third relay contact as soon as the pressure in the main air line exceeds the switching pressure of the second pressure switch or the lower switching point, but still remains below the switching pressure of the first pressure switch or the upper switching point. This mode is only released once the pressure in the main air line exceeds the switching pressure of the first pressure switch or the upper switching point again.

• 1: Schaltplan einer erfindungsgemäßen Bremseinrichtung in Bezug auf das führende Fahrzeug eines Zugverbands
• 2: Schaltplan einer erfindungsgemäßen Bremseinrichtung in Bezug auf ein geführtes Fahrzeug eines Zugverbands

The present invention is explained in more detail below using an exemplary embodiment and the accompanying drawings. It shows:

• 1 : Circuit diagram of a braking device according to the invention in relation to the leading vehicle of a train
• 2 : Circuit diagram of a braking device according to the invention in relation to a guided vehicle of a train

The one in the 1 and 2 The circuit diagram shown visualizes an electropneumatic braking device according to the invention in a currentless and pressureless state, with all actuating devices being shown in an unactuated initial state. The circuit diagram schematically visualizes the electrical and pneumatic integration of a train set, formed by a leading traction vehicle (A) and a plurality of similarly equipped driven vehicles (B), with 1 the circuit diagram of the leading vehicle of the train and in 2 the circuit diagram of a single guided vehicle (B) is shown in a highly abstract manner.

From a pneumatic point of view, all vehicles (A, B) of the train are connected to each other by means of a main air line (1), whereby the main air lines of adjacent vehicles are connected by means of connecting hoses (in 1 or 2 not shown) are pneumatically coupled throughout. A pressure reduction in the main air line (1) controls the braking system (in 2 not shown) of each guided vehicle (B) into a braking state. From an electrical point of view, all guided vehicles (B) of the train are connected by means of an electrical transmission means (4) formed from two wires (41, 42) for transmitting electrical brake request signals to the brakes of the vehicles, wherein the wires (41, 42) of said transmission means can be electrically connected between two adjacent vehicles of the same train by means of a coupling means (48). Furthermore, each guided vehicle (B) has at least one brake valve (2) and at least one release valve (3), which are designed to influence the pressure in the main air line (1) as a function of the aforementioned electrical request signals. For this purpose, the brake and release valves are designed as electrically controllable solenoid valves. The electrical braking and release signals are generated in the leading vehicle (A) in parallel with the control of the pressure in the main air line and are transmitted via the wires (41, 42) of the electrical transmission means (4) to each driven vehicle (B) of the train. To initiate a braking process, the brake valve (2) is activated, which vents the main air line (1) to the atmosphere. To release the brake, the pressure in the main air line (1) is increased from a supply air reservoir (11) by means of the release valve (3), whereby the supply air reservoir (11) is supplied from a main air reservoir line (in 2 not shown). By means of a shut-off valve (12) arranged between the main air line (1) and the brake valve (2), the brake valve (2) can be separated or deactivated, so that the brake of a guided vehicle (B) can also be controlled exclusively pneumatically via the main air line (1) in an alternative operating mode. By means of an electrical switch, the voltage supply to the brake valve (2) can be interrupted when the shut-off valve (12) is in the shut-off state. For reasons of clarity, only one brake valve (2) and one release valve (3) are shown as examples in the guided vehicle (B). However, the inventive idea is not limited to such a singularity, but is in principle also applicable to a plurality of brake or release valves.

Furthermore, each guided vehicle (B) has a manually operated push button (T1, T2) on each of its two long sides, as well as an indicator light for manually testing the functionality of the braking system. Each push button (T1, T2) has three switching positions. The first switching position represents the de-actuated state of the push button (T1, T2). In this first switching position, the voltage supply for the brake valve (2) is active and the brake valve (2) is energized. In a second switching position, the indicator light belonging to the button (T1, T2) is connected in parallel to the brake valve (2) so that it lights up when voltage is applied. This second switching position is used to check whether the associated brake valve (2) is supplied with voltage. In a third switching position, the voltage supply to the brake valve (2) and the indicator light is interrupted. This third switching position is used to check whether the brake valve (2) actually vents the main air line (1) when de-energized.

The leading vehicle (A) has a DC voltage source (43) that can be switched on and off to generate a control voltage that can be transmitted to the driven vehicle (B) via the wires (41, 42) of the electrical transmission means (4), a switching means (46) designed as a relay to switch the polarity of this control voltage, and a wire interruption means (471) acting on the second wire (42), by means of which the control voltage can be interrupted in the event of a service, emergency or full braking triggered by the brake control. In addition, further wire interruption means (472, 473) acting on both wires (41, 42) are provided, by means of which the control voltage can be interrupted, for example, in the event of a train protection system (in 1 not further described emergency braking triggered by the brake system.

In the guided vehicle (B), the brake valve (2) and the release valve (3) are connected in parallel to one another in the electrical transmission means (4), wherein the brake valve (2) is connected in a current direction-independent manner by means of an upstream rectifier circuit (45), and the release valve (3) is connected in the electrical transmission means (4) by means of a blocking diode (D4). Furthermore, a first pressure switch (5) and a second pressure switch (6) are provided, each connected to the main air line (1), wherein the switching point of the second pressure switch (6) is set lower than the switching point of the first pressure switch (5). The first pressure switch (5) has three switching contacts (51, 52, 53), two first switching contacts (51, 52) being provided for switching an interruption of the second wire (42) of the electrical transmission medium (4), and a third switching contact (53) being provided for switching a voltage supply to a relay (7) designed to electrically bridge this aforementioned interruption of the second wire (42). The second pressure switch (6) has a switching contact (61), which is also designed to switch a voltage supply to this aforementioned relay (7). The aforementioned relay (7) for switching the electrical bridging of the interruption of the second wire (42) has three switching contacts (71, 72, 73), two first switching contacts (71, 72) being provided for the aforementioned electrical bridging of the interruption of the second wire (42) which can be brought about by the switching contacts (51, 52) of the first pressure switch (5), and a third switching contact (73) being provided for the self-holding of the relay (7).

Using this circuit diagram, the functions of the braking device according to the invention are discussed below in different operational scenarios during vehicle operation.

• In einem ersten Betriebszustand befindet sich das Umschaltmittel (46) in einer ersten Schaltstellung und die Bestromung des elektrischen Übertragungsmittels (4) erfolgt mit einer Steuerspannung erster Polarität (erste Ader (41): negativ, zweite Ader (42): positiv). Das Bremsventil (2) ist bestromt und somit in geschlossener Stellung, während das Löseventil (3) - bedingt durch die Sperr-Wirkung der mit diesem in Reihe geschalteten Sperr-Diode (D4) - unbestromt ist und somit in ebenfalls geschlossener Stellung ist. In einem solchen ersten Betriebszustand wird die Hauptluftleitung (1) weder über das Bremsventil (2) ins Freie entlüftet noch über das Löseventil (3) aus dem Vorratsluftbehälter (11) nachgespeist. Somit wird der Druck in der Hauptluftleitung (1) auf einem zuvor erreichten Druckniveau gehalten, was eine ungebremste Fahrt des Fahrzeugs (B) ermöglicht.

By means of the switching means (46), the control voltage generated by the DC voltage source (43) can be switched between two polarities and interrupted by means of wire interruption means (471, 472, 473). This initially results in the following operating states of the braking device:

• In a first operating state, the switching means (46) is in a first switching position, and the electrical transmission means (4) is energized with a control voltage of first polarity (first wire (41): negative, second wire (42): positive). The brake valve (2) is energized and thus in the closed position, while the release valve (3) - due to the blocking effect of the blocking diode (D4) connected in series with it - is de-energized and thus also in the closed position. In such a first operating state, the main air line (1) is neither vented to the atmosphere via the brake valve (2) nor replenished from the supply air tank (11) via the release valve (3). Thus, the pressure in the main air line (1) is maintained at a previously reached pressure level, which enables the vehicle (B) to travel without braking.

In a second operating state, the switching means (46) is in a second switching position, and the electrical transmission means (4) is energized with a second polarity opposite to the aforementioned first operating state (first wire (41): positive, second wire (42): negative). In this case, the brake valve (2) remains energized and thus in the closed position due to the upstream rectifier circuit (45), while the release valve (3) is also energized and thus in the open position. In such a second operating state, the main air line (1) is not vented to the atmosphere via the brake valve (2), but is replenished via the release valve from the supply air reservoir (11). The pressure in the main air line (1) is thus increased compared to a previous pressure level, which enables the main air line (1) to be filled or the brake to be released, for example, after a previous pressure reduction or braking.

In a third operating state, the current supply or control voltage of the electrical transmission means (4) is interrupted by actuating one of the wire interruption means (471, 472, 473), regardless of the position of the switching means (46). Thus, both the brake valve (2) and the release valve (3) are de-energized; the brake valve (2) is therefore in the open position and the release valve (3) in the closed position. In such a third operating state, the main air line (1) is vented to the atmosphere via the brake valve (2) without replenishment from the supply air reservoir (11). The pressure in the main air line (1) is thus reduced compared to a previous pressure level, which enables the vehicle to brake.

To fill an empty main air line (1), the (in 1 or 2 not shown) control of the braking device, a voltage with a second polarity (ie the switching means (46) is in the second switching position) is switched to the two wires (41, 42) of the electrical transmission means (4), so that the blocking diodes (D2, D3, D4) have no blocking effect. The release valve (3) is thus energized and in the open position; the Brake valve (2) is energized and in the closed position. The first two switching contacts (51, 52) of the first pressure switch (5) are open when the main air line (1) is still empty or only slightly filled. The third switching contact (53) of the first pressure switch (5) and the switching contact (61) of the second pressure switch (6) are closed when the main air line (1) is still empty or only slightly filled, and the relay (7) is thus energized. The relay (7) has three switching contacts (71, 72, 73) which are closed when the relay (7) is energized. Two of these switching contacts (71, 72) electrically bridge the second wire (42) interrupted by the switching contacts (51, 52) of the first pressure switch (5), and the relays in the vehicles following in the train are thus also energized in a similar way. The brake valve (2) is thus energized via the rectifier circuit (45) and is in the closed position. In this way, the main air line (1) at the brake valve (2) is sealed from the environment and can be actuated either via a driver's brake valve (in 1 not shown) and additionally via the open release valve (3) from the supply air tank (11). As soon as the pressure in the main air line (1) exceeds the lower switching point or the switching pressure of the second pressure switch (6), the switching contact (61) of the second pressure switch (6) is opened. However, this opening is initially bridged by the still closed third switching contact (73) of the relay (7) so that the main air line (1) can continue to be filled as shown above. As soon as the pressure in the main air line (1) exceeds the upper switching point or the switching pressure of the first pressure switch (5), the first two switching contacts (51, 52) of the first pressure switch (5) are closed and thus also the interruption of the second wire (42). At the same time, the third switching contact (53) of the first pressure switch (5) is opened, thus de-energizing the relay (7) and opening its switching contacts (71, 72, 73). The pressure in the main air line (1) has now reached a "service brake pressure range" above the so-called "full brake pressure," i.e., it is within a pressure range intended for the intended operation of the vehicle (B) or train.

In case of a break in the connecting hose (in 1 or 2 not shown), which connects the main air line (1) of the driven vehicle (B) with the main air line of the leading vehicle (A), an almost sudden drop in pressure occurs in the part of the main air line of the train set which trails the separation point, i.e. thus also in the main air line (1) of the driven vehicle (B). When the pressure in the main air line (1) drops below the aforementioned "full brake pressure", the first pressure switch (5) closest to the separation point opens the second wire (42) of the transmission means (4) by means of the two first switching contacts (51, 52) and closes the third switching contact (53) for energising the relay (7). Due to the aforementioned separation of the second wire (42) of the transmission means (4), the electrical transmission means of all other vehicles in the train following the driven vehicle (B) are also immediately de-energized, and their brake valves also respond simultaneously and immediately. However, since the electrical transmission means of the vehicles in the train leading from the separation point are still supplied with power at this time, their brake valves are still closed, so that the part of the main air line leading from the separation point is initially only vented through the separation point of the broken connecting hose. Nevertheless, starting from this separation point, a pressure drop in the main air line also propagates towards the leading vehicle (A) of the train set, so that the first pressure switches of the vehicles leading to the separation point also successively respond when the pressure falls below the upper switching point, which leads to additional venting of the main air line in the leading vehicles through their then de-energized or open brake valves. As long as the pressure in the main air line (1) does not fall below the lower switching point or switching pressure of the second pressure switch (6), its switching contact (61) remains open and the relay (7) is de-energized. Even when a release command is present, the interruption in the second wire (42) of the electrical transmission medium (4) cannot be bridged by closing the relay contacts (71, 72), and the brake valve (2) remains de-energized or in the open position. Provided that the main air line is again intact, i.e. that it is once again continuous at the separation point, the brake valve (2) can only be energized and thus closed after the lower switching point or the switching pressure of the second pressure switch (6) has been undershot.

List of reference symbols:

1

Main air line

11

Supply air tank

12

stopcock

13

control valve

14

Ventilation opening in the surrounding area

2

brake valve

3

release valve

4

electrical transmission medium

41

first wire of the electrical transmission medium (4)

42

second wire of the electrical transmission medium (4)

43

DC voltage source for generating the control voltage

44

third electrical connection between first wire (41) and second wire (42)

45

Rectifier circuit

46

Switching means for changing the polarity of the control voltage

471

Wire interruption device for service, full and emergency braking; controllable by brake control

472

Wire interruption device, controllable by train protection system

473

Wire interruption device for emergency braking

48

electrical coupling agent

5

first pressure switch

51, 52, 53

Switch contacts of the first pressure switch (5)

6

second pressure switch

61

Switching contact of the second pressure switch (6)

7

Relay for switching an electrical bypass

71, 72, 73

Relay switching contacts (7)

D2 ... D4

Blocking diodes

T1, T2

first / second push button for brake test

A

leading vehicle of the train

B

guided vehicle of the train

Claims (5)

Electropneumatic braking device of a guided vehicle (B) which can be coupled into a train with at least one leading vehicle (A), with a main air line (1) which can be coupled air-tight between adjacent vehicles of the train and which controls the compressed air brakes of the vehicles of the train, the pressure of which main air line can be influenced in each guided vehicle (B) by means of at least one electrically switchable brake valve (2) and at least one electrically switchable release valve (3), characterized in that ▪ the braking device further comprises an electrical transmission means (4) comprising at least a first wire (41) and a second wire (42) for energizing the at least one electrically controllable brake valve (2) and the at least one electrically controllable release valve (3) by means of a control voltage, wherein both wires (41, 42) can each be electrically coupled between adjacent vehicles of the train, ▪ wherein each brake valve (2) closes when a control voltage is applied and each release valve (3) is designed to open when a control voltage is applied, ▪ wherein the at least one brake valve (2) and the at least one release valve (3) are connected in parallel to one another in the electrical transmission means (4), ▪ and wherein each brake valve (2) is connected in a current direction-independent manner and each release valve (3) is connected in a current direction-dependent manner in the electrical transmission means (4). Electropneumatic braking device according to Patent claim 1 , characterized in that the braking device comprises a first pressure switch (5) which can be actuated by means of the pressure in the main air line (1) and which is designed to interrupt the second wire (42) of the electrical transmission means (4) as soon as the pressure in the main air line (1) falls below a first switching pressure below the pressure value set during full braking of the train set. Electropneumatic braking device according to Patent claim 2 , characterized in that the braking device comprises a second pressure switch (6) which can be actuated by means of the pressure in the main air line (1), which second pressure switch is designed to energize an electrically controllable relay (7) for switching an electrical bridging of an interruption in the second wire (42) of the electrical transmission means (4) and an energization of the at least one brake valve (2), as long as the pressure in the main air line (1) is below the switching pressure of the first pressure switch. Electropneumatic braking device according to Patent claim 3 , characterized in that the second pressure switch (6) is designed to energize the relay (7) with a third current direction-dependent and in the electrical transmission means (4) parallel to the at least one To switch the electrical connection (44) connected between the brake valve (2) and the release valve (3). Electropneumatic braking device according to Patent claim 4 , characterized in that the first pressure switch (5) is additionally designed to open the third electrical connection (44) which supplies current to the relay (7).

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