Electropneumatic brake device and method for carrying out a brake test using a brake device

Abstract

The invention relates to an electropneumatic brake device of a guided vehicle which can be coupled into a train set with at least one guiding vehicle, comprising a main air line (1) which can be coupled between adjacent vehicles of the train set so as to allow air to pass and actuates the compressed air brakes of the vehicles of the train set and the pressure of which in each guided vehicle can be influenced by means of at least one electrically switchable brake valve (2). The invention also relates to a method for carrying out a brake test using such an electropneumatic brake device. The electropneumatic brake device is intended to allow a reduced complexity and to allow an acceleration with regard to the brake test which is necessary during operation. This is achieved in that the brake device also has a switching means (831, 832) designed to interrupt the energization of the at least one brake valve (2), a sensor means (811, 812) designed to detect a fluidic state variable of the air in the brake valve connection line (11), and a control device (8) with an actuator interface (83) for outputting an actuation signal to the switching means (831, 832) and a first input interface (81) for receiving a state signal of the air in the brake valve connection line (11), said state signal being output by the sensor means (811, 812) after the switching means (831, 832) is actuated.

Description

[0001] Electropneumatic braking device and method for performing a brake test using such a braking device

[0002] The invention relates to an electropneumatic braking device for a guided vehicle that can be coupled into a train consist with at least one leading vehicle, comprising a main air line that can be connected between adjacent vehicles of the train consist via an air-permeable connection and that controls the compressed air brakes of the vehicles of the train consist, the pressure of which can be influenced in each guided vehicle by means of at least one electrically switchable brake valve, wherein the at least one brake valve is connected to the main air line by means of a brake valve connection line and is vented in the unenergized state, and wherein the brake valve connection line can be shut off from the main air line by means of a shut-off valve, as well as a method for carrying out a brake test using such a braking device.

[0003] Braking of moving rail vehicles is usually achieved using pneumatically controlled indirect air brakes. For this purpose, all vehicles in a train consist are connected to each other via a continuous air line (the so-called "main air line"). A drop in pressure in the main air line activates the braking system of each individual vehicle. Even in the event of an unintended drop in pressure in the main air line, for example, due to a leak or the separation of two vehicles in the train consist, the brakes are applied in all vehicles, including those that have 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 vehicles of the train consist. This means that the braking effect on each vehicle controlled by the pressure drop in the main air line begins later with increasing distance from the leading vehicle. As a result, especially in long trains, unbraked vehicles at the rear of the train can push against vehicles in the leading section that have already been braked.

[0004] To remedy this problem, electropneumatic braking systems of this type have long been known in the art. These systems enable electrically transmitted brake request signals to be applied simultaneously to all brakes in the entire train consist. In this way, braking action is achieved simultaneously at all brakes in the entire train, and dynamic longitudinal forces in the train consist caused by time-delayed brake response are reduced to a minimum. While in a direct-acting electropneumatic system the brake cylinders are directly pressurized and vented via electric brake and release valves, in an indirect-acting electropneumatic system the pressure in the main air line is controlled by the brake and release valves, which are combined in an electropneumatic control unit present on each vehicle in the train consist.The brake and release valves are typically designed as electrically actuated solenoid valves. To initiate braking, the brake valve is activated, which vents the main air line to the atmosphere. To release the brake, the pressure in the main air line is increased by the release valve from a reservoir, which is replenished from a separate main air line. As a backup, the brake can also be actuated purely pneumatically via the main air line.

[0005] This so-called "indirect electro-pneumatic brake" has become the standard in Europe for trainsets hauled by a leading locomotive. The electrical brake 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 activation of the relevant brake and release valves throughout the entire trainset.

[0006] According to a more recent development of this indirect electropneumatic brake, which has been known for some time in itself, the venting support of the main air line takes place when the brake valve is de-energized.

[0007] For functional testing, all braking systems of this type must undergo a so-called "brake test" before the start of a journey. To initiate a manual functional test of the braking system, each vehicle has a manually operated push button and an indicator light on each of its two sides, with each push button having three positions. The first position represents the unactuated state of the push button. In this first position, the power supply to the brake valve is active, and the brake valve is energized. In the second position, the indicator light associated with the push button is connected in parallel to the brake valve, so that it illuminates when power is applied. This second position serves to check whether the corresponding brake valve is energized. In the third position, the power supply to the brake valve and the indicator light is interrupted.This third switch position is used to test whether the brake valve actually vents the main air line when de-energized. Such a brake test must be carried out by operating personnel who are in the track area in close proximity to the vehicle being tested and who both manually operate the pushbuttons and verify the resulting reaction. This requires significant personnel resources and is time-consuming.

[0008] The invention is therefore based on the technical problem of providing a generic electropneumatic braking device which enables a reduction in effort and acceleration with regard to the operationally necessary brake test.

[0009] This is solved according to the invention in a device-oriented manner by the fact that the braking device further comprises

[0010] ■ a switching device designed to interrupt the current supply to at least one brake valve,

[0011] ■ a sensory device designed to detect a fluidic state variable of the air in the brake valve connection line,

[0012] ■ and a control unit with an actuator interface for outputting a control signal to the switching device and a first input interface for receiving a status signal of the air in the brake valve connection line output by the sensor after control of the switching device.

[0013] In this way, a generic electropneumatic brake device can be implemented that enables automated verification of the venting performance of a brake valve by means of an interruption of its power supply, initiated for the purpose of functional testing. For this purpose, after the brake valve's power supply is interrupted, the temporal change of a state variable of the air in the brake valve's connecting line is detected by a sensor, and information about the brake valve's function in the de-energized state is generated from this. If the brake valve is functioning correctly, such a temporal change of the sensor-detected fluidic state variable begins immediately after the control signal is sent to the switching device that interrupts the brake valve's power supply.In this way, both the activation state of the brake valve and its function of venting the brake valve connection line (and thus also the main air line) can be checked by means of a computer-aided technical control unit and used for carrying out a remotely controlled or automated brake test. The control unit can also be connected to a train bus. In the context of this invention, a train bus is understood to be a fieldbus used for data communication between the individual vehicles of a train consist. In this way, the remotely controlled or automated brake test can be initiated and monitored at a central point within the train consist.

[0014] According to a first embodiment of the invention, the sensor for detecting a fluidic state variable of the air in the brake valve connection line is designed as a pressure sensor that detects the pressure in the brake valve connection line. This pressure sensor is arranged between the shut-off valve that blocks or releases the brake valve connection line on the one hand and the brake valve on the other, wherein the measured value output of the pressure sensor can be read in the control unit via a first sensor interface. Preferably, the pressure sensor is designed as a pressure switch. The detection of a pressure drop in the brake valve connection line is an indicator of a venting brake valve.

[0015] According to an alternative second embodiment of the invention, the sensor for detecting a fluidic state variable of the air in the brake valve connection line is designed as a flow sensor that detects an air flow in the brake valve connection line. This flow sensor is arranged between the shut-off valve that blocks or releases the brake valve connection line on the one hand and the brake valve on the other, wherein the measured value output of the flow sensor can be read via a first input interface in the control unit. In a particularly preferred manner, the flow sensor is designed as a flow switch that detects a fluid flow directed towards the brake valve in the brake valve connection line. The detection of such an air flow in the brake valve connection line is an indicator of a venting brake valve.Such sensory detection of the flow state is independent of any pressure changes that might be caused by other pressure losses in the brake valve connection line.

[0016] The invention further provides that the braking device includes a means for detecting the switching state of the shut-off valve, and that the control unit has a second input interface for receiving the switching state of the shut-off valve detected by this means. In this way, a signal indicating the state of the shut-off valve can be made available and usable for evaluation in the braking device according to the invention. For example, a signal indicating the closed state of the shut-off valve can be provided to evaluate the braking device as "disconnected from the main air line" or as "switched off," and thus, for example, suppress the output signal from the control unit to the train bus indicating the successful completion of a brake test at the brake valve.

[0017] Conversely, the opening of the shut-off valve, and thus the resulting change in the vehicle brake from a purely pneumatic actuation (exclusively via the main air line) to an electro-pneumatically assisted vehicle brake, can be detected via a unique input signal at the second input interface of the control unit. By means of the continuously measured values ​​of the fluidic state variable of the air in the brake valve connection line, acquired at the first input interface of the control unit, the achievement of a service brake range intended for the proper operation of the vehicle (for example, characterized by reaching the standard operating pressure in the brake valve connection line) can be detected in the brake system according to the invention.Once the service braking range intended for the proper operation of the vehicle is reached, this braking system can be used to perform an automated brake test. Upon receiving an activation signal addressed to it via the train bus, the control unit energizes the switching device, causing it to interrupt the power supply to the brake valve via its switching contact. The resulting change in the measured values ​​of the fluidic state sensor is a prerequisite for verifying that the main air line venting system is functioning correctly via the brake valve. For this purpose, the brake test involves comparing target and actual states through the functional interaction between the control of the switching device and the measured values ​​of the fluidic state sensor.

[0018] The aforementioned technical task is solved in a process-oriented manner by the fact that the procedure for carrying out a brake test comprises the following sub-process steps:

[0019] ■ Output of a control signal to a switching device designed to interrupt the current supply to at least one brake valve by the control unit via its at least one actuator interface,

[0020] ■ Detection of a fluidic state variable of the air in the brake valve connection line and generation of a state signal of the air in the brake valve connection line by the sensor,

[0021] ■ Receiving the status signal of the air in the brake valve connection line in the control unit via its first sensor interface and evaluating this status signal over time,

[0022] ■ Generating a confirmation signal by the control unit to acknowledge the execution of the brake test upon detection of a temporal change in the received status signal.

[0023] This method enables automated verification of a brake valve's venting performance after an interruption of its power supply, initiated for the purpose of a functional test. For this purpose, after the brake valve's power supply is interrupted, the temporal change of a state variable of the air in the brake valve's connecting line is detected by a sensor, and information about the brake valve's function in the de-energized state is generated from this. If the brake valve is functioning correctly, this temporal change of the sensor-detected fluidic state variable begins immediately after the control signal is sent to the switching device that interrupts the brake valve's power supply.In this way, both the activation state of the at least one brake valve and its function of venting the brake valve connection line (and thus also the main air line) can be checked by means of computer-aided sensors and actuators in a technical control unit, and thus used for carrying out a remotely controlled or automated brake test. The control unit can also be connected to a train bus. In the context of this invention, a train bus is understood to be a fieldbus used for data communication between the individual vehicles of a train consist. In this way, the remotely controlled or automated brake test can be initiated and monitored at a central point within the train consist.

[0024] Advantageously, the method additionally provides for receiving a signal indicating the state of the shut-off valve at the second input interface of the control unit, wherein the generation of a confirmation signal by the control unit acknowledging the execution of the brake test additionally requires the presence of a signal indicating an open state of the shut-off valve at the input interface. In this way, a signal indicating the closed state of the shut-off valve can be made available or usable for evaluation in the brake device according to the invention. For example, a signal indicating the closed state of the shut-off valve can be provided to indicate that the brake device is "disconnected from the main air line".to be assessed as "switched off" and thus the output signal acknowledging the successful execution of a brake test at the brake valve is suppressed by the control unit to the train bus.

[0025] The present invention is explained in more detail below with reference to two exemplary embodiments and accompanying drawings. These show:

[0026] Figure 1: Circuit diagram of a braking device according to a first embodiment with a pressure sensor. Figure 2: Circuit diagram of a braking device according to a second embodiment with a flow switch.

[0027] The circuit diagram shown in Figure 1 visualizes the braking system of a guided vehicle that can be coupled into a train consist in a de-energized and depressurized state, with all actuating devices shown in an unactuated initial state. For the sake of clarity, the illustration is limited to the components required for energizing the brake valve (2) and for performing a functional test of this brake valve (2) (hereinafter referred to as the "brake test").

[0028] To better understand the inventive concept, the pneumatic and electrical configuration of the guided vehicle is first explained with regard to its integration into a train consisting of several guided vehicles and a leading vehicle. Pneumatically, all vehicles in a train are connected to each other via a main air line (1), the main air lines of adjacent vehicles being pneumatically connectable by means of connecting hoses. A pressure drop in the main air line (1) activates the braking system of each guided vehicle.Electrically, all vehicles in the train consist are connected by means of an electrical transmission element consisting of two conductors (41, 42) for transmitting electrical brake request signals to the brakes of the vehicles. The conductors (41, 42) of this transmission element can be electrically connected between two adjacent vehicles of the same train consist by means of coupling elements. Furthermore, each vehicle consists of at least one brake valve (2), which is fluidically connected to the main air line (1) by means of a connecting line (11) and is designed to influence the pressure in the main air line (1) depending on the aforementioned electrical request signals. For this purpose, the brake valve is designed as an electrically controlled solenoid valve.The electrical brake signals are generated in the leading vehicle in parallel with the control of the pressure in the main air line and transmitted to each driven vehicle of the train consist via the conductors (41, 42) of the electrical transmission system. To initiate a braking process, the brake valve (2) is activated, which vents the brake valve connection line (11) and thus also the main air line (1) to the atmosphere via a vent opening (14). A shut-off valve (12) located between the main air line (1) and the brake valve (2) allows the brake valve connection line (11) and the brake valve (2) to be isolated from the main air line (1).

[0029] In an alternative operating mode, the brake of a guided vehicle can also be actuated exclusively pneumatically via the main air line (1). In the guided vehicle, the brake valve (2) is connected in the electrical transmission medium in a current-direction-independent manner by means of an upstream rectifier circuit (45). In the event of an interruption of the main air line (1) between the leading vehicle of the train consist and the guided vehicle, a nearly instantaneous pressure drop occurs in the section of the train consist's main air line that lags behind the point of interruption, i.e., also in the main air line (1) of the guided vehicle. When the pressure in the main air line (1) drops below a so-called "full brake pressure," the energization of the brake valve (2) is interrupted by a circuit device (not shown in detail here), causing it to open and vent.

[0030] To perform an automated functional test of the brake valve in the context of a so-called "brake test", which is carried out, for example, before the train set starts moving, the brake device according to the invention has the following features:

[0031] ■ a control device (8), comprising a first input interface designed as a sensor interface (81), configured to receive the output signal of a pressure sensor (811), a second input interface (82), configured to receive the output signal of a means (122) for detecting the switching state of the shut-off valve (12), an output interface designed as an actuator interface (83), configured to output control signals to the relay (831) of a switching means provided for interrupting the energization of the brake valve (2), and a train bus interface, configured for communication connection of the control device (8) to a train bus (9),

[0032] ■ a pressure sensor (811) for determining the air pressure in the brake valve connection line (11) between the pneumatic shut-off valve (12) on the one hand and the brake valve (2) on the other hand, the measured value output of which can be read via the sensor interface (81) in the control unit (8),

[0033] ■ a switch (122) operatively connected to the shut-off valve (12), the position of which can be read via the second input interface (82) in the control device (8), wherein the switch (122) is configured to detect the switching state of the shut-off valve (12) and is in an open state when the shut-off valve (12) is closed and is in a closed state when the shut-off valve (12) is open,

[0034] ■ a relay (831) connected to the actuator interface (83) of the control unit (8), configured to actuate a switching contact (832) which interrupts the current supply to the brake valve (2) in the energized state,

[0035] ■ and a central train brake control device connected via the train bus (9) to the train bus interface (84) of the control unit (8) (not shown in the figure of the exemplary embodiment).

[0036] To perform a brake test on all vehicles in a train consist, an initial initialization signal is first transmitted from the central train brake control unit via the train bus (9) to the control unit (8) of each vehicle in the train consist. This causes the control unit to output a control signal via the actuator interface (83), which energizes the relay (831), thus interrupting the power supply to the brake valve (2) by opening the switching contact (832). The now de-energized brake valve (2) opens and vents the brake valve connection line (11). Any resulting drop in air pressure in the brake valve connection line (11) is detected by the pressure sensor (811) and, via the first input interface (81), also in the control unit (8), and can thus be evaluated metrologically.Such a measurably detectable drop in air pressure in the brake valve connection line (11) is a prerequisite for verifying that the main air line (1) is functioning as a venting aid by the brake valve (2). For this purpose, in the context of the brake test, the control unit (8) performs a comparison between target and actual states in the functional interaction between the control of the relay (831) or switching contact (832) on the one hand, and the air pressure readings from the pressure sensor (811) on the other. If the control unit (8) determines that the main air line (1) is functioning as a venting aid by the brake valve (2), the control unit (8) sends an output signal confirming the successful completion of the brake test at the brake valve (2) via the train bus interface (84) to the train bus (9).to the central brake control unit of the train consist.

[0037] Additionally, the position of the switch (122) operatively connected to the shut-off valve (12) is detected via the second input interface (82) in the control unit (8). This position of the switch (122) represents the switching state of the shut-off valve (12), whereby the switch (122) is in an open state when the shut-off valve (12) is closed and in a closed state when the shut-off valve (12) is open. In this way, the signal processing in the control unit (8) can take into account an operating situation in which the brake valve (2) is separated from the main air line (1) by a closed shut-off valve (12) and therefore cannot have a venting effect on the main air line (1) (i.e., it is in a "switched off" state).If such an open position of the switch (122) is detected in the control unit (8) by means of the signal input at the second input interface (82), the output signal acknowledging the successful execution of a brake test at the brake valve (2) can be suppressed by the control unit (8) to the train bus (9) or to the central train brake control unit of the train consist.

[0038] Furthermore, the guided vehicle is equipped with a manually operated push button (T1, T2) and an indicator light on each of its two longitudinal sides for performing a manual brake test, which may serve as a fallback or for operational redundancy. Each push button (T1, T2) has three switching positions. The first position represents the unactuated state of the push button (T1, T2). In this first position, the power supply to the brake valve (2) is active, and the brake valve (2) is energized. In a second switching position, the indicator light associated with each push button (T1, T2) is connected in parallel to the brake valve (2), so that it illuminates when power is applied. This second switching position serves to check whether the corresponding brake valve (2) is energized.In a third switching position, the power supply to the brake valve (2) and the indicator light is interrupted. This third switching position serves to test whether the brake valve (2) actually vents the main air line (1) when de-energized.

[0039] The second embodiment of a brake device according to the invention, shown in Figure 2, is largely identical to the first embodiment shown in Figure 1 and differs from it only in that the pressure sensor (811) provided in the first embodiment is replaced by a flow switch (812). According to this second embodiment, the fluidic state of the air in the brake valve connection line (11) is therefore not detected by sensing a change in air pressure over time, but by sensing a fluid flow directed towards the brake valve (2). The brake valve (2), which is de-energized by the opening of the switching contact (832), opens and vents the brake valve connection line (11).An airflow caused by this in the brake valve connection line (11) is detected by the flow switch (812) and, via the first input interface (81), also in the control unit (8), and can thus be evaluated metrologically. The occurrence of such a measurably detectable airflow in the brake valve connection line (11) is a prerequisite for verifying that the main air line (1) is functioning as a venting aid by the brake valve (2). The measurement of the airflow state in the brake valve connection line (11) is independent of any pressure changes that might be caused by other pressure losses in the brake valve connection line.

[0040] Reference symbol list: Main air line Brake valve connection line Shut-off valve 2 Switching contact of the shut-off valve (12) Vent opening in the vicinity Brake valve Connection to first conductor of an electrical transmission device Connection to second conductor of an electrical transmission device Rectifier circuit Input / output device , 82 Sensor interface 1 Pressure sensor 2 Flow switch Actuator interface 1 Relay of the switching device 2 Switching contact of the switching device Train bus interface Train bus , T2 First / second push button for brake test

Claims

patent claim 1. Electropneumatic braking device of a guided vehicle that can be coupled into a train consist with at least one leading vehicle, comprising a main air line (1) that can be connected between adjacent vehicles of the train consist via an air-through connection and that controls the compressed air brakes of the vehicles of the train consist, the pressure of which can be influenced in each guided vehicle by means of at least one electrically switchable brake valve (2), wherein the at least one brake valve (2) is connected to the main air line (1) by means of a brake valve connection line (11) and is vented in the unenergized state, and wherein the brake valve connection line (11) can be shut off from the main air line (1) by means of a shut-off valve (12), characterized in that the braking device further comprises ■ a switching device (831, 832) designed to interrupt the current supply to at least one brake valve (2), ■ a sensory means (811 , 812) designed to detect a fluidic state variable of the air in the brake valve connection line (11), ■ and a control device (8) with an actuator interface (83) for outputting a control signal to the switching device (831, 832) and a first input interface (81) for receiving a status signal of the air in the brake valve connection line (11) output by the sensory device (811, 812) after control of the switching device (831, 832).

2. Electropneumatic braking device according to claim 1, characterized in that the sensory means (811 , 812) for detecting a fluidic state variable of the air in the brake valve connection line (11) is designed as a pressure sensor (811) detecting the pressure in the brake valve connection line (11).

3. Electropneumatic braking device according to claim 1, characterized in that the sensory means (811 , 812) for detecting a fluidic state variable of the air in the brake valve connection line (11) is designed as a flow sensor (812) detecting a flow of air in the brake valve connection line (11).

4. Electropneumatic braking device according to one of claims 1 to 3, characterized in that the braking device has a means (122) for detecting the switching state of the shut-off valve (12) and the control device (8) has a second input interface (82) for receiving the switching state of the shut-off valve (12) detected by this means (122).

5. Method for performing a brake test on a guided vehicle that can be coupled into a train formation with at least one leading vehicle using an electropneumatic braking device according to one of claims 1 to 4, characterized in that the method comprises the following sub-method steps: ■ Output of a control signal to a switching device (831 , 832) designed to interrupt the current supply to the at least one brake valve (2) by the control unit (8) via its at least one actuator interface (83), ■ Detection of a fluidic state variable of the air in the brake valve connection line (11) and generation of a state signal of the air in the brake valve connection line (11) by the sensory means (811, 812), ■ Receiving the status signal of the air in the brake valve connection line (11) in the control unit (8) via its first input interface (81) and evaluating this status signal over time, ■ Generating a confirmation signal by the control unit (8) to acknowledge the execution of the brake test when a change in the received status signal is detected.

6. Method for performing a brake test on a guided vehicle that can be coupled into a train consist with at least one leading vehicle according to claim 5, characterized in that the method additionally provides for receiving a signal indicating the switching state of the shut-off valve (12) at the second input interface (82) of the control device (8), wherein the generation of a confirmation signal acknowledging the execution of the brake test by the The control device (8) additionally requires a signal at the input interface (82) indicating an open switching state of the shut-off valve (12).

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