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The invention relates to a device for determining derailment of wagons traveling on rails according to the preamble of patent claim 1.
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In the case of railway accidents in which wagons overturn as a result of derailment of one or more of the wagons of a train composition or are damaged in such a way that, for example, liquid loads can leak, which depending on the load of the wagons in question can result in devastating damage, that the cause is often jumping off the rails of an axle of a car. This causal derailment does not necessarily lead to the car overturning immediately or being damaged to such an extent that a liquid load, for example, can leak. Often, wagons from which an axle has been derailed are still pulled along for a certain distance before a major accident occurs, which can be triggered, for example, by driving over a switch with this corresponding wagon.
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The derailment of an axle of a car cannot normally be noticed by the driver of this moving train composition. If he noticed, quick braking and stopping the train could avoid a major disaster.
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On the basis of these findings, possibilities were sought with which the derailment, for example of an axle of a wagon, could be determined immediately and transmitted to the locomotive driver to initiate the necessary steps.
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A first possibility of this type consisted in the fact that an acceleration detector was installed in each car, by means of which excessive acceleration peaks, which can be determined when an axle derailment occurs, triggers a corresponding alarm signal. However, it is disadvantageous that such acceleration peaks, which would correspond to those of a derailed axis, can also arise from external influences, so that an alarm signal is triggered without derailment having taken place.
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Another possibility was that the change in the trailer load on the locomotive was monitored by suitable monitoring means. With this option, too, it has been found to be disadvantageous that changes in the trailer load, such as occur in the event of derailments, can also occur during the normal running of a train and consequently derailments could not be reliably determined, as a result of which false alarm signals were also given here.
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An object of the invention is to provide a device for detecting derailment of one or more wagons traveling on rails, in which the emission of false signals is practically impossible, and which can be easily installed in existing railway wagons.
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According to the invention, this object is achieved by the features specified in the characterizing part of claim 1.
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This provides a safe means of detecting derailment of just one axle of a car.
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In the case of two-axle carriages, a sensor is advantageously attached in the region of each axle. In four-axle vehicles, a sensor is attached between two axles of a chassis, with one sensor being provided for each rail.
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The design and function of the sensors can advantageously take place in one of the ways specified in claim 3.
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Since the individual wagons are not connected to an electrical supply network, especially in freight trains, it is still advantageous to that the sensors are connected to a power source, which is installed in each car, and which is essentially composed of an alternator, charger and accumulator. As a result, it is not necessary to connect the individual carriages to one another via an electrical feed cable.
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It has proven to be advantageous to design sensors working on an electromagnetic basis in two parts. A first part of it is arranged in a region of the wheel which is immediately adjacent to the rail when the latter rolls off. The location of the first sensor part is preferably the wheel rim. The first part of the sensor essentially comprises a permanent magnet with an induction coil magnetically coupled to it, a charging capacitor and an automatic transponder. When the area of the wheel rim, in which the first part of the sensor is installed, glides past the rail flank when the wheel rolls off, the magnetic flux in the permanent magnet changes. This induces a voltage in the induction coil with which the charging capacitor is charged.
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A second part of the sensor is connected to the chassis and is arranged such that the transponder of the first sensor part glides past it after a partial rotation of the wheel. The transponder recognizes this and uses the charge stored in the charging capacitor to send a signal, which is dependent on the size of the charge or the charging voltage, to the second sensor part. For example, it can be provided to arrange a field plate circuit in the transponder, by means of which discharge of the charging capacity is initially prevented. A further permanent magnet is present in the second sensor part, to whose magnetic field the field plate responds when the first sensor part slides by. The transponder now becomes active and the charging capacitor can discharge, for example, via an oscillating circuit, as a result of which a high-frequency signal can be generated and transmitted, which is received by a receiving circuit in the second sensor part. The amplitude curve of the received signal is a measure of the charge stored in the charging capacitor. The charging capacitor itself has been discharged by this process and is ready to be charged with a charging voltage the next time it glides past the rail flank will. In the event of a derailment, the signals remain off because the charging capacitor is no longer periodically charged. It is preferably provided that the energy stored in the charging capacitor is sufficient to feed the transponder.
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Another object of the invention is to transmit the transmission means for transmitting an interference signal emitted by a sensor in a train, for example to the driver's cab of the railcar, without having to provide an additional line network in the train.
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This object is achieved by the features specified in the characterizing part of claim 7.
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Such a tubular line filled with a fluidic medium is present as a compressed air line for the braking system in every train, which is why this line system is advantageously used as a connection between transmitter and receiver.
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In a first embodiment, the signal that is exchanged between one of the transmitters and the receiver can be an acoustic signal. The transmitter is designed to couple such a signal into the compressed air line and the receiver is designed to couple this signal out of the compressed air line. It has proven to be an advantage if the acoustic signals are in a frequency range from 500 Hz to 1,500 Hz. Interference signals are lowest in this frequency range.
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The transmitter and receiver are advantageously constructed in multiple channels, which makes it possible to transmit and receive further signals or messages in addition to the interference signal. If each transmitter is equipped with an additional receiver and the receiver with an additional transmitter, signals or messages can be transmitted in both directions.
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It can also be provided that the acoustic signal coupled into the compressed air line is keyed according to a specific code, the key number being able to be contained in the keying, for example. The keying can be generated either with a frequency code or with a sequence of signal pulses.
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In a second, very advantageous embodiment, the transmitter is equipped with a valve, preferably with an electromagnetically actuated valve, which valve acts on the compressed air line of the car. The receiver is equipped with a pressure sensor, which is also coupled into the compressed air line. To transmit a signal, the electromagnetic valve is actuated in a certain rhythm, whereby compressed air is briefly released from the compressed air line each time it is actuated. This causes fluctuations in compressed air, which can be recorded by the pressure sensor on the receiving side. Here too, information such as the car number can be present in the key sequence of the signal.
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The signal picked up by the receiver is advantageously indicated optically by display means, for example via a screen, in the driver's cab of the railcar and additionally by an acoustic signal. The train driver can then take the necessary measures based on these displays.
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The invention is explained in more detail below with reference to the accompanying drawings, for example.
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Show it
- Figure 1 shows a simplified representation of the arrangement of a sensor in a chassis of a railroad car.
- 2 shows a schematic representation of the arrangement of the sensors in one train;
- Fig. 3 shows a schematic representation of the arrangement of the transmission means in the compressed air line of the train's braking system;
- Fig. 4 shows the arrangement of an electromagnetic-based two-part sensor on a chassis, and
- 5 schematically shows a functional circuit diagram for the sensor according to FIG. 4.
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In Fig. 1, a chassis 1 of a four-axle rail car, not shown, is shown in a simplified manner, which carries the car body. The chassis 1 is equipped with two axles 2 which carry the wheels 3 which roll on the rails 4. Each of the wheels 3 is equipped with brakes 5 in a known manner.
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In a first embodiment, a sensor 6 is attached between the two axles 2 on the chassis 1 on both sides, each of which comes to rest on the rail 4. With this sensor 6, the position of the rail 4 with respect to the chassis 1 and consequently the wheels 3 can be determined, for example by measuring the distance. If the determined value lies outside a predetermined tolerance range, which is the case in the event of derailment, the sensor 6 emits a signal which can be transmitted to a central location by means of transmission. The tolerance range is selected such that fluctuations in the value measured by sensor 6, which result from normal driving, do not result in a signal being triggered. Ultrasonic measuring sensors, laser diode measuring sensors, CCD measuring sensors or sensors working on an electromagnetic basis can be used as sensors 6 in a known manner.
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In Fig. 2, a train is shown schematically, consisting of a locomotive 7 with coupled cars 8 to 11. Each of the cars 8 to 11 is equipped with two-axle chassis 1, as described in Fig. 1. The sensors 6 are accommodated accordingly in each chassis 1.
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The sensors 6 are coupled to a line 12 which runs through the entire train and which is also provided with couplings at the coupling points of the carriages 8 to 11. As a result, signals which are emitted by sensors 6 in the event of a fault can be transmitted to locomotive 7, which is equipped with corresponding receiving means 13 for this purpose.
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As can be seen from FIG. 3, the signals output by the sensors are transmitted to the locomotive 7 via the compressed air line 14 of the braking system of a train. As can be seen in a simplified representation from FIG. 3, the braking system in the locomotive comprises in a known manner a compressor 15, a compressed air tank 16, an actuatable brake valve 17 and a control device 18, in which the actuation of the brake cylinder 19, by which the effective brakes are actuated, is controlled.
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The compressed air line 14 can be connected via coupling hoses 20 to the compressed air line 21 of the carriage 8, which is coupled to the locomotive 7. In the carriage 8, the control device 22 is actuated to actuate the brake cylinder 23 via the compressed air line 21, the air pressure being indicated by a built-in pressure gauge 29. Actuation is also possible via an emergency brake valve 28. By coupling the carriages 8 to 11 to the locomotive 7, a continuous compressed air line is created throughout the train.
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A transmitter 24 for emitting a signal is installed in the compressed air line 21 of each carriage 8 to 11. This transmitter 24 is connected to the sensor 6. Transmitter 24 and sensor 6 are connected to an autonomous power source 25 for each car 8 to 11, which is essentially composed in a known manner from an alternator, charger and accumulator.
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If the sensor 6 now detects a fault, the transmitter 24 is activated, which triggers a signal that propagates via the compressed air line 21, the coupling hoses 20 into the compressed air line 14 of the locomotive. A receiver 26 with which the signal can be received is arranged in the compressed air line 14 of the locomotive. This signal will be more appropriate Shape visually and / or acoustically indicated by display means 27 attached in the driver's cab of the locomotive 7. Based on this information, which the train driver receives, he can take the necessary precautions, for example, to stop the train immediately.
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Transmitter 24 and receiver 26 can have a multi-channel structure, so that in addition to displaying the derailment, further information can also be transmitted, such as which car caused the fault, what the corresponding car loaded, etc.
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By arranging an additional transmitter in the receiver 26 and arranging an additional receiver in the transmitter 24, information from the locomotive could also be given to the wagons and displayed or evaluated in a suitable form.
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In the present first exemplary embodiment, the signal emitted by the transmitter 24 is an acoustic signal in a frequency range from 500 Hz to 1,500 Hz. In other systems and areas of application, it can be advantageous to work in a different frequency range.
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Instead of the electro-acoustic signal, it can also be provided to work with pneumatic pulses. For this purpose, a controllable valve, preferably an electromagnetically operable valve, is connected to the compressed air line in each car, preferably per axle or per chassis. In the event of a malfunction, this valve is actuated by the transmitter 24 in pulses, whereby compressed air per pulse is briefly released from the compressed air line 21. This creates pneumatic impulses or changes in compressed air in the compressed air line. These can be evaluated in the receiver, where a pressure sensor is connected to the compressed air line. It is planned to work with impulse packages. As a result, different criteria can be serially transmitted and evaluated by changing the time between the individual pulses or by varying the pulse length and / or the pulse intensity. In this sense, it would be conceivable to perform a functional check of the device periodically.
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4 and 5, a sensor 6 operating on an electromagnetic basis is described in more detail as a further exemplary embodiment. This sensor is designed in two parts and comprises a first part 29, which is preferably installed in the wheel rim of at least one wheel 3 per axle 2 or per chassis 1. A second sensor part 30 is present adjacent to the first sensor part 29 and is firmly connected to the chassis 1.
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When the wheel 3 rolls on the rail 4, the first sensor part 29 slides alternately past the flank of the rail 4 and a little later past the first sensor part 30.
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The first part 29 of the sensor essentially comprises a permanent magnet 31, in the magnetic circuit of which an induction coil is arranged. When the permanent magnet glides past the rail 4, the magnetic flux generated by the permanent magnet 31 in the induction coil increases. The change in magnetic flux induces a voltage with which a charging capacitor 32 is charged via a charging diode 34. The differently polarized voltage pulse induced by the decreasing magnetic field after the permanent magnet 31 slides past the rail 4 is short-circuited by the diode 39.
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In the first sensor part 29 there is also a transponder which solves the task of transmitting a signal which is essentially dependent on the charge of the capacitor 32 to the second sensor part 30 when the second sensor part 29 slides past the first sensor part 30. This can be done, for example, with a field plate circuit, the functioning of which has already been described above. In the second part 30 of the sensor 6, a permanent magnet is provided as means 35 for activating this field plate. This has the effect that the charge of the capacitor 32 can be discharged, for example, via an oscillating circuit, as a result of which, at a selected, correspondingly high resonance frequency of the oscillating circuit, a signal is transmitted which is received by a detection means 36 in the second sensor part 30. This signal can be checked in an evaluation logic 37 for its periodic presence when the train is moving. In the event of a malfunction, for example this signal is missing if a wagon is derailed. A transmitter key signal 38 is generated by the evaluation logic 37 and fed to the transmitter 24.
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It should be expressly stated that the circuit with the field plate is only listed for example. Other systems for signal exchange between the two sensor parts 29, 30 are also possible.
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Of course, the processes described here for transmitting a signal via a tubular line filled with a fluidic medium are not limited to the compressed air line of the brake system of trains. Other systems can also be used in other areas of application for the transmission of such signals if, for example, there is no existing line network, so that additional cabling would be required, or if, for example, transmission by radio is exposed to major interference.
