EP1277641A1 - Equipment device for railway tracks - Google Patents

Abstract

The central block has a circuit (42) which couples with right or left blocks (48,47) at first and second frequencies (F1,F2) and coupling circuits (43,45) linked to the transmitter and receiver (44,46). At the first frequency the right block is short circuited and the left block open circuited and at the second frequency the converse applies such that the joint is respectively a receiver and transmitter at the two frequencies. <??>An Independent claim is also included for a method for detecting the passage of a train using a three block joint and frequencies between 20 and 100KHz.

Description

Subject of the invention

The present invention relates to a equipment for rail-type tracks.

The present invention also relates to a method of detecting the passage of a train using the above-mentioned equipment device.

Technological background

Railway network tracks for which train detection is ensured by track are currently equipped with either insulating joints, either electrical seals, in both cases arranged at regular intervals along the track sections (also called "cantonments").

Electric seals have the advantage, with respect to insulating joints, to maintain a track galvanically uninterruptible, i.e. continuous, while limiting the transmission of energy in a portion of way. This considerably reduces the costs of laying, maintenance and monitoring of tracks while allowing higher speeds. This is of interest particularly important for equipping track tracks high speed trains.

From an electrical point of view, the "joint" is consists of two successive "plug circuits" which are separated by a section of track. An electrical joint is therefore made up of two rails of a certain length and each electrically represented by a self, a first and second chord block also called "Tuning Unit" in English (TU) allowing the realization tuning to the frequency of the track circuit.

Usually a first chord block performs the short circuit at a given first frequency while the second chord block ensures the joint agreement electric and coupling at the same frequency. To the second frequency, these functions are reciprocal for two track circuits that each joint separates.

• empêcher la propagation du signal d'un circuit de voie vers le circuit de voie adjacent. Ceci est réalisé par le bloc d'accord extérieur qui présente à la fréquence du circuit de voie une impédance suffisamment faible;
• présenter à l'extrémité du circuit de voie une impédance suffisante à la fréquence utilisée, au moyen d'un accord parallèle au bloc d'accord intérieur et à la portion de voie du joint électrique;
• réaliser le couplage entre le circuit d'émission ou de réception et la voie. Cette fonction est assurée par les blocs d'accord.

The functions of the electrical seal are manifold:

• prevent signal propagation from one track circuit to the adjacent track circuit. This is achieved by the external tuning block which has a sufficiently low impedance at the frequency of the track circuit;
• present at the end of the track circuit a sufficient impedance at the frequency used, by means of a tuning parallel to the internal tuning block and to the track portion of the electrical joint;
• perform the coupling between the transmission or reception circuit and the channel. This function is provided by the chord blocks.

It is usual to use, depending on the condition of the technique, electrical seals as described previously for large track sections, i.e. between 100 meters and 2 kilometers, then that usually the distance between two blocks successive agreement (TU) is between 15 and 30 meters within the same joint.

It is known to use this type of circuit track with electrical seals to detect the presence of a train in the section of track considered. Indeed, at passing of an axle of the train, a short circuit between the two rails will be created via the axle. This will detect the presence of said train according to the evolution of the tension received by the receiver associated with the same frequency.

Aims of the invention

The present invention aims to provide a new configuration of electrical seals which does not have the drawbacks of the state of the art.

The present invention aims to provide a solution which reduces the distances used for placement of electrical seals and thereby reduce uncertainty about the position of the point of occupancy or release of the section in the electrical joint.

The present invention also aims to propose a solution that allows to nest joints provided according to the present invention to equipment such as proposed according to the state of the art to be able monitor any section of track while avoiding presence of insulating gasket.

The present invention aims at everything particularly to offer a solution that can be applicable in the area of stations, where the distances between switches (and therefore the lengths available for placement of electrical seals) are lower than in full lane and where detection of the presence of a train must be performed with more than precision.

The present invention also aims to allow the overlapping of track circuits.

Main characteristic features of the invention

The present invention relates to a device arranged in connection with the two rails of a railway type track to achieve a joint electric, characterized in that this device is presented in the form of three chord blocks, a first block acting as a short circuit at a first frequency and being transparent at a second frequency, a second block playing the role of a short circuit at the second frequency and being transparent (i.e. high impedance for this frequency) at the first frequency, and the central block playing the role of a capacity at each of the two frequencies of use achieving the agreement of the two half-joints with respective frequencies.

Advantageously, the three chord blocks are arranged within the same physical entity which is connected to the two rails by cables arranged over a distance of less than 10 meters.

• un bloc central, comprenant deux branches parallèles, la première branche comprenant un circuit RLC et un premier circuit de couplage, la deuxième branche comprenant un deuxième circuit de couplage,
• un bloc comprenant un circuit RLC, ce bloc jouant le rôle d'un court-circuit à l'une des deux fréquences et étant transparent à la deuxième fréquence.
• un autre bloc comprenant un circuit RLC, ce bloc jouant le rôle d'un court-circuit à la deuxième des deux fréquence et étant transparent à la première fréquence.

The device according to the invention comprises:

• a central block, comprising two parallel branches, the first branch comprising an RLC circuit and a first coupling circuit, the second branch comprising a second coupling circuit,
• a block comprising an RLC circuit, this block playing the role of a short circuit at one of the two frequencies and being transparent at the second frequency.
• another block comprising an RLC circuit, this block playing the role of a short circuit at the second of the two frequencies and being transparent at the first frequency.

The present invention also relates to a method for detecting the passage of a traveling vehicle on a railway type track comprising two rails and in the form of sections of track called cantonments, separated by electrical seals, characterized in that a device is used in the form of three chord blocks, a first block playing the role of short circuit to a first frequency and being transparent to a second frequency, a second block playing the role of a short circuit per second frequency and being transparent to the first frequency, and the central block playing the role of a capacity at each of the two frequencies of use achieving the agreement of the two half joints at the respective frequencies.

According to a preferred embodiment, the frequencies of use of the different chord blocks are high frequencies. By "high frequencies" is meant frequencies above 10 KHz while the bass frequencies can be defined as frequencies less than 5 KHz and that the medium frequencies are between 5 and 10 KHz.

Advantageously, the device presenting itself in the form of three chord blocks is arranged in a longer cantonment delimited by conventional joints with two chord blocks.

Brief description of the drawings

FIG. 1 represents a track provided with conventional electrical seals.

• la figure 2a représente une voie comprenant deux cantonnements séparés par un joint électrique classique,
• les figures 2b et 2c représentent les circuits de voie correspondant aux deux cantonnements séparés par un joint électrique classique,
• la figure 2d représente les potentiels des signaux dans les deux circuits de voie, ceci en utilisant un joint classique, et
• la figure 2e représente les courbes de shunt pour un joint classique.

FIGS. 2 represent an embodiment according to the state of the art and its mode of operation, in which:

• FIG. 2a represents a track comprising two cantonments separated by a conventional electrical joint,
• FIGS. 2b and 2c represent the track circuits corresponding to the two cantonments separated by a conventional electrical joint,
• FIG. 2d represents the potentials of the signals in the two track circuits, this using a conventional joint, and
• Figure 2e represents the shunt curves for a conventional joint.

• la figure 3a représente une voie comprenant deux cantonnements séparés par un joint électrique à trois blocs,
• les figures 3b et 3c représentent les circuits de voie correspondant aux deux cantonnements séparés par un joint électrique à trois blocs,
• la figure 3d représente les potentiels des signaux dans les deux circuits de voie, pour un joint électrique à trois blocs, et
• la figure 3e représente les courbes de shunt pour un joint électrique à trois blocs.

FIGS. 3 represent an embodiment according to the present invention and its mode of operation, in which:

• FIG. 3a represents a track comprising two cantonments separated by an electrical joint with three blocks,
• FIGS. 3b and 3c represent the track circuits corresponding to the two cantonments separated by an electrical joint with three blocks,
• FIG. 3d represents the potentials of the signals in the two track circuits, for an electrical joint with three blocks, and
• Figure 3e shows the shunt curves for an electrical joint with three blocks.

Figures 4 and 5 show two forms preferred execution of a high electrical joint frequency, according to the invention.

Figure 6 shows the elements main of an electrical joint according to the invention.

Figure 7 shows examples of the device according to the invention, capable of receiving or sending two signals at the same time.

Detailed description of the solutions according to the state of the technical

In order to better understand the solutions proposed according to the present invention, an analysis detailed state of the art solutions will considered below.

Conventionally, an electrical joint (called RX / TX electrical seal) as shown in Figure 1 comprises, arranged between two rails 1 and 2, two blocks agree, respectively TU.RX ("Tuning Unit - Receiver") and TU.TX ("Tuning Unit - Transmitter"), which connect the two rails, and which are arranged at a distance included between 15 and 30 m from each other. The distance between two seals 3 and 4 can vary between a few hundred meters and one or even two kilometers. This joint then separates the two-part track 5 and 6, called "cantonments", with an overlap zone 7, corresponding to the distance between the two blocks. Presence detection of a train is carried out via signals present in the circuits corresponding to so-called cantonments at typical frequencies for each cantonment, which allows electrical separation of two adjacent circuits.

In the case of FIG. 1, block 10 of the joint 3 includes RLC circuits, which make this block equivalent to a tuning capacitor to a first frequency F1. At the same time, this block 10 is linked to a transmitter (not shown), which is essentially equivalent to an AC voltage source arranged in series with said capacity and which emits a signal at a frequency F1. In the same way, the block 11 of the joint 4 is equivalent to a tuning capacitor at frequency F1 and this block 11 is linked to a receiver (not shown), which is essentially equivalent to a selective AC voltmeter arranged in parallel on block 11 and which is capable of detect a potential difference at the frequency F1. The block 12 of seal 4 includes RLC circuits which make said block equivalent to a short circuit at frequency F1. Thus, the signal at the frequency F1 cannot go from the circuit of cantonment 5 to the adjacent circuit of cantonment 6.

In turn, block 12 behaves like a second frequency tuning capacitor F2 and this block 12 is linked to a transmitter at this frequency F2, which sends a signal in the block circuit 6. From same, the block 11 of the joint 4 is equivalent to a short circuit at frequency F2. Short circuits, respectively at the frequency F1 and at the frequency F2, thus ensure the effective separation of the two circuits adjacent blocks 5 and 6.

Detection of a train on cantonment 5 for example is due to the fact that the axle of this train forms in itself a short circuit between the rails. In reality, the axle has a low impedance which can be assimilated to a short circuit which will cause a fall of current in the receiver linked to block 11, which is of this way disabled. This deactivation then corresponds to the detection of a train between blocks 10 and 11.

Figures 2a, 2b and 2c show the equivalent circuits for a conventional joint. Figure 2d shows the potentials of the two signals 15 and 16, at near and in the electrical joint.

Figure 2e represents the curves of "shunt" for the joint as shown in Figure 2a. These curves give the resistance which is recognized as being the maximum impedance which causes the deactivation of a receiver (voltage drop detected) and thus allows the train detection. This value is dependent on the position along the track, and at each position, this value must be greater than the effective resistance of the axle, which is represented by the value 17. As long as this value is found below the shunt curves, the train will be detected without problem.

There is, however, uncertainty about the value of this impedance, which depends on the circumstances (ambient humidity, state of the ballast, etc.). Are defined thus the curves 18 and 18 ', which correspond to the optimal circumstances, i.e. for isolation minimum of the ballast and a minimum tension of transmission, and the curves 19 and 19 'which correspond in the worst circumstances, that is to say for a maximum ballast insulation and maximum voltage of transmission.

The position of these curves is particularly important to ensure detection of train when it passes through zone 7 of overlap of a electrical seal. As the shunt resistances decrease very quickly in this area, there comes a time when the axle resistance becomes greater than these curves. AT at this instant, the train is no longer detected.

Suppose a train travels from left to right on the horizontal axis. Taking into account the definition of the curves 18.18 'and 19.19', we can observe than the train (more precisely its first shunt axle) will be detected by circuit 6 (frequency F2) at the latest in point 20. Likewise, the train (more precisely its last shunt axle) will no longer be detected by the circuit 5 (frequency F1), at the earliest at point 21. It is clear that, to ensure detection at all times, either via circuit 5, i.e. via circuit 6, point 20 must precede point 21 on the horizontal axis.

A conventional joint as shown in Figure 2 essentially uses frequencies of around 1.5 to 4 kHz. Using these basses frequencies require distances between chord blocks relatively high successive so as to achieve a sufficient joint impedance.

The present invention provides a seal electric comprising three tuning blocks, such as shown in Figure 3a. Of course, this joint forms the separation between two adjacent track circuits 5 and 6 and called cantonments, for which the signals used are at frequencies F1 and F2.

The central block 25, called TX.RX ("Transmitter and Receiver"), serves as a capacity for both frequencies F1 and F2. Block 26 (on the left side) serves as short circuit at frequency F2 and has an impedance raised to frequency F1. Block 26 therefore constitutes a open circuit at F1; it is also said to be "transparent" at frequency F1. Similarly, block 27 (on the right side) serves short circuit at frequency F1 and this block 27 is transparent at frequency F2. The central block 25 is linked at the same time to a transmitter at the frequency F2 and to a receiver at frequency F1. This implies that in a adjacent joint, these functions will be reversed and we will have a transmitter at the frequency F1 and a receiver at the frequency F2.

Figures 3b and 3c show the equivalent circuits, highlighting the separation effective of the two circuits. Figure 3d shows the potential in both circuits.

The main advantage of a three-block joint can be seen by analyzing the shunt curves shown in Figure 3e. The point from which curves begin their fall towards zero resistance to the short circuit height, is now located in the middle of the joint, i.e. where the voltage source is located. This means that the overlap area of the two curves of least favorable shunt 28 and 29, for the same axle resistance (line 17) becomes more important. The minimum overlap area is located between the points 30 and 31. By comparing Figures 2e and 3e, we observes that the overlap area is larger for the three-block version. This actually leads to a better detection in the electrical joint, which allows reduce the minimum length and therefore increase the maximum length of track circuit.

According to a preferred embodiment of the invention, it is suggested to use for the detection of trains a three-block electrical joint using high frequency signals. This brings the blocks (and thus reduce the length of the joint electric). For example, the present invention provides a version where the distance between the central block and the two exterior blocks is around three meters, i.e. that the length of the full joint is about six meters. Such a seal is especially useful in areas referrals where more precision is needed in the measurement of position and therefore space available for placement of the electrical seal is more low.

According to a preferred embodiment shown in Figure 4, the chord blocks are no longer located in different places, like those shown in Figure 3, but they are in a common unit agreement 35, referred to as "TU.HF" ("Tuning unit - High Frequency ", which is connected by cables 36 to the three adequate positions along the track. Cables additional 37 connect the unit 35 to the transmitter and receiver.

According to another embodiment, the unit common is located next to the track, as shown in Figure 5. The equivalent circuits and the curves of shunt are quite analogous to circuits and curves shown in Figure 3, although the distance between the outer terminals of the joint is reduced.

Figure 6 shows the components of the unit TU.HF agree for a version installed between the rails. The two functions of the tuning unit 35, namely the transmission function and reception function, are therefore grouped within the same entity. Two circuits are connected to this entity on either side of the connections transmission / reception. Each of these circuits can work such as a short circuit or with a high impedance depending on the frequency considered.

The resistance and the self of the rails are modeled by elements 40 and 41. The central block of the joint includes two parallel branches, the first branch comprising an RLC circuit 42 and a circuit 43 of coupling connected to transmitter 44, the second branch comprising a coupling circuit 45, connected to the receiver 46. The two exterior blocks each include a circuit RLC, respectively 47 and 48. A resistor 49 is present between the tuning unit and the transmitter 44. This is a precaution to avoid the appearance of waves stationary in the cable.

• le circuit RLC 42 est conçu de manière à ce que l'unité d'accord soit équivalente à une capacité qui permet le couplage avec l'impédance constituée par le demi-joint du côté droit de la voie à une fréquence F1,
• le circuit RLC 48 de l'unité d'accord (côté droit) agit alors comme un court-circuit à la fréquence F1,
• le circuit RLC 47 de l'unité d'accord (côté gauche) est équivalent à une haute impédance le rendant transparent à cette fréquence F1,
• à la fréquence F1, le joint HF est donc équivalent à un joint RX classique.

The behavior of the high frequency electrical joint for the first circuit (frequency F1) of the track can be summarized as follows:

• the RLC circuit 42 is designed so that the tuning unit is equivalent to a capacitance which allows coupling with the impedance formed by the half-joint on the right side of the channel at a frequency F1,
• the RLC circuit 48 of the tuning unit (right side) then acts as a short circuit at the frequency F1,
• the RLC circuit 47 of the tuning unit (left side) is equivalent to a high impedance making it transparent at this frequency F1,
• at the frequency F1, the HF joint is therefore equivalent to a conventional RX joint.

• le circuit RLC 42 est conçu de manière à ce que l'unité d'accord soit équivalente à une capacité qui permet le couplage avec l'impédance constituée par le demi-joint du côté gauche de la voie à une fréquence F2,
• le circuit RLC 47 de l'unité d'accord (côté gauche) agit alors comme court-circuit à la fréquence F2,
• le circuit RLC 48 de l'unité d'accord (côté droit) est équivalent à une haute impédance le rendant transparent à cette fréquence F2,
• à la fréquence F2, le joint HF est donc équivalent à un joint TX classique.

The behavior of the high frequency electrical joint for the second track circuit can be summarized as follows:

• the RLC circuit 42 is designed so that the tuning unit is equivalent to a capacitance which allows coupling with the impedance formed by the half-joint on the left side of the channel at a frequency F2,
• the RLC circuit 47 of the tuning unit (left side) then acts as a short circuit at the frequency F2,
• the RLC circuit 48 of the tuning unit (right side) is equivalent to a high impedance making it transparent at this frequency F2,
• at the frequency F2, the HF joint is therefore equivalent to a conventional TX joint.

The invention also relates to devices similar to the version of Figure 6, which receive two signals at the same time or send two signals at the same time (Tx / Tx joints, Rx / Rx joints). This is for example the case for the seals 50 and 51 shown in Figure 7. The seal unit 50 is linked to two receivers 52, and the joint unit 51 is linked to two transmitters 53. The function of the coupling circuits 43 and 45 will naturally be adapted to these different forms execution of the seal according to the invention.

For example, a receiver / receiver joint (like the seal 50 shown in Figure 7) would need two identical coupling circuits instead of the two different circuits 43 and 45 as shown in the figure 6, which couple the central block to two receivers.

The present invention also relates to a configuration that there is a superimposition of a low frequency electrical joint on a high frequency electrical seal. This allows the superimposition of a high frequency track circuit on a low frequency track circuit and modulation of the detection according to the required precision on areas specific to the railway track.

Claims (7)

Device arranged in connection with the two rails of a railway type track in order to produce an electrical joint, characterized in that this device is in the form of three chord blocks, a first block playing the role of short- circuit at a first frequency and being transparent at a second frequency, a second block playing the role of a short circuit at the second frequency and being transparent at the first frequency, and the central block playing the role of a capacitance at each of the two frequencies of use. Device according to claim 1, characterized in that the three tuning blocks are arranged within the same physical entity which is connected to the two rails by means of cables arranged over a distance of less than 10 meters. Device according to claim 1 or 2, comprising: a central block, comprising two parallel branches, the first branch comprising an RLC circuit (42) and a first coupling circuit (43), the second branch comprising a second coupling circuit (45), a block (47) comprising an RLC circuit, this block playing the role of a short circuit at one of the two frequencies and being transparent at the second frequency. a block (48) comprising an RLC circuit, this block playing the role of a short circuit at the second of the two frequencies and being transparent at the first frequency. Method for detecting the passage of a vehicle traveling on a railway type track comprising two rails and in the form of track sections called cantonments, separated by electrical joints, characterized in that a device is used which is in the form of three tuning blocks, a first block acting as a short circuit at a first frequency and being transparent at a second frequency, a second block playing the role of a short circuit at the second frequency and being transparent at the first frequency, and the central block playing the role of a capacity at each of the two frequencies of use. Method according to claim 4, characterized in that the frequencies of use of the different tuning blocks are high frequencies, preferably between 20 and 100 KHz. Method according to claim 4 or 5, characterized in that the device is arranged in the form of three chord blocks in a longer block delimited by conventional joints with two chord blocks. Method for detecting the passage of a vehicle traveling on a railway type track comprising two rails and in the form of track sections called cantonments, separated by electrical seals, characterized in that a high frequency track circuit is superimposed on a low frequency track circuit.

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