Rail breakage detection device

Abstract

To provide a method by which a generation or existence of a rail breakage is detected based on the phenomenon that a progress of a train or rail breakage differently influences a level change of a detection signal of a neighboring section in a non-insulated track circuit.SOLUTION: A rail breakage detection device holds reference data K, L, and M each related with level reduction states of a reception level H during a train passing time, for both ends non-insulated sections 13, 14 and so on, detects reduction states (tb) between K and L related with a reception level of each section 13, 14 and so on or a rise state related with M, and determines that rail breakages occur in the non-insulated section, the neighboring sections, and a middle section of three continuous non-insulated sections by comparing those changes with the reference data.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rail breakage detection device that detects a break in a rail on which a train runs. In detail, the present invention relates to a rail break detection device that acquires information indicating a rail break state based on the current state in a detection section of a non-insulated track circuit in a railway track consisting of a pair of rails, and determines whether a rail break exists. [Background technology]

[0002] Track circuits (see, for example, Non-Patent Document 1) perform a train detection function that detects whether a train is present on the line or not depending on whether or not the power transmitted from the transmitting end (one end, starting end) reaches the receiving end (the other end, terminal end) by taking advantage of the fact that parallel rails, i.e. two rails laid side by side for train travel, are electrically short-circuited by the train's wheels and axles (see, for example, Patent Document 1).In addition to this function, track circuits can also perform the following rail breakage detection function. In other words, even when the track is subjected to excessive stress due to the passage of trains, etc., causing a rail break such as a crack, break or breakage, the current flow at that point will deteriorate, leading to a situation where the voltage and current on the power receiving side will decrease or even be cut off, even when there is no train on the line, and therefore the system can also provide a rail break detection function by obtaining information on the rail break condition from the power receiving signal.

[0003] Among such track circuit devices, rail break detection devices have the latter rail break detection function as their main function. Track circuit fault location identification devices measure the voltage at the receiving end of a rail pair of a track circuit in addition to the voltage and current at the sending end to isolate the faulty part with a high degree of accuracy (see Patent Document 2, for example), and rail break detection devices that can detect breaks in a parallel rail pair (see Patent Document 3, for example) have been developed and are in practical use. Furthermore, there are track circuits (for example, see page 10 of Non-Patent Document 1) that are classified into insulated track circuits that have rail insulation at section boundaries and non-insulated track circuits that do not have rail insulation.

[0004] Of the two, the latter, a rail breakage detection device for non-insulated track circuits, is the basis of the present invention, so a specific example thereof will be described here (see FIG. 9). In a non-insulated track circuit, the parallel rail 10 is divided into several sections 11, 12, 13, 14, ..., 1N, ..., and a matching transformer MT is connected to each section boundary closer to the track. Because it is a non-insulated track circuit, the rails of both sections are connected even at the section boundary. In addition, a matching transformer MT on the rail break detection device 20 side is connected one-to-one to each of these matching transformers MT, so that the rail break detection device 20 can send and receive detection signals to and from each of the sections 11, 12, ... of the parallel rail 10.

[0005] The rail breakage detection device 20 is mainly comprised of a transmitting section 21, a receiving section 22, and a processing section . Of these, the transmitting unit 21 is equipped with a plurality of transmitters ST, ST, ... and a transmission switch, and is configured to generate a detection signal of a predetermined frequency and transmit it in a time-division manner to each of the sections 11, 12, ... via matching transformers MT, MT. The receiving section 22 is provided with a plurality of receivers RT, RT, . . . and a receiving switch, and receives the detection signals arriving from the sections 11, 12, .

[0006] The transmitter 21 and receiver 22 transmit and receive signals in a time-division manner in cooperation with each other according to transmission control information C and reception control information D received from the processor 23, thereby detecting the detection signals that have flowed through each of the sections 11, 12, 13, 14, ... of the parallel running rails 10. Since this is a non-insulated track circuit, signal leakage from the section to which the detection signal is sent to the adjacent section and further sections is unavoidable, but since the signal level drops sharply each time the signal passes through a section, it is not the case that reception of the detection signal related to the section to which the detection signal is sent becomes difficult due to signal leakage from other sections.

[0007] The processing unit 23 is mainly composed of electronic circuits, and includes a level setter 24, a controller 25, a determination unit 26, a level detector 27, and an input / output unit 28. The level setter 24 acquires the train detection level A and the transmission setting level B from the outside through manual operation or data communication, and notifies the judgment unit 26 of the train detection level A and the transmission setting level B to the controller 25. The controller 25 creates transmission control information C and reception control information D based on the transmission setting level B, and notifies the determination unit 26 of the information C and D, while also notifying the transmission control information C to the transmitting unit 21 and notifying the reception control information D to the receiving unit 22.

[0008] The level detector 27 obtains the transmission level G from the transmitter 21 and the reception level H from the receiver 22, and also performs correspondence between each of the sections 11, 12, 13, 14, . . . and notifies the determination section 26 of G and H. The input / output unit 28 performs appropriate signal level conversion and data format conversion on the comparison result I outputted by the judgment unit 26, and then outputs it to the outside as train detection information / rail breakage information J.

[0009] The judgment unit 26 determines and adjusts the judgment level by referring to the train detection level A, transmission control information C, and reception control information D mentioned above, and also monitors the levels of the transmission level G and reception level H received from the level detector 27 to determine whether the signal level (for example, the value of the reception level H may be left as is, but the ratio H / G of the reception level H to the transmission level G is often used to eliminate or suppress the effects of differences in track length and cable length, etc.) for each section 11, 12, 13, 14, etc. exceeds the train detection level A, and outputs the comparison result I.

[0010] Therefore, the train detection information / rail break information J outputted from the rail break detection device 20 is output for each section of the parallel rail 10, and if a detection signal is detected for each section, the information takes a value that clearly corresponds to "no train present and no rail break". On the other hand, if a detection signal is not detected for each section, it is not possible to clearly distinguish whether the state is one in which a train is present or one in which a rail break exists, and the information takes a mixed value that corresponds to "train present or rail break".

[0011] To give a specific example (see Figure 10), in this type of rail break detection device 20, when no train is approaching and there is no rail break (see Figure 10(a)), for example, when a detection signal is sent from transmitter ST (13, 14) connected to the boundary between sections 13 and 14 to the parallel rail 10, the detection signal (see dashed double-dashed line with arrow) not only travels around one rail 13a of section 13, receiver RT (12, 13) connected to the boundary between sections 12 and 13, and the other rail 13b of section 13, but also travels around one rail 14a of section 14, receiver RT (14, 15) connected to the boundary between sections 14 and 15, and the other rail 14b of section 14.

[0012] Therefore, when the state of the receiving unit 22 is switched so that receiver RT (12, 13) and receiver RT (14, 15) receive the detection signal, and further transmitter ST (13, 14) sends the detection signal to the parallel running rail 10 in a time-division manner, the detection signal is received by receiver RT (12, 13), so it is determined that no train is approaching section 13 and there is no rail break. In addition, the detection signal is received by receiver RT (14, 15), so it is determined that no train is approaching section 14 and there is no rail break. Therefore, the value of the train detection information / rail break information J is set to "no train on the track and no rail break."

[0013] Then, when the train 30 enters section 13 from that state (see Figure 10(b)), the wheels and axles of the train 30 short-circuit the parallel rails 13a, 13b in section 13, so that the detection signal sent from the transmitter ST (13, 14) to the receiver RT (12, 13) no longer reaches the receiver RT (12, 13). Furthermore, if a rail break 40 occurs in section 13 (see FIG. 10(c)), the detection signal will no longer flow not only to the broken rail 13a, but also to the paired rail 13b and the receiver RT (12, 13) connected to section 13.

[0014] In this way, the presence or absence of a detection signal is the same whether a train is on the track or a rail break is detected, so the value of the train detection information / rail break information J is "train on the track or rail break detected." Although not mentioned in the above explanation, since each of the sections 12, 13, 14, 15, ... of the parallel rail 10 is a non-insulated track circuit, a portion of the detection signal transmitted from the transmitter ST (13, 14) to the receiver RT (12, 13) leaks to section 12, and a portion of the detection signal transmitted from the transmitter ST (13, 14) to the receiver RT (14, 15) leaks to section 15. However, this is attenuated due to an increase in the transmission distance, etc., and does not affect the distant level judgment. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] JP 2005-262895 A [Patent Document 2] JP 2011-207449 A [Patent Document 3] JP 2020-152172 A [Patent Document 4] JP 2016-159784 A [Non-patent literature]

[0016] [Non-Patent Document 1] "Track Circuits", Signaling for Railway Engineers, Published by the Japan Railway Electrical Engineering Association, May 20, 2005, Revised 2nd Edition, pp.3-5,10 Summary of the Invention [Problem to be solved by the invention]

[0017] Conventional rail breakage detection devices that utilize such track circuits are mixed in with train detection devices, making it difficult to distinguish between a train on-track state and a rail break state unless the device is under a management system that utilizes track circuits to provide a train tracking function. In response to this, wireless railway control systems have been developed that can perform train tracking functions without using track circuits (see, for example, Patent Document 4), and such railway control systems do not require not only train detection devices that use track circuits, but even the track circuits themselves. However, the trade-off is that a separate device must be used to detect rail breaks.

[0018] However, a practical rail breakage detection device that is inexpensive and has good performance has not yet been provided. On the other hand, conventional rail breakage detection devices have a long history of use and are easy to use from the standpoint of stable supply and maintenance. Moreover, even in existing tracks where wireless railway control systems have been introduced, they are sometimes left behind without being removed or installed as additional devices and are used for detecting rail breaks. However, conventional rail breakage detection devices use track circuits, and therefore have the disadvantage that it is difficult to compare detection results with wireless railway control systems that do not use track circuits, since the detection sections and methods are different.

[0019] Therefore, the basic technical challenge is to improve rail breakage detection devices that use track circuits and enhance their ability to detect rail breaks separately from train detection. However, as mentioned above, there are insulated and non-insulated track circuits. The difference between them is that it is easier to ensure the independence of each section of a track circuit with an insulated track circuit than with a non-insulated track circuit, while it is easier to keep costs down with a non-insulated track circuit than with an insulated track circuit. Therefore, since there is a limit to how much of a uniform approach can be taken for both types, if further consideration is narrowed down to inexpensive non-insulated track circuits, it may be possible to effectively utilize information on the monitored section when determining the state of the section in question, as well as the influence and information of adjacent sections.

[0020] Specifically, the first technical challenge is to quickly detect the occurrence of a rail break based on the fact that in non-insulated track circuits, the progress of trains and rail breaks in adjacent sections has a different effect on changes in the level of the detection signal in that section. In addition, in non-insulated track circuits, the presence of a train or rail break in an adjacent section has a different effect on the level state of the detection signal in that section, so the second technical challenge is to detect the presence of a rail break with high accuracy. [Means for solving the problem]

[0021] The rail breakage detection device of the present invention (Solution 1) has been invented to solve the first technical problem described above, A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level drop state of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level drop state of a received signal in the non-insulated section at both ends, The device is characterized in that it is so designed that by comparing corresponding data relating to the level drop state of both means, when the level drop state on the detection means side is more rapid than the level drop state on the data holding means side, it is determined that a rail break has occurred in the non-insulated section.

[0022] In addition, the rail breakage detection device of the present invention (Solution 2) is invented to solve the first technical problem described above, A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, The device is characterized in that it is so designed that, by comparing corresponding data relating to the level rise state of both means, when the level value on the detection means side exceeds the level value on the data holding means side, it is determined that a rail break has occurred in the uninsulated section adjacent to the uninsulated sections at both ends.

[0023] Furthermore, the rail breakage detection device of the present invention (Solution 3) is invented to solve the second technical problem described above, A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, The device is characterized in that by comparing corresponding data relating to the level rise state of both means, when the level value on the detection means side exceeds the level value on the data holding means side, it is determined that a rail break exists in the uninsulated section adjacent to the uninsulated sections at both ends.

[0024] In addition, the rail breakage detection device of the present invention (Solution 4) is invented to solve the second technical problem described above, A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, The device is characterized in that, for each of the two end sections in a continuous section consisting of three consecutive uninsulated sections at both ends, corresponding data relating to the level rise state of both means are compared, and when the level value on the detection means side exceeds the level value on the data holding means side, it is determined that a rail break exists in the intermediate section of the continuous section.

[0025] In addition, the rail breakage detection device of the present invention (Solution 5) is invented to solve the second technical problem described above, A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise and a level fall of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, The present invention is characterized in that, for both end sections in a continuous section consisting of three consecutive uninsulated sections at both ends, corresponding data relating to the level increase state of both means are compared to determine that the level value on the detection means side is higher than the level value on the data holding means side, and for an intermediate section in the continuous section, corresponding data relating to the level decrease state of both means are compared to determine that the level value on the detection means side is lower than the level value on the data holding means side, thereby determining that a rail break exists in the intermediate section in the continuous section. Effect of the Invention

[0026] In the rail break detection device of the present invention (Solution 1), most rail breaks occur due to brittle fracture under tensile stress, so when a rail break occurs, the signal level in that section tends to drop suddenly over a short period of time, whereas in uninsulated sections at both ends, the drop in the level of the received signal when a train passes progresses more slowly over the time the train passes through the adjacent section. Based on this difference, the device is designed to determine that a rail break has occurred in the uninsulated section if the drop in signal level in the uninsulated section is more rapid than a reference value, making it possible to detect with high accuracy and without delay that a rail break has occurred and when. Therefore, according to the present invention, the occurrence of a rail break can be detected promptly, and the first technical problem described above is solved.

[0027] In addition, in the rail break detection device of the present invention (Solution 2), based on the difference that in uninsulated sections at both ends, when a train enters the adjacent section, signal leakage from the section to the adjacent section increases and the signal level of the section decreases, whereas when the rail in the adjacent section is broken, signal leakage from the section to the adjacent section is stopped and the signal level of the section increases, the device is designed to determine that a rail break has occurred in the uninsulated section adjacent to the uninsulated section in question when the signal level in the section increases beyond a reference value, making it possible to detect with high accuracy and without delay that a rail break has occurred and when. Therefore, according to the present invention, the occurrence of a rail break can be detected promptly, and the first technical problem described above is solved.

[0028] Furthermore, in the rail break detection device of the present invention (Solution 3), based on the difference that in uninsulated sections at both ends, when a train enters the adjacent section, signal leakage from that section to the adjacent section increases and the signal level of that section decreases, whereas when the rail in the adjacent section is broken, signal leakage from that section to the adjacent section is stopped, the signal level of that section increases, and if the rail break persists, the state after the increase in signal level is maintained and continues, if the signal level of the section exceeds a reference value, it is determined that a rail break exists in the uninsulated section adjacent to the uninsulated section, making it possible to detect the existence of a rail break in the adjacent section with high accuracy. Therefore, according to the present invention, the presence of a rail break can be detected, and the second technical problem described above is solved.

[0029] In addition, in the rail break detection device of the present invention (Solution 4), the detection method of Solution 3 described above is applied to the uninsulated sections on both ends of adjacent sections, and when a rail break is detected in either adjacent section, it is determined that a rail break exists in the intermediate section, thereby narrowing down the section in which the rail break has occurred. Therefore, according to the present invention, the presence of a rail break can be detected and the section identified with high accuracy, thereby solving the second technical problem mentioned above.

[0030] Furthermore, in the rail breakage detection device of the present invention (Solution Means 5), in addition to the detection method of Solution Means 4 above, the device is also adapted to check for level drop in intermediate sections, thereby increasing the accuracy of judgment. Therefore, according to the present invention, the presence of a rail break can be detected and the section identified with higher accuracy, thereby solving the second technical problem mentioned above. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a block diagram showing a configuration of a rail breakage detection device according to first to fourth embodiments of the present invention. [Diagram 2]FIG. 2 shows the operating state of the rail breakage detection device when a train passes, where (a) to (e) are schematic diagrams showing the progress of the train, and (f) is a waveform diagram of the received signal. [Diagram 3] 4 shows the operating state of the rail breakage detection device when a rail breakage occurs, where (a) to (e) are schematic diagrams showing the occurrence of a rail break, and (f) is a waveform diagram of a received signal. [Figure 4] FIG. 2 shows the operating state of the rail breakage detection device when a train passes, where (a) to (e) are schematic diagrams showing the progress of the train, and (f) is a waveform diagram of the received signal. [Diagram 5] 4 shows the operating state of the rail breakage detection device when a rail breakage occurs, where (a) to (e) are schematic diagrams showing the occurrence of a rail break, and (f) is a waveform diagram of a received signal. [Figure 6] FIG. 2 shows the operating state of the rail breakage detection device when a train passes, where (a) to (g) are schematic diagrams showing the progress of the train, and (h) is a waveform diagram of the received signal. [Figure 7] FIG. 2 shows the operating state of a rail breakage detection device when a rail break occurs while a train is passing, where (a) to (g) are schematic diagrams showing the occurrence of a rail break, and (h) is a waveform diagram of a received signal. [Figure 8] 4 shows the operating state of the rail breakage detection device when a rail breakage occurs, where (a) to (e) are schematic diagrams showing the occurrence of a rail break, and (f) is a waveform diagram of a received signal. [Figure 9] FIG. 1 is a block diagram showing a configuration of a conventional rail breakage detection device. [Figure 10] The figures show the operating states of a conventional rail break detection device, where (a) shows the power-on state when there is no rail break and no train is approaching, (b) shows the power-on state when a train approaches an area where there is no rail break, and (c) shows the power-on state when a rail break occurs and thereafter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Specific embodiments for carrying out such a rail breakage detection device of the present invention will be described with reference to the following Examples 1 to 4. Example 1 shown in Figures 1 to 3 embodies the above-mentioned solution 1 (claim 1 as originally filed), Example 2 shown in Figures 4 and 5 embodies the above-mentioned solutions 2 and 3 (claims 2 and 3 as originally filed), Example 3 shown in Figures 6 and 7 embodies the above-mentioned solutions 3 to 5 (claims 3 to 5 as originally filed), and Example 4 shown in Figure 8 embodies the above-mentioned solutions 1 to 5 (claims 1 to 5 as originally filed). In addition, in illustrating these figures, the same components as those in the conventional technology are denoted by the same reference numerals, and since what has been described in the Background Art section about these components is also common to each of the following embodiments, duplicated explanations will be omitted, and the following description will focus on the differences from the conventional technology. EXAMPLES

[0033] A specific configuration of a rail breakage detection device according to a first embodiment of the present invention will be described with reference to the drawings.

[0034] This rail breakage detection device 60 differs from the previously described rail breakage detection device 20 in that the processing unit 23 has been replaced with a processing unit 63. The transmitting unit 21 and receiving unit 22 and their connection to the parallel rail 10 are the same as those in the conventional configuration shown in Fig. 9 previously described, so repeated explanations will be omitted. Processing unit 63 differs from processing unit 23 described above in that level setter 24 has become level setter 64, judgment unit 26 has become judgment unit 66, input / output unit 28 has become input / output unit 68, and timer 69 has been added.

[0035] The level setter 64 differs from the already described level setter 24 in that the setting items notified to the determination unit 66 have been changed and expanded from a single train detection level A to multiple timing start levels K and timing end levels L (both of which are reference data relating to a level drop state). The timing start level K is set as a level value at which it can be said that the reception level H normalized by the transmission level G has started to drop and reached a level that is not fluctuating due to noise, etc., and the timing end level L is set as a level value at which it can be said that the reception level H normalized by the transmission level G has further dropped and is sufficiently close to the minimum value, with the magnitude relationship (high-low relationship) being timing start level K > timing end level L. The timing end level L is set to a value slightly higher than or approximately the same as the already described train detection level A.

[0036] In addition, in the processing unit 63 of FIG. 1, it is shown that the level rise detection level M (reference data related to the level rise state) is also set by the level setter 64 and notified to the judgment unit 66. Since this is used in the embodiment 2 described later, its role and other specific matters will be explained there.

[0037] When the timer 69 receives a timing instruction U to start timing from the judgment unit 66, it starts measuring time, and when a predetermined timer operation time ta (reference data related to the level drop state) has elapsed since the start of measurement, it autonomously notifies the judgment unit 66 of this by sending a timing report V. When the timer 69 receives a timing instruction U requesting a progress report after the start of measurement, it accordingly notifies the judgment unit 66 of the timer operation time tb up to that point (detection value related to the level drop state) as a timing report V.

[0038] The judgment unit 66 (see Fig. 1) monitors the levels based on the control information C, D and the signal levels G, H described above, but also monitors the time. To explain this in detail using section 14 as a specific example (see Figs. 2 and 3), when the reception level H, which was above the timing start level K, falls below the timing start level K, a timing command U is issued to start timing in the timer 69, and when the reception level H further falls below the timing end level L, the timer operation time is obtained from the timer 69 by the timing command U, and this is used as the level change time tb for the comparison judgment described next.

[0039] The timer operation time ta, which is the comparison target for the comparison judgment, is set to a time shorter than the shortest time required for a train to pass through the corresponding section of the parallel running rails 10. For example, if the length of the section to be detected is Lr and the maximum speed of the train is Vr, the calculated value [Lr / Vr] for the timer operation time ta can be said to be the theoretical setting value, but in practical use, it is set to a value that takes into account errors and variations. Note that, although it is possible to improve the effect of preventing erroneous judgment by setting the above-mentioned timing start level K and timing end level L close to each other, it is not preferable to set the values ​​K and L too close, as this will lead to a decrease in accuracy.

[0040] Furthermore, in this comparison, the timer operation time ta is compared with the level change time tb, and if the timer operation time ta≦level change time tb, the level drop state obtained by detecting the current situation is not as drastic as the state change value calculated and set in advance, so a comparison result P (determination) that a rail break has occurred in the non-insulated section is not output. On the other hand, if the timer operation time ta>level change time tb, the level drop state obtained by detecting the current situation is more drastic than the state change value calculated and set in advance, so a comparison result P (determination) that a rail break has occurred in the non-insulated section is output.

[0041] The input / output device 68 performs appropriate signal level conversion and data format conversion on the comparison result P output by the judgment unit 66, and then outputs it to the outside as rail break information Q. Since the rail break information Q is output in response to the detection of a sudden level drop, it is basically temporary or short-term, but it may be output continuously when, for example, the reception level H continues to be below the timing end level L.

[0042] The manner of use and operation of the rail breakage detection device 60 of the first embodiment will be described with reference to the drawings.

[0043] FIG. 2 shows the operating state when a train passes, where (a) to (e) are schematic diagrams showing the progress of train 30, and (f) is a waveform diagram of the reception level H related to the detection signal in section 14 (see the dashed line). FIG. 3 shows the operating state when a rail breaks, where (a) to (e) are schematic diagrams showing the occurrence of rail break 40, and (f) is a waveform diagram of the reception level H related to the detection signal in section 14 (see the dashed line).

[0044] In this example, on the parallel rail 10 to which the rail break detection device 60 is connected (see Figure 1), a series of sections 12, 13, 14 are all uninsulated at both ends (see Figures 2(a) to (e)), and a rail break occurs in section 14 of these sections (see Figures 3(a) to (e)).The operating state of the rail break detection device 60 under such circumstances (specifically, the judgment state according to the reception level) will be explained in chronological order (see Figures 2(f) and 3(f)).

[0045] First, a case will be described in which the train 30 runs through the sections 12, 13, and 14 in this order on the normal parallel rails 10 (see Figs. 2(a) and 2(f)). While the train 30 is traveling through section 12, which is just before section 14 (see FIG. 2(a)), the reception level H(14) for section 14 is stable at a value that exceeds the timing start level K (see FIG. 2(f)t1). Then, when the train 30 moves to section 13, which is just before section 14, and travels there (see FIG. 2(b)), the reception level H(14) for section 14 gradually decreases (see FIG. 2(f)t2).

[0046] Then, when the train 30 passes through the preceding section 13 and reaches the end of section 14 (see FIG. 2(c)), the reception level H(14) for section 14 drops to a value below not only the timing start level K but also the timing end level L (see FIG. 2(f) t3). Then, while the train 30 is traveling through section 14 (see FIG. 2(d) and (e)), the reception level H(14) for section 14 continues to be below the timing end level L (see FIG. 2(f) t4 and t5). In this case, the level change time tb required for the reception level H(14) for section 14 to drop from the timing start level K to the timing end level L is greater than the timer operation time ta described above (see t2 to t3 in Figure 2(f)), so the judgment unit 66 does not determine that a break has occurred, and the processing unit 63 does not issue rail break information Q.

[0047] Next, a case will be described in which a rail break suddenly occurs in section 14 among sections 12, 13, and 14 which were all normal (see FIG. 3). Even if there are no trains passing through, rails are prone to bending due to compressive stress caused by expansion when it is hot, whereas rails are prone to brittle fracture due to tensile stress when it is cold. Most rails are made of steel, and fatigue fracture due to the passage of trains etc. progresses slowly, followed by rapid fracture. For this reason, rail fractures on railways usually lead to complete fracture within a short period of time.

[0048] In this case, before the rail break occurs (see Figs. 3(a) and (b)), the reception level H(14) for section 14 is stable at a value exceeding the timing start level K (see Fig. 3(f) t1 to t3). Then, when rail breakage 40 occurs in section 14 and is completed in a short time (see Figures 3(c) to (e)), the reception level H(14) for section 14 drops rapidly and falls below the timing start level K and then below the timing end level L (see immediately after t3 in Figure 3(f)).

[0049] In this case, since the level change time tb required for the reception level H(14) for section 14 to drop from the timing start level K to the timing end level L is shorter than the timer operation time ta described above (see t3 to t4 in Figure 3(f)), the determination unit 66 determines that a break has occurred, and rail break information Q is issued from the processing unit 63.

[0050] In this way, the level change time tb taken for the reception level H to drop from the timing start level K to the timing end level L is compared with the timer operation time ta which is shorter than the shortest time for the train 30 to pass through the section, and it is determined that a rail break 40 has occurred only when there is a sudden level change. This means that the passage of a train is almost never erroneously determined to be a rail break, and moreover, once a rail break due to brittle fracture occurs, the occurrence of the break is detected promptly. EXAMPLES

[0051] A specific configuration of a rail breakage detection device according to a second embodiment of the present invention will be described with reference to the drawings.

[0052] FIG. 4 shows the operating state when a train passes, where (a) to (e) are schematic diagrams showing the progress of train 30, and (f) is a waveform diagram of the reception level H(13) related to the detection signal in section 13 (see the two-dot chain line) and the reception level H(14) related to the detection signal in section 14 (see the one-dot chain line). FIG. 5 shows the operating state when a rail breaks, where (a) to (e) are schematic diagrams showing the occurrence of rail break 40, and (f) is a waveform diagram of the reception level H(13) related to the detection signal in section 13 shown by the two-dot chain line (see the two-dot chain line) and a waveform diagram of the reception level H(14) related to the detection signal in section 14 (see the one-dot chain line).

[0053] The difference between this embodiment 2 and the above-mentioned embodiment 1 (see Figs. 4(a) to (e) and 5(a) to (e)) is that the boundary between section 12 and section 13 of the parallel rails is insulated, and sections 12 and 13 are not sections with both ends uninsulated. However, section 14 remains a section with both ends uninsulated. Another difference between this rail break detection device and the rail break detection device 60 of the first embodiment described above is that a level rise detection level M is stored in the processing unit 63 as predetermined reference data relating to the level rise state of the received signal when a train passes through a non-insulated section at both ends, and this level rise detection level M is also used by the judgment unit 66.

[0054] The level rise detection level M, like the other level values ​​K and L mentioned above, is set as data in the judgment unit 66 using the level setter 64, and is initially set to the midpoint between the highest value of the reception level H detected when there is no rail break and the highest value of the reception level H reached by the increase in the reception level H related to the section adjacent to the section in question when a rail break occurs. Such a level rise detection level M is the reference data relating to the level rise state of the received signal when a train passes through the uninsulated section 14 at both ends.

[0055] Furthermore, when the receiving level H of the level detector 27 for any of the sections to be detected that are uninsulated at both ends rises and exceeds the level increase detection level M of the determining unit 66 (in this case, the receiving level H corresponds to the detection value relating to the level increase state, and the level increase detection level M corresponds to the reference data relating to the level increase state), the determining unit 66 is configured to determine that a rail break has occurred in the uninsulated section adjacent to the corresponding uninsulated section at both ends. In addition, if the receiving level H of the level detector 27 for any of the uninsulated sections at both ends of the sections to be detected exceeds the level rise detection level M of the judgment unit 66, it is determined that a rail break exists in the uninsulated section adjacent to the corresponding uninsulated section at both ends.

[0056] In this situation, when the train 30 travels on the normal parallel rails 10 in the order of sections 12, 13, and 14 (see FIG. 4), while the train 30 is traveling in the section 12 just before section 14 (see FIG. 4(a)), both the reception level H(13) for section 13 and the reception level H(14) for section 14 are stable at values ​​exceeding the timing start level K (see FIG. 4(f)t1). Then, when the train 30 reaches the section 13 just before section 14, the reception level H(13) for section 13 drops rapidly and falls below the timing start level K and further below the timing end level L, and the level change time tb(13) becomes shorter than the timer operation time ta(13) (see immediately after t1 in FIG. 4(f)). However, since the section 13 is not a section uninsulated at both ends, the determination unit 66 does not determine the occurrence of a break, and the processing unit 63 does not issue rail break information Q.

[0057] On the other hand, the reception level H(14) for section 14 gradually decreases (see t1-t3 in FIG. 4(f)) as the train 30 travels through section 13 (see FIGS. 4(a) and 4(b)) as the train progresses, so that the level change time tb(13) becomes longer than the timer operation time ta(13) (see t1-t3 in FIG. 4(f)), and therefore even if section 14 is an uninsulated section at both ends, the determination unit 66 does not determine that a break has occurred, and the processing unit 63 does not issue rail break information Q. In this way, undesired erroneous determinations for section 13, which is the boundary between an insulated section and a non-insulated section, are reliably avoided.

[0058] Next, a case will be described in which a rail fracture suddenly occurs in section 13 among sections 12, 13, and 14, all of which were normal (see FIG. 5). In this case as well, the rail fracture is a short-term brittle fracture.

[0059] In this case, before a rail break occurs (see FIG. 5(a)), both the reception level H(13) for section 13 and the reception level H(14) for section 14 are stable at values ​​above the timing start level K (see t1 in FIG. 5(f)). Then, when a rail break 40 occurs in section 13 and is completed in a short time (see FIGS. 5(b) to (e)), the reception level H(13) for section 13 drops rapidly and falls below the timing start level K and also below the timing end level L (see immediately after t2 in FIG. 5(f)). However, because section 13 is not a section with no insulation at both ends as described above, this does not result in the determination unit 66 determining the occurrence of a break or the processing unit 63 issuing rail break information Q.

[0060] In contrast, when rail break 40 occurs in section 13 (see FIG. 5(b)), the reception level H(14) for section 14 starts to rise and quickly exceeds the level rise detection level M (see FIG. 5(f) immediately after t2). Therefore, the determination unit 66 determines that a rail break has occurred in either or both of the adjacent section 13 to the left and the adjacent section 15 to the right, and rail break information Q is issued from the processing unit 63. Furthermore, as long as the rail break 40 persists thereafter, the reception level H(14) continues to remain high and above the level rise detection level M, and the processing unit 63 continues to issue the rail break information Q. EXAMPLES

[0061] A specific configuration of a rail breakage detection device according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 6 shows the operating state of the rail break detection device when no rail break occurs while a train is passing, and FIG. 7 shows the operating state of the rail break detection device when a rail break occurs while a train is passing. In both figures, (a) to (g) show the progress of train 30, etc., and (h) shows the waveform of the received signal H.

[0062] This rail breakage detection device differs from the above-mentioned second embodiment in that a determination method for a continuous section having three consecutive uninsulated sections at both ends is added to the determination unit 66. To explain this using a specific example, when the judgment unit 66 focuses on the latter of three consecutive sections 13-15 out of two of three consecutive sections 12-14, 13-15 included in a consecutive section 13-15 that has four or more uninsulated sections at both ends, it makes a first judgment for the two end sections 13, 15 in the three consecutive sections 13-15 and a second judgment for the middle section 14 in the same three consecutive sections 13-15, and when the results of both the first and second judgments are satisfied, it judges that a rail break exists in the middle section 14.

[0063] The first judgment is made when, for either of the sections 13, 15 at both ends, the level increase state of the reception level H acquired by the level detector 27 is compared with the corresponding level increase detection level M set by the level setter 64 and stored as data in the judgment unit 66, and the value of the reception level H exceeds the value of the level increase detection level M. In addition, the second judgment is made by comparing the decreasing state of the reception level H with the corresponding timing end level L set by the level setter 64 and stored as data in the judgment unit 66 for the intermediate section 14, and is made true when the value of the reception level H is lower than the value of the timing end level L.

[0064] We will explain the cases where no rail breakage occurs (see Figure 6) and where a rail breakage occurs (see Figure 7) when a train 30 runs through sections 12 to 15 in that order on a parallel rail 10 equipped with such a rail breakage detection device. First, we will explain the state of the reception level H in each of sections 13 to 15 (see Figures 6(a) to (g)) in the case where train 30 runs from section 12 to sections 13, 14 and then 15 without any rail breakage (see Figure 6(h)). In the following explanation, we will omit repeated detailed explanations and simply state the main points.

[0065] In this case, the reception level H(13) for section 13 falls below the timing end level L (see FIG. 6(h)) at time t1 when the train 30 finishes passing through section 12 (see FIG. 6(a)), and continues to fall below the timing end level L (see FIG. 6(h)) at time t2 when the train 30 is running through section 13 (see FIG. 6(b)). However, between times t3 and t5 when the train 30 leaves section 13 and runs through section 14 (see FIG. 6(c)-(e)), the reception level H(13) exceeds the timing end level L and further rises to between the timing start level K and the level rise detection level M (see FIG. 6(h)). After the train 30 reaches section 15, the reception level H(13) remains between the values ​​K and M from t5 to t7 (see FIG. 6(e)-(g)) (see FIG. 6(h)). Therefore, the processing unit 63 does not output rail break information Q based on the fluctuation of the reception level H(13).

[0066] Furthermore, the reception level H(14) for section 14 maintains a value between the timing start level K and the level rise detection level M (see FIG. 6(h)) before time t1 when the train 30 finishes passing through section 12 (see FIG. 6(a)). However, during the time t1 to t3 when the train 30 leaves section 12 and is traveling through section 13 (see FIG. 6(b)), the reception level H(14) falls below the timing start level K and even below the timing end level L (see FIG. 6(h)). Between times t3 and t5 when the train 30 travels through section 14 (see Figs. 6(c)-(e)), the reception level H(14) remains below the timing end level L (see Fig. 6(h)), but between times t5 and t7 when the train 30 reaches section 15 and travels therethrough (see Figs. 6(e)-(g)), the reception level H(14) exceeds the timing end level L and further rises to between the timing start level K and the level rise detection level M (see Fig. 6(h)), and from time t7 onwards the reception level H(14) remains between the values ​​K and M (see Fig. 6(h)). Therefore, no rail break information Q is output from the processing unit 63 based on a fluctuation in the reception level H(14).

[0067] Furthermore, the reception level H(15) for section 15 maintains a value between the timing start level K and the level rise detection level M (see FIG. 6(h)) before time t3 when the train 30 finishes passing through sections 12 and 13 (see FIG. 6(a) and (b)). However, during the period from time t3 to t5 when the train 30 leaves section 13 and is traveling through section 14 (see FIG. 6(c) to (e)), the reception level H(15) falls below the timing start level K and even below the timing end level L (see FIG. 6(h)). During the period from time t5 to t7 when the train 30 leaves section 14 and is traveling through section 15 (see FIG. 6(e) to (g)), the reception level H(15) continues to fall below the timing end level L (see FIG. 6(h)). However, after time t7 when the train 30 reaches section 15 and is traveling there, the reception level H(15) rises above the timing end level L (see FIG. 6(h)), and further rises to a value between the timing start level K and the level rise detection level M and maintains that value (not shown). Therefore, the processing unit 63 does not output rail breakage information Q based on fluctuations in the reception level H(15).

[0068] In this way, if the train 30 travels from section 12 to sections 13, 14 and further to 15 without a rail break occurring (see Figures 6(a) to (g)), for each of sections 13 to 15 that the train 30 has passed through, the reception level H decreases gradually as the train 30 passes through, specifically, so that the level change time tb is greater than the timer operation time ta, and therefore rail break information Q will not be issued erroneously.

[0069] Next, with reference to Figure 7, we will explain what happens when a train 30 runs through sections 12 to 15 in that order on a parallel rail 10 on which a rail breakage detection device is installed, and a rail break occurs all at once due to the action of the train 30 while traveling through section 14.

[0070] In this case, the reception level H(13) for section 13 is below the timing end level L, just as when there is no rail break as described above, from time t1 to t3 (see Figures 7(a) to (c)) when the train 30 passes through sections 12 and 13 and enters section 14, and begins to rise when the train 30 enters section 14 (see Figure 7(h)). However, when rail break 40 occurs at time t4 while the train 30 is running through section 14 (see Figure 7(d)), the reception level H(13) for section 13 rises higher than when there is no rail break, exceeds the level rise detection level M, and remains at that level (see Figure 7(h)) (see Figure 7(e) to (g)). This satisfies part of the conditions for issuing rail breakage information Q.

[0071] The reception level H(14) for section 14 falls below the timing end level L (see FIG. 7(h)) during the time t1 to t3 (see FIG. 7(a) to (c)) until the train 30 reaches section 14, and continues to fall below the timing end level L (see FIG. 6(h)) during the time t3 to t5 (see FIG. 6(c) to (e)) when the train 30 is traveling through section 14. Moreover, in this embodiment, a rail break 40 occurs in section 14 while the train 30 is passing (see FIG. 7(d)), which causes the detection signal to be continuously cut off in section 14. Therefore, even after time t6 when the train 30 leaves section 14, the reception level H(14) continues to fall below the timing end level L (see FIG. 7(h)). This satisfies another part of the conditions for issuing rail break information Q.

[0072] Furthermore, to briefly state without repeating detailed explanation, the reception level H(15) for section 15 has a waveform similar to that of reception level H(13) delayed by two sections, and after time tn when the train 30 has passed section 15 and moved further away, it rises higher than when there is no rail break, exceeds the level rise detection level M, and continues at that level (see the right end part of Figure 7(h)). This satisfies the remaining part of the issue condition for rail break information Q, and all of the issue conditions for rail break information Q are met.

[0073] Specifically (see the reception level at time tn in FIG. 7(h)), for three consecutive sections 13, 14, and 15 each having non-insulated sections at both ends, the reception level H(13) of section 13 at one end exceeds the level rise detection level M, the reception level H(15) of section 15 at the other end also exceeds the level rise detection level M, and further, the reception level H(14) of section 14 in the middle is below the timing end level L, and this state continues. Therefore, the processing unit 63 continues to output rail break information Q indicating that a rail break exists in the intermediate section 14 of the three consecutive sections 13-15. EXAMPLES

[0074] A specific configuration of a rail breakage detection device according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 8 shows the operating state of the rail breakage detection device when a rail breakage occurs, where (a) to (e) are schematic diagrams showing the occurrence of a rail break 40, and (f) is a waveform diagram of a received signal H.

[0075] The fourth embodiment differs from the first to third embodiments in that the rail breakage detection device 60 of the third embodiment is applied to the parallel rails 10 of the first embodiment. That is, in the first embodiment, it was determined that a rail break had occurred when a sudden drop (level change time tb < timer operation time) in the reception level H(14) related to section 14 where rail break 40 had occurred was detected, whereas here, the reception levels H(13), (15) of sections 13, 15 on either side of section 14 are also used in the determination.

[0076] Specifically (see Figure 8), until rail break 40 occurs (see Figures 8(a) and (b)), the reception levels H(13), (14), and (15) for three consecutive sections 13, 14, and 15, which are made up of three uninsulated sections at both ends, are all halfway between the timing start level K and the level rise detection level M (see Figure 8(f)). However, when rail break 40 occurs in the intermediate section 14 (see Figure 8(c)), the reception level H(14) suddenly drops from above the timing start level K to below the timing end level L, and the reception levels H(13) and H(15) of the adjacent sections 13 and 15 on both sides exceed the level rise detection level M (see Figure 8(c)).

[0077] Then, after that (see Figures 8(d) and (e)), for the three consecutive sections 13, 14, and 15 each having non-insulated sections at both ends, the reception level H(13) of section 13 at one end remains higher than the level rise detection level M, the reception level H(15) of section 15 at the other end also remains higher than the level rise detection level M, and furthermore, the reception level H(14) of section 14 in the middle remains below the timing end level L. All three of these conditions continue to be met. Therefore, the processing unit 63 continues to output rail break information Q indicating that a rail break exists in the intermediate section 14 of the three consecutive sections 13-15.

[0078] [others] In the above embodiment, both the timer operation time ta and the level change time tb are measured by the timer 69, but it is not essential to measure both times ta and tb. For example, the timer operation time ta may simply be held as a fixed value and the level change time tb may be measured using the timer 69, and the two may be compared. Alternatively, the timer 69 may be used to wait for the timer operation time ta to elapse, and the rapidity of the level change may be determined based on whether or not a predetermined level change has occurred up to that point.

[0079] In the above-mentioned Examples 3 and 4, the three conditions adopted as criteria for determining the presence of a rail break in a consecutive section having three uninsulated sections at both ends are that the reception level H for both ends is higher than the level increase detection level M, and that the reception level H for the intermediate section is lower than the timing end level L. However, it is not essential that these three conditions are met simultaneously in order to make a judgment, and appropriate conditions may be adopted depending on the balance between accuracy and oversight rate, etc.

[0080] In the above embodiment, the reference data such as the timing start level K, timing end level L, level rise detection level M, and timer operation time ta have been described as being fixed values ​​common to all sections 11, 12, 13, ... of the parallel rail 10. However, this is a provisional limitation imposed for the purpose of simplifying the explanation of the embodiment, and the reference data may be determined for each section, and the values ​​may be fine-tuned depending on, for example, the outside temperature, which has a significant effect on the rail condition.

[0081] In the already-described rail breakage detection device 20 and the above-mentioned rail breakage detection device 60, when transmitting and receiving detection signals for each section 11, 12, ... of the rail 10, a time division method (scanning method) was used in which the section to be transmitted and received is switched in a time division manner, making multiple signals unnecessary, but the method of transmitting and receiving the detection signals is not limited to this. For example, when transmitting and receiving detection signals to each section 11, 12, ... of the rail 10, a frequency separation method (constant transmission method) may be used in which signals of different frequencies are used for adjacent or nearby sections of the rail 10, eliminating the need for time division. [Explanation of symbols]

[0082] 10...Parallel rail (track), 11,12,13,14,15,1N...section, 13a, 13b, 14a, 14b...Rails, 20...Rail breakage detection device, 21: transmitting unit; 22, 22a, 22b: receiving unit; 23: processing unit; 24... level setter, 25... controller, 26... judgement unit (level monitoring), 27...Level detector, 28...Input / output device, 30…Train, 40…Rail break, 60...Rail breakage detection device, 63: Processing section; 64: Level setting device; 66: Judgment unit (level monitoring, time monitoring), 68: Input / output device, 69: Timer, MT: Matching transformer, ST: Transmitter, RT: Receiver, A...Train detection level, B...Transmission setting level, C...Transmission control information, D...Reception control information, G: Transmission level, H: Reception level, I: Comparison result, J…Train detection information, rail breakage information, K: start level for timing, L: end level for timing, M: level rise detection level, P: Comparison result, Q: Rail breakage information, U: Timing instruction, V: Timing report

Claims

1. A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, This rail break detection device is characterized in that it is configured to compare corresponding data relating to the level rise state of both means and, when the level value on the detection means side exceeds the level value on the data holding means side, it determines that a rail break has occurred in the uninsulated section adjacent to the uninsulated section at both ends.

2. A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, This rail break detection device is characterized in that it is configured to compare corresponding data relating to the level rise state of both means and, when the level value on the detection means side exceeds the level value on the data holding means side, it determines that a rail break exists in the uninsulated section adjacent to the uninsulated section at both ends.

3. A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, A rail break detection device characterized in that, for each of the two end sections in a consecutive section consisting of three consecutive uninsulated sections at both ends, corresponding data relating to the level rise state of both means are compared, and when the level value on the detection means side exceeds the level value on the data holding means side, it is determined that a rail break exists in an intermediate section in the consecutive sections.

4. A rail breakage detection device having a series of non-insulated track circuits in which a transmitter and a receiver are alternately connected to each section of parallel rails to transmit and receive detection signals for each said section, a data storage means for storing predetermined reference data relating to a level rise and a level fall of a received signal when a train passes through a non-insulated section at both ends of each of the sections, and a detection means for detecting a level rise of a received signal in the non-insulated section at both ends, a rail break detection device configured to compare corresponding data relating to the level increase state of both means for each of the two end sections in a continuous section consisting of three consecutive uninsulated sections at both ends, and to compare corresponding data relating to the level decrease state of both means for an intermediate section in the continuous sections, when the level value on the detection means side is lower than the level value on the data holding means side, and to determine that a rail break exists in the intermediate section in the continuous sections.

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