JP2005199838A - Cable fault contact detecting device - Google Patents

Abstract

The present invention is based on the premise of standard methods in the railway field and the use of semiconductor parts, and further has the advantages of a scanning type cable mixture detection device, a voltage addition type mixture detection device, and other mixture detection devices.
In a cable mixture detection device that applies a measurement DC voltage to the midpoint of a device-side matching transformer 34 in order to detect a contact between lines 33 in a cable section 32, a measurement DC voltage is generated by always energizing. A plurality of shunt resistors 12a are provided, connected in parallel to the line 33 so as to continuously apply a voltage, and the shunt resistor 12a is sequentially selected to measure the voltage drop, and based on this measured value A means for determining the presence or absence of incompatibility is provided. As a result, a cable mixture detection device that has both high detection function and performance and excellent stability and safety is realized in a compact manner.
[Selection] Figure 1

Description

  The present invention relates to a cable signal detection device for railway signals, and more specifically, installed together with a railway device such as a train detection device using a track circuit or an ATC ground device, and a cable between those devices and the track. The present invention relates to a cable mixture detection device that detects whether or not lines are mixed.

  The train detection system whose schematic configuration is shown in the block diagram of FIG. 3 is a typical installation example of the cable mixture detection device. In this system, a rail 30 (track) of a railway is divided into track circuits 1T, 2T, 3T,... Having appropriate lengths, and each track circuit and the train detection device are connected to each other so as to be able to send and receive signals with cables. Specifically, the track-side matching transformers 31, 31,... Are connected to the track circuits 1T, 2T, 3T,... So that signals can be transmitted, and one end is connected to each track-side matching transformer 31. A line 33 made up of a pair of signal lines reaches the equipment room via the cable portion 32. In addition, a train detection circuit 37 (train detection device) is installed in the equipment room, which includes a large number (four in the figure) of transmission circuits 35 (transmitters) and reception circuits 36 (receivers). It is attached. Further, a device-side matching transformer 34 is connected to the transmission circuit 35 and the receiving circuit 36 so that signals can be transmitted, and the other end of the line 33 is connected to each device-side matching transformer 34. Yes.

  When an AC transmission signal is sent from the train detection circuit 37 to the line 33 via the transmission circuit 35 and the equipment-side matching transformer 34, the track is connected via the track-side matching transformer 31 to which the line 33 is connected. The transmission signal is transmitted to a circuit, for example, 3T, and then the transmission signal is transmitted to another line 33 via the track-side matching transformer 31 ahead of the track circuit 3T. The signal returns to the train detection circuit 37 via the device 34 and the reception circuit 36. The signal is returned only when the train has not entered the track circuit. When the train enters, the track circuit is short-circuited and the signal transmission is blocked and no longer returns. Can grasp the status.

  When such a contact occurs between the lines 33 of the cable part 32, a signal to be transmitted is not transmitted, or the signal is erroneously transmitted to a place other than the transmission destination. A cable contact detection device 39 for detecting contact between the lines 33 is also installed. In order to send an inspection signal, the cable contact detection device 39 and each line 33 to be inspected are connected to each other by a measurement line 38. In the case of a standard cable contact detection device, one end of each of the measurement lines 38 is cable contact. Connected to the detection device 39, the other end is connected to the midpoint of the cable connection side of the corresponding device-side matching transformer 34.

  4 is a specific example of such a standard device (see, for example, FIG. 1 of Non-Patent Document 1 and Patent Document 1), and includes a device-side matching transformer 34. A DC voltage for measurement is applied as a verification signal to the measurement line 38 connected to the midpoint of the cable part 32 connection side. That is, the cable contact detection device 40 generates a DC voltage for measurement by the DC voltage application circuit 41 and applies it to the measuring lines 38, 38,... Via the coils of the relays R1, R2, R3,. When the cable portion 32 is mixed and a current flows through any of the relays, for example, R2, the relay R2 is operated and the contact is turned on. The contact detection output of the contact detection output circuit 42 including this contact is significant. It becomes that.

  The conventional scanning-type intrusion detection device 50 shown in FIG. 5 is also a specific example of the cable intrusion detection device 39, which is used by the applicant for practical purposes. The touch detection ability is different from the above. Specifically, the DC voltage for measurement is applied from the DC voltage generation circuit 51 to the measurement line 38 connected to the midpoint of the device side matching transformer 34 on the cable part 32 connection side, as described above. However, the relays 1R, 2R,..., 30R, which are connected to the voltage application line together with the current limiting resistor 52 and the surge noise filter 53, are operated one by one by the scan control circuit 54 one by one in order. While changing the application destination 38, the contact is detected. Therefore, the DC voltage generating circuit 51 can be shared to reduce the size of the device, and it is also possible to specify the line 33 that is in contact.

In addition, when detecting contact, a check signal is not applied to the midpoint of the device side matching transformer 34 on the cable portion 32 connection side, but a DC is applied to the cable 32 connection side coil of the device side matching transformer 34 from both ends. A device in which a current flows is known (see, for example, FIGS. 2 and 3 of Patent Document 1). In this cable contact detection device, when the contact occurs, the relay coil current is cut off and the relay is turned off to detect contact.
It is also known that the reception level of the receiver is monitored, and when the reception level exceeds a predetermined value or when an increase in the reception level indicates an incompatibility state, the incompatibility is detected. (For example, refer to Patent Document 2). This also does not apply a check signal to the midpoint of the device side matching transformer 34 on the cable part 32 connection side.

  Furthermore, it has been known that even a poor insulation between track circuits is detected by using train detection in a number of track circuits by a scanning method (see, for example, Patent Document 3). This does not require the installation of a cable mixture detection device and does not eliminate the installation of the cable mixture detection device. When the intrusion detection device is not installed, the detection of the intrusion of the cable is performed as well as the detection of the train, and when the intrusion detection device is installed, the detection of the incompatibility is performed by a different principle. Strengthen functions.

JP 54-26618 A (FIGS. 1 to 3) JP 2001-171520 A (FIG. 1) JP 2001-328533 A Electricity Bureau Shin-tsu Section "ATC (1D type) system design data collection", March 1983, p-218

  However, such conventional cable contact detection devices have their advantages and disadvantages. For example, in the case of the voltage addition type intrusion detection device 40 of FIG. 4, since a method of applying a measurement DC voltage to the middle point of the device side matching transformer 34 is adopted, the device side matching transformer 34 or Since the check current does not flow in the line 33, there is an advantage that it is well suited to the field of railway signals in which signal transmission is performed through the alternating current in the line 33. On the other hand, since the relay is a current sensor, the detection sensitivity and accuracy are increased. It is difficult, and I do not know the degree of contact. In addition, when the insulation resistance is lowered between a plurality of different lines at the same time, it can be detected only by the parallel combined resistance, so that even if the contact state is not reached individually, contact detection is issued. Furthermore, there are also complaints that the voltage that is increased by addition is applied to the line 33 and that a large number of DC voltage application circuits 41 cannot be shared and are difficult to downsize.

  In the case of the scanning-type cable mixture detection device 50 of FIG. 5, the DC voltage generation circuit 51 is shared while maintaining the advantage of the voltage application method to the transformer midpoint, and further, the mixture line is connected. Although the advantage of specifying is additionally acquired, on the other hand, sufficient measures must be taken by paying close attention to the transient state when the circuit to which the measurement DC voltage is applied is switched. In the transient state, for example, charging / discharging to the inter-cable capacitance is performed. In addition, when the line is unbalanced, transient noise is likely to occur on the line, and it is necessary to suppress it. Furthermore, when implementing the scanning function, mercury relays with high contact reliability are often used, but mercury relays require caution and measures for protection and disposal.

Furthermore, in the case of the cable mixture detection device of Patent Document 1, it is possible to detect the occurrence of a self-failure, but the advantage of the method of applying a voltage to the midpoint of the transformer is lost. For this reason, even a train detection device that complies with the standard specification of railroad signals cannot always be installed safely. Moreover, the dissatisfaction of the above-described cable mixture detection device 40 is almost taken over as it is.
In addition, in the case of the intrusion detection device of Patent Document 2, a large number must be installed for each receiver, and the advantage of the voltage application method to the midpoint of the transformer is lacking. In the first place, it is not a direct method using a verification signal, but an indirect method of monitoring the reception level, so it has a strong meaning of reinforcement.

Insulation failure detection between track circuits associated with the train detection method of Patent Document 3 is also an indirect method and is premised on scanning-type train detection. If it is juxtaposed, its function will be strengthened.
On the other hand, with the advancement of semiconductor technology, the adoption of electronic components made of semiconductors is also progressing in the railway field. For example, electromagnetic relays can be replaced with semiconductor relays, or relay circuits can be replaced with equivalent or high-performance electronic circuits. Is being replaced.

Therefore, as for the cable contact detection device, it is a technical trend to reduce the size and voltage by using semiconductor components instead of electromagnetic relays.
However, simply applying replacement with a semiconductor component to a conventional cable mixture detection device will inherit the advantages and disadvantages described above, and the attractiveness of the performance will not increase.
Therefore, it is a technical problem to devise a circuit configuration or the like so as to have as many advantages as possible.

  Specifically, a standard method of applying a DC voltage for measurement to the midpoint of the equipment-side matching transformer to ensure compatibility with the railway signal field is assumed, and this is premised on the adoption of semiconductor components. In addition, the advantages of the scanning type cable mixing detection device that enables sharing of voltage generation circuits and identification of mixed contact lines by switching the line, and a transient state occurs in the application of the DC voltage for measurement because the line is not switched. There is a problem to improve so that the advantages of the voltage addition type intrusion detection device and the advantages of other intrusion detection devices in which a high DC voltage for measurement is not applied to the cable line are combined. Further, it becomes a further problem to make it possible to understand the incompatibility resistance value and the self-failure.

  The cable mixture detection device of the present invention was created to solve such a problem, and detects the cable mixture between the track side matching transformer and the equipment side matching transformer of the railway. Therefore, in the cable contact detection device that applies a measurement DC voltage to the midpoint of the cable connection side of the device-side matching transformer, a plurality of shunt resistors that generate the measurement DC voltage by always energizing are provided. Scanning determination that connects to the line so as to continuously apply voltage, further selects the shunt resistor in order, measures the voltage drop, and determines the presence or absence of contact based on this measured value Means is provided.

  More specifically, a cable line in which one end is connected to a track-side matching transformer installed on the track side of a railway and the other end is connected to a device-side matching transformer installed on a device side such as a train detector. In a cable mixture detection device that applies a measurement DC voltage to a measurement line connected to the midpoint of the cable connection side of the device-side matching transformer when detecting an incompatibility between the two, a constant voltage higher than the measurement DC voltage is determined. A plurality of shunt resistors each having one end connected to the output end of the constant voltage generation circuit and the other end connected to one of the measurement lines, and corresponding to each of the shunt resistors. The idling resistor, one end of which is connected to the other end of the corresponding shunt resistor and the other end is connected to the reference end of the constant voltage generating circuit, and the shunt resistor are sequentially selected one by one. A selection switch circuit for outputting a voltage at the end side, in which a determining section whether a mixed contact, based on said constant voltage and that voltage.

In addition, in order to solve the above-described further problem, means for calculating the value of the contact resistance is provided in the processing unit.
Alternatively, the function of the processing unit has been expanded so that it is determined that there is a risk of contact when the voltage drop at the shunt resistor is large, and that there is a self-failure when the voltage drop at the shunt resistor is small. Is.
Furthermore, the function of the processing unit is further expanded so that when it is determined that there is a risk of contact, the value of the contact resistance is calculated and a warning is issued accordingly.

  In such a cable mixture detection device of the present invention, by taking over the standard method of applying a DC voltage for measurement to the midpoint of the equipment-side matching transformer, ensuring compatibility with the field of railway signals. By adopting a resistance circuit that does not require an electromagnetic relay and voltage measuring means suitable for semiconductors, miniaturization and low voltage are achieved. In addition, shunt resistors are provided corresponding to each cable line to which the DC voltage for measurement is applied, and they are always energized so that changes in current can be detected by measuring the drop voltage. On the other hand, it is possible to perform scanning while applying voltage continuously in parallel. In other words, by selecting shunt resistors in order and measuring the voltage drop, it is possible to specify the location of a line and determine the presence or degree of contact without switching the voltage application itself to the line. .

With such a circuit configuration, it is possible to specify the contact line, and it is possible to avoid the occurrence of a transient state in applying the measurement DC voltage. Furthermore, the voltage generation circuit can be shared by a number of shunt resistors and the measurement DC voltage applied to the cable line is not added, so that it does not need to be so high.
The function and performance of intrusion detection are improved by identifying and determining the level of this line, and by preventing the transient state from reaching the cable line, noise resistance is improved, operation is stabilized and reliability of intrusion detection is improved. Increases nature. In addition, the low voltage applied to the line not only reduces energy consumption, but also contributes to ensuring safety in the event of an electric shock.
Therefore, according to the present invention, it is possible to realize a compact cable touch detection device that has high touch detection functions and performance and is excellent in stability and safety.

  A specific form for carrying out such a cable mixture detection device of the present invention will be described with reference to FIGS. 1 and 2. First, the configuration of the cable mixture detection device 10 of the present invention will be described in detail. Explained. FIG. 1A is a block diagram of the entire circuit, and FIG. 1B is a block diagram of a processing unit. In the drawings, the same reference numerals are given to the same components as those in the prior art, and what is described with reference to FIG. 3 in the background art section is also common to the following embodiments. Therefore, the repeated description will be omitted, and the description below will focus on differences from the prior art.

  The cable mixture detection device 10 (see FIG. 1A) replaces the cable mixture detection device 39 described above without changing external wiring or the like, and detects the mixture between the lines 33 in the cable portion 32. At this time, a measurement DC voltage is applied to the measurement line 38 connected to the midpoint of the cable connection side of the device side matching transformer 34. In the illustrated example, a transmission line 33 connected to five external terminals C1S to C5S by measurement lines 38, and a reception line 33 connected to five external terminals C1R to C5R by measurement lines 38, respectively. Detecting incompatibility for the target. Specifically, the presence / absence determination of the contact, the risk determination of the contact, the calculation of the contact resistance value, and the presence / absence determination of the self-failure are performed. In this example, according to a given required specification, a mixed line must be specified for the transmission line 33 ahead of the external terminals C1S to C5S, but for the reception line 33 ahead of the external terminals C1R to C5R, Assuming that there is no need for line identification, the specific circuit configuration is as follows.

  That is, the cable mixture detection device 10 includes a constant voltage generation circuit 11, a current sensor circuit 12, a selection switching circuit 13, an idling circuit 14, a selection relay control circuit 15, and an alarm buzzer and status indicator (not shown). Among them, the constant voltage generation circuit 11 generates a constant voltage of about 24V, for example. This voltage is stepped down by the current sensor circuit 12 and becomes a measurement DC voltage, which is applied to each measurement line 38 via the transmission-side external terminals C1S to C5S. The voltage is lower than the voltage of 100V to 200V generated in the circuits 41 and 51.

  The current sensor circuit 12 includes a plurality (five in the illustrated example) of shunt resistors 12a and a processing unit 12b described in detail later. Of these, one end of the shunt resistor 12a is connected to the output end of the constant voltage generation circuit 11 (that is, the 24V potential portion), and the other end is connected to any one of the measurement lines 38 via the transmission side external terminals C1S to C5S. It is connected. On the other hand, the receiving-side external terminals C1R to C5R, which do not need to specify a line when detecting contact, are not directly connected to the shunt resistor, but are connected to the reference terminal (that is, the 0 V potential portion) of the constant voltage generating circuit 11. Has been. The shunt resistor 12a is, for example, several kΩ.

  The idling circuit 14 is provided with the same number of idling resistors 14a as the shunt resistors 12a. The idling resistor 14a is in one-to-one correspondence with the shunt resistor 12a and connected in series. That is, one end of the idling resistor 14a is connected to the other end of the corresponding shunt resistor 12a and the transmission side external terminal (any one of C1S to C5S), and the other end of the idling resistor 14a is the reference end of the constant voltage generating circuit 11. Connected to. An example of the idling resistor 14a is 100 kΩ. The series resistance of the idling resistor 14a and the shunt resistor 12a determines the energization amount of the shunt resistor 12a in the normal state, that is, the normal state without incompatibility, that is, the idling current, and the constant voltage generating circuit 11 is determined by the resistance ratio of both. The voltage drop of the shunt resistor 12a and the DC voltage for measurement are determined from the constant voltage output by

  The selection relay control circuit 15 is provided with the same number of relays 1R to 5R as the shunt resistor 12a, and operates these relays one by one in a predetermined cycle, for example, every 1000 ms. Semiconductor relays are employed for the relays 1R to 5R, and their contact portions constitute a selection switching circuit 13. Each of the relay contacts is associated with the shunt resistor 12a on a one-to-one basis, one end of which corresponds to the other end of the corresponding shunt resistor 12a, a transmission-side external terminal (one corresponding to any of C1S to C5S), and one end of an idling resistor 14a. The other end is connected in common and then connected to the input of the processing unit 12b. As a result, the selection switching circuit 13 is a circuit that selects one by one from the shunt resistor 12a and outputs the voltage on the other end side of the shunt resistor 12a to the processing unit 12b (a circuit having a multiplexer configuration).

  The processing unit 12b is also configured to input a voltage at one end of the shunt resistor 12a, that is, a constant voltage output from the constant voltage generation circuit 11 (see FIG. 1B), and together with the selected shunt resistor 12a. Insulation amplifier 12c constituting a current-voltage conversion unit (I / V conversion), V / F conversion circuit 12d and waveform shaping circuit 12e constituting a voltage-digital value conversion unit (A / D conversion), and digital processing unit And a determination circuit 12g. The V / F conversion circuit 12d is embodied by a VCO (voltage controlled oscillation circuit) or the like, the waveform shaping circuit 12e is embodied by a hysteresis characteristic flip-flop or the like, and the counting circuit 12f is embodied by a digital counter or the like. 12g is embodied by a microprocessor, a digital logic circuit, or the like.

The insulation amplifier 12c measures the voltage drop across the shunt resistor 12a by inputting the voltage across the shunt resistor 12a and taking the voltage difference between them. In order to ensure, a transformer is incorporated inside.
In order to simplify digital processing, the V / F conversion circuit 12d converts the drop voltage into frequency information in order to reduce the influence of AC noise superimposed on the DC voltage and instantaneous noise. .
The waveform shaping circuit 12e adjusts the waveform to make it a rectangular wave, for example, in order to make it easier to count the signal carrying the frequency information.

The counting circuit 12f obtains the frequency information, that is, the voltage drop at the shunt resistor 12a by counting the number of waves per unit time for the signal carrying the frequency information, and then calculates the conduction current of the shunt resistor 12a. It has become.
Since the drop voltage and the energization current of the shunt resistor 12a are in one-to-one correspondence, if one of them is present, necessary processing such as intrusion detection can be performed, but in this example, both can be used for convenience. .

The determination circuit 12g compares the voltage drop or energization current with a predetermined threshold value to determine the presence or absence of contact. At this time, which line 33 is contacted using the selection information of the selection relay control circuit 15 However, at least one of the previous lines 33 of the transmission-side external terminals C1S to C5S is clarified as to which the other line 33 is in contact.
Specifically, when the drop voltage of the selected shunt resistor 12a is greater than a predetermined first threshold value, it is determined that contact has occurred, and when the drop voltage is greater than a second threshold value that is smaller than the first threshold value, there is a risk of contact. It is determined that there is.

  In addition, when such a determination is made, the value of the contact resistance is calculated, and the value and the number of the shunt resistor 12a are displayed on the status display or an alarm buzzer is sounded. At this time, the tone color of the alarm buzzer or the display color is changed according to the value of the contact resistance. Furthermore, when the drop voltage of the shunt resistor 12a is smaller than the third threshold value that is smaller than the second threshold value, it is determined that a failure has occurred in the shunt resistor 12a or the relays 1R to 5R, An error is displayed. When the voltage drop across the shunt resistor 12a is between the second threshold value and the third threshold value, the normal state is determined.

  About the cable mixture detection apparatus 10 of such a structure, the use aspect and operation | movement are demonstrated referring drawings. FIG. 2 shows the operation state, where (a) is a normal state and (b) is a mixed contact state. Although a surge noise filter 53 is also shown in this figure, this protects the circuit from surges, and undesired propagation of a transmission / reception signal of the train detection circuit 37 and an ATC wave (about 1.5 kHz) in the ATC system. This is to ensure the separation between the lines, and does not affect the normal operation or the operation of detecting contact.

  In a normal state (see FIG. 2A), the relays 1R to 5R are selected one by one in order, and only the contact of the selected relay iR is turned on, and the voltage Vm on the other end side of the shunt resistor 12a ahead. Is, for example, an inverting input of the insulation amplifier 12c. A voltage Vp on one end side of the shunt resistor 12a is input to the non-inverting input of the insulation amplifier 12c, and a difference voltage (Vp−Vm) between the voltage Vp and the voltage Vm is a voltage drop A at the shunt resistor 12a. This drop voltage A is amplified as it is or appropriately and is output as a measurement value from the insulation amplifier 12c. The voltage drop A is transmitted to the determination circuit 12g while changing its form from analog to digital, and used for determination.

If the voltage drop A is between the second threshold value and the third threshold value, the measurement line 38 and the line 33 to which the shunt resistor 12a selected at that time is connected are determined to be in a normal state. The constant voltage generation circuit 11, the corresponding shunt resistor 12a, and the relay iR are also determined to be normal.
In a normal state, even if a measurement DC voltage is applied to the measurement line 38 and the line 33, no current that would cause a problem flows therethrough, and the energization current of the shunt resistor 12a flows through the idling resistor 14a as it is, so that the voltage Vm Is a value obtained by dividing the voltage Vp by the shunt resistor 12a and the idling resistor 14a.

  On the other hand (see FIG. 2B), the measurement line 38 and the line 33 ahead of the transmission side external terminals C1S to C5S are any other line 33, for example, the measurement line 38 ahead of the reception side external terminals C1R to C5R. When the insulation resistance is lowered to the vicinity of the line 33 when it is in contact with any one or more of the lines 33 or even if it is not said to be mixed, the contact resistance 20 between the lines 33 (this includes Insulation resistance at the time of fear is also included) is not negligible compared to the idling resistance 14a or becomes smaller than the idling resistance 14a, and the parallel resistance of the mixed contact resistance 20 and the idling resistance 14a is reduced, and accordingly the shunt The voltage drop A at the resistor 12a increases.

  When the voltage drop A exceeds the second threshold value, it is determined that there is a risk of contact with the measurement line 38 and the line 33 to which the shunt resistor 12a selected at that time is connected. Further, when the voltage drop A exceeds the first threshold value, it is determined that the measurement line 38 and the line 33 to which the shunt resistor 12a selected at that time is connected are in contact. When the contact resistance 20 becomes smaller, the drop voltage A monotonously increases. When the value of the contact resistance 20 is determined, the value of the drop voltage A is determined first, so that the value of the contact resistance 20 that affects signal transmission on the line 33 is determined. Based on the above, the first and second threshold values are predetermined.

  For example, if the contact resistance 20 is less than 10 kΩ, contact is considered. If the contact resistance 20 is 10 kΩ to 100 kΩ, there is a risk of contact. If the contact resistance 20 exceeds 100 kΩ, it is normal. If the contact resistance 20 is 10 kΩ, the voltage drop The value that should be obtained as A is the first threshold value, and the value that should be obtained as the drop voltage A when the contact resistance 20 is 100 kΩ is the second threshold value. In this way, the first and second threshold values can be set fairly freely, whereas the third threshold value is almost automatically determined from the voltage Vp based on the resistance ratio between the shunt resistor 12a and the idling resistor 14a.

When the voltage drop A exceeds the second threshold and it is determined that there is a risk of contact or contact, the contact resistance 20 is also calculated. The incompatibility resistance 20 is uniquely obtained from the drop voltage A based on a resistance network model in parallel with the idling resistance 14a. In this case, the calculated contact resistance value and the number of the selected shunt resistor 12a are displayed on the status display, and an alarm buzzer sounds with a tone corresponding to the contact resistance value.
Further, when the voltage drop A falls below the third threshold value, a failure (especially an open failure) has occurred somewhere in the shunt resistor 12a selected at that time, the idling resistor 14a ahead thereof, and the relay iR. Determined. In this case, an alarm is issued and an error is displayed when a failure is detected.

  Thus, in the cable mixture detection device 10, not only the presence / absence, but also the fear and the mixture resistance can be detected with respect to the mixture between the lines 33 in the cable portion 32. Furthermore, it is possible to detect even a failure that has occurred in the device itself. Moreover, although the standard method of applying the measurement DC voltage to the midpoint of the device-side matching transformer 34 is taken over, the circuit is embodied with a resistor component and a semiconductor component without using an electromagnetic relay, Miniaturization and low voltage are being achieved. In addition, the shunt resistor 12a also works as a current limiting resistor when the contact occurs.

Further, the voltage drop is measured by sequentially selecting the shunt resistor 12a while applying voltage continuously and in parallel to the line 33 via the shunt resistor 12a. The mixed contact line can be specified without causing a transient state in the application of the DC voltage.
Furthermore, the fact that current is flowing through the contact resistance 20 due to the DC voltage for measurement is detected using the current sensor circuit 12 instead of being detected by an electromagnetic relay, so that even a minute current is detected. In addition, it is possible to measure the current value and thus the value of the incompatible resistance 20.

[Others]
In the above-described embodiment, detection of intrusion is performed with respect to the five transmission lines 33 and the five reception lines 33. However, this is an example, and is not limited to five. And the number of lines may be different for reception. In addition, the contact between the transmission lines 33 and the reception line 33 can be detected by modifying the software of the train detection device based on the mismatch of the message or the like. By incorporating the conditions, it is possible to achieve compactness and lower cost than when the cable contact detection device 10 alone requests the completeness.

In the above embodiment, the current-voltage conversion unit is configured using the insulation amplifier 12c. However, the current-voltage conversion unit is not limited thereto. For example, the current-voltage conversion unit may be configured using a DC amplifier using a Hall element, a photocoupler, or the like. good. However, when a Hall element is used, offset adjustment is necessary at the time of manufacture, and magnetic offset due to long-term operation cannot be ignored. Also, when a photocoupler is used for the current sensor, there is an offset at the time of manufacture, and there is a secular change due to long-term operation unique to the optical element.
Furthermore, the voltage-digital value conversion unit may be configured using a comparator, an A / D converter, or the like.

The structure of the cable contact detection apparatus of this invention is shown, (a) is a block diagram of the whole circuit, (b) is a block diagram of a process part. The operation state is shown, where (a) is a normal state and (b) is a mixed contact state. It is a block diagram which shows the outline | summary structure of the train detection system which attached the cable mixture detection apparatus. This is a conventional voltage addition type intrusion detection device. This is a conventional scanning-type mixed contact detection device.

Explanation of symbols

10 ... Cable contact detection device,
11 ... Constant voltage generation circuit, 12 ... Current sensor circuit,
12a ... shunt resistor, 12b ... processing section,
12c ... insulation amplifier, 12d ... V / F conversion circuit,
12e: waveform shaping circuit, 12f: counting circuit,
12g: determination circuit, 13: selection switching circuit,
14 ... Idling circuit, 14a ... Idling resistance,
15 ... selection relay control circuit, 20 ... incompatibility resistance,
30 ... rail (track),
31 ... Track-side matching transformer, 32 ... Cable part, 33 ... Line,
34 ... device-side matching transformer, 35 ... transmission circuit,
36 ... receiving circuit, 37 ... train detection circuit, 38 ... measuring line,
39 ... Cable contact detection device,
40. Cable contact detection device,
41 ... DC voltage application circuit, 42 ... Touch detection output circuit,
50. Cable contact detection device,
51 ... DC voltage generating circuit, 52 ... Current limiting resistance,
53 ... Surge noise filter, 54 ... Scan control circuit,
1R, 2R ... Relay

Claims (5)

  A cable mixture that applies a DC voltage for measurement to the midpoint of the cable connection side of the equipment-side matching transformer in order to detect the cable-to-wire contact between the track-side matching transformer and the equipment-side matching transformer. In the detection apparatus, a plurality of shunt resistors that generate the DC voltage for measurement with constant energization are provided, and these are connected so as to continuously apply voltage in parallel to the line, and further, the shunt resistor A cable contact detection device characterized by comprising scanning determining means for sequentially selecting and measuring the voltage drop and determining the presence or absence of contact based on the measured value.   Detects incompatibility between cable lines, one end of which is connected to the track-side matching transformer installed on the track side of the railway and the other end is connected to the device-side matching transformer installed on the equipment side such as a train detector. In the cable contact detection device that applies a measurement DC voltage to a measurement line connected to the midpoint of the cable connection side of the device-side matching transformer, a constant voltage that generates a constant voltage higher than the measurement DC voltage A plurality of shunt resistors having one end connected to the output end of the constant voltage generation circuit and the other end connected to any of the measurement lines, and a plurality of shunt resistors provided corresponding to each of the shunt resistors. The idling resistor connected to the other end of the corresponding shunt resistor and the other end connected to the reference end of the constant voltage generation circuit are selected one by one from the shunt resistor, and the voltage at the other end of the shunt resistor is output. Selection and switching circuit for a cable incompatible detecting apparatus characterized by comprising a determining unit whether a mixed contact, based on said constant voltage and that voltage.   3. The cable mixture detection device according to claim 2, wherein the processing unit includes means for calculating a value of the contact resistance.   The processing unit determines that there is a risk of contact when the voltage drop at the shunt resistor is large, and determines that there is a self-failure when the voltage drop at the shunt resistor is small. The cable contact detection device according to claim 2.   5. The cable mixture detection device according to claim 4, wherein when the processing unit determines that there is a risk of contact, the processing unit calculates a value of contact resistance and issues a warning according to the calculated value.

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