JP3303730B2 - Optical fiber disconnection simulation test jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber disconnection simulation test jig in a train derailment / fallover detection system.

[0002]

2. Description of the Related Art Conventionally, in a section where a high-speed Shinkansen and a low-speed train (for example, a freight train) run side by side, such as a maintenance Shinkansen, when a freight train derails or falls over, it enters the track of the Shinkansen. In order to prevent the vehicle from colliding with the Shinkansen, various limit trouble notification devices are provided.

[0003] Such a limit obstruction notification device includes a train derailment / falling detection system which detects the position of a train derailment / falling by disconnection of an optical fiber.

FIG. 4 is a diagram showing a conventional example of a train derailment / overturn detection system, and FIG. 5 is a perspective view of a detection column used in the train derailment / overturn detection system shown in FIG.

[0005] Shinkansen rails and freight train rails 1, 2
Between them, sensors (see FIG. 5) called detection columns 3 molded with plastic concrete 3a are installed at predetermined intervals, and are connected by metal cables 4, respectively. The metal cable 4 is connected to a detection device (not shown) that detects whether or not the metal cable 4 a in the detection column 3 is disconnected.

When the freight train falls or derails and collides with the detection column 3 and the detection column 3 is destroyed, the metal wire 4a therein is cut off and a change in the electric signal is detected by a detection device (not shown). It monitors and detects the occurrence and location of the accident.

FIG. 6 is a diagram showing another conventional example of a train derailment / fallover detection system.

A metal wire called a detection wire 5 is laid along the fence 6 between the rail 1 of the Shinkansen and the rail 2 of the freight train along the fence 6 and connected to a detection device (not shown). I have. When the freight train falls and collides with the detection line 5 and the detection line 5 is cut,
The fact that an accident has occurred is detected from the change in the electric signal.

However, an electric train derailment / fallover detection system using a metal cable 4 or a detection line 5 is susceptible to electromagnetic noise, and has a problem that it is difficult to identify a point where an accident has occurred.

Therefore, a train derailment / fallover detection system using an optical fiber resistant to electromagnetic noise has been proposed.

FIG. 7 is a diagram showing a conventional example of a train derailment / fallover detection system using an optical fiber.

A trunk optical cable 12 containing a pair of trunk optical fibers 10 and 11 is disposed in a trough 13 beside a railroad track buried along a longitudinal direction between a bullet train rail 1 and a freight train rail 2. Has been established. The trough 13 is provided with connection boxes 14a to 14e at predetermined intervals.
The connection boxes 14a to 14c are provided with optical splitters 15a to 15c for branching one main optical fiber 10, and optical splitters 16a to 16c for splitting the other main optical fiber 11, respectively. A pair of sensor optical fibers 18a to 18d and 19a to 19 are provided between the connection boxes 14a to 14e.
d for sensor optical fibers 17a to 17e
Are extended in parallel with the rails 1 and 2 at a predetermined height from the ground. The pair of sensor optical fibers 18a, 19a
One end is connected to both trunk optical fibers 10 and 11 by an optical splitter 15a,
16a, and the other end is fusion spliced at the fusion splicing portion 20a. Optical fiber for sensor 1
Similarly, one end of each of the optical fibers 8b and 19b and the sensor optical fibers 18c and 19c is connected to both trunk optical fibers 10 and 11 via optical splitters 15b (15c) and 16b (16c), respectively, and the other ends are fusion spliced. The parts 20b (20c) are fusion-spliced. Optical fiber for sensor 18d, 19d
Are connected to the ends of the trunk optical fibers 10 and 11, respectively, and the other end is fusion-spliced at a fusion splicing portion 20d. That is, the trunk optical fibers 10 and 11 and the sensor optical fiber cables 17a to 17d are formed in a substantially ladder shape.

A light source 21 for generating pulsed light is connected to one end of one trunk optical fiber 10, and a light receiver 22 is connected to one end of the other trunk optical fiber 11. The light source 21 and the light receiver 22 are connected to a signal processor 23 for detecting the occurrence and location of a train derailment or a fall accident, etc., and are detected by the light source 21, the light receiver 22 and the signal processor 23. An apparatus 24 is configured.

The pulse light emitted from the light source 21 propagates through the main optical fiber 10, and is branched by the optical branching unit 15a. One of the lights split by the optical splitter 15a propagates through the optical fiber cable for sensor 18a. The pulse light propagating through the sensor optical fiber cable 18a is
0a, the optical fiber for sensor 19a, the optical splitter 16a, and the main optical fiber 11 are received by the light receiver 22.

The other light split by the optical splitter 15a is:
The light propagates through the trunk optical fiber 10 and is split by the next optical splitter 15b. One of the lights split by the optical splitter 15b propagates through the sensor optical fiber 18b. The pulse light having propagated through the sensor optical fiber 18b is received by the light receiver 22 via the fusion splicing portion 20b, the sensor optical fiber 19b, the optical splitter 16b, and the trunk optical fiber 11.

From the light source 21, the main optical cable 12, the optical fiber cables 17a to 17d for each sensor, and the light receiver 22
Fiber optic cable 1 for each sensor
7a to 17d, when one pulse light emitted from the light source 21 is received by the light receiver 22, pulse train light is observed.

FIGS. 8A to 8C show waveforms obtained by the light receiving device of the train derailment / fallover detection system shown in FIG.
In the figure, the horizontal axis represents time t, and the vertical axis represents the signal level L.
Indicates _S.

When one pulse light P is emitted from the light source 21 (see FIG. 7) (FIG. 8 (a)), FIG.
As shown in (b), the pulse train returns in the order of pulses Pa, Pb, Pc, and Pd from the side closer to the detection device among the optical fibers for sensors.

For example, if a failure occurs in the section Sb due to a disconnection of a train or the like and the optical fiber cable for sensor 17b is disconnected, the corresponding pulse light Pb as shown in FIG.
Is not observed at the receiver. Since the corresponding pulse light Pb does not return, the signal processing device 23 specifies the location where the accident has occurred.

Here, in the initial adjustment work of the train derailment / fall detection system, whether the train derailment / fall detection system operates normally when the sensor optical fiber cables 17a to 17d are actually disconnected is determined. Need to check. In this case, since it is not possible to cut a part of the sensor optical fiber cables 17a to 17d for the operation test, for example, two of the sensor optical fibers shown in FIG. Optical fiber for sensors 1
8d and 19d are cut off, and after the operation test is completed, fusion splicing is performed again and stored in the connection box 14d.

[0021]

However, in the test method described above, a fusion splicer for fusion splicing is required each time an operation test is performed, so that the test operation becomes complicated.

To solve this problem, a method of connecting an optical connector to the end of the optical fiber for the sensor and simulating the disconnection of the optical fiber for the sensor by attaching / detaching the connector may be considered. Then, there is a problem in vibration resistance. Further, when the test operator is not familiar with the train derailment / fallover detection system, there is a problem that the train derailment / fallover detection system malfunctions due to a connector connection error.

Accordingly, an object of the present invention is to solve the above-mentioned problems and provide an optical fiber disconnection simulation test jig capable of performing an operation test of a train derailment / fallover detection system without disconnecting the sensor optical fiber. To provide.

[0024]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a pair of trunk optical fibers buried along the longitudinal direction outside a train rail, and a predetermined interval between both trunk optical fibers. The provided optical splitter, a columnar connection box for storing the optical splitter, and a line extending between the connection boxes at a predetermined height from the ground, and one end of the optical splitter is connected to the optical splitter of both trunk optical fibers. A pair of sensor optical fibers connected at the other end and fusion spliced, a light source connected to one end of one trunk optical fiber for inputting pulse light, and a sensor light connected to one end of the other main optical fiber A train equipped with a light receiver that receives pulsed light that has propagated through a fiber, and a signal processing device that is connected to the light receiver and detects an abnormality in the line because the optical fiber for a sensor is disconnected due to an accident or the like and the pulsed light does not return. Derailment / fall In known systems, the optical fiber sensor, is provided with a bending applying mechanism applies a bending.

In addition to the above-described structure, the optical fiber disconnection simulation test jig of the present invention has a bending applying mechanism in which a substrate having a concave portion formed in the center and a substrate with the concave portion interposed therebetween are erected and the bending application mechanism is placed on the concave portion. A pair of guides formed with grooves for engaging the sensor optical fiber so as to cross, a protrusion formed on the concave side movably along the guide between the guides, and a stopper formed on the side opposite to the concave side; Bent member, an elastic body provided between the guide and the stopper, for urging the bent member in a direction away from the optical fiber for sensor, and a state in which the bent member provided on the guide is pressed against the optical fiber for sensor. And holding means for holding.

Here, in general, a train derailment / fallover detection system using an optical fiber is designed so that the intensity of a pulse signal from each sensor optical fiber is at the same level. Therefore, the branching ratio of the sensor optical fiber closer to the detection device is set to be small, and the branching ratio of the sensor optical fiber far from the detection device is set to be large. For example, as shown in FIG. 7, when the number of sensor optical fiber cables 17a to 17d is four, the branch ratios closer to the detection device are 18/82, 28/72, and 28/72, respectively.
The loss of each sensor optical fiber as viewed from the detection device side is 38.6 dB in section Sa:
Section Sb: 39.4 dB, section Sc: 40.5 dB, section Sd: 40 dB. Output of light source 21 is 20 dBm
Then, the sensor optical fiber cables 17a to 17
The signal level L _S of the pulse signal returned from d is as shown in FIG.

FIG. 2 is a diagram showing the level of the received pulse in the detection device when the disconnection simulation test jig shown in FIG. 1 described later is used. The horizontal axis represents time t, and the vertical axis represents the signal level L. Indicates _S.

Optical fiber cables 17a-1 for each sensor
The variation in the loss at 7d is caused by the optical splitters 15a to 15c,
These are values that allow for manufacturing errors of 16a to 16c and variations due to temperature.

[0029] The received signal design level L _D1 (maximum value), L _D2 is set and the (minimum) and the determination threshold value L _J, optical fiber cable 17a~17d for each sensor
Come signals back to the detection device 24 from, the determination threshold value L _J are received by greater than, the sensor optical fiber cable 17a~17d is broken, design level L _D1
When (L _D2 ) becomes lower than the determination threshold L _J , the signal processing device 23 of the detection device 24 determines that the pulse signal from the sensor optical fiber cables 17a to 17d has not returned, and Fiber cable 1
Abnormalities 7a to 17d are detected. In addition, as the loss amount, for example, a bending loss of 10 to 15 dB is required, but the disconnection simulation test jig of the present invention can give a loss of 10 dB by itself, so depending on the installation location of the sensor optical fiber. It is necessary to provide a loss of 10 dB or more by arranging a plurality of disconnection simulation test jigs in series with the sensor optical fiber.

That is, according to the present invention, a bending loss is applied to a part of the sensor optical fiber during the operation test by the bending applying mechanism, so that a bending loss is added to the sensor optical fiber. Then, the pulse light incident on the optical fiber for sensor attenuates to below the judgment threshold value at the bent portion. Since the receiver does not receive pulsed light from the sensor optical fiber to which bending loss has been added,
The signal processing device determines that an abnormality has occurred in the section in which the sensor optical fiber to which the bending loss has been added is provided. At the end of the operation test, the original state is restored by releasing the bending by the bending applying mechanism. Therefore, a signal in which the optical fiber is broken can be simulated without breaking the optical fiber for the sensor. Therefore, it is possible to provide an optical fiber disconnection simulation test jig capable of performing an operation test of the train derailment / fallover detection system without disconnecting the sensor optical fiber.

A jig body in which a bending applying mechanism is engaged with the sensor optical fiber and has a concave portion; a guide provided on the jig body perpendicular to the sensor optical fiber;
A bending member for movably pressing the optical fiber toward the recess along the guide, an elastic body for urging the bending member in a direction away from the optical fiber, and a state in which the bending member is pressed against the optical fiber When the bending member is pressed, a bending loss is added to the optical fiber for the sensor, and a certain bending loss is held by the holding means. The concave portion of the jig body prevents the sensor optical fiber from being unnecessarily damaged.

[0032]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the same members as those of the conventional example shown in FIG.

FIG. 1 is a conceptual view showing an embodiment of a simulation test jig for disconnection of an optical fiber according to the present invention.

A disconnection simulation test jig 30 shown in FIG. 3 includes a substrate 32 having a concave portion 31 formed in the center, a sensor 32 standing on the substrate 32 with the concave portion 31 interposed therebetween, and crossing the concave portion 31. A pair of guides 35 and 36 in which grooves (or through holes) 33 and 34 for preventing the optical fiber 18a from engaging and disengaging, and along the guides 35 and 36 between the guides 35 and 36. A convex portion 38a is formed so as to be movable in the direction of arrow A and oppose the concave portion 31 (lower side in the figure), and an upper portion 38 opposite to the convex portion 38a (upper side in the figure).
b, a bending imparting member 38 having a stopper 37 formed thereon,
A spring 39 is provided between the guides 35 and 36 and the stopper 37 and urges the bending applying member 38 in a direction away from the optical fiber 18a for a sensor. The upper ends of the guides 35 and 36 are rotatable in the directions of arrows B and C. The bending imparting member 38 is engaged with the stopper 37 provided on the optical fiber 1 for sensor.
Key 40 having an L-shaped cross-section for holding the pressed state at 8a
It is composed of Projection 38a of bending applying member 38
Is formed in a hemispherical shape with a radius of about 10 mm in order to prevent the sensor optical fiber 18c from being extremely bent. When the bending applying member 38 is pressed to some extent,
The stopper 37 hits the upper ends of the guides 35 and 36 so that the optical fiber for sensor 18a is not bent any more.

In this embodiment, the case where the disconnection simulation test jig 30 is provided on the sensor optical fibers 18a and 19a has been described. However, the present invention is not limited to this, and other sensor optical fibers 18b to 18d, You may provide in 19b-19d.

FIG. 3 is a conceptual diagram showing a state in which the disconnection test jig shown in FIG. 1 is attached to the sensor optical fiber in the connection box shown in FIG.

In the connection box 14b connected to the other end of the sensor optical fiber cable 17a, the sensor optical fiber 1
8a and 19a are formed in a loop shape (a double loop in the drawing, but not limited thereto), and then fusion-spliced at both ends, and a plurality of disconnection test jigs 30 (four in the drawing) along this optical fiber line. (But not limited to).

Next, the operation of this embodiment will be described.

When confirming the operation of the train derailment / fallover detection system, an operator opens a lid (not shown) of the connection box 14b, for example, and performs a disconnection simulation test of the sensor optical fiber cable 17a. The upper portion 38 b of the bending applying member 38 of the disconnection simulation test jig 30 is pressed, and the bending applying member 38 is fixed to the guides 35 and 36 by the key 40. When the bending applying member 38 is pushed down, a part of the optical fiber for sensor 18a is bent and a loss is added (the loss of about 10 dB is applied to the optical fiber for sensor 18a by the disconnection simulation test jig 30). Can be given). Accordingly, since the signal level at the sensor optical fiber 18a is lower than the threshold value, the pulse light that should be able to be received by the light receiver 22 of the detecting device 24 does not arrive, and the sensor optical fiber 18a is apparently disconnected. It is in the same state as.
Therefore, a disconnection simulation test can be performed without disconnecting the sensor optical fiber 18a.

If the signal level does not fall below the threshold unless the fiber loss is given by several dB depending on the location of the sensor optical fiber, several disconnection simulation test jigs are provided in series along the sensor optical fiber. , They may be activated simultaneously during the disconnection test.

With this configuration, it is possible to perform a disconnection simulation test required for the initial test of the train derailment / fallover detection system without disconnecting the sensor optical fiber or separating the sensor optical fiber into two using a connector or the like. As a result, erroneous connection of the optical fiber by the operator is eliminated, and a highly reliable train derailment / fallover detection system operation becomes possible.

[0042]

In summary, according to the present invention, the following excellent effects are exhibited.

By providing a bending applying mechanism for applying a bend to the sensor optical fiber, an operation test of the train derailment / falling detection system can be performed without breaking the sensor optical fiber. Provision of a test jig can be realized.

[Brief description of the drawings]

FIG. 1 is a conceptual view showing an embodiment of a simulation test jig for disconnection of an optical fiber of the present invention.

FIG. 2 is a diagram showing a level of a received pulse in the detection device when the disconnection simulation test jig shown in FIG. 1 is used.

FIG. 3 is a conceptual diagram showing a state where the disconnection test jig shown in FIG. 1 is attached to a sensor optical fiber in a connection box shown in FIG.

FIG. 4 is a diagram showing a conventional example of a train derailment / fallover detection system.

5 is a perspective view of a detection pole used in the train derailment / fallover detection system shown in FIG.

FIG. 6 is a diagram showing another conventional example of a train derailment / fallover detection system.

FIG. 7 is a diagram showing a conventional example of a train derailment / fallover detection system using an optical fiber.

8 (a) to 8 (c) are waveforms obtained by the light receiver of the train derailment / fallover detection system shown in FIG.

[Explanation of symbols]

 18a Optical fiber for sensor 22 Optical receiver 24 Detector 30 Disconnection simulation test jig 35, 36 Guide 38 Bending member 40 Key

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Tokushima 880 Sunasawa-cho, Hitachi City, Ibaraki Prefecture Hitachi Cable Co., Ltd. Inside Takasago Plant (72) Inventor Kazuhide Motoki 880 Sunasawa-machi, Hitachi City, Ibaraki Prefecture Hitachi Cable, Ltd. Inside the Takasago Plant (56) References JP-A-5-45116 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B61K 13/00

Claims (2)

(57) [Claims] 1. A pair of trunk optical fibers buried along the longitudinal direction outside a rail for a train, optical splitters provided at predetermined intervals in both trunk optical fibers, and the optical splitters are housed. A pair of sensors having a columnar connection box and a wire extending between the connection boxes at a predetermined height from the ground and having one end connected to each of the optical branching devices of both trunk optical fibers and the other end fusion-spliced. For the optical fiber, a light source connected to one end of one trunk optical fiber and injecting pulse light, and a light receiver connected to one end of the other trunk optical fiber and receiving the pulse light propagated through the sensor optical fiber, A train derailment / fallover detection system comprising: a signal processing device connected to the light receiver and detecting a line abnormality due to the disconnection of the optical fiber for the sensor due to an accident or the like and the pulse light not returning. H An optical fiber disconnection simulation test jig, wherein a fiber is provided with a bending applying mechanism for applying a bending. 2. The bending applying mechanism according to claim 1, wherein the substrate has a concave portion formed in the center, and a groove is provided on the substrate with the concave portion interposed therebetween, and the optical fiber for sensor is engaged so as to cross over the concave portion. A pair of formed guides, a bending applying member movable along the guides between the guides, a convex portion formed on the concave side, and a stopper formed on the opposite side to the concave side, between the guide and the stopper; An elastic body provided on the guide for urging the bending applying member away from the sensor optical fiber, and holding means provided on the guide for holding the bending applying member pressed against the sensor optical fiber. Item 1
3. The optical fiber disconnection simulation test jig according to 1.