JP5990603B2 - Flood detection module and flood detection method - Google Patents

Description

  The present invention relates to an inundation detection module for detecting inundation into a closure provided in the middle of an optical fiber cable, and an inundation detection method using the same.

  The present invention uses an optical fiber tape (hereinafter referred to as an intermittently bonded optical fiber tape) in which a plurality of optical fiber cores are juxtaposed, and adjacent optical fiber cores are partially connected at predetermined intervals in the longitudinal direction. It is applied when detecting the flooded underground light equipment.

  In recent years, with the increase in optical access services such as FLET'S Hikari and the expansion of the optical service area, the amount of optical facilities has increased, and preventive maintenance of facilities has become increasingly important from the viewpoint of ensuring service quality. .

  Compared to metal cables, optical fiber cables have extremely good transmission characteristics. However, if the optical fiber connection is immersed in water for a long time, optical loss increases and mechanical strength decreases, causing failure. As a maintenance work for underground optical fiber cables, it is necessary to regularly monitor the presence or absence of inundation.

  In the underground connection part, an inundation detection module is installed in an optical fiber core wire (maintenance core wire) different from that for communication. As shown in FIG. 1, the inundation detection module has a structure in which the optical fiber 20 is sandwiched. If water enters the connection part, the expansion material 18 in the inundation detection module 15 swells in response to water, and the movable piece 17 is pushed up and bending loss is given to the optical fiber 20. Therefore, the presence or absence of inundation at each connection is monitored by periodically measuring the presence or absence of bending loss from the communication equipment building 11 using an OTDR (Optical Time Domain Reflectometer) 12.

  In the underground section of the access system, an optical fiber cable using a 4-core or 8-core optical fiber tape is used. Since the above-described infiltration detection module 15 is attached to a four-core optical fiber tape, in the case of an eight-core optical fiber tape, the immersion detection module 15 is attached after separation into a four-core optical fiber tape.

Masahito Arii et al., “Optical media network operation technology supporting the expanding optical access network”, NTT Technical Journal, vol. 18, no. 12, pp. 58-61, Dec. 2006.

  In recent years, high-density optical fiber cables using intermittently bonded optical fiber tapes in which optical fiber cores are bonded in parallel are being studied. An example of an intermittently bonded optical fiber tape is shown in FIG. When the water immersion detection module 15 is attached to the intermittently bonded optical fiber tape 10, it is necessary to insert the intermittently bonded optical fiber tape 10 in a straight state as shown in FIG.

  However, the intermittently bonded optical fiber tape 10 may not be connected without gaps between the optical fiber core wires 22 by a cured resin or the like. The optical fiber tape 10 may be pushed or twisted, so that one to three of the four cores may be bent inside the water immersion detection module 15 and the rest may be bent outside the water immersion detection module 15. In this case, when measured with the OTDR 12 from the communication equipment building 11, the bending loss described above may be erroneously determined to be due to water immersion, and unnecessary repair work of the underground light closure 13 may be performed.

  In addition, the intermittently bonded optical fiber tape 10 may not be connected without gaps between the optical fiber core wires 22 by a cured resin or the like. In order to improve the bending characteristics, it has the characteristics of flexibly deforming and suppressing the increase of strain and the like to ensure the mechanical characteristics. Therefore, the intermittently bonded optical fiber tape 10 has low rigidity.

  Therefore, even if the intermittently bonded optical fiber tape 10 is straightly inserted into the inundation detection module 15, the rigidity of the intermittently bonded optical fiber tape 10 when the intermittently bonded optical fiber tape 10 is twisted when the tray is accommodated in the inundation detection module 15. Therefore, some optical fiber core wires 22 may be bent as shown in FIG.

  FIG. 4 shows an example in which two of the four cores are bent inside the inundation detection module 15 and the remaining two cores are bent outside. Since the upper cover 16 and the movable piece 17 inside the inundation detection module 15 have the bent portion 24, if the intermittently bonded optical fiber tape 10 is bent along the shape, the measurement is performed from the communication equipment building 11 with the OTDR 12. In this case, the bending loss described above may be mistakenly determined to be due to water immersion, and unnecessary repair work for the underground light closure 13 may be performed.

  As a method that does not give bending loss to such an optical fiber core wire 22, there is a method using not only the intermittently bonded optical fiber tape 10 but also a related-art four-core optical fiber tape as a maintenance core wire. This will affect the densification of the product.

  In addition, there is a method of measuring from the communication equipment building 11 with the OTDR 12 or the like at the time of installation of the inundation detection module 15 and checking whether a bending loss is given by mistake, but it is necessary to dispatch an operator to the communication equipment building 11.

  In order to solve the above-mentioned problems, the present invention focuses on the shape of the optical fiber tape inlet of the water immersion detection module, and by devising this shape, the water immersion detection can be mounted without twisting the optical fiber tape. The purpose is to provide modules.

  In order to achieve the above object, in the present invention, the inundation detection module has a configuration in which the shape of the optical fiber tape inlet for passing the optical fiber tape formed in the inundation detection module main body is prevented from rotating the optical fiber tape. Is provided.

Specifically, the inundation detection module according to the present invention is:
An introduction port portion having dimensions of a long side and a short side for introducing an optical fiber tape in which two or more optical fiber core wires are intermittently bonded;
A bending detection unit for detecting bending of the optical fiber introduced from the introduction port that occurs when the water is immersed, and
The short side has a dimension shorter than the width distance of the optical fiber tape in the direction between the optical fiber cores.

In the inundation detection module according to the present invention,
While introducing the optical fiber tape into the introduction port portion and moving it back and forth along the longitudinal direction of the optical fiber tape, the optical fiber tape may be positioned.

In the inundation detection module according to the present invention,
The shape of the inlet port of the inlet port portion may be a square shape or an elliptical shape.

Specifically, the inundation detection method according to the present invention includes:
An introduction port portion having dimensions of a long side and a short side for introducing an optical fiber tape in which two or more optical fiber core wires are intermittently bonded;
A bending detection unit for detecting bending of the optical fiber introduced from the introduction port that occurs when the water is immersed, and
The short side is configured to have a dimension shorter than the width distance of the optical fiber tape in the direction between the optical fiber cores.

  The above inventions can be combined as much as possible.

  According to the present invention, paying attention to the shape of the optical fiber tape inlet of the water immersion detection module, it is possible to provide a water immersion detection module that can be mounted without twisting the optical fiber tape by devising this shape. it can.

  In addition, even with intermittently bonded optical fiber tapes, it is possible to provide an inundation detection module that easily eliminates optical fiber tape twist and prevents malfunctions by simply sliding the optical fiber tape in the axial direction after installation. It becomes.

An example of the block diagram of the inundation detection module which concerns on related technology is shown. An example of the block diagram of the intermittent adhesion type | mold optical fiber tape which concerns on related technology is shown. An example of the block diagram of the water immersion detection module which attached the intermittent adhesion type | mold optical fiber tape which concerns on related technology is shown. An example of the block diagram of the water immersion detection module which attached the intermittent adhesion type | mold optical fiber tape which concerns on related technology is shown. An example of the block diagram of the inundation detection module and inlet part which concerns on Embodiment 1 is shown. 1 shows an example of a configuration diagram of an intermittently bonded optical fiber tape in which a water immersion detection module is attached to an intermittently bonded optical fiber tape having two or more cores that are intermittently bonded according to Embodiment 1. FIG. An example of the block diagram of the inundation detection module 15 which has an upper cover which concerns on Embodiment 1 is shown. An example of the block diagram of the water immersion detection module which attached the intermittent adhesion type | mold optical fiber tape which concerns on Embodiment 1 is shown. An example of the block diagram of the water immersion detection module which attached the intermittent adhesion type | mold optical fiber tape which concerns on Embodiment 1 is shown. An example of the block diagram of the water immersion detection module which attached the intermittent adhesion type | mold optical fiber tape which concerns on Embodiment 1 is shown. 1 shows an example of a configuration diagram of an intermittently bonded optical fiber tape obtained by intermittently bonding two or more intermittently bonded optical fiber tapes according to Embodiment 1. FIG. An example of the block diagram of the water immersion detection module which attached the intermittent adhesion type | mold optical fiber tape which concerns on Embodiment 2 is shown. An example of the block diagram of the vertical surface which has attached the water immersion detection module to the 4-fiber intermittent adhesion type | mold optical fiber tape which concerns on Embodiment 2 is shown.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to embodiment shown below. These embodiments are merely examples, and the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art. In the present specification and drawings, the same reference numerals denote the same components.

(Embodiment 1)
The first embodiment will be described with reference to FIGS. In the present embodiment, an optical fiber tape (hereinafter referred to as an intermittently bonded optical fiber tape) in which optical fiber core wires are intermittently bonded to each other is used as a maintenance core wire for the optical fiber. Moreover, the water immersion detection module 15 according to the present embodiment includes an introduction port for introducing the intermittently bonded optical fiber tape and a bending detection unit. The bending detection unit may be configured by an expansion material, a movable piece, and an outer cover in order to detect bending of the optical fiber introduced from the introduction port part that occurs when the water is immersed.

  The inundation detection module 15 of the embodiment is shown in FIG. FIG. 6 shows a configuration diagram when the water immersion detection module 15 is attached to the intermittently bonded optical fiber tape 10 having two or more cores bonded intermittently according to the present embodiment. As shown in FIG. 5, the height b of the inlet port 25 of the intermittently bonded optical fiber tape 10 is shorter than the width Y of the intermittently bonded optical fiber tape 10. A procedure for attaching the water immersion detection module 15 to the intermittently bonded optical fiber tape 10 will be described. First, as shown in FIG. 7, the upper cover 16 is removed from the main body of the inundation detection module 15.

  Here, for example, the shape of the opening portion of the introduction port portion 25 of the intermittently bonded optical fiber tape 10 shown in FIG. 5 is an ellipse, a trapezoid, and a quadrangular shape with four corners chamfered having dimensions of a long side a and a short side b. It may be. In this case, the introduction port portion 25 has a short side b shorter than the width Y of the intermittently bonded optical fiber tape 10. The width Y of the intermittently bonded optical fiber tape 10 indicates the distance in the direction between the optical fiber cores 22 in which a plurality of optical fiber cores 22 are arranged in parallel and integrated by a common coating. Therefore, the distance relationship of each dimension mentioned above has the relationship of Y> b.

  Next, as shown in FIG. 8, the intermittently bonded optical fiber tape 10 is set between the upper cover 16 and the main body, and the upper cover 16 is attached to the main body. Next, as shown in FIG. 9, the water immersion detection module 15 is shifted back and forth so as to slide along the intermittent adhesion optical fiber tape 10, and the intermittent adhesion optical fiber tape 10 in the water immersion detection module 15 is straightened. .

  As shown in FIG. 9, the height b of the inlet port 25 of the intermittently bonded optical fiber tape 10 is shorter than the width Y of the intermittently bonded optical fiber tape 10. Even if the type optical fiber tape 10 is twisted, the height is shorter than the width, so that it does not rotate more than 90 degrees in the inundation detection module 15. Thereafter, the intermittently bonded optical fiber tape 10 to which the water immersion detection module 15 is attached is accommodated in the tray.

  In the present embodiment, the optical fiber tape 10 is obtained by intermittently bonding optical fiber strands shown in FIG. 5, but as shown in FIG. 11, two or more intermittently bonded optical fiber tapes 10 are intermittently bonded. The same applies to the intermittently bonded optical fiber tape 10. In addition, the adhesion part 21 can employ | adopt the arbitrary means which makes it possible to isolate | separate each core wire 22 each, without using a special division tool. For example, it may be fastened with a tape, or may be fixed with any adhesive having a viscosity that does not peel off the coating of the core wire.

(Embodiment 2)
The second embodiment will be described with reference to FIGS. FIG. 12 is a top view in which a two-fiber optical fiber tape is intermittently bonded and the water immersion detection module 15 is attached to the four-fiber intermittently bonded optical fiber tape 10.

  FIG. 13 is a vertical view in which the immersion detection module 15 is attached to the four-fiber intermittently bonded optical fiber tape 10. The height b of the inlet 25 of the intermittently bonded optical fiber tape 10 of the inundation detection module 15 is shorter than the width Z of the two-core intermittently bonded optical fiber tape 10 as shown in FIG. Yes.

  Since the height b of the inlet port 25 of the intermittently bonded optical fiber tape 10 is shorter than the width Z of the two-fiber intermittently bonded optical fiber tape 10, as shown in FIG. Even if the intermittently bonded optical fiber tape 10 is twisted when the tray is accommodated to rotate the two-fiber intermittently bonded optical fiber tape 10, the height is shorter than the width. It will not rotate more than degrees.

  As described above, according to the present embodiment, since the height of the inlet port 25 of the inundation detection module 15 is shorter than the width of the optical fiber tape, the intermittently bonded optical fiber tape 10 is not twisted by 90 degrees or more. When the inundation detection module 15 is accommodated in the tray when the 15 is attached or after the attachment, it is possible to prevent bending of only a part of the optical fiber core wires 22 inside the inundation detection module 15.

  Further, after the attachment, the infiltration detection module 15 is slid back and forth along the intermittently bonded optical fiber tape 10, so that even if the optical tape fiber inside the inundation detection module 15 is bent, it is aligned straight. In some optical fibers, bending does not occur. As a result, the flooded underground light closure 13 can be correctly identified, and unnecessary repair of the underground light closure 13 can be avoided.

  The present invention can be applied to the information communication industry.

10: Intermittent adhesive type optical fiber tape 11: Communication equipment building 12: OTDR
13: Underground light closure 15: Inundation detection module 16: Upper cover 17: Movable piece 18: Expandable material 20: Optical fiber 21: Adhering portion 22: Optical fiber core wire 24: Bending portion 25: Inlet 26: Connection point portion 30: Core wire storage

Claims (3)

Two introduction ports having long side and short side dimensions for introducing an optical fiber tape in which two or more optical fiber core wires are intermittently bonded,
A bending detection unit for detecting bending of the optical fiber introduced from the introduction port that occurs when the water is immersed, and
The short side is configured to have a dimension shorter than the width distance of the optical fiber tape in the direction between the optical fiber cores, and the optical fiber core wires are straightly arranged between the introduction ports. An inundation detection module. The infiltration detection module according to claim 1, wherein the shape of the inlet of the inlet is a quadrangle or an ellipse.   An optical fiber tape in which two or more optical fiber cores are intermittently bonded between the introduction ports of the inundation detection module according to claim 1 or 2, is introduced,
  After moving back and forth along the longitudinal direction of the optical fiber tape and aligning the optical fiber tape straight, positioning the optical fiber tape,
  Inundation is detected by applying a bend to the optical fiber introduced from the introduction port at the bend detection unit.
An inundation detection method characterized by that.

Images