JP5435478B2 - Connection method - Google Patents

Description

The present invention relates to a method for passing a small-diameter, low-friction indoor optical fiber suitable for passing through an existing pipeline.

In recent years, with an increase in demand for optical communication, FTTH (Fiber To The Home) that realizes a high-speed communication service by directly drawing an optical fiber into a general home is rapidly expanding. When an FTTH is constructed in an existing housing complex, indoor optical fibers are often installed using an empty space in an existing pipe line in which a metal cable such as a telephone line is installed.
Thus, when laying indoor optical fiber in the existing pipeline, the indoor optical fiber is routed through the existing cable, and therefore the wiring work is extremely difficult if the friction resistance with the existing cable is large. Become. Therefore, in order to efficiently lay indoor optical fibers in existing pipelines, a small-diameter, low-friction indoor optical fiber (hereinafter, small-diameter, low-friction indoor) that has been reduced in diameter and friction has been proposed. (For example, Non-Patent Document 1).

  By using this small-diameter low-friction indoor, it is possible to perform a push-in construction method in which the small-diameter low-friction indoor is pushed into the pipe line. This indentation method prevents the tip surface of the small-diameter, low-friction indoor from coming into contact with the existing cable and causing scratches on the existing cable surface. In order to avoid this, the leading end portion of the small-diameter low-friction indoor is folded back by approximately 180 °, and the folded portion is pushed into the pipe line to perform the line work (see FIG. 7).

Development of new optical wiring technology in existing apartment buildings, NTT Technical Journal 2009 vol. 21 No. 6 Sea Cube Co., Ltd., Small-diameter indoor optical fiber cap, Telecommunications Industry Newspaper, October 12, 2009

However, in the conventional wiring method, the tip of the small-diameter low-friction indoor is folded and passed, so that the height of the folded portion is more than twice the height of the small-diameter low-friction indoor, and the tube The space factor in the road will increase. And when troubles, such as crushing, have occurred in the middle of the pipeline to be laid, the probability that the tip of the small-diameter low-friction indoor loses its place at the crushing portion of this pipeline increases.
In addition, to avoid clogging the tip, if the small diameter low-friction indoor is moved back and forth, the folded tip will touch the existing cable and damage the existing cable surface. There is a risk of it. In addition, if the folded portion sandwiches an existing cable, the small-diameter low-friction indoor that is going to be connected cannot move and cannot be even removed from the pipeline.

  As described above, as a technique for preventing catching when the small-diameter low-friction indoor is pulled back, it has been proposed to attach a cap to the tip (for example, Non-Patent Document 2). However, since the outer shape is increased to a large extent by attaching the cap, the probability that the small-diameter low-friction indoor is clogged at the collapsed portion of the pipe line is increased. Further, if the cap is removed at the time of pulling back, it will remain as a foreign substance in the pipe line, and there is a risk of hindering the subsequent installation of the small diameter low friction indoor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for passing a small diameter low friction indoor that can improve workability when a small diameter low friction indoor is passed through an existing pipeline.

The invention described in claim 1 was made to achieve the above object,
A wiring method for passing a small-diameter low-friction indoor optical fiber formed by coating an optical fiber core wire and a tension member together with a jacket, into a pipe line,
Removing the jacket from one end of the small-diameter low-friction indoor optical fiber to expose the tension member by a predetermined length;
A coating material is adhered to the exposed portion of the tension member, and the outer shape of the coating material is processed to be equal to or less than the outer shape of the small-diameter low-friction indoor optical fiber.
The machined portion is connected by being pushed into the pipeline with the processed portion as a tip.

  According to a second aspect of the present invention, in the wiring method according to the first aspect, the tip portion of the covering material is rounded.

Invention of Claim 3 is the wiring method of Claim 1 or 2, The said coating | covering material is comprised with the heat-shrinkable tube shrink | contracted to radial direction at predetermined | prescribed temperature,
The heat-shrinkable tube is inserted into the exposed portion of the tension member, and the heat-shrinkable tube is heated and contracted to adhere to the exposed portion of the tension member. It is characterized by being processed so as to be equal to or less than the outer shape of the indoor optical fiber.

  According to a fourth aspect of the present invention, in the wiring method according to the third aspect, an adhesive resin is disposed between the heat shrinkable tube and the tension member.

The invention according to claim 5 is a wiring method for passing a small-diameter low-friction indoor optical fiber formed by covering an optical fiber core wire and a tension member collectively with a jacket, into a pipeline,
The tension member is removed by a predetermined length from one end side of a wire-passage device configured to be covered with a jacket similar to the small-diameter low-friction indoor optical fiber, to expose the tension member,
While adhering the covering material to the exposed portion of the tension member, the outer shape of the covering material is processed to be equal to or less than the outer shape of the wire passing device,
By pushing this processed portion into the pipe line as a tip, a small-diameter low-friction indoor optical fiber connected to the other end of the wire-passing device is connected.

  A sixth aspect of the invention is characterized in that, in the wiring method according to the fifth aspect, a rounding process is performed on a tip portion of the covering material.

The invention according to claim 7 is the wiring method according to claim 5 or 6, wherein the covering material is constituted by a heat shrinkable tube that shrinks in a radial direction at a predetermined temperature.
The heat-shrinkable tube is inserted into the exposed portion of the tension member, and the heat-shrinkable tube is heated and contracted to adhere to the exposed portion of the tension member. It is characterized by being processed so as to be equal to or less than the outer shape.

  The invention according to claim 8 is the wiring method according to claim 7, wherein an adhesive resin is disposed between the heat shrinkable tube and the tension member.

In addition, “the outer shape of the covering material is equal to or smaller than the outer shape of the small-diameter low-friction indoor optical fiber” in claim 1 or “the outer shape of the covering material is equal to or smaller than the outer shape of the wire passing device” in claim 5 The thickness of the coating material is the same as or narrower than that of the small-diameter low-friction indoor optical fiber or wire-passage. It means that it is easy to shape and size. That is, it is only necessary that the cross section of the covering material is included in the cross section of the small-diameter low-friction indoor optical fiber (including the same case), and the outer shape does not need to be similar.
In addition, the “sheath similar to the small-diameter low-friction indoor optical fiber” in claim 5 is the same material and shape as the thin-diameter low-friction indoor optical fiber. This means that the lineability is comparable.

  According to the present invention, there is no need to fold the tip portion of the small-diameter low-friction indoor optical fiber at the time of wiring as in the prior art, and since the small diameter is secured at the tip portion, the small-diameter low-friction indoor optical fiber is secured in the existing pipe line. The friction indoor optical fiber can be smoothly passed. Further, even when the small-diameter low-friction indoor optical fiber becomes stuck at the crushing portion in the pipe, it can be easily pulled back and does not get entangled with the existing cable at the time of pull-back. Therefore, workability at the time of line connection is significantly improved.

It is a top view which shows the general structure of a small diameter low friction indoor optical fiber. It is sectional drawing which shows the general structure of a small diameter low friction indoor optical fiber. It is a figure which shows an example of the wiring method which concerns on 1st Embodiment. It is a top view which shows the structure of the wire feeder used for the wire work of 2nd Embodiment. It is sectional drawing which shows the structure of the wire feeder used for the wire work of 2nd Embodiment. It is a figure which shows an example of the wiring method which concerns on 2nd Embodiment. It is a figure which shows the front-end | tip shape of the small diameter low friction indoor optical fiber in the conventional wiring operation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 are diagrams showing a general configuration of a small-diameter low-friction indoor optical fiber. In general, a thin, low-friction indoor optical fiber having an outer shape of a substantially rectangular cross section with a width of 2.0 mm and a height of 1.6 mm and a dynamic friction coefficient of about 1/5 that of a conventional indoor optical fiber. Called.
As shown in FIGS. 1 and 2, the small-diameter low-friction indoor 1 includes an optical fiber core wire 11 and two tension members (strength members) 12 and 12 disposed on both sides of the optical fiber core wire 11. It is covered and configured.

The optical fiber core 11 is an SM (single mode) optical fiber core having a diameter of 0.25 mm, for example. As shown in the figure, there may be a single core or a plurality of cores. In addition, there may be a tape core wire in which a plurality of optical fibers are integrated in a horizontal row.
The tension member 12 is made of, for example, a steel wire having a diameter of 0.5 mm, fiber reinforced plastics (FRP), or the like, and prevents the optical fiber core wire 11 from being applied with a tension exceeding an allowable amount.
The jacket 13 is made of, for example, a flame-retardant resin, and is made low in friction by adding a lubricant, forming it with a resin having a small friction coefficient, or forming a small uneven shape on the surface, for example. Yes. In addition, a notch 13a is formed in the outer jacket 13 along the longitudinal direction so that the optical fiber core wire 11 can be taken out without using a special tool when laying.

[First Embodiment]
In the first embodiment, a case will be described in which the small-diameter low-friction indoor 1 itself is passed through an existing pipe line by a pushing method. By adopting the pushing method as in the first embodiment, the wiring process is greatly simplified as compared with the pulling method using the wiring device.

FIG. 3 is a diagram illustrating an example of a wiring method according to the first embodiment.
First, as shown in FIG. 3A, the jacket 13 is removed from one end side of the small-diameter low-friction indoor 1 to expose the optical fiber core wire 11 and the tension member 12 by a predetermined length. The length to be exposed is not particularly limited, but it is desirable to expose the tension member 12 to the extent that terminal processing is easy (for example, 10 mm).

Next, as shown in FIG. 3B, the heat-shrinkable tube 14 cut out longer than the length of the exposed tension member 12 is inserted so as to cover the entire tension member 12. At this time, it arrange | positions so that the edge part of the heat contraction tube 14 may not overlap with the jacket 13 of the small diameter low friction indoor 1. As shown in FIG. This is because if the heat-shrinkable tube 14 overlaps the outer sheath 13 of the small diameter low friction indoor 1, the outer shape of this portion becomes larger than the outer diameter of the small diameter low friction indoor 1 when thermally contracted. Conversely, a slight gap may be formed between the heat-shrinkable tube 14 and the jacket 13.
Here, the heat-shrinkable tube is a tube that is deformed at a predetermined temperature (shrinkage temperature) and shrinks in the radial direction (circumferential direction). For example, it is composed of ethylene-vinyl acetate copolymer resin (EVA) having a shrinkage temperature of 70 to 90 ° C. In the present embodiment, a heat-shrinkable tube having an outer diameter before shrinkage of 4.0 mm and a shrinkage rate of 60% is used.

  Next, as shown in FIG. 3C, the heat-shrinkable tube 14 is filled with a pellet-like adhesive resin 15. The adhesive resin 15 is made of, for example, EVA having a melting point of 70 to 90 ° C. so as to be melted at the same time when the heat shrinkable tube is heated.

Next, as shown in FIG. 3D, the heat-shrinkable tube 14 is heated to 70 to 90 ° C. with a dryer or the like, so that the width of the heat shrinkable tube 14 is approximately the same as that of the small-diameter low-friction indoor 1, and the height is 1 mm Shrink to 6 mm. As shown in FIG. 3, in the small-diameter low-friction indoor 1, the tension members 12 and 12 and the fiber 11 are exposed even after the jacket 13 is removed, and the width is about 1.5 mm and the height is 0. .5mm. Therefore, when the heat-shrinkable tube 14 contracts, the tension members 12 and 12 on both sides first come into contact with each other, and the contraction in the width direction is forcibly stopped. At this time, the contraction further proceeds in the height direction because the tension member 12 is not yet contacted. Therefore, the heat-shrinkable tube 14 will finally form a square shape.
In addition, while the tube after contraction is warm, the dimensional accuracy can be further improved by correcting the outer diameter of the small-diameter low friction indoor 1 with the fingertip or the like.

Thereby, the front-end | tip part is processed into the external shape equivalent to the external shape of the small diameter low friction indoor 1, or less. At this time, since the adhesive resin 15 filled in the heat shrinkable tube 14 is melted, the heat shrinkable tube 14 and the tension member 12 are firmly bonded. Further, as the heat shrinkable tube 14 contracts, the adhesive resin 15 overflows from the tip portion, so that the overflowed portion is rounded with a fingertip or a scissors. In addition, since the jacket 13 is not deformed when the heat-shrinkable tube 14 and the adhesive resin 15 are heated, there is no possibility that the performance of the indoor cable 1 is deteriorated.
Then, with the rounded portion as the tip, the small-diameter low-friction indoor 1 is passed through the pipe line by the indentation method.

  As described above, in the first embodiment, the outer cover 13 is removed from one end of the small-diameter low-friction indoor 1 to expose the tension member 12 by a predetermined length, and the exposed portion of the tension member 12 is covered with a covering material (heat shrinkage). The tube 14) is bonded, and the outer shape of the covering material is processed so as to be equal to or less than the outer cable 1, and the processed portion is pushed into the pipe line as a tip, thereby reducing the diameter of the low friction indoor 1 Route through.

As a result, it is not necessary to fold the tip of the small-diameter low-friction indoor 1 at the time of wiring as in the prior art, and the small-diameter is secured also at the tip of the small-diameter low-friction indoor 1, so that the existing pipe line The small diameter low friction indoor 1 can be smoothly routed. Further, even when the small-diameter low-friction indoor 1 becomes stuck at the crushing portion in the pipe, it can be easily pulled back and does not get entangled with the existing cable when pulled back. Therefore, workability at the time of line connection is significantly improved.
Further, since the probability of being able to pass through even if there is a crushed portion in the pipe line is greatly improved, it is possible to efficiently lay out the small-diameter low-friction indoor 1 efficiently.

  Moreover, in 1st Embodiment, the rounding process is performed to the front-end | tip part (adhesive resin 15 extruded from the front-end | tip of the heat contraction tube 14) of a coating | covering material. Thereby, the existing cable can be effectively prevented from being damaged by passing the small-diameter low-friction indoor 1 through the pipe line.

Further, in the first embodiment, the heat shrinkable tube 14 is inserted into the exposed portion of the tension member 12, and the heat shrinkable tube 14 is heated and contracted to adhere to the exposed portion of the tension member 12, and the heat contraction is performed. Processing is performed so that the outer shape of the tube 14 is equal to or smaller than the outer shape of the small-diameter low-friction indoor 1.
As described above, since the tip of the small diameter low friction indoor 1 is processed by a very simple method, the work efficiency at the site is not significantly reduced.

  In the first embodiment, the adhesive resin 15 is disposed between the heat shrinkable tube 14 and the tension member 12. Thereby, since the heat-shrinkable tube 14 and the tension member 12 are firmly bonded, the possibility that the heat-shrinkable tube 14 is detached and remains in the pipe line at the time of passing or pulling back is extremely low.

[Second Embodiment]
2nd Embodiment demonstrates the case where the small diameter low friction indoor 1 is connected in an existing pipe line using a wire-passing device. In this case, it is necessary to connect the small-diameter low-friction indoor 1 to the wire feeder, and the number of processes is larger than that of the indentation method described in the first embodiment. Since the bending rigidity of the pipe is high, there is an advantage that the probability of being able to pass through the crushing portion in the pipe line is increased, that is, it is possible to efficiently lay multiple lines in the pipe line.

4 and 5 are diagrams showing a configuration of a wire pass device used for the wire work according to the second embodiment.
As shown in FIGS. 4 and 5, the wire passing device 2 is configured such that three tension members (strength members) 21, 21, 21 are collectively covered with an outer cover 23.
The tension member 21 is made of, for example, a steel wire or fiber reinforced plastic (FRP). The configuration of the material and number of the tension members 21 is appropriately selected so that the bending rigidity of the wire passing device 2 is higher than that of the small-diameter low-friction indoor 1 and bends appropriately.
The outer cover 23 is made of, for example, a flame-retardant resin, like the small-diameter low-friction indoor 1, and is made of, for example, a lubricant, a resin having a small friction coefficient, or a small uneven shape on the surface. For example, low friction is achieved. Further, the outer shape of the jacket 23 is the same as that of the small-diameter low-friction indoor 1, and a notch 23a is formed along the longitudinal direction although it is not essential as a wire passer.
That is, the wire passing device 2 has a configuration in which the optical fiber core wire 11 is replaced with the tension member 21 in the small diameter low friction indoor 1 shown in FIGS.

  In addition, what is necessary is just to let the length of the wire pass device 2 be about +10 m of the length of the existing pipe line which connects the thin diameter low friction indoor 1, for example. A small diameter low friction indoor 1 is connected to one end of the wire pass device 2. For example, the outer cover 23 is removed by a predetermined length, and only one of the exposed tension members 21 is left, and the tension member 12 of the small diameter low friction indoor 1 is connected thereto. Further, for example, a connector portion that can easily connect the small-diameter low-friction indoor 1 may be provided at one end of the wire passing device 2, and the tension member 12 of the small-diameter low-friction indoor 1 may be connected thereto.

As described above, in the second embodiment, the wire passing device 2 configured by covering the tension member 21 with the outer cover 23 similar to the small-diameter low-friction indoor 1 is used.
As in the first embodiment, when the small diameter low friction indoor 1 is routed by the indentation method, an excessive load is often applied to the tip of the small diameter low friction indoor 1 and the small diameter low friction indoor 1 is damaged. We cannot deny the possibility of doing. On the other hand, by using the wire-passing device of the second embodiment, the possibility that the small-diameter low-friction indoor 1 is damaged by applying an unexpected load during the wire-connection becomes extremely low. This is because when passing through the wire passing device 2, a passing line through which the small-diameter low-friction indoor 1 can pass is surely formed in the existing pipe line. Conversely, it can also be easily determined that there is no space in the existing pipe line through which the small diameter low friction indoor 1 can be passed.

FIG. 6 is a diagram illustrating an example of a wiring method according to the second embodiment.
First, as shown in FIG. 6A, the jacket 23 is removed from one end of the wire passing device 2 to expose the tension member 21 by a predetermined length. The length to be exposed is not particularly limited, but it is desirable to expose the tension member 21 that is easy to process the terminal (for example, 10 mm).

Next, as shown in FIG. 6B, the heat-shrinkable tube 24 cut out longer than the length of the exposed tension member 21 is inserted so as to cover the entire tension member 21. At this time, it arrange | positions so that the edge part of the heat contraction tube 24 may not overlap with the jacket 23 of the wire_liner 2. This is because if the heat-shrinkable tube 24 overlaps the outer sheath 23 of the wire passing device 2, the outer shape of this portion becomes larger than the outer shape of the wire passing device 2 when heat shrinking. Conversely, a slight gap may be formed between the heat shrinkable tube 24 and the jacket 23.
As in the first embodiment, the heat-shrinkable tube 24 is made of, for example, EVA having a shrinkage temperature of 70 to 90 ° C.

  Next, as shown in FIG. 6C, the heat-shrinkable tube 24 is filled with a pellet-like adhesive resin 25. The adhesive resin 25 is composed of, for example, EVA having a melting point of 70 to 90 ° C., as in the first embodiment.

Next, as shown in FIG. 6 (d), by heating to 70-90 ° C. with a dryer or the like, the heat-shrinkable tube 24 is approximately the same size as the wire-liner, having a width of 2.0 mm and a height of 1.6 mm. Shrink. As shown in FIG. 6, in the wireliner 2, even after the outer sheath 23 is removed, the three tension members 21 are exposed and the width is about 1.5 mm and the height is 0.5 mm. ing. Therefore, when the heat-shrinkable tube 24 contracts, it first contacts the tension members 21 and 21 on both sides, and the contraction in the width direction is forcibly stopped. At this time, the contraction further proceeds in the height direction because the tension member 21 is not yet contacted. Therefore, the heat shrinkable tube 24 will finally form a square shape.
In addition, while the tube after contraction is warm, the dimensional accuracy can be further improved by correcting it to the same dimension as the outer shape of the wire passing device 2 (small diameter low friction indoor 1) with a fingertip or the like.

Thereby, a front-end | tip part is processed into the external shape equivalent to or less than the external shape of the main-body part of the wire pass device 2. FIG. At this time, since the adhesive resin 25 filled in the heat shrinkable tube 24 is melted, the heat shrinkable tube 24 and the tension member 21 are firmly bonded. Further, since the adhesive resin 25 overflows from the distal end portion as the heat shrinkable tube 24 contracts, the overflowed portion is processed into a round shape with a fingertip or a scissors. In addition, when the heat-shrinkable tube 24 and the adhesive resin 25 are heated, the jacket 23 is not deformed.
Then, with the rounded portion as a tip, the wire passing device 2 is routed in the pipe line by the pushing method. After the tip of the wire passer 2 reaches the other end side of the pipe line, the small diameter low friction indoor 1 connected to the wire passer 2 is passed through the pipe line by pulling the wire passer 2. To do.

  As described above, in the second embodiment, the outer cover 23 is removed by a predetermined length from one end side of the wire passing device 2 configured by covering the tension member 21 with the outer cover 23 similar to the small-diameter low friction indoor 1. Then, the tension member 21 is exposed, the covering material (heat-shrinkable tube 24) is adhered to the exposed portion of the tension member 21, and the outer shape of the covering material is processed to be equal to or less than the outer shape of the wire passing device 2. Then, by pushing the processed portion as a tip into the pipe line, the small diameter low friction indoor 1 connected to the other end of the wire passing device 2 is passed.

As a result, it is not necessary to fold the tip of the small-diameter low-friction indoor 1 during wiring, and the tip of the wire-passage 2 has a small diameter. The diameter low friction indoor 1 can be smoothly passed. Moreover, since the bending rigidity of the wire passing device 2 is higher than the bending rigidity of the small diameter low friction indoor 1, the wire passing device 2 can be efficiently passed through the empty space in the pipe line. Further, even when the wire passing device 2 becomes stuck at the crushing portion in the pipe line, it can be easily pulled back and is not entangled with the existing cable at the time of pulling back. Therefore, workability at the time of line connection is significantly improved.
Further, since the probability of being able to pass through even if there is a crushed portion in the pipe line is greatly improved, it is possible to efficiently lay out the small-diameter low-friction indoor 1 efficiently.

  In the second embodiment, the tip of the covering material (adhesive resin 25 squeezed out from the tip of the heat-shrinkable tube 24) is rounded. Thereby, it can prevent effectively that an existing cable is damaged by letting the wire pass 2 pass.

In the second embodiment, the heat shrinkable tube 24 is inserted into the exposed portion of the tension member 21, and the heat shrinkable tube 24 is heated and contracted to adhere to the exposed portion of the tension member 21, and the heat contraction is performed. Processing is performed so that the outer shape of the tube 24 is equal to or smaller than the outer shape of the wire passing device 2.
As described above, since the tip end of the wire passing device 2 is processed by an extremely simple method, the work efficiency at the site is not significantly reduced.

  In the second embodiment, an adhesive resin 25 is disposed between the heat shrinkable tube 24 and the tension member 21. Thereby, since the heat shrinkable tube 24 and the tension member 21 are firmly bonded, the possibility that the heat shrinkable tube 24 is detached and remains in the pipe line at the time of passing or pulling back is extremely low.

As mentioned above, although the invention made by this inventor was concretely demonstrated based on embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.
In the first and second embodiments, the heat-shrinkable tubes 14 and 24 and the tension members 12 and 21 are bonded by the adhesive resins 15 and 25 filled in the heat-shrinkable tubes 14 and 24. The method of bonding is not limited to this.
For example, the tension members 12 and 21 are preliminarily formed with a layer (adhesive layer) made of an adhesive resin so as to be firmly bonded to the jackets 13 and 23. Can be removed. In this case, if pellets of thermoplastic resin such as polyethylene are filled in the heat-shrinkable tubes 14 and 24, the polyethylene and the adhesive layer are melt-bonded by heating, and the polyethylene and the heat-shrinkable tube (EVA) are melt-bonded. Therefore, the heat-shrinkable tubes 14 and 24 and the tension members 12 and 21 are firmly bonded.
Further, the heat shrinkable tubes 14 and 24 may be bonded to the tension members 12 and 21 by using a resin imparted with adhesiveness to the heat shrinkable tubes 14 and 24. Furthermore, if these bonding methods are applied in combination, the heat-shrinkable tubes 14 and 24 and the tension members 12 and 21 can be bonded more firmly.

Moreover, you may make it cover the cap member of a diameter smaller than a main-body part instead of processing the front-end | tip part of the small diameter low friction indoor 1 or the wire_liner 2 using a heat contraction tube. However, it is desirable to use a heat shrinkable tube from the viewpoint of work and cost.
When the small-diameter low-friction indoor 1 is passed through the existing pipe line using the wire passing device 2 as in the second embodiment, the tip of the wire connecting device 2 is processed at the site where the wire passing work is performed. You may make it use it, and you may make it use the wire pass device 2 by which the front-end | tip processing was made | formed beforehand.
In addition, for example, as the heat shrinkable tubes 14 and 24, those having an adhesive property and a thickened heat shrinkable tube can be used. In this case, the tension member and the heat shrinkable tube can be firmly bonded by shrinking the heat shrinkable tube.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Small diameter low friction indoor optical fiber 11 Optical fiber core wire 12 Tension member 13 Outer jacket 14 Heat-shrinkable tube 15 Adhesive resin

Claims (8)

A wiring method for passing a small-diameter low-friction indoor optical fiber formed by coating an optical fiber core wire and a tension member together with a jacket, into a pipe line,
Removing the jacket from one end of the small-diameter low-friction indoor optical fiber to expose the tension member by a predetermined length;
A coating material is adhered to the exposed portion of the tension member, and the outer shape of the coating material is processed to be equal to or less than the outer shape of the small-diameter low-friction indoor optical fiber.
A wiring method, wherein the processed part is passed by being pushed into a pipe line with a tip as a tip.   The wire passing method according to claim 1, wherein a rounding process is performed on a tip portion of the covering material. The covering material is composed of a heat-shrinkable tube that shrinks in a radial direction at a predetermined temperature,
The heat-shrinkable tube is inserted into the exposed portion of the tension member, and the heat-shrinkable tube is heated and contracted to adhere to the exposed portion of the tension member. The wiring method according to claim 1, wherein the wiring method is processed so as to be equal to or less than an outer shape of the indoor optical fiber.   The wiring method according to claim 3, wherein an adhesive resin is disposed between the heat shrinkable tube and the tension member. A wiring method for passing a small-diameter low-friction indoor optical fiber formed by coating an optical fiber core wire and a tension member together with a jacket, into a pipe line,
The tension member is removed by a predetermined length from one end side of a wire-passage device configured to be covered with a jacket similar to the small-diameter low-friction indoor optical fiber, to expose the tension member,
While adhering the covering material to the exposed portion of the tension member, the outer shape of the covering material is processed to be equal to or less than the outer shape of the wire passing device,
A wiring method characterized in that a small-diameter low-friction indoor optical fiber connected to the other end of the wire-passing device is routed by pushing the processed portion into a pipe line as a tip.   The wire passing method according to claim 5, wherein a rounding process is performed on a front end portion of the covering material. The covering material is composed of a heat-shrinkable tube that shrinks in a radial direction at a predetermined temperature,
The heat-shrinkable tube is inserted into the exposed portion of the tension member, and the heat-shrinkable tube is heated and contracted to adhere to the exposed portion of the tension member. The wiring method according to claim 5 or 6, wherein processing is performed so as to be equal to or less than an outer shape.   The wiring method according to claim 7, wherein an adhesive resin is disposed between the heat shrinkable tube and the tension member.

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