JP2009048128A - Drop optical cable and its installation method - Google Patents

Abstract

[PROBLEMS] To easily lay down an optical fiber, perform it efficiently and in a short time, and to perform the extra length processing after laying effectively without impairing aesthetics, and without slack. A drop optical cable capable of surely laying and a laying method thereof are provided.
A drop optical cable 11 in which an optical cable cut in a predetermined length is bundled in a coil shape and optical connectors 14a and 14b are attached to both ends thereof, and a winding portion 13a bundled in a coil shape is accommodated in a storage case 15. Is provided with through holes 16a and 18a through which both ends of the storage case 15 are inserted between the support wires 12 stretched between the buildings. The through hole 18a on one end side supports the winding portion 13a. It can be extended along the line 12.
[Selection] Figure 1

Description

  The present invention relates to a drop optical cable used for drawing an optical fiber from a trunk optical cable or the like to a subscriber's house or the like via a closure and a method for laying the optical fiber.

  With the expansion of broadband services such as video distribution and data communication in recent years, the number of subscribers to home-use data communication services (FTTH: Fiber To The Home) using optical fibers is increasing. In this FTTH, for example, an optical cable called a drop optical cable is often used to draw an optical fiber from an imaginary trunk optical cable to a subscriber's house or the like via a closure. For example, an optical fiber is dropped to a subscriber's home by branching a trunk optical cable installed on a utility pole in a city by a connection box usually called a closure, and connecting the branched optical fiber to a drop optical cable. Has been done.

  In this case, as the drop optical cable for drawing the optical fiber, a cable body part and a suspended line part that are integrally connected with a neck part that can be easily cut are used, and both ends of the suspended line part are fixed to a building such as a house. There is a method of pulling down the part in a form of hanging and supporting. In addition, an optical cable that does not have a hanging portion is used as the drop optical cable. For example, as disclosed in Patent Document 1, a metal linear body or an existing telephone line or power line is used as a support line, and is wound around and supported by a spiral. There is also a way to withdraw in form.

  FIG. 4 is a diagram illustrating a method of pulling down an optical fiber disclosed in Patent Document 1. For example, a distribution line 1 of a distribution line system, a trunk optical cable 2 of a communication optical cable wiring system, and the like are installed on the utility pole 3 in an urban area. Then, the lead-in wire 4 from the distribution line 1 on the adjacent utility pole 3 and the drop optical cable 5 from the trunk optical cable 2 are drawn down to the house 6. Both ends of the lead-in wire 4 are fixed to the utility pole 3 and the house 6 side, and the drop optical cable 5 is supported so as to be spirally wound around the lead-in wire 4. Note that the lead-in wire 4 may be a simple messenger wire.

The method of laying the drop optical cable 5 is to drop the drop optical cable ring bundle 5 'bundled in a ring shape from the other end side (the house 6 side) that is not retained in a state where one end of the lead-in wire 4 is retained on the utility pole 3. . Next, the other end of the lead-in wire 4 is fixed to the attachment portion 7 on the house 6 side, and one end of the drop optical cable ring bundle 5 ′ is connected to the connection box 8 on the house side. Thereafter, the drop optical cable 5 is fed out, and the drop optical cable ring bundle 5 ′ is moved to the utility pole 3 side while being spirally wound around the lead-in wire 4. And the front-end | tip of the drop optical cable 5 is connected to the trunk optical cable 2 via the closure 9 supported by the optical cable 2 of the optical cable wiring system, and the optical fiber is pulled down to the house 6.
JP 2002-142319 A

When laying a drop optical cable by the method disclosed in Patent Document 1 (FIG. 4), the cable length is made slightly longer than the laying distance so as not to be short. For this reason, it is necessary to process the cable remaining as the extra length after laying is completed, but there is no disclosure in Patent Document 1, and even if it is bundled and supported on a house wall or the like, there are problems with aesthetics or people touching it There is a risk that the bundle will collapse due to the wind.
Further, in Patent Document 1, only by moving the drop optical cable ring bundle, the linear body (leading line) serving as a support line and the spiral portion of the drop optical cable are not in close contact with each other, and a gap is largely left. For this reason, there is a risk of disconnection due to a car accident or a mischief caused by birds.

  The present invention has been made in view of the above-described circumstances, and it is easy to lay down an optical fiber, can be carried out efficiently in a short time, and the extra length processing after laying is impaired in aesthetics. It is an object of the present invention to provide a drop optical cable and a method for laying it, which can be carried out effectively and without any slack and can be laid securely.

The drop optical cable according to the present invention is a drop optical cable in which optical cables that have been cut to a predetermined length are bundled in a coil shape and optical connectors are attached to both ends of the optical cable. In addition, a through hole for inserting a support line stretched between the buildings is provided at both end surface portions of the storage case, and the through hole on one end surface side can feed the winding portion along the support line. It is characterized by that.
Moreover, it is preferable to provide the aperture | diaphragm | squeeze member which has a taper-shaped through-hole for facilitating unwinding on the end surface side which unwinds a winding part from the said storage case. Moreover, you may make it provide the tension string for installation in a storage case.

  Further, the drop optical cable laying method according to the present invention uses the drop optical cable described above, and inserts a support line stretched between the buildings into the through hole of the storage case, and the storage case is connected to one end side of the support line. To the other end side, and the winding part of the optical cable in the storage case is sequentially drawn out and wound around the support wire in a spiral shape, with the remaining winding part in the storage case as the extra length, together with the storage case It is characterized by being fixedly held in a building. An existing telephone line may be used as the support line.

  According to the drop optical cable of the present invention, since the winding portion bundled in a coil shape is held by the storage case, the handling property during transportation and laying work is good, and the laying workability is improved and shortened. It becomes possible to carry out in time. In addition, the optical cable can be wound around the support wire without sag and installed, so that it is possible to prevent a hook accident caused by a vehicle or the like and a disconnection caused by mischief such as birds. Furthermore, the remaining length of the remaining optical cable can be stored in a storage case as it is, and can be held and fixed to a building or the like, and can be stored and held without impairing the aesthetic appearance.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1A is a diagram for explaining an outline of a drop optical cable according to the present invention, FIG. 1B is a diagram illustrating an example of an optical cable used in the present invention, and FIG. 1C is a diagram illustrating an example of a diaphragm member. It is. In the figure, 11 is a drop optical cable, 12 is a support wire, 13 is an optical cable, 13a is a winding portion, 13b is a feeding portion, 14a and 14b are optical connectors, 15 is a storage case, 16 is a base member, 16a is a through hole, Reference numeral 17 denotes a case member, 18 denotes a throttle member, 18a denotes a tapered through hole, 19 denotes a tension string, 20 denotes an optical fiber core wire, 21 and 21 ′ denote strength members, and 22 and 22 ′ denote cable jackets.

  In the drop optical cable 11 according to the present invention, as shown in FIG. 1A, optical connectors 14a and 14b (SC connector, FC connector, etc.) are attached in advance to both ends of a predetermined length of an optical cable 13 bundled in a coil shape. Configured. A portion of the optical cable 13 that is bundled in a coil shape is indicated by a winding portion 13a, and a portion that is spirally extended from the winding portion 13a in the coil axis direction is indicated as an extension portion 13b. Further, the drop optical cable 11 according to the present invention is configured such that the optical cable 13 is stored in the storage case 15 and is inserted through the support wire 12 and laid.

  The optical cable 13 used in the drop optical cable 11 according to the present invention has a rectangular cross section (A) or a circular shape (B) as shown in FIG. A shape is used. However, in order to improve the feeding property, it is preferable that the storage case is wound in an aligned state, and a rectangular shape that is easy to wind in an aligned state is desirable. The optical cable 13 is formed with one to several optical fibers in the cable.

  (B) For a rectangular cross-section as shown in the figure, for example, a tensile body 21 is arranged on both sides of the optical fiber core wire 20, and the entire cable jacket 22 made of flame-retardant polyethylene or the like (for example, on the long side side) 3.1 mm and about 2 mm on the short side). The optical fiber core 20 is made by coating a glass fiber having a standard outer diameter of 125 μm with a protective coating having an outer diameter of about 250 μm. The tensile body 21 is formed of a non-metallic wire (FRP) in which a steel wire having an outer diameter of about 0.5 mm or a high-strength fiber is hardened with a resin. In addition, a V-shaped notch for tearing may be provided on the side surface on the long side of the cable jacket 22, but it may have a shape not having a notch.

  Also, as shown in (b), when the cross section is circular, a high-strength fiber such as an aramid fiber is arranged around the optical fiber core wire 20 as a strength member 21 ′, and these are circular in cross section. It is formed by covering with a cable jacket 22 ′ (for example, an outer diameter of about 2 mm). The high-strength fiber of the strength member 21 ′ functions not only as a strength member of the optical fiber core wire 20 but also as a buffer against external force.

  In the optical cable 13 as described above, the winding portion 13a is stored in the storage case 15, and the coiled winding state is maintained. As the optical cable 13, a rectangular cross section having a long side of about 3.1 mm and a short side of about 2 mm is used, and the coil inner diameter D1 of the winding portion 13a is 30 mm, the coil outer diameter D2 is 120 mm, and the optical cable 13 is high. When the length H is wound at about 30 mm, the optical cable 13 of about 50 m can be stored. The coil inner diameter D1 and the coil outer diameter D2 of the winding portion 13a can be arbitrarily set. However, in order to suppress the deterioration of transmission quality due to the bending diameter of the optical cable, the coil inner diameter D1 is set to 30 mm or more. Is desirable.

  In addition, when the storage case 15 is inserted into the support line and extended, it is not caught by nearby obstacles, and is fixed to a building such as the eaves of a house after laying as a storage body for the extra cable length. In particular, it is not desirable to make the storage case 15 too large, and the coil outer diameter D2 is preferably about 200 mm or less. Moreover, when the coil outer diameter D2 becomes excessively large, the winding pitch around the support wire 12 becomes too large, and the adhesion is deteriorated and the slack is likely to occur. Also from this point, the coil outer diameter D2 is 200 m or less. It is preferable to do this.

  The storage case 15 is configured, for example, by assembling three members of a base member 16, a case member 17, and a throttle member 16 with an adhesive or the like. The base member 16 and the case member 17 can be formed of various materials. For example, the base member 16 and the case member 17 can be formed by molding plastic (polypropylene, polyethylene, polycarbonate, etc.). The base member 16 is provided with a through hole 16a for allowing the support wire 12 to pass through at the center, and a hole (not shown) for fixing the drop optical cable to a building or the like with a screw after laying the drop optical cable. ing. In the space formed by the base member 16 and the case member 17, the winding portion 13 a of the optical cable 13 is accommodated in a donut-shaped coreless coil shape, and is sequentially drawn out from the inner coil turn and supported through the diaphragm member 18. It is fed out while being spirally wound around the wire 12.

  The diaphragm member 18 is formed of a soft material such as synthetic rubber, natural rubber, or polyethylene, for example, so that the cable jacket is not damaged when the optical cable 13 is extended. In addition, the drawing member 18 has a feeding hole 18a tapered so as to realize smooth feeding. Further, the aperture can be set to an appropriate diameter so that the extended portion 13b of the optical cable 13 is tightly wound around the support wire 12 and extended. For example, when the outer diameter of the support wire 12 is 2 mm and the outer dimension of the optical cable 13 is 3 mm, the aperture S of the aperture 18b may be about 5 mm.

  Moreover, it is good to attach the tension string 19 to the suitable part of the storage case 15. FIG. This is convenient for moving the storage case 15 along the support line when laying the drop optical cable 11 from a high place to a low place or from the opposite low place to a high place. The laying can be performed only by operating the pulling cord 19. In addition, although the thing of a various material can be used for the tension string 19, an aramid fiber string etc. with a tensile strength are preferable, for example.

FIG. 2 is a diagram illustrating an example of a procedure for manufacturing a drop optical cable in which an optical cable having a predetermined length is stored in the storage case described above. First, as shown in FIG. 2A, a disassembleable reel 23 having flange portions 23a and 23b on both sides of a body portion 23c is prepared. The above-described optical cable used for pulling down the optical fiber on the reel 23 is wound up by a predetermined length with aligned winding to form a winding portion 13a.
Next, as shown in FIG. 2B, one of the flange portions 23b of the reel 23 is removed, and one end face of the winding portion 13a is exposed. It is assumed that the reel 23 is easily assembled with the flange portions 23a and 23b to the body portion 23c by an adhesive or screws.

  Thereafter, as shown in FIG. 2C, the case member 17 is attached so as to cover the side from which the flange 23b is removed. The case member 17 is fixed to the remaining other flange 23a with an adhesive or a screw, and prevents the winding portion 13a from collapsing. The case member 17 is formed with a hole through which the winding end 13c of the winding portion 13a is drawn, and the optical connector 14b is attached to the winding end 13c.

Next, as shown in FIG. 2 (d), the coupling state of the flange portion 23a and the body portion 23c is released, and the body portion 23c is extracted from the wound portion 13a. At this stage, the flange portion 23a is used as a base member 16 that forms a storage case, and the winding portion 13a has a coreless coil shape.
Next, as shown in FIG. 2 (e), the diaphragm member 18 described in FIG. 1 (c) is attached and fixed to the opening of the case member 17. A drop optical cable as described with reference to FIG. 1 (a) is obtained by pulling out the winding start end portion 13d on the inner end side of the winding member 13a from the tapered through hole of the aperture member 18 and attaching the optical connector 14a. can do.

  FIG. 2F is a diagram illustrating an example of a configuration in which the terminal-side optical connector 14b is drawn into the house and directly connected to the optical connection unit installed in the house. In this case, a drop optical cable is laid, and the extra length of the cable together with the storage case is moved to the eaves of a building such as a house, and then the base member 16 is temporarily removed. Then, the optical connector 14b is passed through the through hole 16a through which the central support line of the base member 16 is inserted, and the end portion 13c on the winding end side remaining as the extra length of the winding portion 13a is fed out by a predetermined length. It is possible to lay up to the optical connection inside the house. After unwinding the optical cable of a predetermined length, the base member 16 is coupled with the case member 17 again and fixedly installed under the eaves of the house.

  3A and 3B are diagrams illustrating an example of a laying method for laying the above-described drop optical cable. Here, as shown in FIG. 3A (a), it is assumed that an optical fiber is drawn down to a nearby house 6 via a closure 9 from a trunk optical cable 2 wired overhead on the utility pole 3. In this case, it is assumed that the utility pole 3 is one building, the house 6 is the other building, the closure 9 is supported by the utility pole 3 or the trunk optical cable 2, and the support line 12 is provided between the utility pole 3 and the house 6. It is assumed that a drop optical cable is laid along the support line 12 by newly stretching.

  As the support wire 12, for example, a steel wire having an outer diameter of about 1.2 mm and a polyethylene coating having an outer diameter of about 2.0 mm is used. The support wire 12 has one end portion fixed to the attachment portion 7 of the house 6 serving as a user of the optical cable using a retainer or the like, and the other end portion is extended toward the upper portion of the utility pole 3. Next, as shown in FIG. 3A (b), the drop optical cable 11 according to the present invention described in FIG.

  After the support wire 12 is inserted into the through hole of the storage case of the drop optical cable 11, the other end of the support wire 12 is attached to the upper side of the utility pole 3 as shown in FIG. In the same manner as in the house side, it is fixed using a retainer or the like, and the support wire 12 is stretched so as not to be slack. At this time, the storage case 15 of the drop optical cable 11 is supported on the other end side of the support wire 12 and is located near the closure 9. Therefore, the optical connector 14b drawn out to the cable feeding side of the storage case 15 is further pulled out and connected to a connection portion prepared in advance in the closure 9, and one end side of the drop optical cable 11 is fixed. .

  At this time, as shown in FIG. 3B (a), the pull string 19 is attached to the storage case 15 of the drop optical cable 11, and the operator is hung with a length that can be pulled from the ground. Next, as shown in FIG. 3B (b), the operator moves the storage case 15 along the support line 12 in the direction of the house 6 while slowly pulling the pull string 19 from the ground. As a result, the optical cable 13 wound and housed in a coil shape in the storage case 15 is drawn out and installed so as to be spirally wound around the outer periphery of the support wire 12.

  When the storage case 15 is pulled down to the position below the eaves of the house 6, as shown in FIG. 3B (c), the storage case 15 is fixedly installed on a predetermined mounting portion of the house with the cable remaining in the interior. To do. The optical connector 14b provided on the terminal end side of the drop optical cable 11 is connected to an optical connector (not shown) attached to an optical cable for wiring in the house using an appropriate connection box or the like. When the optical connector on the terminal end side of the drop optical cable 11 is drawn into the house and optically connected in the house, the method described with reference to FIG.

3A and 3B show an example in which a support line is newly laid, but an existing metal telephone line can be used as a support line and the drop optical cable according to the present invention can be laid on the outer periphery. In this case, for example, the following procedure can be used.
(1) At the existing telephone line terminal unit that has come under the eaves of the house, the support line of the telephone line is removed from the fixture and the communication line part of the telephone line is disconnected.
(2) The drop optical cable described in FIG. 1 is passed through the end portions of the telephone line and the support line that have become free in the above operation, and the telephone line and the support line are inserted into the through hole of the storage case.
(3) Next, the supporting line of the telephone line removed from the fixing tool is fixed again by the fixing tool and returned to the stretched state.

(4) Pull the storage case along the telephone line and its support line in the direction of the main optical cable closure.
(5) An optical connector attached to one end portion of the drop optical cable is connected to a connection portion prepared in advance in the closure, and one end portion side of the drop optical cable is fixed.
(6) Next, the storage case is moved in the downward direction of the house along the support line by the same method as described in FIGS. 3B (a) to 3B (c). As a result, the optical cable wound and housed in a coil shape in the housing case is drawn out and installed so as to be spirally wound around the outer periphery of the support line and the telephone line.

(7) When the storage case is drawn to the position below the eaves of the house, the storage case is fixedly installed on a predetermined mounting portion of the house with the cable remaining length remaining inside. The optical connector provided on the terminal end side of the drop optical cable is connected to the optical connector attached to the optical cable for wiring in the house using an appropriate connection box or the like. The existing telephone line that has been cut may be reconnected using an electrical connection member, or may be connected by providing a metal terminal block on the base member of the drop optical cable storage case.

  In addition, when using the new support line of FIG. 3A-FIG. 3B, or when using the said existing telephone line etc., the example which extends and lays a drop optical cable toward the user's house side from a closure side However, it may be laid and extended from the user's house side toward the closure side.

It is a figure explaining the outline of the drop optical cable by this invention. It is a figure explaining an example of the procedure which manufactures a drop optical cable. It is a figure explaining an example of the installation method of the drop optical cable by this invention. It is a figure explaining the laying method following FIG. 3A. It is a figure explaining a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Drop optical cable, 12 ... Support line, 13 ... Optical cable, 13a ... Winding part, 13b ... Feeding part, 13c, 13d ... End part, 14a, 14b ... Optical connector, 15 ... Storage case, 16 ... Base member, 16a DESCRIPTION OF SYMBOLS ... Through-hole, 17 ... Case member, 18 ... Restriction member, 18a ... Tapered through-hole, 18b ... Restriction opening, 19 ... Tension string, 20 ... Optical fiber core wire, 21, 21 '... Strength member, 22, 22 '... cable jacket, 22a23 ... reel, 23a, 23b ... collar, 23c ... trunk.

Claims (5)

A drop optical cable in which optical cables that have been cut in advance to a predetermined length are bundled in a coil shape, and optical connectors are attached to both ends thereof,
The coiled portion bundled is stored and held in a storage case, and provided with a through hole through which a support wire stretched between buildings is inserted at both end surface portions of the storage case, and the through hole on one end surface side is The drop optical cable is characterized in that the winding portion can be extended along the support line.   The drop optical cable according to claim 1, wherein an aperture member having a tapered through hole is provided on an end face side that feeds the winding portion from the storage case.   The drop optical cable according to claim 1 or 2, wherein a tension string for installation is provided in the storage case.   The drop optical cable according to any one of claims 1 to 3, wherein a support line stretched between buildings is inserted into a through hole of the storage case, and the storage case is inserted into one of the support lines. Move from one end side to the other end side, sequentially roll out the winding portion of the optical cable in the storage case and spirally wind around the support line, and then leave the remaining winding portion in the storage case A method for laying a drop optical cable, wherein the drop optical cable is fixed and held together with the storage case as a length.   The drop optical cable laying method according to claim 4, wherein the support line is an existing telephone line.

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