JP2009020221A - Optical closure and method of optical wiring from optical cable assembly to subscriber's house - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical closure manufactured inexpensively. <P>SOLUTION: The optical closure is adapted to house and protect an optical connecting part 17 of a first optical cable 2A branching from an aggregate (optical cable assembly) formed by twining a plurality of optical fibers and a second optical cable 5 of a subscriber's house connected to the above. The optical closure includes two split pieces 8, 9 formed substantially cylindrical when they are closed, wherein both ends of the respective split pieces 8, 9 are provided with optical cable fixing grooves 11, 12 to which the coated parts 2d, 5d of the first or second optical fiber 2A, 5 are fitted and fixed when they are closed, and the middle parts outside of the both end parts are provided with recessed parts 13, 14 which form a support line fixing structure or a single wide internal space without partition when they are closed. The respective split pieces 8, 9 are very simple in structure, easily formed of resin and manufactured inexpensively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical closure and an optical wiring method for branching optical wiring from an aggregate obtained by simply twisting a plurality of optical cables to a subscriber's house or the like.

In an optical communication network, withdrawal to a subscriber is usually performed using a drop cable from an optical closure provided on an optical communication line. In general, leading wiring using a multi-core slot cable in which a plurality of slots are provided in a slot rod is performed from a station to an optical closure. In the optical closure, the drop cable and the optical fiber taken out from the trunk optical cable are connected by an optical connector, fusion or mechanical splice connection.
On the other hand, for optical wiring to areas where the distribution density of subscribers is small, an assembly formed by simply twisting a plurality of optical fibers of one or two cores around a steel core instead of a multi-core slot cable ( Hereinafter, there may be a case where the preceding wiring is performed). That is, it can be said that this aggregated optical cable has a structure in which a plurality of drop cables are aggregated. In this case, the collective optical cable does not have a sheath covering the whole like a normal optical cable, and the optical cable itself as a constituent unit is covered with a weather-resistant sheath. As described above, it is not drawn from an optical closure having a complicated configuration in which an optical fiber core is taken out from the cable, but is directly wired, that is, one optical cable of one or two cores constituting a collective optical cable. Is simply branched from the aggregated optical cable as it is, and the branched optical cable is optically connected to the extended optical cable for extending to the subscriber's home side. Therefore, a simple optical closure that protects the optical connection portion with the extension optical cable is required even in the case of the withdrawal from the collective optical cable.

Incidentally, there is an optical closure 30 having a structure described in Patent Document 1 as a simple optical closure. As shown in FIG. 9, the optical closure 30 is formed of a resin-molded frame 31 and a cover 32 as a whole and has a small openable / closable cylindrical shape, and the optical cable covering portion is fixed to the frame 31 side. The optical cable fixing portions 33 at both ends having the fixing groove 33a, the support wire fixing portion 34 at the center side of the closure length direction, and the connection portion accommodating portion 35 near the center in the longitudinal direction of the closure are provided. The connecting portion accommodating portion 35 is partitioned by a partition 36 at the center in the closure width direction, and can accommodate two optical connecting portions. As shown in FIG. 10, the optical closure 30 includes a drop cable 2 ′ in which a central two optical fiber cores 2a ′ and tension members 2b ′ on both sides thereof are coated with a resin wire 2d ′ together with a support wire 2e ′. It is an optical closure that protects the optical connection between the two.
JP 2005-107014 (optical closure for connecting optical fiber cable)

  The above-mentioned conventional optical closure is for a two-core drop cable with a support wire, but has a complicated structure with a support wire fixing part 34 and a partition 36 inside, and the product cost of the optical closure is high. It becomes.

By the way, this type of simple optical closure accommodates and protects the connection part of one or two optical cables having substantially the same structure, so that it is like an optical closure used for pulling from a multi-fiber slot cable. It is sufficient to have a simple waterproof performance without requiring a complicated structure.
Also, in general, an optical connection between one optical cable branched from a collective optical cable stretched at a high place and an extension optical cable is made at an intermediate portion in the route to the subscriber's house, and therefore the optical closure is in the air. Although it is in a floating state, there is a problem in that the orientation of the optical closure cannot be determined if there is no mechanism that supports the attitude of the optical closure by simply connecting the optical cables as in the optical closure 30 of Patent Document 1.
The optical closure used here has sufficient function even with simple waterproofing as described above, but if the orientation of the optical closure is not fixed and water droplets accumulate in the optical closure, an unexpected communication failure may occur. .

  The present invention was made based on the above background, and as an optical closure used in a wiring system using an aggregate optical cable, it can be easily attached to a pulling point of the aggregate optical cable, and an optical closure main body is manufactured at low cost. An object of the present invention is to provide an optical closure that can be used. It is another object of the present invention to provide an optical wiring method from a collective optical cable to a subscriber's house, in which the posture of the optical closure is stabilized and no problem occurs even with a simple waterproof structure.

According to the first aspect of the present invention for solving the above-mentioned problem, the optical device for storing and protecting the optical connection portion between the first optical cable branched from the assembly in which a plurality of optical cables are twisted together and the second optical cable connected thereto is stored. A closure,
It consists of two split pieces that can be opened and closed in a generally cylindrical shape when they are closed together, and each split piece is fixed by fitting the covering portion of the first or second optical cable at both ends when closed. An optical cable fixing groove is provided, and the intermediate portion excluding the both end portions has a recess that forms a single wide internal space that does not have a support wire fixing structure or partition when closed. To do.

  According to a second aspect of the present invention, the optical closure of the first aspect is a resin-integrated molded article in which two divided pieces are connected via a thin hinge portion, and the outer surface of the intermediate portion excluding both ends when closed is a cylindrical surface The inner surface is made of a surface having no irregularities.

The invention of claim 3 is an optical wiring method in which an optical cable is branched from an assembly in which a plurality of optical cables are twisted together and optically wired to a subscriber's house using the optical closure of claim 1 or 2.
The optical closure is fixed at the pulling point of the assembly, and the optical connection between the first optical cable and the second optical cable extending to the subscriber's house is simply stored in the internal space of the optical closure, And the covering portions of both optical cables are simply fitted and fixed in the optical cable fixing groove, and this optical closure is fixed to the pulling point of the aggregate by a fixing member in a posture along the aggregate optical cable. To do.

  According to a fourth aspect of the present invention, in the optical wiring method according to the third aspect, the fixing member to be used is a binding band or a binding string.

According to the optical closure of the first aspect of the present invention, each divided piece has a simple optical cable fixing groove at both ends and a simple recess at the intermediate portion. Therefore, the structure is extremely simple and resin molding is easy. Therefore, the product cost of the optical closure can be greatly reduced.
In particular, if the resin integrated molded product having the shape as in claim 2 is used, the product cost can be further reduced.

According to the optical wiring method of claim 3, not only can the light closure be easily fixed to the pulling point to the subscriber, but the optical closure is bound and fixed to the aggregated optical cable by the elongated binding material in a posture along the aggregated optical cable. The closure can be maintained in a horizontal posture, and can be maintained in a posture in which the joint of the two divided pieces is placed downward.
Therefore, unlike the conventional wiring system in which the optical closure is in a floating state between the collective optical cable and the subscriber's home, there is no problem that the attitude (tilt and rotation angle) of the optical closure is not fixed. Therefore, even if it is a simple waterproof that simply fits the cover of the optical cable into the optical cable fixing grooves on both ends of the closure, water droplets are less likely to enter, and even if it enters, it is easily discharged from the downward joint. Thus, there is little risk of water droplets collecting in the light closure. This reduces the possibility of communication failure.

  Hereinafter, an optical closure embodying the present invention and an optical wiring method from a collective optical cable to a subscriber's house will be described with reference to the drawings.

  FIG. 1 is a perspective view of an optical closure 1 according to an embodiment of the present invention, and FIG. 2 is a view showing the optical closure 1 in an opened state. As shown in FIGS. 3, 7, and 8, the optical closure 1 includes a first optical fiber 2 that is branched from an imaginary collective optical cable 4 in which a plurality of optical cables 2 are simply twisted around a steel core 3. This is a small optical closure that accommodates and protects the optical connection portion between the first optical cable 2 (2A) and the second optical cable 5 that is optically connected to the optical cable 2 and extends toward the subscriber's home 6 side. In FIG. 7 (a), the arrangement of the optical cables 2 in the cross section of the collective optical cable 4 is shown in an orderly arrangement, but is schematically shown, and is actually an irregular arrangement. As shown in FIG. 7 (b), each optical cable 2 constituting the aggregated optical cable 4 is formed by integrating the central two optical fiber core wires 2a and the tension members 2b on both sides thereof with a resin coating 2d having notches 2c. This is a so-called drop cable structure. The second optical cable 5 which is an extended optical cable extending to the subscriber's home side also has the same structure (same cross section) as the optical cable 2.

  The optical closure 1 is composed of two divided pieces 8 and 9 that are substantially cylindrical when closed, and the divided pieces 8 and 9 are integrally connected via a thin hinge portion 7 so as to be openable and closable. It is. Each of the divided pieces 8 and 9 has optical cable fixing grooves 11 and 12 for fitting and fixing the covering portions 2d and 5d of the first or second optical cable 2A and 5 at both ends, and the both ends. Recesses 13 and 14 having no support wire fixing structure or partition are formed in the intermediate portion excluding. The recesses 13 and 14 are mere square recesses, and are recesses having a surface without unevenness. When both the divided pieces 8 and 9 are closed, a single wide internal space 15 having no support line fixing structure or partition is formed as shown in FIG.

When using this optical closure 1 to drop an optical cable from the collective optical cable 4 to a subscriber's house, for example, a first optical cable 2A branched from the collective optical cable 4 and a second optical cable 5 extending to the subscriber's house are used. Optical connection (optical connection portion is indicated by 17) by fusion connection or the like, and this optical connection portion 17 is housed inside the optical closure 1, and the covering portions 2d of the first optical cable 2A and the second optical cable 5; 5d is fitted into the optical cable fixing grooves 11 and 12 of one divided piece (divided piece 8 in the illustrated example) of the optical closure 1, and both the divided pieces 8 and 9 are closed to cover the first optical cable 2A. The portion 2d is fitted and fixed to the optical cable fixing grooves 11a and 12a on the left side in FIG. 2 of the two split pieces 8 and 9, and the covering portion 5d of the second optical cable 5 is on the right side in FIG. Light cave Securing groove 11b, it is fitted and fixed to 12b. Although not shown in the drawings, the two split pieces 8 and 9 are provided with engaging portions that engage with each other when they are closed.
Thus, the optical closure 1 stores and protects the optical connection portion 17 of the first optical cable 2A and the second optical cable 5 in a simple waterproof state.
The optical connection portion between the optical cables 2A and 5 is not limited to the fusion connection, and may be a connection by an optical connector or a mechanical splice.

  Next, the optical closure 1 is bound and fixed to the steel core 3 of the collective optical cable 4 with, for example, a binding band 18 as shown in FIGS. In this case, as shown also in FIG. 5, the two split pieces 8 and 9 are bound and fixed so that the joint of the two divided pieces 8 and 9 comes down. The binding band 18 in the illustrated example is a resin molded product in which an engagement portion 18b having an engagement hole is formed at one end of an elongated band 18a, and is tightened through the one end side of the band 18a into the engagement hole of the engagement portion 18b. It can be united.

The optical closure 1 has only the optical cable fixing grooves 11 and 12 for fitting and fixing the covering portions 2d and 5d of the optical cables 2A and 5 at both ends, and the inside does not have a support line fixing structure or partition. Since it has a single wide internal space 15, the structure is extremely simple, and the cost of resin molding the optical closure 1 is low.
Further, since the optical closure 1 is bound and fixed to the aggregated optical cable 4 by the binding band 18 in a posture along the aggregated optical cable 4, the optical closure 1 is maintained in a horizontal posture and the joint 19 of the two divided pieces 8 and 9 is provided. The posture is kept down.
Therefore, unlike the conventional wiring system in which the optical closure is in the air in the middle between the collective optical cable and the subscriber's home, there is no problem that the attitude (tilt and rotation angle) of the optical closure 1 is not fixed. If the optical closure 1 is tilted, water droplets can easily enter from the optical cable fixing grooves 11 and 12 at the end, but since the water droplets are kept horizontal, the water droplets rarely enter. Even if a water droplet enters, the joint 19 is always kept downward, so that it is easily discharged from the joint 19 and there is little possibility that the water droplet accumulates in the optical closure 1. Therefore, there is little possibility of communication failure due to accumulation of water droplets.

When the optical closure 1 is bound and fixed to the collective optical cable 4 with the binding band 18, it is appropriate that the optical closure 1 is bound to the steel core 3 as in the illustrated example, but some optical cables 2 can also be bound and fixed together. Moreover, it is also possible to bind and fix the optical fiber cable 4 so as to surround the whole.
In addition, when the posture of the optical closure in the rotation direction is not sufficiently restricted only by tightening with the binding band 18, an object between the optical closure 1 and the collective optical cable 4 is arranged so that the posture of the optical closure 1 in the rotation direction does not change. It is also possible to bind in a state of filling.

FIG. 6 shows another embodiment in which the optical closure 1 is fixed to the collective optical cable 4. In this embodiment, instead of the binding band 18, the optical closure 1 is bound and fixed to the steel core 3 of the collective optical cable 4 by a so-called cable binding string 21 used for electric wire binding (electric wire movement prevention).
The means for fixing the optical closure to the collective optical cable is not limited to this, and various elongated binding materials and other fixing members that can fix the optical closure to the collective optical cable so that the posture (tilt and rotation angle) does not change are adopted. it can.

It is a perspective view of the optical closure of one Example of this invention. It is the perspective view shown in the open state of the said optical closure. It is a figure which shows the state which fixed the said optical closure to the aggregated optical cable with the binding band. It is the figure which expanded the fixing | fixed part by the binding band in FIG. It is AA expanded sectional drawing of FIG. FIG. 6 is a view corresponding to FIG. 5, showing an embodiment in which the optical closure is fixed to the collective optical cable with a string. (A) is a cross-sectional view of the collective optical cable in the above embodiment, and (B) is a cross-sectional view of the first optical cable or the second optical cable. It is the figure which showed typically the aspect which branches from a collective optical cable to a subscriber's house using the said optical closure. It is a disassembled perspective view of the conventional optical closure. It is sectional drawing of the optical drop cable which the optical closure of FIG. 9 makes object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical closure 2 Optical cable 2A which comprises an aggregate optical cable 1st optical cable 2d, 5d Covering part 3 Steel core 4 Aggregate optical cable (Aggregate which twisted together a plurality of optical cables)
5 Second optical cable (extension optical cable)
6 Subscriber's house 7 Thin hinge part 8, 9 Divided piece 11 (11a, 11b) Optical cable fixing groove 12 (12a, 12b) Optical cable fixing groove 13, 14 Recess 15 Single wide internal space 17 Optical connection part 18 Cable tie 19 Seam 21 of two split pieces Cable tie

Claims (4)

An optical closure that houses and protects an optical connection portion between a first optical cable branched from an assembly in which a plurality of optical cables are twisted together and a second optical cable connected thereto,
It consists of two split pieces that can be opened and closed in a generally cylindrical shape when they are closed together, and each split piece is fixed by fitting the covering portion of the first or second optical cable at both ends when closed. An optical cable fixing groove is provided, and the intermediate portion excluding the both end portions has a recess that forms a single wide internal space that does not have a support wire fixing structure or partition when closed. Light closure.   It is a resin integrated molded product in which two divided pieces are connected via a thin hinge, and the outer surface of the intermediate portion excluding both ends when closed is a cylindrical surface and the inner surface is a surface with no irregularities. The optical closure according to claim 1. An optical wiring method for branching an optical cable from an assembly in which a plurality of optical cables are twisted together and optically wiring to a subscriber's house using the optical closure according to claim 1 or 2,
The optical closure is fixed at the pulling point of the assembly, and the optical connection between the first optical cable and the second optical cable extending to the subscriber's house is simply stored in the internal space of the optical closure, And the covering portions of both optical cables are simply fitted and fixed in the optical cable fixing groove, and this optical closure is fixed to the pulling point of the aggregate by a fixing member in a posture along the aggregate optical cable. An optical wiring method from a collective optical cable to a subscriber's house.   4. The method of optical wiring from an aggregated optical cable to a subscriber's house according to claim 3, wherein the fixing member is a binding band or a binding string.

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