JP3129788B2 - Optical withdrawal connection box and withdrawal method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drop-down connection box and a drop-down method for branching a plurality of optical fiber cores supplied from an optical cable in a box body and connecting a part to an outdoor light line.

[0002]

2. Description of the Related Art A subscriber's optical line is sequentially added according to subscriber's demand, and each time a subscriber's demand occurs at a connection point of an aerial cable, the subscriber is deducted to a subscriber via an optical outdoor line. Most withdrawals to this subscriber are made fictitiously, using a fictitious withdrawal connection box.

FIG. 3 is a conceptual diagram showing an aerial withdrawal connection box mounted in the middle of an optical cable connected from a station device to a subscriber's house. The distribution cable 2 connected to the station apparatus 1 is laid underground, and is connected via a pull-up cable 4 to a switchboard 3 arranged imaginarily. The wiring cable 2 connected to the switching board 3 is laid over a telephone pole 5 and is dropped down to a subscriber via an optical drop-down connection box 6.

[0004] Since this overhead drop-down connection box is attached to an optical cable in the vicinity of a telephone pole, it is necessary that the work can be safely performed on the pole regardless of new construction and maintenance, and that it is easy to handle (see "9. Study on installation and configuration technology of optical fiber optical line for subscribers ", Research and Application Report, Vol. 33, No. 2 (1984),
p.68).

FIG. 4 is a perspective view showing the structure of a conventional overhead pull-down connection box (“9. Study on installation and configuration technology of low-fiber-count subscriber optical line”, Research and Application Report, Vol. 33, No. 2). (1
984), p. 70). The distribution cable 2 includes an optical cable 2a and a suspension line 2b, and is attached to the box body 6a from both sides. The plurality of optical fiber cores 7 supplied from the optical cable 2a are branched inside the box body 6a, and some of them are drawn down to the subscriber. The optical fiber core 7 is connected to the extra length processing section 6b installed inside, and the extra length of the optical fiber core 7 is accommodated therein.

[0006]

However, in the conventional overhead pull-down connection box, the optical fiber cores to be dropped and the optical fiber cores to be passed without being dropped are interlaced with each other. There is a problem that it takes time for sorting and extra length processing, and the work efficiency in withdrawal work is poor.

Accordingly, an object of the present invention is to provide a drawdown connection box having a structure for improving work efficiency and a drawdown method with good work efficiency.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an optical drop connection box for branching a plurality of optical fiber cores supplied from an optical cable and connecting a part to an outdoor optical line. A box body into which the optical cable is introduced, a branch optical fiber detachably housed in the box body and connected to the optical cable and the outdoor line via the optical connector and connecting the optical cable and the outdoor line; and And a wiring board that houses therein through optical fibers for connecting them.

The present invention also relates to a drawing method using the above optical drop connection box, wherein a plurality of types of wiring boards having different numbers of branch optical fibers are prepared in advance, and an optical fiber core supplied from an optical cable is provided. To change the number of lines withdrawn,
The wiring board housed in the box body is replaced with another type of wiring board having the number of branch optical fibers corresponding to the number of dropped cores to be changed.

[0010]

According to the present invention, the wiring board is detachably housed in the box body and is connected to the optical cable and the outdoor cable via the optical connector. For this reason, by preparing a plurality of types of wiring boards that are pre-wired so that the number of branch optical fibers is different, when the number of drawn optical fibers supplied from the optical cable is changed, the wiring board is replaced. Just do it. Thereby, the working time in the withdrawal work is shortened, and the working efficiency is improved.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an optical drop connection box according to an embodiment of the present invention. In the description, the same elements will be denoted by the same reference symbols, without redundant description. FIG. 1 is a perspective view (FIG. 1A) showing the structure of an optical drop-down connection box according to one embodiment of the present invention, and a longitudinal sectional view (FIG. 1B) of a wiring board housed therein. .

The optical drop connection box according to the present embodiment comprises a box body 8
And a wiring board 9 housed in a detachable state. The wiring board 9 is connected to the optical cable 2a and the outdoor light line 10 by connector connection. The connector connection with the optical cable 2a is realized by the cable collective connector 11 connected to the end of the optical cable and the optical connector 13 mounted on the front and rear surfaces of the wiring board 9. In this case, since a plurality of optical fiber cores are supplied collectively by the optical connector, the extra length processing device is unnecessary. Therefore, the inside is further simplified. The connector between the wiring board 9 and the outdoor cable 10 is connected to the optical connector 1 attached downward by a connector fixing jig (first connection member) 14.
6 through an optical connector (not shown) fixed to the end of the light outdoor line 10 exposed from the guide pipe 12. The light outdoor line 10 is protected and restrained by the guide pipe 12, penetrates through the bottom of the box body 8, and is drawn into the wiring board 9. Further, the suspension wire 2b constituting the wiring cable 2 is not connected to the wiring board 9 housed in the box body 8, but penetrates the box body 8.

Inside the wiring board 9, a connector fixing jig 1 is provided.
Reference numeral 4 denotes a bottom surface, and a connector fixing plate (second connection member) 15 is fixed to a side surface. Also, a plurality of optical fiber cores 7 having optical connectors 16 connected to the ends from the optical cable 2a.
Are supplied to the inside of the wiring board 9 in a separated state. If necessary, the optical fiber core wire 7 may be 16
An optical fiber ribbon is used. An optical connector 16 fixed to an end of an optical fiber core 7 (hereinafter, referred to as a “branch fiber”) connected to the outdoor light line 10 is fixed to the connector fixing jig 14. 1
The optical connector 16 fixed to the end of the remaining optical fiber core wire 7 (hereinafter referred to as “through fiber”) not connected to “0” is fixed to the connector fixing plate 15. Therefore, the branch fibers are branched in an orderly manner without intersecting with each other (see FIG. 1B).

The connector fixing jig 14 includes an optical connector 16
Of the optical connector 16 is attached downward.
An opening is formed at the bottom of the wiring board 9 facing the opening. Therefore, it can be easily connected to the outdoor light line 10 supplied from the guide pipe 12 penetrating the bottom surface of the box body 8.

Next, a drawing method using the above-described optical drawing connection box will be described. For example, a 40-fiber wiring cable containing ten four-fiber tape-shaped optical fibers is laid and connected to a wiring board. In this distribution board, one tape-shaped optical fiber core wire is connected to the outdoor optical fiber line. However, when the number of subscribers increases, one tape-shaped optical fiber core wire is further dropped to the outdoor optical fiber line. Is assumed. In this case, if the optical drop-down connection box according to the present embodiment is used, the drop-down work can be easily realized, which will be described below.

First, another wiring board in which two tape-shaped optical fibers are connected to the connector fixing jig 14 is prepared in advance. Remove the cover and remove the existing distribution board from the optical cable. Then, the prepared wiring board is attached to the optical cable. Since the wiring boards are connected to the optical cable by cable connection, they can be easily attached and detached.

[0017]

Next, a description will be given of experimental results according to the above-described embodiment used in actual withdrawal work. Using the structure of the optical drop connection box shown in FIG. 1, an optical drop connection box for dropping two 4-core tape-shaped optical fiber cores from a 40-core wiring cable accommodating ten 4-core tape-shaped optical fiber cores. Produced. When the debit work was actually performed, the work time was reduced to one tenth as compared with the case where the optical deduction connection box according to the present embodiment was not used.
It was shortened to the following.

Next, an optical drop connection box according to another embodiment of the present invention will be described. FIG. 2 is a perspective view showing the structure of an optical drop connection box according to another embodiment. This embodiment differs from the first embodiment in that a plurality of wiring boards are housed inside the box body. In this embodiment, three sets of wiring boards 9
Is housed in On the front and rear surfaces of each wiring board 9, dozens of
A cable collective connector 11 in which several hundred optical fiber cores are unitized is arranged, and is connected to an optical connector (not shown) fixed before and after the wiring board 9. Further, each wiring board 9 has a structure that can be separately detached from the box body 8 by the connector connection described above. Since the inside of each wiring board 9 is as described above, the description is omitted.

In this case, the present embodiment is suitable for a case where the number of optical fiber cores accommodated in an optical cable is relatively large, and by suppressing the number of optical fiber cores supplied to each wiring board. This facilitates the work of attaching the connector to the cable terminal.

Further, since the number of combinations of the through fiber and the branch fiber is reduced, a wiring board of an assumed combination is manufactured in advance, and an arbitrary combination may be provided as necessary at the time of new construction or a change in the number of drawn cores. A combination of wiring boards can be installed.

Further, in the case of the conventional structure, it is necessary to select the branch fiber and the through fiber and to store the extra length of the optical fiber core on the pillar, which causes a decrease in work efficiency. By adopting the structure of the example (see FIGS. 1 and 2), the processing of the branch and the connection that require the most time can be performed in advance on a safe ground, so that the construction time can be greatly reduced. .

Further, the branch fiber and the through fiber are accommodated in a drawdown wiring board and packaged, so that downsizing is possible, and collective connection with a multi-core connector can be easily realized as shown in the figure. . Therefore, the working time on the pillar can be further reduced.

In the optical drop connection box according to the above-described embodiment,
Since the wiring board 9 is attached to the wiring cable 2 with the cover 17 attached, the wiring board 9 is not exposed to the weather.

The present invention is not limited to the embodiment described above. For example, in this embodiment, an optical fiber core is used as a connection method between the optical fiber core exposed on the wiring board and the first connection member. The medium for connecting the one connecting member is not limited to the optical fiber, but may be an optical waveguide.

[0026]

The optical drop-down connection box according to the present invention is detachably attached to an optical cable by connector connection. The drop-down method according to the present invention uses an optical drop-down connection box in which internal wiring has been completed beforehand. The work time in the work is shortened, and the work efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an optical drop connection box according to one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing an optical drop connection box according to another embodiment of the present invention.

FIG. 3 is a conceptual diagram showing an aerial withdrawal connection box attached to an optical cable connected from a station device to a subscriber's house.

FIG. 4 is an exploded perspective view showing an optical drop connection box according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... station apparatus, 2 ... wiring cable, 3 ... switch board, 4 ... pulling cable, 5 ... telephone pole, 6 ... drop connection box, 7 ... optical fiber core wire, 8 ... box body, 9 ... wiring board, 10 ... light Outdoor line, 1
1 ... Cable batch connector, 12 ... Guide pipe, 1
3, 16: Optical connector, 14: Connector fixing jig, 15
... Connector fixing plate, 17 ... Cover

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Sano 1st, Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Wataru Katsurashima 1st, Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries Inside Yokohama Works Co., Ltd. (72) Inventor Shigeru Tomita 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Hiroyuki Akimoto 1-16-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone (56) References JP-A-63-136007 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/00 G02B 6/38

Claims (3)

(57) [Claims] 1. An optical drop-down connection box for branching a plurality of optical fiber cores supplied from an optical cable and connecting a part to an outdoor light line, wherein: a box main body into which the optical cable is introduced; It is housed freely and connected to the optical cable and the optical outdoor line via an optical connector,
An optical drop-down connection box, comprising: a branch optical fiber for connecting the optical cable and the outdoor light line; and a wiring board in which a through optical fiber for connecting the optical cables is housed. 2. The optical drop-down connection box according to claim 1, wherein a plurality of the wiring boards are detachably accommodated in the box body. 3. A drop-down method using the optical drop-down connection box according to claim 1, wherein a plurality of types of wiring boards having different numbers of the branch optical fibers are prepared in advance and supplied from the optical cable. When changing the number of dropped cores of the optical fiber core wire, the wiring board accommodated in the box body is replaced with another type of wiring board having the number of the branch optical fibers corresponding to the number of dropped cores to be changed. Withdrawal method characterized by replacement.