JPS6012605B2 - Optical fiber cable switching connection method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for switching and connecting optical fiber cables.

Since optical fiber transmission systems have various advantages, their use in place of conventional conductive wire transmission systems is being promoted. By the way, optical fiber cables used in optical fiber transmission systems are usually installed using underground equipment such as pipes buried underground, but the installation location may have to be changed due to above ground construction etc. be. In other words, a new optical fiber cable is laid avoiding the construction area, and the newly installed optical fiber cable is switched and connected to the existing optical fiber cable, but during this work, the line is always kept so as not to interrupt signal transmission. We need to take advantage of it. Regarding the connection of the cable sheath at the switching connection, it is considered that the method used in the conventional switching connection of conductive wire cables can be used, but this method uses a lead pipe and vertically splits it by heat. Since it is processed and caulked to connect the outer sheath and keep the part airtight, it is recommended for connecting optical fiber cables, which are susceptible to heat due to their pongee diameter and can cause permanent loss due to heat. Applying the law is difficult. Furthermore, this conventional method has the disadvantage that there are many vertically split parts of the lead pipe, resulting in a lack of reliability. SUMMARY OF THE INVENTION An object of the present invention is to switch and connect optical fiber cables without affecting the optical fiber core line while always utilizing the line.

The gist of the present invention for achieving the above object is that when a part of an existing optical fiber cable is switched and connected to a newly installed optical fiber cable laid at a different location, the present invention provides a method for connecting the jacket to the newly installed optical fiber cable. Connect the unused optical fiber core wire of the existing optical fiber cable and the optical fiber core wire of the newly installed optical fiber cable to the jacket connection component and the connection portion sealing component through the component and the connection part sealing component. Connect through other sheath connection parts and joint sealing parts to be combined, utilize the connected optical fibers, and similarly connect other optical fibers in the existing optical fiber cable with the sheath connection. The optical fiber core wire of the newly installed optical fiber cable is connected to the optical fiber core wire of the newly installed optical fiber cable through the connecting parts and the connecting part sealing parts, and then the above-mentioned jacket connecting parts are connected to each other to connect the optical fiber core wire of the existing optical fiber cable and the newly installed optical fiber cable. The present invention resides in a method for switching and connecting optical fiber cables, characterized in that the outer sheaths are connected to each other and the connecting portion sealing parts are connected to each other to seal the joint portion.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the optical fiber cable switching connection method according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows how an optical fiber cable 1 is laid through an underground facility 2 such as a tunnel or a pipe.

In the figure, 3 is the connection part of the optical fiber cable, and 4a
, 4b, 4c, and 4d are manholes. For example, in Figure 1, switching connections of optical fiber cables are carried out between manholes 4b and 4c, so construction work is carried out between manholes 4b and 4c. 1' (hereinafter referred to as the new cable), and is necessary when creating a detour route. FIG. 2 shows a state in the middle of implementation of the switching connection method according to the present invention, and FIG. 3 shows a partially fractured cross section of the connection after the switching connection is completed.

First, the connecting part sealing part and the jacket connecting part are passed through the newly installed cable 1'.

The connection part sealing parts include a rubber tube 7 with a protrusion 4 having a protrusion 5 on its outer circumferential surface, which is iron-fitted into the cable sheath 6 of the newly installed cable 1', and a rubber tube 7 which is iron-fitted into the rubber tube 7 with the protrusion 5 sandwiched therebetween. The inner end plate 8a and the outer end plate 8 are rarely connected to each other.
b, a metal sleeve 9 for connecting these end plates 8a, 8b to the end plates 8a, 8b on the existing cable 1 side, and a gasket fitting 12 attached to the end thereof via a flat rubber ring 10 and a gasket 11. Consisting of The protrusion 5 of the rubber tube 7 is sandwiched between the end plates 8a and 8b, and these are tightened with bolts to form an airtight part around the cable jacket 6. The sheathing parts include an internal fitting 13 and an external fitting 14 that are inserted into the inside and outside of the cable sheath 6 at the end of the newly installed cable 1' and grip the cable sheath 6 by sandwiching it therebetween. These form a mechanical strength retaining portion at the end of the newly installed cable 1'. 15 is the tension member of the newly installed cable 1', 1
6 is an optical fiber core wire.

For the existing cable 1, peel off the cable sheath 6 to an appropriate length (1.2 mm or more) at the part where the direction is changed for connection.
Take out the tension member 15 and cut it to an appropriate length.

Then, this tension member 15 is attached to the rubber 7 with protrusions in an unroughened state, and the inner and outer end plates 8a and 8b.
, flat rubber ring 10, gasket 11, gasket fittings 12, etc., and outer fittings such as internal fittings 13, external fittings 14, etc., and are used as supports thereof. After that, connect the intervening core wire (polyethylene coated steel core wire) on the existing cable 1 side to the tension member 1.
It is passed through the holes of the connecting part sealing part and the jacket connecting part supported by 5, and is switched and connected to the intervening core wire of the newly installed cable 1'.

Next, the position of the connecting portion 3 is determined.

Incidentally, in the optical fiber cable 1, there are some empty optical fiber cores 16 that are not used as lines. These empty optical fiber cores 16 in the existing cable 1 are cut with a required extra length in accordance with the connection position, and these empty optical fiber cores 16 are cut into plastic strings as shown in FIGS. 4a and 4b. --shaped pipe 17, and then pass it through the hole of the connection part sealing part and the jacket connection part supported by the tension member 15, and then connect it to the optical fiber core wire 16 on the newly installed cable 1' side. Do the following. 1
Reference numeral 8 denotes a connecting portion between the optical fiber core wires 16.

After the optical fibers 16 have been connected, they are bundled and temporarily organized using vertically split plastic organizing pipes 19 as shown in FIGS. 5a and 5b. The line of the optical fiber core wire 16 is transferred. Next, the optical fiber core 16 of the existing cable 1, which has become empty due to line transfer, is passed through the hole in the connection part sealing part and the jacket connection part through the pipe 17, and the optical fiber of the new cable 1' is inserted. Connect to the core wire 16.

Below, in the same way, the existing cable route and the new cable 1'
All optical fiber core wires 16 are connected to each other.
When connecting optical fiber I Z6, optical fiber 16
Since the optical fibers 16 are bundled with the straw-shaped pipe 17 and the vertically divided pipe 19, the optical fiber core wires 16 are not tangled, and the connection work is facilitated. When the switching and connection of all the optical fiber core wires 16 is completed Z, move the connection part sealing part and the jacket connection part to the jacket 6 side of the existing cable 1, and then move the connection part sealing part to the jacket 6 side of the existing cable 1, is placed in a predetermined position, the protrusion 5 is sandwiched between the inner end plate 8a and the outer end plate 8b, and they are connected with bolts to seal the circumferential surface of the outer sheath 6. The 6 ends of the cable jacket are gripped with the external metal fittings 14.

Next, the external metal fittings 14 at the ends of the existing cable 1 and the newly installed cable 1' are connected to each other at the connecting portion 20.

After attaching the extra length processing bobbin 212 to the connecting member 201, the optical fiber core 16 is housed therein. still,
Organizing plastic pipe 1 used for temporary processing before storing the optical fiber core 16 in the extra length processing bobbin 21
Remove 9. Next, the sleeve 9, which is one of the parts for sealing the 3-way part that has been passed through the new cable 1' in advance, is inserted between the end plates 8a and 8b of the existing cable 1 and the end plates 8a and 8b of the new cable 1'. and iron-fit the end plates 8a and 8b on both ends of each outer machine plate 8a.
Then, the gasket fittings 12 are tightened with bolts 22 via the flat rubber ring 10 and gasket 11, respectively, to complete the connection.

In addition, the sealing quality of the connection part 3 is inspected using gas.
A gas valve 23 used for supplying the gas into the connecting portion 3 is provided in the sleeve 9. As described above in detail with reference to one embodiment, the method for switching and connecting optical fiber cables of the present invention does not require any heat, and therefore does not cause permanent loss in the optical fiber core wire. Furthermore, since the sheath connection parts and the connection part sealing parts are used without vertically divided parts which lack reliability, highly reliable connection part airtightness can be ensured.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the optical fiber cable switching connection method according to the present invention, Fig. 2 is a sectional view showing the state in the middle of implementation of the method of the present invention, and Fig. 3 is a part of the connection part after the reversible connection is completed. 4A and 4B are a front view and a side view of a plastic straw-shaped pipe, and FIGS. 5A and 5B are a front view and a side view of a vertically split type plastic pipe for organizing. In the drawings, 1 is an existing optical fiber cable, 1' is a new optical fiber cable, 3 is a connection part, 6 is a cable jacket, 7 is a rubber tube with a protrusion, 8a is an inner end plate, 8b is an outer end plate, and 9 is an outer end plate. 1 is a sleeve, 13 is an internal metal fitting, 14 is an external metal fitting, 15 is a tension member, 16 is an optical fiber core wire, 1
7 is a plastic straw-shaped pipe, 18 is a plastic organizing pipe, and 20 is a connecting member. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. When switching and connecting a part of an existing optical fiber cable to a newly installed optical fiber cable installed at a different location, pass the sheath connection parts and connection sealing parts through the newly installed optical fiber cable, and Other jacket connecting parts and connections that connect the unused optical fiber core wire of the optical fiber cable and the optical fiber core wire of the newly installed optical fiber cable to the jacket connecting parts and connection part sealing parts. Using the connected optical fiber cores, the other optical fiber cores in the existing optical fiber cables are connected through the sheath connection parts and connection part sealing parts, and the newly installed optical fibers are sequentially connected through the jacket connection parts and connection part sealing parts. By connecting the optical fiber core wire of the fiber cable and then joining the sheath connecting parts, the sheaths of the existing optical fiber cable and the newly installed optical fiber cable are connected to each other, and the parts for sealing the connection part are connected to each other. A method for switching and connecting optical fiber cables, characterized in that the joints are sealed by joining together.