JP2877915B2 - Connection structure of optical fiber composite submarine cable - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a connecting portion of an optical fiber composite submarine cable in which a plurality of optical fiber units are arranged on the outer periphery of a power cable core and integrated.

2. Description of the Related Art Cables, such as power cables and optical cables, have limited lengths in terms of manufacturing and transportation, so they must be unavoidably connected at the time of laying, and connection points may be provided for expansion and relocation etc. . As a connection structure of a power cable, a structure in which conductors are connected to each other and then insulated on the outer periphery thereof is known, and as a connection structure of an optical cable, a permanent connection such as fusion or connection by a connector is known. I have. In the case of the latter optical cable connection, an extra cable length is required to bring it to the connection device, to prepare for connection failure, and to replace the connection in the future, and accordingly to connect after the connection Extra length needs to be handled. In connection with ordinary optical cables, this extra connection length is handled by bending the extra long core wire with a radius greater than the allowable bending radius and storing it in a tray, or bending the extra long core wire and storing it in a plastic sheet. Has been adopted.

Problems to be Solved by the Invention The optical fiber composite submarine cable has a configuration in which an optical fiber unit is arranged on the outer periphery of a power cable composed of a conductor, an insulator, a sheath, and the like, and an anticorrosion layer and an iron wire armor are provided outside the optical fiber unit. Yes, when connecting this, the power cable core can adopt the conventional power cable connection structure,
For the optical cable, a permanent connection method such as fusion can be adopted, but the extra length processing of the optical cable cannot be performed by the conventional method. That is, the composite submarine cable is
Since it is necessary to provide an anticorrosion layer and a protective layer such as an iron wire armor on the outer layer, there is no room for providing the above-mentioned tray or plastic sheet.

Therefore, in an optical fiber composite submarine cable, the connection length of the optical cable must be processed along the outer surface of the power cable core. However, since the optical cable cannot be bent to a radius smaller than the allowable bending radius in order to prevent an increase in the loss, if only emphasis is placed on smoothly bending each of the excess connection lengths of the large number of optical cables, the excess connection length can be obtained. However, not all of them are the same, so that many intersections between optical cables occur, and many intersections in multiple layers occur. Since such an intersecting portion projects outward with respect to other portions, the load from the outside is likely to concentrate and act, and as a result, the loss or damage due to crushing at that portion may occur. Was.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a connection structure capable of reducing intersections in excess connection lengths of optical fibers when connecting an optical fiber composite submarine cable in which a number of optical fiber units are arranged around an outer periphery of a power cable. It is.

Means for Solving the Problems In order to achieve the above object, the present invention provides a connection structure for an optical fiber composite submarine cable in which a plurality of optical fiber units are arranged on the outer periphery of a power cable core. The optical fiber units are connected with a predetermined extra length on the outer peripheral side of the connection portion, and the optical fiber units are divided into two groups for each predetermined number, and one of the optical fiber units is a connection portion of the power cable core. And the other group of optical fiber units is provided with slack at the other axial position relative to the connection portion of the power cable core, and The slack portions of the optical fiber units of each group should be arranged along the outer circumference of the power cable core so that It is characterized by the following.

In the connection structure of the present invention, the optical fiber units are connected to each other on the outer peripheral side of the connection portion of the power cable core, and each optical fiber unit is connected with a predetermined extra length, so that slack occurs. In addition, the connection portion of the power cable core has a large diameter due to insulation treatment and lead coating. The optical fiber units are divided into two groups for each predetermined number, and one of the optical fiber units is given slack at a position shifted in one axial direction with respect to the connection portion of the power cable core, and the slack is given. The portion is smoothly curved and received along the outer circumference of the power cable core. Further, the other group of optical fiber units is provided with slack at a position shifted to the other side in the axial direction with respect to the connection portion of the power cable core, and the slack portion is smoothly curved and formed on the outer periphery of the power cable core. It is stored along.

Since these slack portions have a different winding direction from other portions, the optical fiber units are arranged on the lower layer side or the upper layer side, and the extra connection length is not necessarily required for all the optical fiber units. Since they are not the same, there is a possibility that an intersection between the slack portions occurs. However, since the optical fiber unit is divided into two groups and the extra length processing of each group is performed at two places on the left and right sides of the connection portion of the power cable core, the space margin is increased,
The number of excess length processing at each location is reduced, and as a result, the number of intersections between optical fiber units is reduced, and at the same time, the occurrence of multiple intersections where optical fiber units overlap in multiple layers is prevented.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically showing a connecting portion according to the present invention, and shows an optical fiber composite submarine cable 1 connected to each other.
Is constructed, for example, as shown in cross section in FIG. That is, the power cable core 2 has an insulator 4
In addition, the outer cover 5 and the reinforcing layer 6 are sequentially provided to a required thickness, and an anticorrosion layer 7 is formed on the outer periphery of the reinforcing layer 6. For the insulator 4, the outer cover 5, the reinforcing layer 6, and the anticorrosion layer 7, various conventionally known configurations and materials can be adopted according to the power transmission capacity and the installation depth. A plurality of optical fiber units 8 are spirally wound around the outer periphery of the anticorrosion layer 7 at regular intervals and in a helical manner. The cords 9 are arranged, and accordingly, the polyethylene cords 9 are also spirally wound around the outer periphery of the anticorrosion layer 7 like the optical fiber unit 8. Here, an example of the optical fiber unit 8 is as shown in FIG. That is, the optical fiber core wire 10 is inserted into a metal pipe 11 made of stainless steel or the like, the jelly 12 is filled in the metal pipe 11, and an anticorrosion layer 13 made of polyethylene or the like is formed around the metal pipe 11 further. As a whole, it is configured to have a circular cross section. On the other hand, the polyethylene string 9 as an inclusion
The outer diameter, that is, the radial dimension of the cable wound around the anticorrosion layer 7 is the same as that of the optical fiber unit 8, and the gap between the optical fiber units 8 is almost completely It is arranged to fill in.
In addition, in order to prevent water running, the optical fiber unit 8
Alternatively, jelly may be filled in the minute gap between the polyethylene strings 9.

The optical fiber unit 8 and the polyethylene string 9 are fixed by a holding roll 14 provided on the outer periphery thereof. Further, an anticorrosion layer 15 is formed on the outer periphery.

The power cable cores 2 are connected to each other by ordinary connection means such as connecting the conductor 3, performing insulation treatment on the outer periphery thereof, and further performing lead coating on the outer periphery. Portion 16 has a larger diameter than the other portions.

On the other hand, the optical fiber units 8 are connected to each other with a necessary and sufficient extra length, and the extra connection length is accommodated at a position outside the power cable core connection portion 16. That is, each optical fiber unit 8 is, for example, fusion spliced, and in this state, an extra connection length 17 is generated as shown in FIG. Extra connection length
The slack portion 18 of the optical fiber unit 8 due to 17 can be given at any place, where the optical fiber units 8 are divided into two groups for each predetermined number, and are preferably bisected, The slack portion 18 of the optical fiber unit 8 in one group (tentatively group A) is provided at a position off the left side of the drawing with respect to the power cable core connection portion 16 as shown in FIG. A slack portion 18 of the other group (tentatively referred to as a group B) of the optical fiber units 8 is provided at a position deviated to the right side of the drawing with respect to the power cable core connection portion 16. Therefore, on the outer peripheral side of the power cable core connection portion 16, both the optical fiber units 8 of the A group and the B group are arranged along the outer peripheral surface of the power cable core connection portion 16. Only one group of the optical fiber units 8 is arranged along the outer peripheral surface of the power cable core 2, and the other group of the optical fiber units 8 is slack, so that the arrangement state is completely different. Therefore, for example, in the left part of the figure with respect to the power cable core connection part 16, the optical fiber units 8 of the B group are
Are arranged along the outer peripheral surface of the optical fiber unit 8, and these are pressed and wrapped with a cotton tape (not shown) or the like. Are arranged along the outer peripheral surface of the power cable core 2 and these are pressed and wound with a cotton tape (not shown) or the like. In this case, the polyethylene string 9 for interposition is also arranged with the optical fiber unit 8. (See FIG. 6). Also, since the slack portion 18 of each optical fiber unit 8 is to be along the upper side of the press-winding portion as described above, a gap is provided in a section corresponding to the slack portion 18 (section l in FIG. 6). Therefore, in the section l, it is preferable to dispose a line for wire extension, for example, a polyethylene string 19 having substantially the same diameter as the optical fiber unit 8 so as to fill the section l.

As described above, the slack portions 18 of each group distributed to the left and right with the power cable core connection portion 16 interposed therebetween are smoothly curved so that the bending radius of each portion does not become less than the allowable bending radius, and the power cable core 2 Along the outer periphery, more precisely, it is arranged along the outer peripheral surface of the above-mentioned presser winding. In that case, since the optical fiber units 8 are aligned as much as possible, the intersection of the optical fiber units 8 is prevented.

As described above, the slack portion 18 is connected to the power cable connection portion 16.
After being arranged on the left and right sides of the power cable core 2 and arranged along the outer peripheral surface of the power cable core 2, a presser winding, an anticorrosion coating, and a protective layer are formed on the whole.

Effect of the Invention As described above, in the structure of the present invention, the excess connection length of the optical fiber unit is stored separately on both sides of the power cable core connection portion, so that the number of processing and storage per location is reduced, As a result, the intersections at the so-called slack portions between the optical fiber units are reduced, and multiple intersections intersecting the multilayer can be eliminated or reduced. Therefore, according to the present invention, it is possible to prevent damage to the optical fiber unit and increase in loss due to an external crushing force. Further, in the present invention, since the excess connection length of the optical fiber unit is stored in a portion other than the power cable core connection portion, the outer diameter of the power cable core connection portion is increased due to the large diameter of the power cable core connection portion. The increase can be prevented, and also in this respect, the adverse effect of the external force can be effectively avoided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view for explaining the configuration of an optical fiber composite submarine cable, FIG. 3 is a cross-sectional view of the optical fiber unit, FIG. FIG. 5 is a schematic view showing a process of processing the extra connection length, and FIG.
The figure is a perspective view for explaining the arrangement of the polyethylene strings for the interposition and the wire increase. 1 ... optical fiber composite submarine cable, 2 ... power cable core, 8 ... optical fiber unit, 16 ... power cable core connection part, 17 ... extra connection length, 18 ... slack part.

Continuation of the front page (72) Inventor Kazuo Ohata 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Electric Wire Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) H02G 15/00-15 / 196

Claims (1)

(57) [Claims] 1. A connection structure for an optical fiber composite submarine cable in which a plurality of optical fiber units are arranged on the outer periphery of a power cable core, wherein the optical fiber unit has a predetermined extra length on the outer peripheral side of the connection portion of the power cable core. While being connected, the optical fiber units are divided into two groups for each predetermined number, and one of the optical fiber units is slackened at a position off one side in the axial direction with respect to the connection portion of the power cable core. And the other group of optical fiber units is provided with slack at a position off the other side in the axial direction with respect to the connection portion of the power cable core, and the slack portion of each group of optical fiber units is smoothly curved. A connection structure for an optical fiber composite submarine cable, which is arranged along the outer periphery of a power cable core.