JPH0524098Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a composite power cable in which optical cables are collectively twisted.

(Prior Art) Generally, the connecting portion of an optical cable tends to be larger because it includes the extra length of the optical fiber core wire. For example, in order to prevent static fatigue caused by bending an optical fiber core wire with a diameter of 125 μm and to keep the strain to 0.18% or less, it is usually necessary to maintain an extra length with a curvature of 40 mm. In the prior art, in order to maintain this extra length, a disk-shaped structure with a radius of 40 mm is provided at the connection part, and the optical fiber core wire is wound along the outer peripheral surface of this structure.

However, in this structure, in order to accommodate the extra length of the optical fiber core, it is necessary to have enough extra length of the optical fiber core to wrap it around the disk at least once, and the minimum length is 2 x π x 40 mm≒ 240mm (24
cm).

Therefore, the diameter of the connecting portion of the optical cable becomes 100 mm or more due to this disc-shaped structure.
As the connection part of the optical cable becomes larger in this way,
Not only does it lose flexibility, but when combined with a submarine power cable, it becomes difficult to manufacture a composite power cable that includes an optical cable connection. For this reason, in the past, the total length of the composite power cable was controlled by the length of the optical cable, making it difficult to lengthen the composite power cable.

(Purpose of the invention) The purpose of the invention is to provide a composite power cable that can include an optical cable having a connection part and can easily make extra length of the optical fiber core wire in this connection part. be.

(Structure of the invention) The composite power cable of the invention includes a cable core including a central tension member and a plurality of optical fiber core wires provided around the center tension member, and a sheath provided on the cable core. The optical cable is formed by collectively twisting the optical cable with the power cable core, and the optical cable is provided across the connecting part of the central tension member of the two optical cable parts, the connecting part of the optical fiber core wire, and the sheath of the two optical cable parts. It includes a connecting part consisting of an externally reinforcing pipe and a plurality of guides having an outer diameter slightly smaller than the internal diameter of the externally reinforcing pipe and through which the central tension member passes, and the optical fiber core wire in the connecting part is provided on the outer periphery of the guide. It is characterized by passing through the notch with a slack.

Without using a disc-shaped structure that increases the diameter of the connection part, the notch in the guide through which the optical fiber core wire passes can be slackened and the excess length can be stored in a nearly straight state, making it easy to connect optical cables. Since the outer diameter of the part is extremely small and does not impair its flexibility, an optical cable with a connection part can be inserted into the composite power cable, and the excess length of the optical fiber core wire can be cut into the guide. Since the notch is passed through and accommodated with a slack, the extra length can be made extremely small compared to the conventional case of winding around a disc-shaped structure, and the extra length can be easily removed.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a composite power cable 10 according to the present invention. The composite power cable 10 is an assembly 1 having a power cable core 12 including, for example, three power lines and an optical cable 14 bundled and twisted together.
6, a sheath 18 placed thereon, an iron wire armor 20 provided thereon, and an outer protective layer 22.

Optical cable 14 is shown in detail in FIG. 2 and includes a connection 24 of two optical cable sections 14A, 14B. The two optical cable sections 1 to be connected by this connection 24
4A and 14B have a cable core 30 including a central tension member 26 and a plurality of optical fiber cores 28 twisted around the central tension member 26, and a sheath 32 provided on the cable core 30. Although the cable core 30 is not shown, the tension member 26 and the optical fiber core 28
The twisted body is wrapped with a core wrap, and a wrapping sheath is provided on top of the core wrap.

The connecting portion 24 of the optical cable 14 is formed by connecting the center tension members 26 of the two optical cable portions 14A and 14B with a connecting sleeve, and fusion splicing the optical fiber core wire 28 to the connecting portion 26a, and then placing a transparent sleeve on top of the connecting portion 26a. An aluminum external reinforcing pipe 34 is provided over the connecting portion 28a and the sheath 32 of these two optical cables, and an external reinforcing pipe 34 and the sheath 32 are provided on the outer periphery of this external reinforcing pipe 34. It consists of a heat-shrinkable tube 36 that closes the gap between the outer reinforcing pipe 34 and a plurality of guides 38 having an outer diameter slightly smaller than the inner diameter of the external reinforcing pipe 34, through which the central tension member 26 penetrates and determines the center of the optical fiber core wire. 28 passes through a notch 38a provided on the outer periphery of the guide 38 as shown in FIG. It has an extra length of slack. When fusion splicing optical fibers, there is a difference in length of about 1 cm, so for optical cables with 10 fibers or less, an extra length of about 1 cm is sufficient, but when inserting this into a composite power cable If the outer diameter of the composite power cable is 10 cm or less, an extra length of about 2 cm is usually sufficient. Therefore, if the length of the connecting portion 24 is 660 mm, the extra length may be about 3 cm. This corresponds to about 5% of the length of the connecting portion, and therefore, the appropriate extra length is 5% or less of the length of the connecting portion.
Incidentally, it is preferable that a ring 40 is attached to the outer periphery of the guide 38 in order to maintain the extra length of the optical fiber core wire 28 within the notch 38a.

In this way, the external reinforcing pipe 34 is connected to the optical cable 1.
Since it is directly covered with the sheath 32 of the optical cables 14A and 14B, the outer diameter of the connecting portion 24 is the same as that of the optical cables 14A and 1.
Since it has almost the same diameter as 4B, the connection part 24 does not become large, and the optical cables 14A and 14B
has approximately the same flexibility as the optical cable 14.
can be collectively twisted together with the power cable core 16.

In a specific embodiment of the present invention, the outer diameter of the optical cable used in the composite power cable was about 11 mm, the inner diameter of the external reinforcing pipe was about 12.5 mm, and the outer diameter of the guide was 7 mm. When the extra length of the optical fiber core wire was set to 5% of the length of the connection part, the increase in transmission loss due to bending and tension of the optical cable was OdB.

(Effects of the invention) According to the invention, as described above, the optical cable connection part to be inserted into the composite power cable does not increase in size and is flexible, so that the optical cable having this connection part can be used. It is possible to increase the length of the composite power cable included in the optical fiber cable, and there is a practical benefit that the extra length of the optical fiber core wire in the connection part of the optical cable can be small and that the extra length of the optical fiber core wire can be easily removed.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the composite power cable according to the present invention, Figure 2 is a vertical cross-sectional view of the connection part of the optical cable used in the present invention, and Figure 3 is an enlarged front view of the guide used in the present invention. be. 10...Composite power cable, 12...Power line, 14...Optical cable, 16...Aggregation, 24
... Connection part, 14A, 14B ... Optical cable, 2
6... Central tension member, 26a... Connection portion of the center tension member, 28... Optical fiber core wire, 28a... Connection portion of the optical fiber core wire, 30... Cable core, 32... Sheath,
34... External reinforcement pipe, 38... Guide, 38
a... Notch.

Claims (1)

[Claims for Utility Model Registration] (1) An optical fiber having a cable core including a central tension member and a plurality of optical fiber cores provided along the circumference thereof, and a sheath provided on the cable core. In a composite power cable in which fibers are collectively twisted together with a power cable core, the optical cable is provided across a connecting part of a central tension member of two optical cable parts, a connecting part of an optical fiber core wire, and a sheath of the two optical cable parts. a plurality of guides having outer diameters slightly smaller than the inner diameter of the outer reinforcing pipes and through which the central tension member passes; A composite power cable characterized by passing through a notch provided on the outer periphery of the cable with a slack. (2) The composite power cable according to claim 1, wherein the slack of the optical fiber core wire is an extra length of 5% or less of the length of the connecting portion.