JPH0590745U - Fiber optic cable - Google Patents

Abstract

(57) [Abstract] [Purpose] To have the characteristics of small diameter, light weight, high compressive force, and high allowable tension so that communication and control by electric signals can be performed. [Advantageous Effects] A tensile strength body is arranged in the center, a spacer is arranged outside the tensile strength body, and a plurality of storage grooves are formed in a spiral shape in the longitudinal direction on the outer peripheral surface of the spacer. A copper-coated steel wire is fitted into one or a plurality of storage grooves of an optical fiber cable in which a fiber core wire is stored.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an optical fiber cable that is thin and requires high tension, and more particularly to an optical fiber cable that is thin and has high tension and is capable of transmitting electrical signals.

[0002]

[Prior Art]

 Generally, an optical fiber has a significant difference in physical or mechanical characteristics compared to a conventional copper conductor, so a primary coating, a secondary coating, etc. are applied, and the mechanical characteristics and handling as an optical fiber core wire are performed. We are trying to improve ease. However, when making a cable, if a large external force such as lateral pressure is applied to the optical fiber core, a slight bending (micro-bending) will occur in the optical fiber, increasing the transmission loss. Therefore, consider the cable structure and manufacturing. There is a need to. Considering this point, there is a spacer type as the structure of the optical fiber cable. This spacer type fiber cable has a structure aiming at improving the mechanical properties of the cable, and especially for high reliability against lateral pressure.

Further, the optical fiber core wire is drawn from an electric furnace and spun in an optical fiber drawing device. However, in this state, the surface is easily scratched and the mechanical strength is weak. An optical fiber core wire is formed by coating a curable resin or the like.

Conventionally, the optical fiber cable in which the optical fiber core wires are gathered together has a configuration as shown in FIG. That is, the optical fiber cable 100 is provided with a tension member (tension member) 110 at the center thereof. A spacer 120 having a circular cross section is provided outside the strength member 110. On the outer peripheral surface of the spacer 120, a plurality of storage grooves 130 having a rectangular cross section (four in FIG. 4) are formed in a spiral shape in the longitudinal direction as shown in FIG. An optical fiber core wire 140 is inserted into each of the plurality of storage grooves 130. In this way, the outer side of the spacer 120 in which the optical fiber core wire 140 is inserted in the housing groove 130 is pressed and held by the winding tape 150, and the aluminum laminated polyethylene sheath 160 is further coated thereon.

The tensile strength member 110 has a function of supporting the tension applied to the optical fiber cable 100, and is made of a solid wire or a stranded wire. The aluminum laminated polyethylene sheath 160 is a conductive protective film for grounding the optical fiber cable 100, and the aluminum laminated polyethylene sheath 160 is usually connected to a connection box for grounding. When the optical fiber cable 100 configured as described above is required to have a small diameter and high tension, a steel wire is inserted into the empty storage groove 130 of the storage groove 130 of the spacer 120 in which the storage groove 130 is formed. A cable structure with a small diameter and large allowable tension is inserted by inserting a tensile strength member such as.

[0006]

[Problems to be solved by the device]

 However, in the conventional optical fiber cable, when there is a demand for communication or control by an electric signal, the spacer 120 in which the optical fiber core wire 140 and a tensile body such as a steel wire are inserted in the housing groove 130, In addition, a metal communication line and a control line must be added to form a composite structure that covers the outer layer, which results in problems that the diameter cannot be reduced, the cable weight increases, and the weight cannot be reduced. .

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to have characteristics of having a small diameter, a light weight, a high compression force, and a high allowable tension. , Is intended to provide an optical fiber cable capable of communication and control by electric signals.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the optical fiber cable of the present invention has a tensile strength member at the center, a spacer outside the tensile strength member, and a storage groove formed in a spiral shape on the outer peripheral surface of the spacer. An optical fiber cable in which a plurality of threads are formed and optical fiber core wires are housed in the plurality of housing grooves, and a copper-coated steel wire is fitted into one or more of the plurality of housing grooves. Is.

Then, it is preferable that the copper-coated steel wire is made of one having a conductivity of 20% IACS or more.

[0010]

[Action]

 A tensile strength member is arranged in the center, a spacer is arranged outside the tensile strength member, a plurality of storage grooves are formed in a spiral shape in the longitudinal direction on the outer peripheral surface of the spacer, and the optical fiber is placed in the plurality of storage grooves. Since the copper-clad steel wire is fitted in one or more of the multiple grooves of the optical fiber cable that contains the core wire, it has the characteristics of thin diameter, light weight, high compressive force, and high allowable tension. It can be used for communication and control by electric signals.

[0011]

【Example】

 Embodiments of the present invention will be described below. FIG. 1 shows an embodiment of an optical fiber cable according to the present invention.

In the figure, reference numeral 1 denotes an optical fiber cable, which is a spacer type fiber cable capable of improving the mechanical characteristics of the cable, and in particular, achieving high reliability against lateral pressure.

Reference numeral 2 denotes a tensile strength member (tension member), which is made of steel wire or steel stranded wire. The strength member 2 is for preventing the cable from being stretched by its own weight. In the optical fiber cable 1, a plurality of optical fiber core wires that constitute the optical fiber cable are made of a brittle material. If they are laid as they are, the cable will be stretched due to its own weight, and stress will be applied to the optical fiber core wires. The residual stress is the stress on the optical fiber core due to. The generation of this residual stress shortens the life of the optical fiber cable. A tensile strength member 2 made of steel wire or steel stranded wire is used so that such residual stress does not occur in the optical fiber cable.

Reference numeral 3 denotes a spacer, which accommodates a plurality of optical fiber core wires. The spacer 3 is extruded and coated on the strength member 2 so that the strength member 2 is located at the center. Polyethylene is generally used as the spacer 3, but the spacer 3 is not limited to polyethylene and can be made elastic by using urethane, rubber-based polymer material elastomer, or the like, and water such as PVC or ABS can be used. It can also be made of resin, which is a material that does not easily pass through, so that a side pressure protection effect on the optical fiber cable 1 can be obtained. The outer periphery of the spacer 3 is formed in a substantially circular shape.

A storage groove 4 is provided on the outer peripheral surface side of the spacer 3 in a spiral shape along the cable longitudinal direction (8 rows in FIG. 1, 4A to 4H). The storage groove 4 has a rectangular cross section.

Reference numeral 5 denotes an optical fiber core wire, which is formed by coating the optical fiber element wire with resin. As for this optical fiber core wire 5, the number of lines corresponding to the number of signals to be transmitted is 6 for the storage groove 4A, the storage groove 4B, the storage groove 4D, the storage groove 4E, the storage groove 4F, the storage groove 4H and the storage groove 4. It is stored in a place.

Reference numeral 6 denotes a copper-coated steel wire, which is stored in the storage groove 4C and the storage groove 4G in a bare state without an insulating coating. As shown in FIG. 2, the copper-coated steel wire 6 is formed by thickly and uniformly coating the outer surface of the steel wire 61 with copper by an electroplating method. The copper-coated steel wire 6 has a conductivity of 20% IACS or more.

The electrical conductivity (% IACS) of the copper-coated steel wire 6 is determined by the thickness of the coated copper relative to the wire diameter of the steel wire 61, as shown in FIG. That is, in FIG. 3, when the wire diameter of the steel wire 61 is 3.0 mm as an example, in order to obtain the conductivity of 20% IACS when the wire diameter is 3.0 mm, the thickness of the copper plating should be about 0. It is necessary to make it 0.1 mm. Further, in order to obtain the conductivity of 40% IACS using the steel wire 61 having the similar wire diameter, the thickness of the copper plating needs to be about 0.3 mm. The conductivity (% IACS) of the copper-coated steel wire 6 may be 20% IACS or more in consideration of the attenuation rate during signal transmission in order to obtain a communication control function by an electric signal.

When the optical fiber core wire 5 and the communication control copper-coated steel wire 6 are housed in the housing groove 4 of the spacer 3 in this way, the optical fiber core wire 5 and the communication control copper-coated steel wire housed in the housing groove 4 are stored. The push-up tape 7 is wound from above and pressed so that 6 and 6 do not jump out. Thereafter, an aluminum laminating tape is wrapped around it, and a laminating sheath (LAP) 8 covering an outer jacket (sheath) is further coated thereon to form the optical fiber cable 1.

[0020]

[Effect of the device]

 According to the present invention, since it is configured as described above, it has characteristics of having a small diameter, a light weight, a high pressure compressive force, and a high allowable tension, and it is possible to perform communication and control by electric signals.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an optical fiber cable according to the present invention.

FIG. 2 is a cross-sectional view showing the configuration of the copper-coated steel wire shown in FIG.

FIG. 3 is a diagram showing conductivity characteristics of the copper-coated steel wire shown in FIG. 2 depending on the coated copper thickness and the steel wire diameter.

FIG. 4 is a sectional view of a conventional optical fiber cable.

5 is a perspective view of the conventional optical fiber cable shown in FIG.

[Explanation of symbols]

1 …………………………………………………………………… Optical fiber cable 2 ………………………………………………………… … Strength member 3 ……………………………………………………………… Spacer 4 ………………………………………………………… …… Storing groove 5 ……………………………………………………………… Optical fiber core 6 …………………………………………… ……………… Copper coated steel wire 8 ……………………………………………………………… Laminated sheath

Claims (2)

[Scope of utility model registration request] 1. A tensile strength body is arranged at the center, a spacer is arranged outside the tensile strength body, and a plurality of storage grooves are formed spirally in the longitudinal direction on the outer peripheral surface of the spacer, and the plurality of storage grooves are formed. 2. An optical fiber cable in which an optical fiber core wire is housed in the optical fiber cable, wherein a copper-coated steel wire is fitted into one or a plurality of the housing grooves of the plurality of seats. 2. The optical fiber cable according to claim 1, wherein the copper-coated steel wire has a conductivity of 20% IACS or more.