JP2001318286A - Optical fiber cable and electric power-light combined line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable which facilitates the disclosing of optical fibers in wiring and is superior also in mechanical strength and an electric power-light combined line which facilitates the disclosing of optical fibers in wiring and is superior also in optical transmission characteristics. SOLUTION: The optical fiber cable 30 is obtained by coating optical fibers 31 and high tensile strength bodies 32 with a protective sheath 33, having notches 34 filled with a resin 35 which is different from the constituted resin of the sheath 33 along the longitudinal direction of the sheath 33. The electric power-light combined line is obtained by intertwisting the optical fiber cable 30 with an electric insulated wire or an electric power cable 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable in which an optical fiber core and a tensile member are covered with a protective sheath, and the optical fiber cable, an electric wire or a power cable (hereinafter referred to as "power line"). And a combined power / optical cable.

[0002]

2. Description of the Related Art Conventionally, there has been known a power / optical combined line in which a power line and an optical fiber cable are twisted. FIG.
Is a cross-sectional view showing an example of the power / optical combined line,
A power line 10 formed by coating a conductor 1 with a coating layer 2 and an optical fiber cable 20 are twisted. For the purpose of preventing local bending and deformation, an optical fiber cable 20 having a structure in which a high tensile strength wire 22 is attached to an optical fiber core wire 21 and covered collectively by a protective sheath 23 is widely used. .

When such a combined power / optical cable is erected and wired, the connection of the optical fiber cable 20, in particular, involves removing the protective sheath 23 with a nipper, a cutting knife or the like, and taking out the optical fiber core cable 21. However, the cutting edge of the nipper or the cutting knife may damage the optical fiber core wire 21 or cut the optical fiber core wire 21, so that the operation must be carefully performed and the wiring is not easy.

[0004]

Therefore, as shown in FIG. 1, a combined power / optical cable using an optical fiber cable 20 having a notch 24 formed along the longitudinal direction of a protective sheath 23 is also used. For example, JP-A-11-33957
No. 1). In the optical fiber cable 20 having such a notch 24, the notch 24 is cut into the tip of the notch 24 using a nipper, a cutting knife, or the like, and then the protective sheath 23 can be torn by hand along the notch 24. , The optical fiber 21 can be easily taken out.

However, due to the presence of the notch 24, the mechanical strength of the protective sheath 23 at the notch 24 is weakened, especially the resistance against lateral pressure is reduced, and depending on the state of twisting with the power line 10, the optical fiber core is 21 may degrade the optical transmission characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an optical fiber cable which can easily take out an optical fiber core at the time of wiring and has excellent mechanical strength. It is an object of the present invention to provide a power / optical composite line that is easy to take out an optical fiber core at the time of wiring by twisting a fiber cable and a power line, and has excellent optical transmission characteristics.

[0007]

According to a first aspect of the present invention, there is provided an optical fiber cable, wherein the protective sheath covering the optical fiber core and the strength member has a notch along a longitudinal direction thereof. And a resin different from the resin forming the protective sheath in the notch. This makes it possible to compensate for the decrease in the mechanical strength of the notch while securing the ease of taking out the optical fiber core by the notch.

The optical fiber cable according to claim 2 is characterized in that the resin filled in the notch is a resin having a lower hardness than the resin forming the protective sheath. This makes it easier to tear the protective sheath along the notch.

The optical fiber cable according to claim 3 is characterized in that the resin filled in the notch is a resin having a higher hardness than the resin forming the protective sheath. Thereby, the mechanical strength of the notch portion can be further increased as compared with the case where there is no notch.

According to a fourth aspect of the present invention, the resin filled in the notch contains a coloring agent. This makes it possible to visually identify each optical fiber cable, which is particularly effective for a power / optical composite line in which a plurality of optical fiber cables are twisted with a power line.

[0011] The combined power and optical line according to claim 5 is:
The optical fiber cable according to any one of the above and a power line are twisted. As a result, it is possible to obtain a power / optical composite cable including an optical fiber cable that is easy to take out the optical fiber core wire, has excellent mechanical strength, and can be visually identified.

A combined power / optical cable according to a sixth aspect of the present invention is characterized in that the power line and the optical fiber cable are collectively covered with an outer sheath via an interposition in a state where both are twisted.
This facilitates storage, installation, and wiring, and absorbs external force by the outer cover, so that the power line and the optical fiber cable are protected, and the twisted state of both can be kept extremely stable.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of the optical fiber cable according to the present invention,
As shown, the fiber optic cable 30 is
The two optical fibers 31 are arranged close to each other, two strength members 32 are arranged on both sides thereof at a predetermined distance from each other, and the whole is covered with a protective sheath 33 at a time, and the outer peripheral surface of the protective sheath 33 is further covered. Has a notch 34 formed along the longitudinal direction of the cable. The notch 34 has a substantially V-shaped cross section, and is positioned such that the top thereof is directed to the center of the interval between the two optical fiber core wires 31. Due to the formation of the notch 34, the protective sheath 33 can be subsequently torn by, for example, a hand if a notch is made in the tip using a nipper or a cutting knife, and the optical fiber core 31 is exposed at the same time as the tearing. Can be done. Thereby, workability at the time of wiring is remarkably improved.
The notch 34 is formed of a resin 35 (hereinafter, referred to as a resin 35).
(Referred to as “filling resin”). In addition, this notch 3
The width and depth of 4 are not particularly limited, and are appropriately set in consideration of the diameter of the protective sheath 33 and the diameter of the optical fiber 31 so as to be easily torn by hand.

The filling resin 35 is not particularly limited as long as it is different from the resin forming the protective sheath 33. However, by selecting a resin having lower hardness than the resin forming the protective sheath 33 as the filling resin 35, the protective sheath 33 can be more easily torn along the notch. Various foamed resins such as foamed polyethylene can be suitably used as such a low-hardness resin. Further, by selecting a resin having higher hardness than the resin forming the protective sheath 33 as the filling resin 35, the mechanical strength of the notch 34 can be further increased as compared with the case where the notch 34 is not provided. . As such a resin having high hardness, for example, nylon or the like can be suitably used. Since the high-hardness resin is not integrated with the resin forming the protective sheath 33 when cured, the high-hardness resin can be easily separated from the notch 34 by a cutter knife or the like.

Further, an appropriate coloring agent may be added to each of the filling resins 35 described above. This makes it possible to visually identify the optical fiber cable 30. For example, in a power / optical combined line in which a plurality of optical fiber cables 30 are twisted with a power line, the optical fiber cable 3 for wiring is used.
0 can be easily identified.

The above-mentioned optical fiber cable 30 can be manufactured by using, for example, an apparatus shown in FIG. That is,
The optical fiber core 31 and the tensile strength member 32 are continuously sent out from the supply drum 41 and aligned by the aligning roller 41 so that the tensile strength members 32 are positioned on both sides of the two optical fiber cores 31 as shown in FIG. Then, while maintaining the aligned state, the extruder 42 sends the extruder 42 to extrude the protective sheath material, and collectively coats the protective sheath 33 with the notch 34 formed therein. In addition, this extruder 4
2 includes an extrusion die having a circular cross section having a projection corresponding to the notch 34. Next, the extruder 43 protects the protective sheath 3
The filling resin 35 is filled in the third notch 34. Then, after the protective sheath material and the filling resin 35 are cured in the curing furnace 44, they are wound up by the winding drum 46 through the cooling furnace 45. Thus, the optical fiber cable 30 of the present invention can be obtained only by adding the extruder 43 for the filling resin to the conventional production line.

The present invention also provides a combined power / optical cable in which the optical fiber cable 30 and the power cable are twisted. FIG. 3 is a cross-sectional view showing one embodiment of the present invention. As shown, three known power lines 10 and one optical fiber cable 30 are used, and outer peripheral surfaces of two power lines 10 are shown. The optical fiber cable 30 is twisted so as to be placed thereon. Since the optical fiber cable 30 has the notch 34, it is easy to take out the optical fiber core 31 at the time of wiring, and since the notch 34 is filled with the filling resin 35, The optical transmission loss does not increase even when twisted with the power line 10 because of its high mechanical strength.

Various modifications can be made to the optical fiber cable 30 and the combined power / optical cable of the present invention. Hereinafter, preferred embodiments will be exemplified.

The protective sheath 33 of the optical fiber cable 30
May have an elliptical or flat shape in addition to a circular shape. That is, as shown in FIG. 4, an optical fiber cable 30 having a cross-sectional shape having, on the outer peripheral surface of a protective sheath 33, a flat portion 33a substantially parallel to a plane in which the optical fiber core wire 31 and the tensile strength member 32 are aligned. Can be. The notch 34 is formed on the flat portion 33a along the central portion of the two optical fiber core wires 31, and the filling resin 35 is similarly filled. By using this optical fiber cable 30, when the optical fiber cable 30 and the power line 10 are twisted, the flat portion 33a of the optical fiber cable 30 and the outer peripheral surface of the power line 10 come into contact with each other, and the cylindrical shape is formed. As compared with the case where an optical fiber cable is used, the optical fiber cable 30 can be prevented from protruding or falling out of the core of the power line 10 due to bending, and the characteristic deterioration due to twisting of the optical fiber cable 30 can be prevented. Become like

When the amount of transmitted information is relatively small,
Alternatively, when wiring is performed in a place where external force is relatively low, the optical fiber cable 30 in which the number of the optical fiber core wires 31 and the tensile strength members 32 is reduced while also reducing costs,
In addition, an electric power / optical combined line can be used. For example, as shown in FIG. 5, an optical fiber cable 30 in which one optical fiber core 31 and one strength member 32 are covered with a protective sheath 33, and a power / optical composite wire in which this is twisted with the power line 10. Can be exemplified. The notch 34 is formed along the center of the optical fiber 31 and the strength member 32, and is filled with the filling resin 35 in the same manner. Further, as shown in FIG. 6, a power / optical composite line obtained by twisting one optical fiber cable 30 and two power lines 10 may be used.
As a result, it is possible to save space by reducing the finished outer diameter of the power / optical combined line. Notch 3
4 is formed along the central portion of the two optical fiber core wires 31 and is similarly filled with the filling resin 35.

Further, as shown in FIG. 7, the power / optical composite line can be covered with an outer sheath 39 via an interposition 38 in a state where the power line 10 and the optical fiber cable 30 are twisted. This facilitates storage, installation and wiring. In addition, since external force is absorbed by the outer cover 39 and external force is less likely to be applied to the contact surface between the power line 10 and the optical fiber cable 30, the power line 10 and the optical fiber cable 30 are protected, and the twisted state of both is extremely stabilized. Can be kept.

In addition, any known materials such as the conductor 1, the power line coating layer 2, the optical fiber core 31, the tensile strength member 32, the protective sheath 33, the interposition 38, and the outer cover 39 shown in each of the above-described embodiments can be used. They can be used, and their shapes, dimensions, forms, numbers, locations, and the like are arbitrary and are not limited as long as the present invention can be achieved. In addition, the filler resin 35 may contain an appropriate filler in addition to the colorant.

[0023]

As described above, the optical fiber cable of the present invention has a notch along the longitudinal direction of the protective sheath, and the notch is filled with a resin different from the resin forming the protective sheath. The optical fiber core can be easily taken out, and a decrease in mechanical strength due to the presence of the notch can be suppressed. In addition, such a combined power / optical cable in which an optical fiber cable and a power line are twisted also makes it easy to take out the optical fiber core wire and has excellent optical transmission characteristics.

[Brief description of the drawings]

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

FIG. 2 is a schematic view showing a configuration of an apparatus for manufacturing an optical fiber cable according to the present invention.

FIG. 3 is a cross-sectional view showing one embodiment of a combined power / optical line according to the present invention.

FIG. 4 is a cross-sectional view showing another embodiment of the combined power / optical line according to the present invention.

FIG. 5 is a cross-sectional view showing still another embodiment of the combined power / optical cable according to the present invention.

FIG. 6 is a cross-sectional view showing still another embodiment of the combined power / optical cable according to the present invention.

FIG. 7 is a sectional view showing still another embodiment of the combined power / optical cable according to the present invention.

FIG. 8 is a sectional view showing a conventional power / optical combined line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor 2 Power line coating layer 10 Power line 30 Optical fiber cable 31 Optical fiber core 32 Strength member 33 Protective sheath 34 Notch 35 Filled resin

Claims (6)

[Claims] 1. An optical fiber cable comprising an optical fiber core and a strength member covered with a protective sheath, wherein the protective sheath has a notch along a longitudinal direction thereof, and the protective sheath is formed in the notch. An optical fiber cable characterized by being filled with a resin different from the resin. 2. The optical fiber cable according to claim 1, wherein the resin filled in the notch has a lower hardness than the resin forming the protective sheath. 3. The optical fiber cable according to claim 1, wherein the resin filling the notch is a resin having a higher hardness than the resin forming the protective sheath. 4. The optical fiber cable according to claim 1, wherein the resin filled in the notch contains a coloring agent. 5. A combined power / optical cable comprising the optical fiber cable according to claim 1 and an insulated wire or a power cable. 6. The power line and the optical fiber cable,
6. The power / optical composite wire according to claim 5, wherein the two wires are collectively covered with an outer skin via an intervening state in a state where both are twisted.