JPH1160286A - Optical fiber core resistant to tension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tension-resistant optical fiber core having characteristics hardly extended by the tension and easy in curvature and enabling to contrive a small diameter. SOLUTION: This tension-resistant optical fiber core is provided by forming tension-resistant coating layers 2a, 2b on the outer periphery of an optical fiber core 1 comprising an optical fiber 11 and a protecting coating 12. The tension-resistant coating layer is formed by burying long high tension fibers using glass fibers, carbon fibers or aramid fibers in a flexible resin selected from thermosetting resins such as urethane resins, UV light-curable resins, thermoplastic resins such as polyvinyl chloride, and the like in an integrated state. The high tension fibers are buried by embedding long fibers surrounding the periphery of the optical fiber core and continued in the longitudinal direction or many short fibers continued in the longitudinal direction in a mutually interlaced state 10 the resin. When the surface property of the tension-resistant coating layer is tacky, the tension-resistant coating layer is covered with a thermoplastic resin to improve the handling workability of the optical fiber core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension-resistant optical fiber used for connection or wiring between optical transmission devices, for example.

[0002]

2. Description of the Related Art Conventionally, an optical fiber cord D as shown in FIG. The structure of the optical fiber cord D is such that the optical fiber 11 is provided with a protective coating 12 on the optical fiber core 1.
A high-tensile fiber bundle 102 that is continuous in the longitudinal direction is arranged in a ring shape so as to surround the periphery of the bundle, and the outer periphery of the high-tensile fiber bundle 102 is extruded using polyvinyl chloride (PVC) to form a pipe. The coating 103 is provided. That is, while the tensile strength is exhibited by the annular high-tensile fiber bundle 102, the pipe-shaped coating 10 made of polyvinyl chloride is used.
3, while forming a protective coating capable of exhibiting flexibility, the high-tensile fiber bundle 102 is held so as not to move due to external force (such as bending). For this reason, the pipe-shaped coating 103 is relatively thick, and the outer diameter of the optical fiber cord D currently used is formed by the annular high-tensile fiber bundle 102 and the pipe-shaped coating 103 as described above. 2 mm.

[0003]

By the way, in recent years, the demand for optical transmission has been increasing, and the intra-office wiring for connecting and wiring optical transmission equipments tends to be overcrowded, so that thousands of optical fiber cores are wired. There is a need. However, if the above-mentioned optical fiber cord D is used to perform intra-office wiring in response to this request, the outer diameter of one optical fiber cord D becomes 2
However, when the number of optical fiber cords is several thousand as described above, the bundle of the optical fiber cords D alone becomes a mountain-like volume, which is hindering intra-office wiring.

[0004] Therefore, it is necessary to reduce the diameter of the tensile strength optical fiber core while securing the tensile strength. On the other hand, it is only necessary to reduce the diameter by using a material or a material exhibiting high strength against tension. However, if the optical transmission equipment is too hard to bend at all, or if it is difficult to bend, the connection work of the optical transmission equipment becomes impossible or difficult.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a tension-resistant light capable of reducing the diameter while being hardly stretched and easily bent in tension. It is to provide a fiber core.

[0006]

According to a first aspect of the present invention, there is provided an optical fiber formed of a flexible resin containing a high-tensile fiber and a flexible resin. And a tension-resistant coating layer covering the periphery of the core wire.

[0007] In the case of the above structure, the tensile strength coating layer covering the outer periphery of the optical fiber core wire contains high-tensile fibers, so that it exhibits tensile strength. Since it is integrated in a state embedded in the fiber, it is possible to reduce the diameter while having the same tensile strength as compared to the conventional annular high-tensile fiber bundle and the optical fiber cord coated with pipe-like coating Become. In addition, since the tension-resistant coating layer is formed of a flexible resin, it is easy to bend and the connection operation of the optical transmission device can be performed well.

According to a second aspect of the present invention, the high-tensile fiber according to the first aspect of the present invention is arranged such that a long one surrounds an optical fiber core and continuously extends along the optical fiber core. It is configured to be embedded in the tensile strength coating layer.

In the above configuration, the long high-tensile fiber surrounds the optical fiber core wire and is continuously arranged in the longitudinal direction, and the long high-tensile fiber is placed in the tension-resistant coating layer. Since it is embedded and firmly integrated, the diameter can be reduced while exhibiting excellent tensile strength.

According to a third aspect of the present invention, the high tensile strength fiber of the first aspect of the present invention is provided in the tension-resistant coating layer such that the short fibers are continuous with each other in the longitudinal direction of the optical fiber in a state where the short fibers are tangled with each other. It is configured to be embedded in the.

In the above configuration, the short high-tensile fibers are continuous with each other in the longitudinal direction of the optical fiber in a state where they are entangled with each other, and are embedded and integrated in the tension-resistant coating layer in that state. Therefore, even in a mode different from that of the second aspect, the diameter can be reduced while exhibiting excellent tensile strength.

According to a fourth aspect of the present invention, in the first aspect of the invention, the periphery of the tensile strength coating layer is covered with a thin resin outer skin.

In the case of the above construction, since the tension-resistant coating layer is further covered with a resin outer cover, the handling workability of the connection operation is improved regardless of the surface properties of the tension-resistant coating layer. There is no loss.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, the tension-resistant coating layer is formed of a thermosetting resin, and the outer skin is formed of a thermoplastic resin.

In the case of the above construction, even if the tension-resistant coating layer has a relatively low viscosity and its surface is sticky, it is covered with the outer skin and does not impair the handling workability. The outer skin can be easily formed of a thermoplastic resin.

The high-tension fiber according to the first aspect of the present invention may be a glass fiber, a carbon fiber,
Any one of a composite fiber of a glass fiber and a carbon fiber may be adopted (Claim 6), and a thermosetting resin (Claim 7) or a thermoplastic resin is used as a resin for forming the tensile strength coating layer. (Claim 8) may be adopted. Here, any of urethane resin, epoxy resin, and unsaturated polyester resin may be used as the thermosetting resin, and any of polyvinyl chloride, polyester elastomer, polyaramid, and polyethylene may be used as the thermoplastic resin. .

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 1 shows a tension-resistant optical fiber core wire F according to a first embodiment of the present invention, wherein 1 is an optical fiber core wire, and 2a is a tension-resistant coating layer containing a high-tensile fiber. , 3
Is the hull.

The optical fiber core 1 is formed by covering an optical fiber 11 having a small diameter (for example, 0.125 μm) with an ultraviolet curing resin (UV resin).

The tension-resistant coating layer 2a is formed of a flexible thermosetting resin containing high-tensile fibers so as to have a predetermined tensile modulus and bending rigidity. Examples of the high-tension fiber include glass fibers such as alkali glass roping or high-strength glass roping (T glass) for electrical insulation, carbon fibers such as carbon fiber, and the like.
Any of aramid fibers such as Kevlar (trade name of DuPont) or a composite of two or more selected from these various fibers may be used. On the other hand, a predetermined amount is contained.

As the thermosetting resin, any one of a urethane resin, an epoxy resin, an unsaturated polyester resin and the like is adopted, and the one having an elongation amount, strength and hardness not less than a predetermined value is used. At the product stage of the core wire, it should exhibit flexibility to realize a predetermined bendability.

The outer shell 3 is made of a relatively thin material using a thermoplastic resin such as polyvinyl chloride, polyester elastomer, or polyaramid. Preferably, the thermoplastic resin has an elongation amount, strength and hardness not less than a predetermined value.

Next, a method of manufacturing the above-mentioned tensile strength optical fiber core wire will be described. First, an optical fiber 11 is drawn from a preform of an optical fiber by a known method. The optical fiber core 1 coated with the coating 12 is obtained by curing through a filled die.

Then, a tension-resistant coating layer 2a is formed around the optical fiber core wire 1. The formation of the tension-resistant coating layer 2a can be roughly classified into a method using a die using a liquid resin and a method using extrusion molding. Further, in each method, the method of adding the high tension fiber is different depending on the mode of the high tension fiber.

FIG. 2 shows that the high-tensile fibers 21, 21,... Surround the outer periphery of the optical fiber core 1, and the high-tensile fibers 21, 21,. A method of manufacturing using the die 4 will be described for a case where the semiconductor device is continuously embedded in the tensile strength coating layer 2a. In this case, a number of long high-tension fibers 21, 21,... Are arranged in parallel around the outer periphery of the optical fiber 1, and the optical fiber 1 and the high-tension core 21 in this state are arranged. ,
Are passed through the die hole 41 of the die 4. Then, while the liquid thermosetting resin 22 is supplied to the pool portion 42 of the die 4 at a predetermined supply pressure, the optical fiber core wire 1 and the high tension core wires 21, 21,. The vehicle is caused to travel downward in FIG. 2 at a predetermined traveling speed. After passing through the die 4, it is heated by a heater (not shown) while running, so that the large number of long high-tensile fibers 21, 21, 21.
Are hardened in a state where... Are embedded therein. After the tension-resistant coating layer 2a is cured, the outer cover 3 is formed by extrusion molding or a die using a thermoplastic resin.

FIG. 3 shows short high-tensile fibers 23 and 2.
In the case where 3,... Are entangled with each other and are continuously embedded in the tensile strength coating layer 2 a in the longitudinal direction of the optical fiber core wire 1, a method of manufacturing using the die 4 in the same manner as described above. Show. In this case, short high-tensile fibers 23, 23,... Cut to a predetermined size are mixed into a thermosetting resin so as to have a predetermined content, and the short high-tensile fibers 23, 23,. And the mixture is stirred so as to be entangled with each other to prepare the high-tensile fiber-containing resin 24 in advance. Then, the optical fiber core wire 1 is caused to run at a predetermined speed through the die hole 41 while supplying the high-tensile fiber-containing resin 24 to the pool part 42 of the die 4 at a predetermined supply pressure. Thereafter, curing is performed by the heater in the same manner as described above, and after curing, the outer skin 3 is formed in the same manner as described above.

The tension-resistant optical fiber cores F formed as described above are elongated in the tension-resistant coating layer 2a and are continuous with each other in the longitudinal direction. Short high-tensile fiber 2 continuous in the longitudinal direction
Are firmly integrated with the resin forming the tension-resistant coating layer 2a, so that the tension-resistant coating layer 2a itself has a considerably large tensile strength in the longitudinal direction of the optical fiber core 1. This makes it possible to withstand a force, and it is difficult to extend in the longitudinal direction even when a tensile force acts. Therefore, it is possible to reduce the diameter (for example, to an outer diameter of about 1 mm) while having the same tensile strength as that of the conventional optical fiber cord D. In addition, since the tension-resistant coating layer 2a is formed of a resin having flexibility, it is easy to bend, and the connection operation of the optical transmission device can be performed satisfactorily.

Further, even if the tension-resistant coating layer 2a formed of the above-mentioned thermosetting resin has a relatively low viscosity and the surface properties are sticky even after curing, it is covered by the outer skin 3. Therefore, the workability of the connection work is not impaired, and the shape of the tension-resistant coating layer 2a is maintained. Further, since the outer skin 3 is formed using a thermoplastic resin, the outer skin 3 can be easily formed.

<Second Embodiment> FIG. 4 shows a second embodiment. In the second embodiment, the optical fiber core 1 and the tension-resistant coating layer are structurally formed without forming the outer sheath 3 of the first embodiment. 2a
Or 2b constitutes a tension-resistant optical fiber core wire F. The second embodiment is different from the first embodiment in that the tension-resistant coating layer 2a is formed using a thermosetting resin as in the first embodiment (part 1). There are two types, one in which the tensile strength coating layer 2b is formed using a resin (No. 2). Note that the optical fiber core 1 itself is the same as in the first embodiment, and a description thereof will be omitted.

(Part 1) When the tension-resistant coating layer 2a is formed of a thermosetting resin, the same thermosetting resin and high-tensile fiber as those in the first embodiment are used, and the manufacturing method is the same as that of the first embodiment. As in the case of the embodiment, it may be manufactured using the long high-tensile fiber 21 or the short high-tensile fiber 23 (see FIG. 2 or FIG. 3).

(Part 2) When the tension-resistant coating layer 2b is formed of a thermoplastic resin, the above-mentioned resistance is adjusted so that the thermoplastic resin containing high-tensile fibers and having flexibility has a predetermined tensile modulus and bending rigidity. The tension coating layer 2b is formed. The high-tension fibers in this case include, as in the first embodiment, glass fibers such as alkali glass roping for electrical insulation or high-strength glass roping (T glass), carbon fibers such as carbon fibers, and Kevlar. Any of aramid fibers or a composite of two or more selected from these various fibers may be employed, and the employed high-tensile fibers are contained in the thermoplastic resin in a predetermined amount.

As the above-mentioned thermoplastic resin, any one of polyvinyl chloride, polyester elastomer, polyethylene, polyaramid, etc., preferably polyvinyl chloride or polyester elastomer is employed, and the elongation, strength and hardness of which are not less than predetermined values are employed. In particular, it is assumed that a material having a flexibility that can realize a predetermined bendability at the product stage of a high-strength optical fiber is used.

The method of manufacturing the above-mentioned tension-resistant optical fiber core will be described. First, an optical fiber core 1 is obtained by the same method as in the first embodiment, and then this optical fiber core 1 is obtained.
A tensile strength coating layer 2b is formed around the outside. As in the case of the first embodiment, the formation of the high-strength coating layer 2b includes a method using a die and a method using extrusion molding. A method of molding a thermoplastic resin in a molten state in a state where the fibers 21 are arranged around the optical fiber core wire 1, a method of using a resin in which short high-tensile fibers are previously mixed in the thermoplastic resin, and There are two ways. In general, extrusion molding is preferable to form the tensile strength coating layer 2b using a thermoplastic resin. However, when a method using a die 4 is adopted, for example, the die 4 itself is heated to remove the thermoplastic resin. What is necessary is just to make it into a molten state.

In the case of "Part 2" of the second embodiment, since the tensile strength coating layer 2b of the tensile strength optical fiber F is formed using a thermoplastic resin, the workability is good and the manufacturing is easy. Can be performed.

<Other Embodiments> The present invention relates to the first embodiment.
The present invention is not limited to the second embodiment, and includes various other embodiments. For example, an aramid fiber may be used as the high-tensile fiber, and a UV resin may be used as the resin for forming the tensile-resistant coating layer, and the tensile-resistant coating layer may be formed by the manufacturing method described in the first embodiment.

[0036]

As described above, according to the tension-resistant optical fiber according to the first aspect of the present invention, the high-tensile fiber covering the outer periphery of the optical fiber is embedded in the tension-resistant coating layer. Since they are integrated in a state, the diameter can be reduced while having the same tensile strength as that of the conventional optical fiber cord, and the tension-resistant coating layer is formed of a flexible resin. Therefore, it is possible to provide a characteristic that is easily bent, and to provide a material suitable for use in intra-office wiring, which is becoming more and more dense.

According to the second aspect of the present invention, the long high-tensile fibers surrounding the optical fiber core and continuously arranged in the longitudinal direction thereof are embedded in the high-strength coating layer and firmly integrated. Therefore, the diameter can be reduced while exhibiting excellent tensile strength, and the effect of the first aspect can be more reliably obtained.

According to the third aspect of the present invention, the short high-tensile fibers continuous in the longitudinal direction of the optical fiber in a state of being entangled with each other are embedded and integrated in the high-strength coating layer. Thus, the diameter can be reduced while exhibiting excellent tensile strength, and the effect of the first aspect can be more reliably obtained.

According to the fourth aspect of the present invention, since the tension-resistant coating layer is further covered with the resin outer cover,
Whatever the surface properties of the tensile strength coating layer, the workability of the connection work is not impaired, and in particular, according to the invention of claim 5, the tensile strength coating layer has a relatively high viscosity. Even if the surface is low and the surface properties are sticky, it is covered by the outer skin without impairing the handling workability, and moreover, the outer skin can be easily formed of thermoplastic resin. Become.

Furthermore, according to any one of the sixth, seventh and eighth aspects of the present invention, the components of the tensile strength coating layer according to the first aspect of the present invention are specified more specifically. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional view illustrating a method for manufacturing a tensile strength coating layer according to the first embodiment.

FIG. 3 is an explanatory sectional view showing a manufacturing method different from that of FIG. 2 for the tensile strength coating layer in the first embodiment.

FIG. 4 is a sectional view showing a second embodiment.

FIG. 5 is a cross-sectional view showing an optical fiber cord which is a conventional tension-resistant optical fiber core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber core wire 2a, 2b Tensile coating layer 3 Outer skin 21 Long high-tensile fiber 23 Short high-tensile fiber F Tensile-resistant optical fiber core

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Higashikubo 4-3 Ikejiri, Itami-shi, Hyogo Mitsubishi Electric Cable Industry Co., Ltd. Itami Works

Claims (8)

[Claims] 1. An optical fiber core comprising: an optical fiber core; and a tension-resistant coating layer formed of a flexible resin containing high-tensile fibers and covering the optical fiber core. Tensile strength optical fiber cable. 2. The high-tension fiber according to claim 1, wherein the high-tensile fiber is embedded in the high-strength coating layer so that a long one surrounds the optical fiber core and continuously extends along the optical fiber core. A tensile strength optical fiber core wire. 3. The high-tension fiber according to claim 1, wherein the short fibers are embedded in the high-strength coating layer so that the short fibers are intertwined with each other in the longitudinal direction of the optical fiber. Tensile strength optical fiber cable. 4. The tension-resistant optical fiber core according to claim 1, wherein the periphery of the tension-resistant coating layer is covered with a thin resin sheath. 5. The tensile-strength optical fiber according to claim 4, wherein the tensile-strength coating layer is formed of a thermosetting resin, and the outer skin is formed of a thermoplastic resin. 6. The high-strength optical fiber core according to claim 1, wherein the high-tension fiber is one of glass fiber, carbon fiber, and composite fiber of glass fiber and carbon fiber. line. 7. The high-strength optical fiber according to claim 1, wherein the high-strength coating layer is formed of a thermosetting resin. 8. The tension-resistant optical fiber core wire according to claim 1, wherein the tension-resistant coating layer is formed of a thermoplastic resin.