JPS62286005A - Optical fiber cable - Google Patents

Abstract

PURPOSE:To prevent adjacent tension resisting bodies from applying a lateral pressure to optical fibers by fixing a central tension resisting body, optical fibers twisted together around the central tension resisting body or optical fiber strands, and tension resisting bodies into one body with a thermosetting of ultraviolet ray hardened resin. CONSTITUTION:Optical fibers 2 and tension resisting bodies 1 are twisted together around a central tension resisting body 3, and the central tension resisting body 3, optical fibers 2, and tension resisting bodies 1 are fixed into one body with a thermosetting or ultraviolet ray hardened resin 4, and a coating 5 is provided around them. In the case of an optical fiber composite overhead earth wire, a heat resisting coating 7 consisting of a silicone resin or the like is coated and hardened to fix optical fiber strands 6, tension resisting bodies 1, and the central tension resisting body 3 into one body when optical fiber strands 6 and tension resisting bodies 1 are twisted together around the central tension resisting body 3, and the heat resisting coating 7 is provided thereafter.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Summary of the Invention] Optical fibers or optical fiber strands and a tensile strength body are twisted around a central tensile strength body, and a thermosetting or ultraviolet curing resin is , central tensile body.

By creating a structure in which the optical fiber or optical fiber strand and the tensile strength body are solidified and coated on the outer periphery, the tensile strength is increased, and the twisted tensile strength body protects the optical fiber or the optical fiber strand. Optical fiber cable with improved crushing characteristics.

[Industrial application field]

The present invention relates to the structure of an optical fiber cable, and more particularly to an improvement in an optical fiber cable having a structure in which optical fibers or optical fiber strands and a tensile strength member are twisted around a central tensile strength member.

[Conventional technology]

Conventional technology of this type includes, for example, an optical fiber cable whose cross-sectional structure is shown in FIG. 4, in which an optical fiber 2 and a tensile strength member 1 are twisted around a central tensile strength member 3, and a coating 5 is applied to the entire structure. (For example, the 1985 National Conference of the Telecommunications Division of the Institute of Electronics and Communication Engineers). Compared to a structure in which two optical fibers are twisted around a central tensile strength member 3, the optical fiber cable of this structure has an increased tensile strength.■ The tensile strength member 1 twisted with the optical fiber 2 It has the advantage of improved crushing properties for protection.

[Problem that the invention seeks to solve]

In an optical fiber cable with a conventional structure as shown in FIG. 4, when a crushing force is applied as a static load, the tensile strength member 1 twisted together with the optical fiber 2 suppresses deformation of the optical fiber cable. However, when a straining force is applied, the tensile strength member 1 can move in the circumferential direction within the cable, so the tensile strength member 1 applies an external force due to lateral pressure to the optical fiber 2, and the optical There is a problem that the transmission loss of the fiber 2 increases.

[Means for solving problems]

In order to solve the problems of the conventional art, the present invention is designed to heat a fiber strand and a tensile strength body, which are made by applying a coating to the outer periphery of an optical fiber or an optical fiber strand and a tensile strength body twisted together around a central tensile strength body. It is characterized by an integrated structure that is solidified with a curable or ultraviolet curable resin.

[For production]

In the present invention, the optical fiber, the tensile member, and the central tensile member are integrated and are mutually restrained, so that the optical fiber and the tensile member do not move in the circumferential direction even if mechanical external forces such as straining or bending are applied. This prevents the adjacent tensile strength member from applying lateral pressure to the optical fiber. Examples will be described below based on the drawings.

〔Example〕

FIG. 1 shows a cross-sectional structure of an optical fiber cable according to the present description. After a plurality of optical fibers 2 and tensile strength members 1 are twisted together around the central tensile strength member 3, the central tensile strength member 3, the optical fibers 2, and the tensile strength are It has a structure in which the body 1 is solidified as one piece, and the same amount of the body 1 is coated with a coating 5.

FIG. 2 shows a cross-sectional structure of an embodiment in which an optical fiber cable according to the present invention is applied to an optical fiber composite overhead ground wire, and the same reference numerals as in FIG. 1 indicate the same parts.

6 is an optical fiber wire, and 7 is a heat-resistant coating.

In this embodiment, when twisting the optical fiber strand (j) and the tensile strength member 1 around the central tensile strength member 3, a heat-resistant coating 7 of, for example, silicone resin is applied and cured to form the optical fiber strand 6.
, after integrating the three members, the tensile strength member 1 and the central tensile strength member 3,
It has a structure in which a heat-resistant coating 7 is applied. Tensile strength body 1
In general, it may be either metallic or non-metallic, but in the case of the optical fiber composite overhead ground wire shown in Fig. 2, non-metallic is preferable since induced voltage is likely to occur. For example, T'RPC fiber, reinforced plastic, I'i
b 14 rReinforced Plastic)
i (applicable.

The curable resin 4 used to integrate the optical fiber strand 6, the central tensile strength member 3, and the tensile strength member 1 is not limited to silicone resin, but is a thermosetting or ultraviolet curable resin, and has a tensile strength Any material that can restrain the body 1 may be used.

The optical fiber cable in this example has a replaceable cable configuration in which only the optical fiber cable can be pulled out after connecting the optical fiber composite overhead ground wire and a new optical fiber cable can be inserted. When replacing an optical fiber cable, external mechanical forces such as straining are likely to be applied.

FIG. 3 shows another embodiment of the present invention, in which the same reference numerals as in FIG. 1 indicate the same parts. In this embodiment, the outer diameter of the tensile strength member 1 is larger than the outer diameter of the optical fiber 2, and the optical fiber 2 is protected by the tensile strength member 1, so that it is superior to the optical fiber cable shown in FIG. 1 in terms of lateral pressure resistance. . In addition, in the structure of this embodiment, in addition to the problem of movement of the tensile strength member 1, when using the conventional structure shown in FIG. However, according to the present invention, this problem can be solved by finishing the outer periphery into a circular shape using a cured resin.

〔Effect of the invention〕

As described above, the present invention integrates an optical fiber or optical fiber strand, a central tensile strength member, and a tensile strength member using a thermosetting or ultraviolet curable resin, thereby improving lateral pressure such as bending and ironing characteristics. The improvement in mechanical properties is remarkable and the effect is large.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional structural diagram of an optical fiber cable according to the present invention, FIG. 2 is a cross-sectional structural diagram of a composite overhead ground wire according to an embodiment of the present invention, and FIG. 3 is a cross-sectional structural diagram of another embodiment of the present invention. FIG. 4 shows a cross-sectional structure of a conventional optical fiber cable. ■...Tensile strength body, 2...Optical fiber, 3...Central tensile strength body, 4...Curable resin, 5...Coating, 6...
・Optical fiber strand, 7...heat-resistant coating

Claims (1)

[Scope of Claims] An optical fiber cable in which an optical fiber or an optical fiber strand and a tensile strength body are twisted around a central tensile strength body and a coating is applied to the outer periphery of the cable, the central tensile strength body and the periphery of the central tensile strength body. 1. An optical fiber cable characterized in that an optical fiber or optical fiber strand and a tensile strength member are twisted together and solidified together with a thermosetting or ultraviolet curable resin.