JPH0423205Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention is an optical fiber cable used for communication cables, etc., in which multi-core wires are coated with a metal sheath and outer covering, and repeaters, etc. The present invention relates to an optical fiber cable termination section that can be applied to a core wire lead-out section of an optical fiber cable when connecting the fiber optic cables to each other.

[Conventional technology]

When connecting an optical fiber cable to a repeater or the like, it is necessary to accommodate the optical fiber cable in a repeater housing or the like, and to lead out and connect the optical fiber core wire. In this case, the optical fiber cable is fixed within the housing to protect the optical fiber core. In the case of conventional metal cables, external pressure does not cause transmission loss, but in the case of optical fiber cables, external pressure causes optical loss and breakage of the core wire. Sometimes. Therefore, when fixing the cable end when processing the end of the optical fiber cable, it is necessary to use rubber or
Cables were fixed using cable pushing made of PVC material. For example, when an optical fiber cable has a metal sheath on the outside of the optical fiber core wire, when this metal sheath needs to be grounded, a lead wire is soldered to it. It was designed to be grounded through the wire. Furthermore, in optical fiber cable lines, in order to prevent water droplets, rainwater, etc. from entering the cable, conventionally a dam sleeve is provided in the middle of the cable or at the end of the cable. The waterproof wall is constructed by injecting insulating resin.

[Problem that the invention attempts to solve]

At the end of the conventional optical fiber cable, if the cable bushing is made of soft material such as rubber or PVC, the cable bushing may bend due to the pressure applied when tightening the cable bushing from the outside. This can cause optical loss, and the core wire is likely to break when the optical fiber is drawn out through this wire.Furthermore, if the metal sheath is to be grounded, it is necessary to solder the metal sheath and the lead wire. In addition, in order to achieve waterproofing, it is necessary to separately provide a dam sleeve, which causes problems such as poor workability and an increase in the size of the connecting portion.

The present invention solves the above-mentioned conventional problems and can prevent optical loss and bending and breakage of the core wire at the end of the optical fiber cable.By attaching the end of the optical fiber cable to the inner body, the metal sheath can be removed. To provide an optical fiber cable termination part that can be electrically connected to an inner main body, can be easily and reliably grounded, and can have a waterproof effect at the cable termination part.

[Means for solving problems]

The present invention provides an optical fiber cable in which a metal sheath is arranged around a core wire formed of an optical fiber, and a jacket is arranged around the metal sheath. In an optical fiber cable termination section for holding and shaping the terminal section, the terminal section is inserted through one open end and is formed by shifting each terminal position in the axial direction to expose the core wire and the metal sheath. an electrically conductive inner body comprising a through-hole formed with a through-hole having an inner diameter larger at both ends than the central part; an annular recess that is provided toward the opening of the inner body, into which the terminal end of the metal sheath of the inserted terminal portion is tightly fitted to electrically connect the metal sheath to the inner main body; and the other of the through holes. a moisture-proof cap that is attached to the inner body so as to close an open end of the cap and has a hole through which at least the core wire passing through the through-hole is passed through in a moisture-proof state; and an injection hole for resin injection formed so as to communicate with the space between the opening end and the other opening end.

[Effect]

One open end of the optical fiber cable, which is made by shifting the end positions of the core wire, metal sheath, and outer jacket in the axial direction to expose the core wire and metal sheath, is inserted into the through hole formed in the inner body. When the core wire is inserted through the through hole and pushed to a position where the core wire protrudes from the other open end of the through hole, the terminal end of the metal sheath is tightly fitted into the recess formed on the inner surface of the peripheral wall of the through hole, thereby causing the metal sheath to Electrically connected to the inner body. Further, when the moisture-proof cap is attached in the above state, the other open end side of the through hole is hermetically sealed. In addition, when resin is injected through the injection hole for resin injection and allowed to solidify in this state, the core wire is fixed to the inner surface of the peripheral wall forming the through hole through the resin, and the terminal portion is waterproofed. be exposed. As a result of the above, the optical fiber core wire is not affected by pressure applied from the outside, so it is possible to prevent the optical fiber core wire from bending or breaking due to external pressure and to cause optical loss, and to maintain good transmission characteristics. The work of grounding the metal sheath is easily carried out automatically and via the inner main body at the same time as the work of attaching the inner main body to the end portion of the optical fiber cable. Furthermore, the waterproof effect can be easily obtained at the cable termination without separately providing a waterproof dam sleeve as in the conventional case.

〔Example〕

1A and 1B are diagrams showing the configuration of an embodiment of the present invention, in which FIG. 1A is a partial vertical sectional view, FIG. 1B is a side view, and FIG. 2A is a front view of the main parts. , Figure B is a longitudinal sectional view of the main part. In these figures, 1
1 is a conductive inner body made of metal, for example, and has a through hole with an inner diameter larger than the inner diameter of the central portion; 2 is an outer peripheral wall thereof; 3 and 4 are openings at both ends of the inner body 1; 6 is a concave portion, 7 is an optical fiber cable, 8 is a cable jacket, 9 is a metal sheath, 10 is an optical fiber core, 11 is a tension member, 12 is an uneven portion provided on the inner peripheral wall surface of the opening 3;
13 is a moisture-proof cap, 13 is a core wire outlet, 14 is a resin injection port, 15 is a stop bolt, 16 is a stepped portion for attaching the moisture-proof cap 12, 17 is an outlet for the tension member 11, and 18 is a taping.

In FIGS. 1A and B and FIGS. 2A and B, the optical fiber cable 7 has a metal sheath 9 on the outer periphery of the optical fiber core 10, and a cable jacket 8 on the outer periphery of the metal sheath 9. There is. Openings 3 and 4 are provided at both ends of the inner main body 1, respectively, and a resin injection port 14 is provided in the outer peripheral wall 2. Among the openings 3 and 4 of the inner body 1, a step 16 on the outer periphery of the opening 4 on the side from which the optical fiber core 10 is led out has an outlet 13 for the optical fiber core 10 and a guide for the tension member 11. Exit 17
A moisture-proof cap 12 having a cap 12 is airtightly attached by taping 18.

In order to obtain the optical fiber cable termination section according to the present invention, the cable jacket 8 is removed by leaving a predetermined length of the optical fiber core 10 and the tension member 11 at the core wire lead-out portion of the optical fiber cable 7. Cut and peel in the circumferential direction. In this case, the metal sheath 9 is exposed to the outside by a length slightly longer than the cable sheath 8, and the terminal is processed. The optical fiber cable 7 whose terminal has been treated in this manner is inserted into the inner body 1 through one opening 3 of the inner body 1. In this case, since the inner diameter of the uneven portion 5 on the inner peripheral wall surface of the opening 3 is formed to be slightly smaller than the outer diameter of the cable jacket 8, the uneven portion 5 on the inner peripheral wall surface of the cable jacket 8 and the opening 3 The terminal end of the metal sheath 9 exposed from the cable sheath 8 is held tightly fitted into the recess 6. The optical fiber core 10 and the tension member 11 pass through the inner body 1 from one opening 3 of the inner body 1 and are led out to the other opening 4, and are connected to the outlet ports 13 and 17 of the moisture-proof cap 12, respectively. Closely led to the outside.
Thereafter, a resin such as silicone resin is injected into the inner body 1 through the resin injection port 14 of the inner body 1, and the resin injection port 14 is sealed with a stop bolt 15, thereby completing the optical fiber cable termination section according to the present invention.

[Effect of idea]

As described above, according to the present invention, optical loss at the end of the optical fiber cable, bending of the core wire, and step breakage are prevented, and the metal sheath is connected to the ground in the recess formed in the inner body. By tightly fitting the terminal end, this can be done simply and reliably, and excellent effects such as waterproofing can be achieved at the cable terminal.

[Brief explanation of drawings]

1A and 1B are diagrams showing the configuration of an embodiment of the present invention, respectively, in which FIG. 1A is a partial longitudinal sectional view, FIG. 1B is a side view, and FIGS. It is a front view and a longitudinal cross-sectional view of the inner main body in A. 1... Inner body, 3, 4... Opening, 7...
...Optical fiber cable, 8...Cable jacket, 9
...Metal sheath, 10...Optical fiber core, 12
...Moisture-proof cap, 14...Resin injection port.

Claims (1)

[Scope of utility model registration request] A metal sheath is arranged around a core wire formed of an optical fiber, and a jacket is arranged around the metal sheath.The terminal positions of the core wire, the metal sheath, and the jacket are The device is for holding and shaping the terminal portion formed by exposing the core wire and the metal sheath by shifting in the axial direction, and the terminal portion inserted through one open end is penetrated and the center portion is A conductive inner body comprising a through hole formed with a larger inner diameter at both ends, and an opening on the inner surface of a peripheral wall forming a central portion of the through hole, with an opening facing the one opening end side. an annular recess in which the terminal end of the metal sheath at the inserted terminal portion is tightly fitted to electrically connect the metal sheath to the inner body, and the other open end of the through hole is closed. a moisture-proof cap that is attached to the inner body and has a hole through which at least the core wire passes through the through-hole in a moisture-proof state; 1. An optical fiber cable termination section comprising an injection hole for resin injection formed so as to communicate with a space between the ends.