JPH03293607A - Manufacture of excessive-length containing metallic pipe coated optical fiber - Google Patents

Abstract

PURPOSE:To manufacture the excessive-length containing metallic pipe coated optical fiber which has desired excessive length by winding a partially thick metallic pipe wherein an optical fiber is present with the thick part in. CONSTITUTION:A pipe which is partially thick is used as the metallic pipe 50 and drawn while wound around a roller such as a take-up capstan 30 with the thick part 58 in. Namely, the thickness of the thick part 58 is made proper for the pipe diameter and then when the metallic pipe 50 is bent with the thick part 58 in, the position of a neutral part 34 is set inside the center of the optical fiber 12 inscribed in the internal surface of the metallic pipe 50. For the purpose, the metallic pipe is wound around the take-up capstan 30, etc., with the thick part 58 in, the length of the optical fiber 12 is longer than the length of the metallic pipe 50. Consequently, the excessive length is optionally variable, and the excessive-length containing metallic pipe coated optical fiber is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing an optical fiber core in a metal pipe with a long length, in which one or more optical fibers are loosely inserted into the metal pipe. It is.

[Prior Art] Conventionally, a pipe-type optical fiber core has generally been made by extruding a thermoplastic resin around an optical fiber. This method had the advantage that it was possible to obtain an extra length of optical fiber in the pipe by utilizing the contraction of the resin during extrusion processing. However, from the viewpoint of mechanical strength, it is necessary to increase the wall thickness, which has the disadvantage of increasing the outer diameter of the core wire.

To overcome this drawback, a metal pipe optical fiber core 10 has been proposed in which the optical fiber 12 is loosely accommodated in a metal pipe 14, as shown in FIG.

This method has the advantage of being able to have a thin wall and a small diameter, and also has good mechanical strength.

[Problems to be Solved by the Invention] This metal pipe optical fiber core wire 10 is manufactured as follows.

In FIG. 5, 20 is the delivery of the optical fiber 12;
is the delivery of the metal tape 13 (for example, made by 5LIS).

While continuously wrapping the optical fiber 12, the metal tape 13 is rolled up with the roll forming machine 24, and then the metal tape 13 is rolled up with the welding machine 2.
6 to form a pipe, and a metal fiber 1° having a predetermined outer diameter to form an optical fiber core 10 by a drawing machine 28.

The metal pipe optical fiber core wire 10 is wound around a take-up capstan 30 and taken off, and then wound onto a roll 26.

In addition, 33 is a Sherry pump that is filled as necessary.

By the way, when the metal pipe optical fiber core 10 is taken out by being wound around the take-up capstan 30, the optical fiber 12 sinks inside the metal pipe 14 due to pack tension, as shown in FIG. Then, it comes into contact with the inside of the inside.

As is well known, when the metal pipe 14 is bent, it expands on the outside of the bend, contracts on the inside, and remains unchanged in length at the neutral part.

In this case, since the optical fiber 12 is wound inside the neutral portion 34, the length of the optical fiber 12 becomes shorter than the length of the metal pipe 14.

Therefore, when the optical fiber 12 is stretched, tension is applied to the optical fiber 12, significantly shortening its lifespan.

[Means for Solving the Problems] As shown in Fig. 1, a metal pipe 50 that has been partially thickened by thickening is used, and the thickened part 58 is placed inside, and a take-up capstan is installed. Make sure to wind it around a roller such as No. 30 while taking it out.

[Function] By appropriately setting the thickness of the portion 58 by +1 with respect to the pipe diameter, the metal pipe 50 is made with the thick portion 58 inside.
When bent, the neutral portion 34 can be positioned inside the center of the optical fiber 12 inscribed inside the metal pipe 50.

Therefore, as shown in FIG. 3, when the optical fiber 12 is wound around the take-up capstan 30 with the thick portion 58 inside, the length of the optical fiber 12 becomes longer than the length of the metal pipe 50.

[Description of manufacturing method] (Fig. 1) As the metal tape 52, as shown enlarged in Fig. F,
One side of the central portion 54 is raised and is thicker than both sides.

When this raised side is turned inward and rolled and welded, a metal pipe 50 with an uneven thickness is obtained, as shown in an enlarged cross section in the same figure, with a partial PJL portion 58. Note that 56 is a welded portion.

Note that, similarly to the conventional art, when the metal tape 52 is rolled up, the optical fiber 12 is continuously wrapped therein.

The position of the neutral portion 34 when bent can be adjusted by the outer diameter and wall thickness deviation (ratio of the thickness of the thick portion 58 to the thickness of other portions) of the metal pipe 50.

Therefore, for example, if the neutral part 34 is positioned within the thick part 58 and the capstan 30 is wound around the take-up capstan 30 with the thick part 58 facing inside (FIG. 3), as described above, The optical fiber 12 is longer than the metal pipe 50.

That is, a metal pipe optical fiber core @40 with extra length is manufactured (FIG. 2).

The length of the extra length can be arbitrarily changed by changing the position of the neutral portion 34 and the outer diameter of the take-up capstan 30.

[Example] Optical fiber 12: 25G-a $ UV #II Material of metal pipe 50: SUS Dimensions of metal pipe 50 (Fig. 2): Outer diameter a = 1.7 @@ Thickness of thick wall portion 58 Thickness b = 0.6 ml Other thickness c = 0.2 m - Outer diameter of take-up capstan 30 = 400 + am or more, and as a result of investigation, approximately 0.15% The remaining fiber length is II! did.

[Effects of the Invention] Since the cylindrical metal pipe in which the optical fiber exists is wound up with the thick wall section as the inner core, the outer diameter and wall thickness unevenness of the metal pipe 50 and the take-up capstan can be adjusted as described above. By adjusting the outer diameter of 30, it is possible to manufacture a metal pipe optical fiber core wire with an extra length having a desired extra length.

[Brief explanation of the drawing]

Figures 1 to 3 relate to the present invention; Figure 1 is an explanatory diagram of the manufacturing method, Figure 2 is a cross-sectional view of the manufactured optical fiber core of the metal pipe with extra length, and Figure 3 is the optical fiber 12. 4 is a cross-sectional view of a conventional metal pipe optical fiber core wire, and FIG. 5 is a conventional metal pipe optical fiber core manufacturing method. FIG. 6 is an explanatory diagram of a state in which the metal pipe 50 containing the optical fiber 12 is taken up and wound around the capstan 30. 10: Metal pipe optical fiber core wire 12: 13: 14: 24 = 26 = 28: 30: 34: 40: 50: 52 = 54: 56: 58: Optical fiber metal tape Metal pipe roll forming machine welding machine drawing machine Pick-up capstan neutral part metal pipe optical fiber core metal pipe metal tape central part welded part meat 11E part

Claims (1)

[Claims] A metal pipe comprising the steps of continuously creating a state in which an optical fiber exists inside the metal pipe, and continuously winding the metal pipe with the optical fiber inside and taking it off while being wound around a roller. In the method for manufacturing an optical fiber core, a metal pipe with uneven thickness is used as the metal pipe, and the metal pipe with an extra length is pulled out while being wound around the roller with the thick part of the uneven thickness metal pipe inside. How to make wire