JP2004126306A - Member and method for splicing optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and speedily splice optical fibers in a narrow place with high operability and reliability by using an inexpensive device and a splicing member. <P>SOLUTION: The splicing member for optical fiber is provided with tapered or trumpet-shaped insertion holes 6a and 6b into which optical fibers 3a and 3b are inserted at both ends of a splicing sleeve 1 to splice the two optical fibers 2a and 2b in an abutting state in the sleeve 1 made of a metallic material, and the sleeve 1 is provided with a slit 4 which enables a splicing part to visually be confirmed when the optical fibers 2a and 2b are made to abut against each other and can supply an adhesive 5. The optical fibers 2a and 2b are inserted into the sleeve 1 and after the splicing part is visually confirmed through the slit 4, a cyanoacrylate-based adhesive 5 is injected into the sleeve 1 to fix and splice end surfaces of the bare optical fibers 2a and 2b together. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical fiber connecting member and an optical fiber connecting method, and more particularly, connects an optical fiber using a metal connecting sleeve and an adhesive, and accommodates the optical fiber in a metal hollow tube, which is expensive. The present invention relates to an optical fiber connecting member and an optical fiber connecting method that can easily and inexpensively improve the durability and reliability without using an apparatus.
[0002]
[Prior art]
When laying optical fiber cables, for example, a cable having a unit length of 2 km is laid for each section, and corresponding optical fibers of the cables in both sections are connected using a connection box called a closure. In a cable for long-distance transmission, the number of closures is large, and in a multi-core cable, the number of optical fiber connections becomes enormous. Therefore, it is necessary to improve the connection accuracy of the optical fiber, reduce the number of connection steps, and realize an optical fiber connection with low cost and high durability.
[0003]
Conventionally, as a method of connecting optical fibers, (1) a method of melting and heating an optical fiber for connection, so-called fusion splicing, (2) a method of mechanically fixing the optical fiber in a connection container, a so-called mechanical splice, (3) A method of abutting optical fibers in a V groove having a transparent sleeve or a transparent lid and fixing the optical fibers with an ultraviolet-curing adhesive, a so-called adhesive splice, is known. Fusion splicing is the mainstream in Japan.
[0004]
[Problems to be solved by the invention]
However, the fusion splicing requires an expensive optical fiber fusion splicing device, the splicing device is difficult to connect in a large and narrow place, and the optical fiber is set in the fusion splicing device. However, there is a problem that the extra length is necessary and the extra length for reconnection is necessary in case of failure.
[0005]
Although a mechanical splice is cheaper than a fusion splicing device, a mechanical splice container as a connecting member is expensive, and the cost per connection is high. Further, there is a problem that the durability of the optical fiber is inferior in durability because the optical fiber depends only on the mechanical tightening force. Further, the adhesive splice has problems such as poor workability on site.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to use an inexpensive device and a connecting member to achieve high operability and reliability and an optical device that can be easily and quickly connected even in a narrow place. An object of the present invention is to provide a fiber connecting member and a method of connecting an optical fiber.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the present invention provides an optical fiber connecting member in which two optical fibers are butt-connected in a connecting sleeve, wherein the connecting sleeve is made of a metal material. Along with providing a tapered or trumpet-shaped insertion port for inserting the optical fiber at both ends of the connection sleeve, the connection sleeve can be visually confirmed at the joint when the optical fiber is abutted, and A slit capable of supplying an adhesive is provided, and a reinforcing member is integrally provided on the connection sleeve.
[0008]
According to a second aspect of the present invention, in the first aspect of the invention, the reinforcing member is a metal body having a diameter and a length larger than the diameter and the length of the connection sleeve. .
[0009]
According to a third aspect of the present invention, in the optical fiber connecting method of butt-connecting two optical fibers in a connection sleeve, an adhesive is injected into the connection sleeve and fixed after the optical fibers are butt-connected. Further, the metal sleeve is moved so as to cover the connection sleeve with a metal hollow tube previously passed through the optical fiber, and both ends of the metal hollow tube are resin-sealed and integrally reinforced. I do.
[0010]
According to a fourth aspect of the present invention, in the third aspect, a reinforcing member is integrally provided on the connection sleeve.
[0011]
According to a fifth aspect of the present invention, in the fourth aspect of the invention, the reinforcing member is a metal body having a diameter and a length larger than a diameter and a length of the connection sleeve. .
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram for explaining an embodiment of an optical fiber connecting member according to the present invention. In the drawing, reference numeral 1 denotes a metal connecting sleeve, and 2a and 2b denote optical fibers inserted into the connecting sleeve 1. (Naked), 3a and 3b are optical fibers (coating) for coating the optical fibers 2a and 2b, 4 is a slit provided in the connection sleeve, 5 is an adhesive filling the slit 4, and 6a and 6b are connection sleeves. 1 shows insertion ports provided at both ends.
[0013]
The connecting member of the optical fiber according to the present invention has a tapered shape in which the optical fibers 3a and 3b are inserted into both ends of the connecting sleeve 1 in order to butt-connect the two optical fibers 2a and 2b in the connecting sleeve 1 made of a metal material. Alternatively, insertion holes 6a and 6b having a trumpet shape are provided, and a slit 4 is provided in the connection sleeve 1 so that the joint portion can be visually checked when the optical fibers 2a and 2b are abutted, and the adhesive 5 can be supplied. Is configured.
[0014]
Next, an optical fiber connecting method of the present invention will be described.
First, it has an inscribed circle that is larger than the outer diameter of the optical fibers 3a, 3b by 1 to 2 μm, has tapered or trumpet-shaped insertion ports 6a, 6b at both ends, and joins the optical fibers 2a, 2b when they abut each other. A metal optical fiber connection sleeve 1 having a slit 4 through which the mating portion can be visually checked and the adhesive 5 can be supplied is prepared. Next, the optical fibers 2a and 2b are inserted into the connection sleeve 1, and after visually confirming the spliced portion through the slit 4, for example, a cyanoacrylate-based adhesive 5 is injected into the connection sleeve 1 and the bare fibers 2a and 2b are inserted. Are fixedly connected to each other.
[0015]
2 and 3 are cross-sectional views illustrating an example of the connection sleeve, and show a connection sleeve in which the shape of the insertion port is a tapered shape or a trumpet shape. FIG. 2 shows a tapered shape, and FIG. 3 shows a trumpet shape.
[0016]
The insertion ports 6a and 6b at both ends are tapered or trumpet-shaped so that the optical fibers 2a and 2b can be easily inserted, and the size of the tapered or trumpet-shaped is such that the adhesive 5 can form a fillet. It is also possible to
[0017]
4 (a) and 4 (b) are views showing a cross-sectional shape in which the connection sleeve is cut into a ring, FIG. 4 (a) is a cross-sectional view taken along line AA of the slit portion in FIG. 2, and FIG. 4 (b) is FIG. 3 is a sectional view taken along line BB of a non-slit portion in FIG. 2.
[0018]
The reason for using a metal material for the connection sleeve 1 is that the inner diameter accuracy can be easily obtained, the taper shape or the trumpet shape of both end surfaces can be processed by plastic processing, etc., and the cost can be reduced for mass production. Because it is. The material is suitably stainless steel, and the thin tube is processed by press molding or drawing. The processing of the slit is preferably a method that does not generate burrs, such as pressing, cutting, and laser cutting.
[0019]
FIG. 5 is a diagram showing schematic dimensions of the metal sleeve of the present invention. The thickness of the connection sleeve is reduced to about 0.85 to 1.5 mm and the length of the connection sleeve is reduced to about 15 to 40 mm in order to process the tapered shape or the trumpet shape of both end surfaces. It can be difficult to handle like a needle, and as a countermeasure, if a metal rod with another appropriate length and outer diameter is bonded and integrated, handling at the time of mounting becomes easier and the metal sleeve It becomes reinforcement.
[0020]
FIG. 6 is a block diagram for explaining another embodiment of the optical fiber connecting member according to the present invention. In the figure, reference numeral 7 denotes a metal hollow tube (pipe) for housing the connecting sleeve 1, and 8 denotes a connecting sleeve. Reinforcing members 9a and 9b attached to 1 denote sealing members for sealing both ends of the metal hollow tube 7.
[0021]
The reinforcing member is preferably a metal body having a diameter and length larger than the diameter and length of the connection sleeve 1, and is provided integrally with the connection sleeve 1.
[0022]
In this case, the connection method of the optical fibers is as follows. First, after the optical fibers 2a and 2b are abutted, the adhesive 5 is injected into the connection sleeve 1 and fixed, and then passed through the optical fibers 3a and 3b in advance. The metal hollow tube 7 is moved so as to cover the connection sleeve 1, and both ends of the metal hollow tube 7 are resin-sealed with sealing materials 9a and 9b to be integrally reinforced.
[0023]
That is, the stainless tube previously passed through the optical fibers 3a and 3b is moved to the position of the butted connection sleeve 1, and both ends of the stainless tube are resin-sealed to integrally reinforce the connection. . With such a structure, a connection member having improved strength and durability reliability can be obtained.
[0024]
Hereinafter, the present invention will be described in detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.
[Example]
In order to connect and fix a single mode optical fiber having an outer diameter of 0.125 mmφ, a 0.3 mmt thin plate of stainless steel was formed and drilled to form a connection sleeve 1 having the shape shown in FIG. The inscribed circle to which the tapered optical fiber was connected and fixed was a connection hole having a shape of 0.126 mmφ, and was a connection sleeve having an outer diameter of about 0.7 mm and a length of 18 mm. The optical fibers 2a and 2b to be connected are inserted from the tapered insertion ports 6a and 6b at both ends, and after visually confirming that the optical fibers 2a and 2b abut each other at the center of the connection sleeve 1, the ethylene cyanoacrylate adhesive 5 is removed from the slit 4. It was injected and connected and fixed. Further, the stainless steel tube (3.9 mm in inner diameter, 4.4 mm in outer diameter, 60 mm in length) is moved to the position of the connection sleeve where the stainless steel tubes (3.9 mm in inner diameter, 4.4 mm in outer diameter, and 60 mm in length) are passed through the optical fibers 3a and 3b in advance. By doing so, the connection portion was integrally reinforced.
[0025]
The connection loss of the obtained single mode optical fiber was 0.02 dB or less at a wavelength of 1.5 μm. The light loss fluctuation of the connection part in the temperature cycle test at −20 to + 60 ° C. was 0.2 dB or less. Further, the tensile strength of this connection part was 2.0 kg, and the strength was kept at 1.5 kg or more even when this connection part was immersed in water at 60 ° C. for two weeks.
[0026]
【The invention's effect】
As described above, according to the present invention, the connection sleeve is made of a metal material, and a tapered or trumpet-shaped insertion port for inserting an optical fiber is provided at both ends of the connection sleeve, and the optical fiber is abutted on the connection sleeve. When connecting, the joint can be visually checked and a slit that can supply the adhesive is provided, and the reinforcing member is provided integrally with the connection sleeve. It has high reliability and durability, and can easily and quickly connect an optical fiber even in a narrow place.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an embodiment of an optical fiber connecting member according to the present invention.
FIG. 2 is a cross-sectional view illustrating an example of a connection sleeve, and is a diagram illustrating a tapered shape.
FIG. 3 is a cross-sectional view illustrating an example of a connection sleeve, and is a diagram illustrating a trumpet shape.
FIGS. 4A and 4B are cross-sectional views each showing a cross-sectional shape of a connection sleeve cut into a circle; FIG. 4A is a cross-sectional view taken along line AA of a slit in FIG. 2; It is sectional drawing.
FIG. 5 is a view showing schematic dimensions of a metal sleeve of the present invention.
FIG. 6 is a configuration diagram for explaining another embodiment of the optical fiber connecting member according to the present invention.
[Explanation of symbols]
1 Metallic connection sleeves 2a, 2b Optical fiber (bare)
3a, 3b Optical fiber (coating)
4 Slit 5 Adhesive 6a, 6b Insertion port 7 Metal hollow tube (pipe)
8 Reinforcing members 9a, 9b Sealing material

Claims (5)

In an optical fiber connecting member for butt-connecting two optical fibers in a connecting sleeve, the connecting sleeve is made of a metal material, and a tapered or trumpet-shaped insertion opening for inserting the optical fiber at both ends of the connecting sleeve. Along with the provision, the connection sleeve is provided with a slit capable of visually confirming a spliced portion when the optical fibers are butted, and supplying an adhesive, and a reinforcing member is integrally provided on the connection sleeve. Characteristic optical fiber connection member. The optical fiber connecting member according to claim 1, wherein the reinforcing member is a metal body having a diameter and a length larger than a diameter and a length of the connecting sleeve. In an optical fiber connecting method in which two optical fibers are butt-connected in a connecting sleeve, after butting the optical fibers, an adhesive is injected into the connecting sleeve and fixed, and further passed through the optical fiber in advance. An optical fiber connection method, comprising: moving the covered metal hollow tube so as to cover the connection sleeve, and sealing both ends of the hollow metal tube with a resin to integrally reinforce the hollow fiber tube. The optical fiber connection method according to claim 3, wherein a reinforcing member is provided integrally with the connection sleeve. The optical fiber connection method according to claim 4, wherein the reinforcing member is a metal body having a diameter and a length larger than a diameter and a length of the connection sleeve.

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