JP2937155B2 - Multi-core optical connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multi-fiber optical connector, and more particularly to a multi-fiber optical connector used for optical communication.

[0002]

2. Description of the Related Art An optical fiber comprises an optical fiber, an optical fiber, a tensile member, and a sheath made of a soft material. The optical fiber line further comprises an optical fiber line through which light passes and a coating for protecting the optical fiber line. In general, when the optical fiber is made of quartz or glass, if an optical fiber having a long distance is to be manufactured, the optical fiber itself is easily damaged and therefore easily broken. For this purpose, a coating for protection is provided around the optical fiber strand to form an optical fiber core, and a tensile strength member is disposed around the optical fiber core before covering with a soft material. This strength member increases the tensile strength and alleviates the strain applied to the optical fiber. For example, Kevlar (aramid fiber) sold by DuPont is very smooth, in which the optical fiber core runs smoothly. For this reason, it is hardly affected by the expansion and contraction of the jacket due to thermal expansion and the like.

[0003] An optical connector is attached to an end of an optical fiber. The basic configuration is that the ferrule is attached to the tip of the optical fiber core, and the ferrule for positioning the optical fiber, the housing, the tensile strength member fixing member and the ferrule are housed in one place in the housing, and the ferrule is pressed with a constant pressure. And a rubber tube for protecting the optical connector including a part of the jacket. In this, the strength member fixing part is conventionally generally divided into an inner ring and an outer ring,
A tensile member was fixed between the two members with scissors or adhesive. Another example is disclosed in
2-92902. FIG. 4 shows Japanese Patent Application Laid-Open No. 62-92902.
FIG. This is not an optical connector, but shows an attachment structure of the tensile strength member 106 for attaching an optical fiber to an electro-optical component. An optical fiber core 102 having a bare optical fiber 102 is provided on a tubular extension 101 extending from a part of the component envelope 104.
Has been inserted. The adhesive 105 is applied to the tubular stretching portion 1
01 inside and outside. Strength member 106
Is extended outside the tubular extension 101. The heat-shrinkable tube 107 is the tensile member 1 on the tubular stretched portion 101.
06 and a part of the jacket 108. The heat-shrinkable tube 107 to which the heat is applied makes the tensile strength member 106 adhere to the tubular extension portion 101, and the optical fiber 103, the tubular extension portion 101, the tensile strength member 106 and the heat-shrinkable tube 107 are integrally fixed by the adhesive 105. .

[0004]

A first problem with the prior art is the use of an adhesive. The use of adhesives involves many steps of mixing, defoaming, coating and curing, and the working time is long. In addition, in mixing, the adhesive becomes uncured due to fluctuations in the amounts of the main agent and the curing agent, or the adhesive protrudes or some unadhered portions appear depending on the method of application, and there are many unstable elements.

The second problem of the prior art is that the tubular extension portion 101, the optical fiber core 103, and the tensile strength member 10 are made of an adhesive.
6 are fixed at once. In the case of the optical connector, when the ferrule members for fiber alignment attached to the tip of the optical fiber core come into contact with each other, the ferrule members are pressed against each other and are slightly retracted in the housing by a spring inserted into the housing.
For this reason, if the housing, the optical fiber 103 and the tensile member 106 are fixed together as in Japanese Patent Application Laid-Open No. 62-92902, the optical fiber 103 is bent in the housing and causes light loss. Along with the strip, a permanent strain due to bending may cause fiber breakage, which may cause a loss of reliability.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a multi-fiber optical connector in which a tensile member can be easily fixed to a housing in a short period of time and has a certain tensile strength. An object of the present invention is to improve the reliability without causing distortion in the optical fiber by allowing the optical fiber to move freely in the tensile strength member.

[0007]

SUMMARY OF THE INVENTION A multi-fiber optical connector according to the present invention comprises an optical fiber core having a ferrule at a tip, a tensile strength member surrounding the circumference, a jacket for protecting the circumference, and an internal cavity. And a housing having two heat-shrinkable tubes, a saw-toothed part having a periodic structure formed at the rear part of the housing, and the strength member coming out of the outer casing on the saw-shaped part. A part is disposed, a first heat-shrinkable tube is disposed thereon, and the remaining strength member is folded back, and a second heat-shrinkable tube is disposed thereon, and the two heat-shrinkable tubes are in a heat-shrinkable state. Is characterized in that:

[0008]

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

FIG. 1 is a perspective view of a multi-core optical connector according to a first embodiment of the present invention, and FIG. 2 is a sectional view of FIG. As shown in FIGS. 1 and 2, the multi-fiber optical connector according to the first embodiment of the present invention includes a ferrule 1, a housing front part 2, an ejector 3, a housing rear part 4, a tensile strength member holding part 5, A heat-shrinkable tube 6 including a shrinkable tube A61 and a heat-shrinkable tube B62, a tensile member 7, a cord protection tube 8, an optical fiber cord 9, and an ejector spring 10
And a ferrule spring 11.

Next, a method for forming a multi-core optical connector according to the first embodiment of the present invention will be described. First, the cord protection tube 8, the heat shrink tube B62, and the heat shrink tube A
61 is inserted into the optical fiber cord 9. Next, the sheath 14 of the optical fiber cord 9 is cut, and the strength member 7 and the optical fiber core 13 are exposed. The tensile strength member 7 is generally made of Kevlar (aramid fiber) manufactured by DuPont, but has a large number of flexible synthetic fibers and has a very strong tensile force. This strength member 7 is also cut to a length required for assembly. The optical fiber 12 is exposed from the distal end of the optical fiber core 13, the ferrule spring 11 is inserted, and the ferrule 1 is mounted. At this point, the end face of the ferrule 1 is polished. Next, the ejector 3 and the ejector spring 10 are also assembled so that the ferrule 1 and the ferrule spring 11 enter the hollow portion 15, and the housing front portion 2 and the housing rear portion 4 are fitted together. At this time, the strength member 7 is put out around the strength member holding portion 5.

First, of the two shrink tubes previously inserted into the optical fiber cord 9, the heat shrink tube A61 is arranged on the tensile strength member holding portion 5. At this point, heat is applied to the heat-shrinkable tube to shrink it, and the strength member 7 is fixed to the strength member holding portion 5. Next, the rest of the tip of the strength member 7 is turned back, and is bent along with the strength member holding portion 5 so that another one is formed.
Two heat shrink tubes B62 are placed thereon. Then, the remaining strength member 7 is fixed to the strength member holding portion 5 by applying heat and contracting. Finally, the cord protection tube 8 (preferably made of a soft material) is put on the strength holding member 5 to complete the assembly.

The strength member 7 has a very good sliding property, and the strength member 7 is fixed to a smooth surface with a heat-shrinkable tube.
Escapes. Therefore, a saw-like portion 19 is provided for the tensile strength member holding portion 5. By doing so, the tensile members 7
Increases strength against tension. Further, by turning the strength member 7 back and fixing it with the heat-shrinkable tube B62, the tensile force is reversed at the turn-back portion of the strength member 7 and the end portion of the heat-shrink tube A61 is caught. Never escape. The housing rear part 4 and the strength member holding part 5 are integrally formed by plastic molding. However, the surface of the saw-like part 19 of the strength member holding part 5 is roughened and embossed, and the heat-shrinkable tubes A61 and B62 are formed as follows. It is desirable to use rigid heat shrink tubing.

FIG. 3 is a sectional view of a multi-core optical connector according to a second embodiment of the present invention. As shown in FIG. 3, the multi-core optical connector according to the second embodiment of the present invention has a housing rear portion 4.
A rubber band 17 is put in advance. The strength member 7 is made of a large number of fibers, and it is difficult to turn the strength member tip 18 back together. Therefore, rubber band 1
By shifting 7 backward, the strength member tips 18 can be neatly aligned and folded. Thereafter, the heat-shrinkable tube B62 is placed on the strength holding member 5, and thereafter, the assembly is performed in the same process as the multi-core optical connector of the first embodiment. In the multi-core optical connector according to the second embodiment, a rectangular portion 16 is provided in the strength holding member 5. In the case of a rectangular shape, the corners are at right angles, so it is considered that the hooking is better than in a saw-tooth shape.

[0014]

The first effect is that the number of working steps is small, the assembling can be performed in a short time, and stable fixing can be performed. The reason is that, as a conventional example, the method of covering the heat-shrinkable tube with the adhesive and fixing the adhesive requires time for mixing, defoaming, and application of the adhesive, and the adhesive is required for stable fixing as described above. Although there is a problem, the present invention uses only a heat-shrinkable tube, so the work is completed only by applying heat, and a periodic structure is provided in the tensile-strength body holding part, and the strength-resistant body is strengthened by doubling the heat-shrinkable tube. This is because it can be held.

The second effect is that no optical loss occurs and there is no possibility of breakage of the optical fiber. The reason is that, unlike the conventional example, the tensile strength member, the housing, and the fiber core are not fixed together, and the fiber core has a structure in which the fiber core can move freely within the tensile strength member, so that no distortion occurs.

[Brief description of the drawings]

FIG. 1 is a perspective view of a multi-core optical connector according to a first embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a sectional view of a multicore optical connector according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of an example of a conventional tensile strength member fixing structure of a multi-core optical connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferrule 2 Housing front part 3 Ejector 4 Housing back part 5 Tensile body holding part 6 Heat shrinkable tube 61 Heat shrinkable tube A 62 Heat shrinkable tube B 7 Tensile body 8 Cord protection tube 9 Optical fiber cord 10 Ejector spring 11 Ferrule spring 12 Optical fiber strand 13 Optical fiber core cord 14 Jacket 15 Hollow part 16 Rectangular part 17 Rubber band 18 Strengthening element tip part 19 Saw-shaped part 101 Tubular extension part 102 Optical fiber strand 103 Optical fiber core 104 Part enclosure 105 Adhesive 106 Strength member 107 Heat shrink tube 108 Jacket

Claims (3)

(57) [Claims] An optical fiber core having a ferrule at a tip thereof, a tensile member surrounding the optical fiber core,
An outer cover for protecting the periphery of the strength member, a front portion of the housing having an internal cavity, a rear portion of the housing having a strength member holding portion, and a saw-shaped portion having a periodic structure are formed on the strength member holding portion. A part of the strength member protruding from the jacket is disposed on the saw-shaped portion, a first heat-shrinkable tube is disposed on the strength member, and the remaining strength member is folded back to form the strength member. A multi-core optical connector, wherein a second heat-shrinkable tube is disposed thereon, and the first heat-shrinkable tube and the second heat-shrinkable tube are heat-shrinked. 2. The multi-core optical connector according to claim 1, wherein said heat-shrinkable tube is a hard heat-shrinkable tube. 3. The multi-fiber optical connector according to claim 1, wherein a surface of said saw-shaped portion is a rough surface.