JPH04184305A - Method for fixing optical fiber cord terminal - Google Patents

Abstract

PURPOSE:To obtain a fixing method in which adhesion is sure and productivity is not lowered by fixing the end of an optical fiber cord and optical parts with adhesive after contracting the end of a jacket coating layer by the plastic deformation of a calking ring. CONSTITUTION:After removing the jacket coating layer of a specified length from the end of an optical fiber connector 1, a tension member is cut and removed in a state where the specified length of the member is left. Next, the coating layer of a coated optical fiber is removed and an optical fiber 9 is exposed. After the calking ring 7 is attached near the end of the jacket layer 2 which is left, it is calked. Finally, an optical fiber cord 1 is inserted in an optical connector 6 whose inside is filled with adhesive 5, and the adhesive 5 is hardened. Namely, since the jacket of the calking ring 7 fixed near the jacket terminal is pressed to inside when the optical fiber cord 1 and the optical parts of the optical connector 6 are fixed with the adhesive, a gap is crushed and the adhesive 5 is prevented from deeply infiltrating. Work becomes simple, working time is very short and workability is not lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a novel means for securing the ends of optical fiber cords. More specifically, the present invention provides for securely and easily handling the end portion of an optical fiber cord, which is integrally composed of an optical fiber core, a tension member, a coating layer, etc., to an optical component such as an optical connector using an adhesive. Regarding a new fixing method when fixing.

Conventional technology Optical fibers, which are typical optical transmission media, are actually integrated with tension members and coating layers for the purpose of supplementing the mechanical strength of the optical fibers and protecting the optical fibers from deterioration due to abrasion, etc. It is often handled as an optical fiber cord constructed in the following manner.

Further, such an optical fiber cord is handled by attaching some kind of optical component such as an optical connector to its end.

FIG. 2 is a diagram showing a typical method for fixing the end of an optical fiber cord as described above to an optical connector.

As shown in the figure, the optical fiber cord l includes an optical fiber core 3 made of an optical fiber 9 coated with resin or the like, and a tension member 4 disposed around the optical fiber core 3.
Furthermore, it is constructed integrally with an outer covering layer 2.

In addition, when fixing the end of such an optical fiber cord 1 to the optical connector 6, first, a predetermined length of the jacket layer 2 and tension member 4 are removed from the end of the optical fiber cord 1, and then the optical fiber core is The coating layer of the wire 3 is also removed to expose the optical fiber 9 at the end of the optical fiber cord 1.

Next, while only the optical fiber wire 9 is inserted into the ferrule formed in the optical connector, the optical fiber cord 1 and the optical connector 6 are inserted together with the ends of the jacket layer 2 and the tension member 4.
and are fixed to each other with adhesive 5.

The work of fixing the optical fiber cord 1 with an adhesive as described above is carried out by first filling the inside of the optical connector 6 with the adhesive 5, and then fixing the end of the optical fiber cord 1 by removing the coating near the end over a predetermined length. This procedure is performed by inserting the optical connector into the optical connector 6 and curing the adhesive 5.

Here, if the viscosity of the adhesive used in the above work is high, it will be difficult to insert the optical fiber cord 1, and furthermore, in the exposed part of the optical fiber cord 9 after removing the coating, the optical fiber cord 1 will be difficult to insert. There is a risk of it breaking. However, if a low viscosity adhesive is used, the tension member 4
Then, the adhesive 5 enters the gap formed between the jacket layer 2 of the optical fiber cord 1 and the optical fiber core 3 due to capillary action. Such penetration of the adhesive 5 sometimes extends for several cm to several centimeters or more, and if the adhesive 5 hardens as it is, the flexibility of the optical fiber cord 1 will be lost in the portion near the optical connector 6.

Therefore, a method has also been proposed in which the end portion of the optical fiber cord 1 is first inserted into the optical connector 6, and the gap between the two is filled with the adhesive 5 later. However, even in this method, if a highly viscous adhesive 5 is used, the filling of the adhesive 5 will be insufficient, and air bubbles will be generated between the optical fiber cord 1 and the optical connector 6, resulting in poor adhesive strength and reliability. It leads to a decline in sexuality.

On the other hand, when an adhesive with low viscosity is used, it is impossible to prevent the adhesive 5 from entering the inside of the optical fiber cord 1, as in the above-described method.

Therefore, as shown in FIG. 3, a highly viscous adhesive 8 is first applied to the end of the optical fiber cord 1 from which the outer covering layer 2 has been removed, and the outer covering layer 2 and the optical fiber core 2 are bonded together. A method has also been proposed in which the optical connector 6 and the optical fiber cord 1 are glued together using a low-viscosity adhesive 5 after sealing the gap, but in reality, the gap is completely sealed using a high-viscosity adhesive 8. While it was difficult to seal, the workability was poor and a decline in productivity was unavoidable.

Problems to be Solved by the Invention Therefore, the present invention solves the above-mentioned problems of the prior art, and ensures reliable adhesion between the optical fiber cord and the optical component, and
The purpose of this invention is to provide a novel method for fixing the end of an optical fiber cord without reducing productivity.

Means for solving the problem, that is, according to the present invention, a coated optical fiber, a tension member disposed around the coated optical fiber, and a coated coated optical fiber and the tension member are integrated. In the method of removing a predetermined length of an outer covering layer from an optical fiber cord provided with an outer covering layer near an end thereof, and then fixing the end of the optical fiber cord to another optical component with an adhesive, An end of an optical fiber cord comprising a process of reducing the diameter of the end of the outer covering layer by plastic deformation of a caulking ring, and then fixing the end of the optical fiber cord and the optical component with an adhesive. A fixing method is provided.

Function The method for fixing the end of an optical fiber cord according to the present invention has the advantage of preventing low-viscosity adhesive from penetrating under the jacket layer by reducing the diameter of the jacket layer of the optical fiber cord using a caulking ring. There are major characteristics.

In other words, in the conventional fixing method, the viscosity of the adhesive prevents the adhesive from entering without sealing the gap created between the outer coating layer of the optical fiber cord and the optical fiber core due to the tension member. I was trying. For this reason, the disadvantages that occur when using a high viscosity adhesive cannot be avoided.

On the other hand, the fixing method according to the present invention reduces the diameter of the outer covering layer using, for example, a metal caulking ring that easily deforms plastically, thereby sealing the gap under the outer covering layer in advance, and then bonding the outer covering layer. Fixation is performed with an agent. Therefore, even if a low viscosity adhesive with good adhesion is used, the adhesive will not penetrate under the outer covering layer.

Furthermore, sealing the gap with the caulking ring is easy and reliable, the time required to actually caulk the ring is short, and the workability of fixing the optical fiber cord is not reduced.

Hereinafter, the present invention will be described in more detail with reference to the drawings, but the following disclosure is only one embodiment of the present invention, and does not limit the technical scope of the present invention in any way.

Embodiment FIG. 1 is a sectional view showing the structure of a fixing part of an optical fiber cord fixed according to the fixing method according to the present invention.

As shown in the figure, the outer covering layer 2 and the like are removed from the end of the optical fiber cord 1, and only the optical fiber 9 is inserted through a ferrule formed in an optical connector. On the other hand, a caulking ring 7 is attached near the end of the outer sheath layer 2 remaining on the optical fiber cord 1, and by reducing the diameter with the caulking ring 7, the gap under the outer sheath layer 2 is sealed. has been done. The optical core cord 1 treated in this manner is fixed to the optical connector 6 by the adhesive 5 filled inside.

Fixing of the optical fiber cord 1 with the adhesive as described above is carried out in the following simple manner.

First, a predetermined length of the outer covering layer is removed from the end of the optical fiber connector l, and then the tension member is cut and removed, leaving a predetermined length. Next, the coating layer of the optical fiber core is removed to expose the optical fiber 9. A caulking ring 7 is attached near the end of the remaining outer covering layer 2 and then caulked. Finally, the optical fiber cord 1 is inserted into the optical connector 6 whose inside is filled with the adhesive 5, and the adhesive 5 is cured.

As described above, when the optical fiber cord 1 and optical parts such as the optical connector 6 are fixed with adhesive, the adhesive 5 is applied to the gap between the jacket layer 2 and the optical fiber core 3 due to capillary action. However, in the method according to the present invention, the caulking ring 7, which is caulked and fixed in the diametrical direction near the end of the outer cover, presses the outer cover inward, so the gap is crushed and the adhesive This prevents the agent 5 from penetrating deeply.

Note that the caulking ring 5 used in the method according to the present invention as described above is a short cylindrical member having an inner diameter slightly larger than the outer diameter of the outer covering layer 2, and is a short cylindrical member that It is attached at a position slightly apart from the end of the outer covering layer 2.

Further, the diameter of the caulking ring 5 is reduced, for example, by applying pressure from the outside at a plurality of equally spaced positions on its circumference. The amount of deformation at this time needs to be sufficient to seal the gap between the jacket layer 2 and the optical fiber core 3, while lateral pressure is applied to the internal optical fiber strand 9. It is preferable that the amount of deformation is such that it does not occur. Furthermore, the material and dimensions of the caulking ring 5 are determined so that the above deformation can be maintained for a long period of time. In practice, metal rings such as aluminum can be suitably used.

As described in detail of the invention, in the fixing method according to the present invention, the diameter of the jacket layer of the optical fiber cord is reduced by a caulking ring to seal the gap under the jacket layer, and then the cable is fixed with an adhesive. There is.

Therefore, while it is possible to use a low-viscosity adhesive that provides good adhesion, the adhesive is reliably prevented from penetrating into the optical fiber cord.

In addition, the diameter reduction operation using the caulking ring is an extremely simple operation and takes a very short time, and does not reduce the workability of fixing the optical fiber cord.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a specific example of a method for fixing an optical fiber cord end according to the present invention, and FIGS. 2 and 3 are diagrams showing a conventional method for fixing an optical fiber cord end. [Main reference numbers] 1... Optical fiber cord, 2... Outer coating layer, 3... Optical fiber core, 4... Tension member, 5... Adhesive, 6... Light Connector (optical component), 7... Caulking ring, 8... High viscosity adhesive, 9... Optical fiber patent applicant Sumitomo Electric Industries, Ltd.

Claims (1)

[Scope of Claims] An optical fiber comprising a coated optical fiber, a tension member disposed around the coated optical fiber, and a jacket layer covering and integrating the coated optical fiber and the tension member. A method of removing a predetermined length of an outer covering layer from a fiber cord near its end, and then fixing the end of the optical fiber cord to another optical component with an adhesive, wherein the end of the outer covering layer is A method for fixing an end of an optical fiber cord, comprising a process of reducing the diameter by plastic deformation of a caulking ring, and then fixing the end of the optical fiber cord and the optical component with an adhesive.