JPS6061706A - Reinforcing method of optical fiber connecting part and its reinforcing member - Google Patents

Abstract

PURPOSE:To raise an effect of reinforcement and an execution efficiency by providing a heat melting resin on the inside of an outside tube having a heat contracting property, and providing a tensile strength body on the inside of this resin. CONSTITUTION:A pair of covered optical fibers 1A, 1B having covering removed parts 3A, 3B in the connecting end side are welded and connected in a state that the tips of each covering removed part concerned 3A, 3B are butted to each other. A tube-shaped tensile strength body 9 having a resin path part 10 on the circumferential surface is provided together with a heat melting resin 8 placed along with said body, on the inside of an outside tube 7 having a heat contracting property, and an optical fiber connecting part is contained in the tensile strength body 9. The outside tube 7 is contracted by a heating means, also the heat melting resin 8 is melted, filled into the inside of the tensile strength body 9, and the connecting part in the tensile strength body 9 is covered with the heat melting resin 8, the tensile strength body 9 and the outside tube 7. Since this process is executed for heating only, it can be executed easily and quickly. The connnecting part is protected by the resin 8 and the tensile strength body 9, and the reinforcement can be executed with a high reliability against an external force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reinforcing an optical fiber connection portion and the reinforcing portion thereof.

In the optical fiber fusion splicing method, which is often used to achieve a low-loss splicing effect, the ends of a pair of coated optical fibers IA and IB, called optical fiber cores, are coated as shown in Figure 1. layer or coating layer is removed, and a bare wire-shaped coating removal portion 3A is exposed from the ends of the coating portions 2A and 2B.
After cutting 3B to a predetermined length, both coating removal parts 3A, 3B
The tips of the two are butted against each other and fused and spliced using electrical discharge heating, laser heating, etc.

Such an optical fiber connection portion is a coating removal portion 3A.

The optical fiber is in the state of a strand made up of 3B, and therefore has poor strength.To compensate for this, reinforcement measures must be taken at the optical fiber connection.When reinforcing, it is necessary not only to reduce mechanical loss but also to reduce the loss. , technical considerations including workability are required, and the development of reinforcing means that satisfies these considerations is desired.

FIG. 2 shows an example of a proposed reinforcing member that satisfies the above requirements to a large extent.
They are combined as shown.

When reinforcing the optical fiber/fiber connection through the reinforcing member shown in FIG. 2, as shown schematically in FIG.
A reinforcing member is placed over the outer periphery of A, and after the connection, the reinforcing member is moved to the outer periphery of the connection part, and the outer tube 4 is shrunk and the inner tube 5 is melted by external heating means to strengthen the connection part. It has a reinforced structure around its outer periphery.

The reinforcement part advantage in the above is that the tensile strength member 6 is removed from the covering part 3a1.
3b is placed in parallel with the internal tube 5, the cross-sectional structure of the reinforcing portion formed by the heating means becomes an ellipse as shown in FIG. Although the surrounding area is covered with hot-melt resin, there is a problem in that it is almost defenseless against external impact, and even if the cross-sectional shape is made after reinforcement, the optical fiber connection part and the outer tube 4 are Since they are eccentric from each other, handling is troublesome, and there is a problem in that space must be secured and consideration must be given to the work when storing the reinforcing connection portion in the connection box.

The present invention aims to provide a method and a reinforcing member for reinforcing optical fiber connections in order to cope with the above-mentioned problems.The specific method and structure thereof will be explained below with reference to the illustrated embodiments. .

FIG. 4 shows a cross-sectional view of the reinforcing member according to the present invention. It consists of a resin 8 and a tensile strength body 9. The thermofusible resin 8 is housed inside the outer tube T, and the tensile strength body 9 is housed inside the resin 8.

As clearly shown in FIG. 5, the tensile strength member 9 has a tubular shape having a resin passage portion 10 along its longitudinal direction, such as a slit (not shown) or a long hole (not shown) or a circular hole (not shown). Metals such as stainless steel, glass, hard plastic, FRP, etc. are used.

FIG. 6 shows another embodiment on the reinforcing part side, which differs from the above embodiment in that the thermofusible resin 8 is not tube-shaped but rod-shaped, and the thermofusible resin 8 is heated. The diameter of the melted material is larger than the inner diameter of the tensile strength member 9 so that it is completely filled into the tensile strength member 9 as described later.

Further, the rod-shaped hot-melt resin 8 is the resin passage portion 1 of the tensile strength member 9.
0 and is housed in the outer tube 7 together with the tensile strength body 9, and the inner diameter of the outer tube 7 in the state before heat shrinkage is heated by the heat-melting resin 8 so as to maintain the abutting state. and the outer periphery of the tensile strength member 9, respectively.

Alternatively, as shown in FIG. 7, by further reducing the inner diameter of the outer tube 7, the tube 7 may be intentionally deformed to increase the force of holding the thermofusible resin 8 and the tensile strength member 9 in contact with each other. good.

Next, an embodiment of the method of the present invention using the reinforcing member shown in FIG. 4 will be described.

In FIG. 1, the reinforcing member is placed on one of the outer peripheries of both optical fibers, for example, on the outer periphery of optical fiber 1A, before connection.
After the connection, the reinforcing part is moved to the outer periphery of the connection part so that the connected parts 3A and 3B are located in the center of the tensile strength body 9, as shown in FIG.
Thereafter, the outer tube 7 is shrunk by heating means and the hot-melt resin 8 is melted, and the molten resin 8 is transferred to the resin passage portion 1 of the tensile strength body 9 by the shrinkage of the outer tube 7.
0 and fills the inside of the tensile strength body 9 with the hot-melt resin 8 as shown in FIG. As shown in the figure, the above-mentioned connection portion is reinforced by encasing it with a hot-melt resin 8, a tensile strength member 9, and an outer tube 7.

Of course, even when the reinforcing member shown in FIG. 6 is used, the optical fiber connection portion can be reinforced in the same manner as described above, and in this embodiment, a reinforced state as shown in FIG. 9 can be obtained.

As explained above, in the method of the present invention, a pair of coated optical fibers IA and IB having coated optical fibers 3A and 3B on the splicing end side are fusion-spliced with the tips of the coated optical fibers 3A and 3B abutted against each other. In order to reinforce the optical fiber connection section, a tubular tensile strength member 9 having a resin passage 10 on its circumferential surface is placed inside a heat-shrinkable outer tube 7 together with a heat-melting resin 8 attached thereto. After storing the optical fiber connection part in the tensile strength body 9, the outer tube 7 is shrunk by heating means and the thermofusible resin 8 is heated.
is melted and at least a portion of the molten resin 8 is filled into the tensile strength member 9 from the resin passage portion 1o, thereby connecting the optical fiber connection portion within the tensile strength member 9 between the hot melt resin 8 and the tensile strength member 9. Since the optical fiber connection part is encapsulated with the outer tube 7, the connection part can be reinforced by simply storing the optical fiber connection part in the tensile strength body 9 and heating it, so no skill is required at all. Not only can it be carried out easily and quickly even when working in In addition, since the tensile strength member 9 has the coating removal parts 3A and 3B concentrically installed, the cross-sectional shape of the connection part is circular and is stable in shape, making it easy to store the connection part. can also be done easily.

Further, the reinforcing member of the present invention is composed of a tubular tensile strength member 9 having a resin passage portion 10 on the circumferential surface, a heat-melting resin 8, and a heat-shrinkable outer tube 7. are arranged in parallel to each other in the outer tube 7, which provides optimal conditions for carrying out the method, and therefore, except for reinforcing the optical fiber connection. By using the reinforcing member, this can be carried out efficiently and without any problems.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the optical fiber connection section, Figures 2 and 3
The figure is a cross-sectional view showing a conventional reinforcement part side and a reinforcement example using the same, FIG. 4 is a cross-sectional view showing an example of a reinforcement part side according to the method of the present invention, and FIG. 6 and 7 are sectional views showing different embodiments of the method of the present invention, and FIGS. 8 and 9 are perspective views of the tensile strength member according to the method of the present invention. FIG. 10 is a longitudinal sectional front view showing different reinforcement examples of the fiber connection portions, and FIG. 10 is a sectional view taken along the line X--X in FIG. 8. IA, IB...Coated optical fibers 3A, 3B...Coating removal section 7...Outer tube 8...Thermofusible resin 9...Tensile strength body 1o... ...Resin passage part Fig. 2 Fig. 31! I Figure 4 Figure 5 Figure 6 N 7 Figure 8 Figure 9 Leap Figure 10

Claims (6)

[Claims] (1) A pair of coated optical fibers each having a coating removed portion on the connection end side are fusion-spliced with the tips of the coating removed portions abutting each other, and a resin passage portion is formed around the optical fiber connecting portion. A reinforcing member in which a tubular tensile strength body and a heat-melting resin attached thereto are housed in the tensile strength body of a heat-shrinkable outer tube, and the outer tube is shrunk and thermally melted by a heating means. melting a thermofusible resin and filling at least a portion of the molten resin into the tensile strength member through the resin passage, thereby enclosing the optical fiber connection portion within the tensile strength body with the thermofusible resin, the tensile strength member, and the outer tube. A method for reinforcing an optical fiber joint, characterized by: (2) A heat-shrinkable tube for reinforcing an optical fiber splicing portion in which a pair of coated fibers each having a sheath removed portion on the splicing end side is fusion-spliced with the tips of the sheath removed portions abutting each other. In the reinforcing member for an optical fiber connection portion, the heat-shrinkable tube is equipped with a tubular tensile strength member having a resin passage on the circumferential surface and a heat-melting resin in parallel with each other. A reinforcing member for optical fiber connections. (3) A reinforcing member for an optical fiber connection portion according to claim 2, wherein the hot-melt resin is tube-shaped, and a tensile strength member having a resin passage is housed within the hot-melt resin. (4) Reinforcement of the optical fiber connection portion according to claim 2, wherein the hot-melt resin is rod-shaped, and the diameter of the hot-melt resin is larger than the inner diameter of the tensile strength member having the resin passage portion. Element. (5) A reinforcing member for an optical fiber connection portion according to claim 2 or 4, wherein the hot-melt resin is brought into contact with the resin passage portion of the tensile strength member. (6) A reinforcing member for an optical fiber connection portion according to any one of claims 2 to 5, wherein the resin passage portion comprises a slit.