JPS6042923B2 - Optical fiber connection part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to reinforcing the joints of optical fibers.

Reinforcement of a conventional optical fiber connection will be explained with reference to FIGS. 1 to 3, taking as an example a connection in which the ends of opposing glass fibers are butted against each other and fused together by heat.

FIG. 1 is an axial cross-sectional view of the above-mentioned connection part, FIG. 2 is a cross-sectional view taken along the line AA' in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line B-B' in FIG. The glass fibers 1 and 1' are sequentially coated with cushion layers 2 and 2' made of soft plastic such as silicone resin for reinforcing and improving transmission characteristics, and mechanical protective coating layers 3 and 3' made of hard plastic such as polyethylene and nylon. The core wires 4 and 4' are constructed in this way. The coating layers 2 and 1' at the opposite ends of the core wire are exposed, and the abutted portions 5 are fused by heat to form the fusion-spliced central glass fiber exposed portion 6 and the opposing end protective coating layers 3 and 3. ' are covered and bonded together with a two-split reinforcing body 8 via an adhesive 7. In general, the main environmental resistance conditions for optical fiber connections are due to temperature changes, humidity changes, or a combination thereof.

Resin expands and contracts in response to temperature changes, but the degree of expansion and contraction is greater than that of glass, and when expansion and contraction are repeated over a long period of time, resin tends to shrink. Therefore, in the case of a core wire, the cushion layer 2 is made of a soft material, and the glass fiber 1 is made of a hard resin.
is bonded to the glass fiber 1, and the stiffness and strength of the cushion layer 2 are sufficiently smaller than those of the glass fiber, so that it operates in unison with the glass as the glass expands and contracts. On the other hand, the protective coating layer 3 is located outside the soft cushion layer 2 and has high rigidity and strength, so that it expands and contracts independently. Therefore, over a long period of time, the glass fiber 1 and the cushion layer 2 apparently protrude. In the structure of the conventional optical fiber connection part, the glass fiber 6 and the protective coating layer 3 are integrated with the reinforcing body 8 by the adhesive 7, so when the end protective coating layer 3 contracts, the glass fiber 1 and the cushion layer 2 is subjected to compression, causing buckling deformation and, in the worst case, breaking. In order to solve the above-mentioned drawbacks, the present invention aims to rectify the cut end of the protective coating layer of the optical fiber connection part from the cut end of the cushion layer, and to fix the optical fiber core at the end of the reinforcing body that covers the optical fiber connection part. An optical fiber core connection section comprising: fitting the protective coating layer into the mating hole so as to be movable in the axial direction with a very small gap; and integrally bonding the cushion layer and the exposed connecting glass fiber to the reinforcing body. It is.

To explain this in detail with reference to FIG. 4, the same reference numerals as in FIG.
3", and move this in the axial direction to the optical fiber core fitting holes 9, 9" having a hole diameter slightly larger than the outer diameter of the protective coating layers 3, 3" at both ends of the reinforcing body 8. Fitted so as to be freely and diametrically constrained.

Note that the cushion layers 2, 2' and the core wire 6 are integrally bonded to the reinforcing body 8 using an adhesive 7. The connecting portion of the optical fiber core of the present invention is separated so that the expansion and contraction of the protective coating layer does not affect the internal cushion layer and the glass fiber, so even if the protective coating layer contracts, nothing will happen to the glass fiber. Regardless, the glass fibers do not protrude and therefore no buckling failure of the glass fibers occurs.

Further, since the outer periphery of the wire connection portion is held down in the diametrical direction by the reinforcing body, even if a bending action is applied to the core wire, no trouble will occur to the connection portion.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional optical fiber connection section, FIG. 2 is a cross-sectional view taken along line AA, FIG. 3 is a cross-sectional view taken along line B-B, and FIG. 4 is a cross-sectional view of a conventional optical fiber connection section. FIG.

Claims (1)

[Claims] 1. Retreat the cut end of the protective coating layer of the optical fiber connection part from the cut end of the cushion layer, and apply the protective coating layer to the optical fiber fitting hole at the end of the reinforcing body that covers the optical fiber connection part. What is claimed is: 1. An optical fiber cable connection unit, characterized in that the optical fiber cable connection unit is fitted so as to be movable in the axial direction through a small gap, and is formed by integrally bonding a cushion layer and an exposed connection glass fiber to the reinforcing body.