JPS5940615A - Branch connecting method of bunch fiber - Google Patents

Abstract

PURPOSE:To perform easily a branch connection of a bunch of optical fibers even at a factory site, by arraying coating-removed optical fibers similarly to the bunch of fibers and cutting them by fusion, and connecting this cut end surface to the bunch fiber end surface. CONSTITUTION:A bare bunch of fibers 5 obtained by removing a coating 16 from a bunch of fibers has the same diameter with a drawn part 14, so they are fixed in a V groove, etc., to align their end surfaces with each other easily. The external diameter ratio of each single-core bare fiber 4 and its core is equalized to the external diameter ratio of the each core of the bunch fiber and core part and they are arrayed similarly, so that cores are aligned with each other automatically at end surfaces during the alignment by drawing work. In this case, both abutting parts may be adhered together fixedly to the V groove and connected by heat sealing while fixed in the V groove. For a connection which allows detachment, connectors are attached to the end parts of the drawn part 14 and bunch fibers 15.

Description

DETAILED DESCRIPTION OF THE INVENTION The unexploded BA relates to a method for branching and connecting punched fibers.

FIG. 1 is a cross-sectional view of a punched fiber, where ] is a single-core optical fiber, and 2 is its core.

Single-core optical fiber 1 is usually made by arranging seven fibers as shown in Figure 1 and drawing them all at once.
, it has the advantage that the seven fibers can be handled as if they were a single optical fiber. Such a bar connection 4. This can be done by connecting a connector or the like.

For punched fibers consisting of 7 tons as in No. 1 (2), it is possible to connect 7 fibers in one connection operation,
This has the advantage of allowing efficient connections. However, despite these advantages, in the end, +, L-,
If all the optical fibers were to be branched to each terminal, there was no suitable means, which hindered practical application.

The present invention provides a method for branching and connecting batch fibers that can be easily branched and connected even at construction sites.

The following explanation will be given by taking as an example the branch connection of 7-fiber punched fibers, but the present invention can be implemented regardless of the number of fibers in the batch fiber.

As shown in FIG. 1, the diameter d (i.e., the outer diameter of 1) of each of the fibers constituting the batch fiber 5 is generally larger than the outer diameter d' of a single-node bare optical fiber. The reason for this is that if d = d', the diameter of the punched fiber will be D23d = 3d', which means it will be three times as thick, so it will be difficult to accommodate the optical fiber per unit cross-sectional area of the cable. The efficiency decreases, and when bending is applied, the stress generated on the surface increases the diameter and thickness, which is unfavorable in terms of reliability.

Therefore, when single bare fibers are arranged, the position of the core of the optical fiber becomes thick and scrapes, so it is necessary to reduce the diameter of the single bare fiber side.

The embodiment shown in the second prisoner will be described below.

In FIG. 2, numeral 3 is the plastic coating of the optical fiber, and numeral 4 is seven bare fibers. 1. When removing the coating,
The sheathing section 3 is fixed with a fixing section I2 on the core side consisting of a stand 7 and a presser plate 6, the sheathing section 4 is stripped off, and the free end of the exposed bare fiber 4 is fixed using a stand 9 and a presser plate 8. It is fixed with the bare fiber side identification part 13. Next, the bare fiber 4 is fixed by the fixing parts 12 and 13, and the fixing part 13 is rotated in the direction of the arrow.

In this way, a twisted portion 5 is created in the central portion. Next, discharge electrode 10. During step II, a discharge circuit (not shown) generates discharge, and the twisted portion 5 is heated and melted and bonded. At this time, one or both of the I wire side fixing section] 2 and the bare fiber side fixing section 13 are moved in a direction in which the distance between them becomes wider. If this is done, necking will occur in the fused portion, and by appropriately selecting the amount of stretching, the diameter can be made to be the same as the diameter of the batch fiber 15.

In this case, the discharge electrode 10. Il'i twisted as a pair 8
Since the heating is carried out over a longer distance by moving in the longitudinal direction of 5, a longer section, that is, a portion with a diameter equal to the diameter of the punched fiber can be obtained.

Although the second embodiment has been described using discharge heating, the heating source may be a gas torch, a CO2 laser, or the like. Furthermore, if the single-core bare fiber has a large diameter and heat is not applied uniformly, the heat source or fixed RII+2.13 may be rotated around the twisted portion 5.

- Also, in this explanation, we have focused on the case of d(d'), but in the case of d-d', stretching is not necessary.

In this way, after heating and stretching, cutting is performed at the appropriate position of the stretching section.

FIG. 3 shows the state after cutting, and numeral 14 in the figure is the stretched n-leg portion. Cutting is performed using known techniques, e.g.
Methods such as scratching the surface with a knife, bending, applying tensile stress, and cutting with a diamond cutter are used. The process of connecting the batch fiber 15 to the n-L stretching fiber 14 whose outer diameter is reduced to the same diameter as the punch fiber 15 in this manner will be described with reference to FIG.

16 is a coating of the batch fiber; this coating 164
Since the bare punched fiber 15 and the stretched portion 14 have the same diameter, by fixing them in a groove or the like, it is easy to fully align their axes using their end faces. In other words, it is possible to automatically match the ratio of the outer diameter of the bare fiber 4 of the batch fiber to its core in advance for each year, as well as the axis of the core of each batch fiber. be. In this state, the abutting portions of the two may be adhesively fixed to the V-groove, or they may be fused and spliced to the V-groove in a controlled manner.

Furthermore, when it is desired to make a connection that can be attached and detached, an end 73BK connector of the stretching portion 14 and the batch fiber 15 may be attached.

In the above embodiment, each single bare fiber was twisted and arranged, but it is not necessarily necessary to arrange it by twisting. For example, in the case of a batch fiber made of 7 fibers, as shown in FIG. It is also possible to insert the fibers into the hexagonal holes and arrange them in the same way as the seven single fibers, as shown in the figure.

If the diameter d of the critical center of the batch fiber is equal to the diameter d' of the single-core bare optical fiber 4, the bare optical fiber 4 is melt-heated, and the fiber 15 and phase good.

As described above, according to the present invention, not only can branch connection parts of punched fibers be easily made, but also the stretching process shown in FIG. 2 and the connection of the stretched part 111 and punched fibers shown in FIG. With appropriate design, this can be done using the same equipment, making it an extremely practical method.

Therefore, by carrying out the method shown in the present invention,
The problem of difficulty in branching punched fibers can be solved, and the practical application of batch fibers can be promoted.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an example of a punched fiber. FIG. 2 shows the diameter reduction process of the present invention. FIG. 3 shows the state after cutting in % after carrying out the present invention. FIG. 4 shows the connection process of the present invention. FIG. 5 shows another implementation of the invention. 1... Single) L optical fiber, 2... Same core part, 3 Coating of single core optical fiber, 4... Bare fiber, 5... 9 twisted parts, 6.8... Holding plate, 7.9 ...stand, 10. I+
discharge electrode, 12 core wire side fixing part, 13 bare fiber side fixing part, I4 enlarged part, 15 punch fiber.

Claims (4)

[Claims] (1) Arrange bare fibers from which the coating of single-core optical fibers has been removed in a manner similar to the punched fibers to be connected, melt and heat the arranged portion, stretch if necessary, weld and bond the bare fibers together, When stretched, the diameter is reduced so that it has the same shape as the punched fiber to be connected, and it is cut at the same shape as the punched fiber at the welded adhesive part, and the end face of the cut part and the end face of the punched fiber to be connected are connected. A method for branching and connecting punched fibers. (2) A method for branching and connecting punched fibers according to claim 1, characterized in that the stock fibers are twisted to arrange them similarly to the punched fibers. (3) The method for branching and connecting punch fibers according to claim 1, wherein the stretched and cut cut portion and the punch fiber to be connected are connected by fusion splicing. (4) A method for branching and connecting punched fibers according to claim 1 or 2, characterized in that a connector is attached to the stretched and cut portion, and the punched fibers to be connected are connected to the connector.