JPH07104452B2 - Clamping method for multi-fiber coated optical fiber fusion splicing - Google Patents

Description

The present invention relates to a clamping method for fusion splicing of multi-core coated optical fibers.

"Prior art" For the connection of coated optical fibers, regardless of whether they are single-core or multi-core,
Although the fusion splicing method is widely adopted, it is the multi-core coated optical fiber that has a large number of optical fiber strands that has a high degree of difficulty in splicing.

As is well known, in the connection of multi-core coated optical fibers, each optical fiber strand is exposed from the end of the multi-core coated optical fiber through the sheath removing means, and these optical fiber strands are connected to the tip through the collective cutting means. Trim.

During such coating removal and batch cutting, it is common that distortion of the coating layer or a slight misalignment between the coating layer and each optical fiber strand inevitably causes misalignment of the tips of the optical fiber strands. When the layer is made of an ultraviolet curable resin, the unevenness of the tip is about 100 to 200 μm.

Such non-uniformity of the tips causes a failure in collectively fusion-splicing the optical fiber strands, and therefore, in the conventional example as well, a measure as shown in FIG. A is taken as a countermeasure.

The conventional example of FIG. 8 will be described below.

First, as shown in FIG. 8 (A), the optical fiber strands 1a to 1e and 2a to 2e after coating removal and tip cutting are mounted on the guide stands 3 and 4.
Set on top and clamp with slippery soft clamps 5,6.

Next, as shown in FIG. 8 (B), the optical fiber strands 1a-1
e, 2a to 2e are advanced toward both sides of the abutting plate 9, and the advance is continued until the end face of the shortest optical fiber element wire hits the abutting plate 9.

At this time, since the other optical fiber wires except the shortest optical fiber wire are held by the soft clamps 5 and 6 so as to be able to slip, there is no advance after the collision of the abutting plate, and the soft clamps 5 and 6 do not move. No bending occurs with the abutting plate 9.

That is, the misalignment of the tips of the optical fiber strands is absorbed to the base end side.

Then, as shown in FIG. 8 (C), the optical fiber wires 1a to 1e and 2a to 2e having no irregular ends are firmly clamped on the guide bases 3 and 4 via the hard clamps 7 and 8 and hit. The plate 9 retreats from between the end faces of these optical fiber wires.

As shown in FIG. 8 (D), the following are the optical fiber strands 1a to 1
e, 2a to 2e are relatively moved in the direction in which these ends are abutted with each other, and at the same time, discharge heat is provided, and thus each optical fiber strand is 1: 2a to 1e: 2e. It is fusion spliced at 1.

[Problems to be Solved by the Invention] In the case of the conventional example described above, the fusion spliced optical fiber
1a + 2a, 1b + 2b, 1c + 2c, 1d + 2d, 1e + 2e inevitably have irregular lengths.

Therefore, when the clamps are released and the connected optical fiber strands are removed from the guide base, the relatively long portions are bent and the short portions are strained, resulting in increased transmission loss at these optical fiber connection portions.

On the other hand, when the process is examined, the steps shown in FIGS. 8 (B) and (C) are additionally required to absorb the misalignment of the tips, resulting in a decrease in work efficiency. When each optical fiber element wire is abutted, or when the abutting plate 9 is withdrawn from between the optical fiber element wires in the abutting state, the optical fiber element wires may be erroneously damaged.

In terms of equipment, it is necessary to provide hard clamps on the guide bases 3 and 4, and the corresponding equipment becomes troublesome.

In view of the above problems, the present invention is to provide a clamp method for multi-core coated optical fiber fusion splicing which can solve the irregularity of the tips of the optical fiber strands and can rationalize this type of fusion splicing.

[Means for Solving Problems] The clamping method of the present invention is intended to achieve the intended purpose.
The optical fiber strands are exposed from the ends of the multi-core coated optical fibers forming a pair, and one optical fiber strand and the other optical fiber strand are made to face each other at a ratio of 1: 1. The pair of multi-core coated optical fibers are paired with each other through means for relatively moving the both multi-core coated optical fibers in the direction of butting the strands and means for supplying thermal energy to the end of each optical fiber strand. In a fusion splicing method for a multi-core coated optical fiber that is connected in the longitudinal direction, a substrate and a lid plate that can be opened and closed mutually, a concave groove formed in these substrates and a closing surface of the lid plate, and at least both sides of the substrate are formed. A fixture having a locking portion is provided, the end of the multi-core coated optical fiber is fitted into the groove of the fixture, the substrate and the cover plate are held closed, and the multi-core coating is performed. Attach a fixture to the outer circumference of the end of the optical fiber, The coating layer of the coated optical fiber and the respective optical fiber of the coating layer was constrained to each other, then,
The coating layer after the fixture in the multi-core coated optical fiber is removed to expose each optical fiber strand from the end of the multi-core coated optical fiber, and the tips of these optical fiber strands are cut and aligned. The end of the core-coated optical fiber is placed on a movable table together with a fixture, and a clamp member provided on the movable table is engaged with the locking portion of the fixture,
It is characterized in that the fixing tool is detachably fixed to the moving table.

[Operation] In the case of the clamping method of the present invention, a fixture is attached to the outer periphery of the end of the multi-core coated optical fiber to mutually restrain the coating layer and each optical fiber element wire in the coating layer, Since the coating layer is removed and the tips of the optical fiber strands are trimmed, the tips of the optical fiber strands can be trimmed with almost no misalignment, and then the end of the multicore coated optical fiber is fixed. Since the fixing tool is placed on the movable table together with the tool and the fixing tool is detachably fixed on the movable table, there is no misalignment of the tips of the optical fiber wires even in the state of being set on the movable table.

Therefore, at the time of fusion splicing of the multi-core coated optical fibers, it becomes possible to omit each step that should absorb the misalignment of the tips of the optical fiber wires, and the damage of the optical fiber wires caused by adopting such a step can be avoided. impossible.

On the other hand, since the lengths of the optical fiber strands in each connection state are almost the same as a whole, there is no increase in transmission loss of the connection section due to tension or bending, and a good connection state can be achieved, and in terms of equipment, Along with the omission of steps, the mechanical parts associated with these steps can be omitted, and the device configuration is simplified.

[Examples] Examples of the clamping method of the present invention will be described below with reference to the drawings.

1 and 2 exemplify a fixture used in the clamping method of the present invention.

The fixture 11 shown in FIGS. 1 and 2 has a base plate 12 and a cover plate 13 which are joined together so that the hinges can be opened and closed.
Permanent magnets (closing tool 14) are provided as a pair of closing tools 14, 15 for holding these closed states on the closing surface on the open / close end side of
And a magnetic attraction piece (closer 15) are attached in an embedded state.

In the fixture 11, a notch-shaped locking portion 16 extending over the substrate 12 and the lid plate 13 is formed on the hinge side thereof, and a notch-shaped locking portion 17 is formed at the open / close end side of the substrate 12, A concave engaging portion 18 is formed on the back surface of the substrate 12.

Further in the fixture 11, the upper surface of the substrate 12 is formed multifiber coated optical fiber F _a to be described later, the groove 19 for Komu fitting the F _b over its longitudinal direction.

In the present invention the clamping process, as shown in FIG. 3, multi-core coated optical fiber F _a, predetermined by a length covering layer from the end of the F _b
When S _a and S _b are removed and the ends of the optical fiber strands 1a to 1e and 2a to 2e exposed by such coating removal are trimmed,
While using a predetermined fixture, FIG. 1, fastener 11 described in FIG. 2 multi-core coated optical fiber F _b for, that is, for the right,
The fixture for the multi-fiber coated optical fiber F _a , that is, the left fixture has the same configuration as the right fixture symmetrically.

Therefore, in the following description, the left fixture and the right fixture will be described with the same reference numerals.

Left in FIG. 3, the fixing device 11 for the right, respectively multi-core coated optical fiber F _a, when attached to the outer circumference of the end portion of the F _b, these fasteners 11 as one tan open lid state, the concave of the substrate 12 groove
After fitting the ends of the multi-core coated optical fibers F _a and F _b into the inside 19, the cover plate 13 is closed to the substrate 12 side and the closed state is held by the closing tools 14 and 15.

Here the depth of the groove 19 is D, multi-core coated optical fiber F _a,
When the thickness of F _b is t, it is slightly t> D. Therefore, when the fixing tool 11 is closed, the coating layers S _{a of the} multi-core coated optical fibers F _a and F _b are , S _b and the optical fiber strands 1a to 1e and 2a to 2e in the coating layers S _a and S _b are in a restrained state in which they do not move relative to each other.

When the closures 14 and 15 of the fixture 11 consist of permanent magnets and magnetic attraction pieces (iron pieces), the above-mentioned binding force is about 2 kg.

Thus multi-core coated optical fiber F _a, fixture outer circumference of the end portion of the F _b
After installing 11, in the part after the fixture,
Suitable length only covering layer S _a by well-known coating removal means to remove the S _b, thereby the multi-core coated optical fiber F _a, F _b each from end optical fiber 1 a to 1 e, exposing the 2a~2e .

Then, the tips of the optical fiber wires 1a to 1e and 2a to 2e are cut and aligned by a known collective cutting means.

Thereafter, as shown in Fig. 4-Fig. 7, the multi-core coated optical fiber F _a, placed on a moving table of the fusion splicing apparatus together with the fixture 11 the end of the F _b, the fastener 11 its wear stop removably on a moving platform in the multi-core coated optical fiber F _a, to clamp on a moving platform and F _b.

In describing the clamp example, FIGS. 4 to 7 will be briefly described below.

In FIGS. 4 to 7, a movable base 21 mounted on the body 20 is used.
Are for _a multi-core coated optical fiber F _{a and} for a multi-core coated optical fiber F _b , which have a common configuration except that they are bilaterally symmetric.

That is, on the upper surface of the movable table 21, a recess 22 is formed along the longitudinal direction for fitting the fixing tool 11 described above, and a positioning stopper 23 is provided at the front end of the recess 22 and the recess 22 is formed. Rotation stoppers 24 are attached to the rear ends of the respective members 22.

The clamp mechanism equipped on the moving table 21 includes a first clamp member 25, a second clamp member 26, and both clamp members 25,
It is configured mainly with 26 operation levers 27.

The operation lever 27 supported via the movable table 21 is movable in the same direction by penetrating the movable table 21 in the front-back direction, and is pivotally attached to the rear part of the movable table 21 to move in the vertical direction. The lower end of the rotatable first clamp member 25 has an operating lever 27.
The second clamp member 26, which is connected to the rear end of the movable base 21 and is located at the front of the movable table 21, is attached to the operation lever 27 so as to interlock with the operation lever 27.

In the fusion splicing device of FIG. 4, a pair of left and right guide bases 28 having vertically movable wire clamps 31 are arranged between the two movable bases 21, and between these guide bases 28. A vertically movable butting plate 29 and a pair of front and rear discharge electrodes 30 are arranged.

In Figure 4-Figure 7, when placed to clamp on the movable table 21 of the fusion splicer device multi-core coated optical fiber F _a, the end of the F _b together with the fixture 11, as follows .

That is, the fixture 11 for the multi-fiber coated optical fiber F _{d and} the fixture 11 for the multi-fiber coated optical fiber F _b are placed in the recess 22 of the left movable table 21 and in the recess 22 of the right movable table 21, respectively. At this time, the tips of the fixing members 11 are brought into contact with the positioning stoppers 23, and the rotation stoppers 24 are fitted into the locking portions 18 on the back surfaces of the fixing members 11, and then the operating lever of the clamp mechanism. When 27 is pushed in the direction of arrow Z _{1 in} Figs. 4 to 6,
The same clamp member 25 is lowered and rotated, and the tip of the same clamp member 11 is fixed.
The second clamp member at the same time as being fitted into the locking portion 16 of
The tip of 26 enters into the locking portion 17 of the fixture 11, and thus the fixture 11 is clamped, whereby the multi-core coated optical fiber is
The ends of F _a and F _b are held immovably on the left movable table 21 and the right movable table 21.

In this way, the multi-core coated optical fibers F _a and F _b set on the left moving table 21 and the right moving table 21 are set at the time of setting,
Each of the optical fiber strands 1a to 1 exposed from these ends
e and 2a to 2e are placed on the left guide base 28 and the right guide base 28 and face each other at a ratio of 1: 1.

The operation after this is almost the same as the general example,
21, the right moving base 21 is moved toward the abutting plate 29, and a predetermined end face spacing is set by abutting the end faces of the optical fiber wires 1a to 1e and 2a to 2e to the abutting plate 29. , After setting the end face spacing, retreat from between the end faces of these optical fiber strands, and then by the left moving table 21, one of each optical fiber strand 1a ~
1e is butt-moved toward each of the other optical fiber strands 2a to 2e, and at the same time, discharge heat is supplied to these ends from the pair of discharge electrodes 30, and thus each optical fiber strand is 1a: 2.
It is fusion spliced at 1: 1 like a to 1e: 2e.

After the fusion splicing, each fixture 11 is removed from each movable table 21, and then these fixtures 11 are coated with a multi-fiber optical fiber F _a ,
It is removed from the outer circumference of the end of F _b .

"Effects of the Invention" As described above, when the clamping method of the present invention is used,
A fixture is attached to the outer circumference of the end of the multi-core coated optical fiber to remove the coating layer, trim the ends of the optical fiber strands, and then place the end of the multi-core coated optical fiber together with the fixture on the moving table. Since the fixture is placed and fixed on the movable table in a detachable manner, the misalignment of the tips of the optical fiber wires is eliminated in the clamped state.

Therefore, at the time of fusion splicing of the multi-core coated optical fibers, it is possible to omit each step that should absorb the misalignment of the tips of the optical fiber strands, which makes it possible to rationalize the steps up to the subsequent fusion splicing. In addition, the optical fiber bare wire is not damaged, and a good connection state can be expected, and the equipment configuration is simplified in terms of equipment.

[Brief description of drawings]

1 and 2 are perspective views showing the opened and closed states of the fixture used in the clamping method of the present invention, and FIG. 3 shows the fixture attached to the outer circumference of the end of the multi-fiber coated optical fiber. Fig. 4 is a schematic view of the state, Fig. 4 is a plan view showing a state in which the end of the multi-fiber coated optical fiber with a fixture is clamped on the moving base of the fusion splicer, and Fig. 5 is a part of Fig. 4. 6 and 7 are schematic cross-sectional views taken along lines VI-VI and VII-VII of FIG. 5, and FIGS. 8A to 8D are conventional optical fibers. FIG. 6 is a process diagram schematically showing a fusion splicing method. 11 …… Fixing tool 12 …… Fixing tool substrate 13 …… Fixing tool cover plate 16 …… Fixing tool locking part 17 …… Fixing tool locking part 19 …… Fixing tool groove 21 …… Movement pedestal 25 ...... operating lever F _a of the first clamping member 26 ...... second clamping member 27 ...... clamping member, F _b ...... multifiber coated optical fiber S _a, S _b ...... coating layer 1 a to 1 e ...... light Fiber strands 2a to 2e ... Optical fiber strands

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigeru Tategami, 6th Hachiman Kaigan Dori, Ichihara City, Chiba Prefecture Furukawa Electric Co., Ltd. Chiba Electric Wire Works (72) Inventor, Michito Matsumoto Tokai-mura, Naka-gun, Ibaraki Prefecture No. 162 Shirane, Nippon Telegraph and Telephone Corporation, Ibaraki Research Institute of Electrical Communication (56) Reference JP-A 61-235805 (JP, A) JP-A 57-135909 (JP, A) JP-A 53-7344 (JP, A)

Claims (1)

[Claims] 1. An optical fiber wire is exposed from each end of a pair of multi-core coated optical fibers, and one optical fiber wire and one optical fiber wire are made to face each other at a ratio of 1: 1. After that, the paired optical fibers are paired through means for relatively moving both the multi-core coated optical fibers in the abutting direction of the optical fiber strands and means for supplying thermal energy to the ends of the optical fiber strands. In a fusion splicing method of a multi-core coated optical fiber for connecting core-coated optical fibers in a longitudinal direction, a substrate and a lid plate which can be opened and closed mutually, a concave groove formed in a closed surface of the substrate and the lid plate, and at least A fixture provided with locking portions formed on both sides of the substrate is prepared, and the end portion of the multi-core coated optical fiber is fitted into the groove of the fixture, and the substrate and the lid plate are closed and held. , Attach a fixture to the outer circumference of the end of the multi-core coated optical fiber, Thereby, the coating layer of the multi-core coated optical fiber and each optical fiber element wire in the coating layer are mutually restrained, and then the coating layer after the fixture in the multi-core coated optical fiber is removed to remove the multi-core coated optical fiber. While exposing each optical fiber strand from the end of the core-coated optical fiber, the tips of these optical fiber strands are cut and aligned, and then the end of the multi-core coated optical fiber is placed on a movable table together with a fixture, For fusion splicing of multi-core coated optical fibers, characterized in that a clamp member provided on the movable table is engaged with the locking portion of the fixture to fix the fixture on the movable table in a detachable manner. Clamping method.