JP2001208931A - Fusion splicing method, fusion splicing machine and coat removing device for optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fusion splicing method and its device for optical fiber preventing a defective fusion splicing by directly clamping an optical fiber of a loose fiber with a coat clamp and surely thrusting it. SOLUTION: The optical fiber is exposed by cutting a tube 3 with respect to a loose tube fiber 1. Successively, the tip end of the tube is butted against the difference in level of a coat removing device to position the fiber, a coat 4 of a prescribed length is left at the root part of the optical fiber and the coat of the optical fiber is removed. The worked loose tube fiber 1 is placed on the chuck stage 26 of a fusion machine, a clamp chassis 27 is lowered, and the coat 4 of the optical fiber and the tube 3 are respectively pressed by the projecting part 24a of the coat clamp 24 and the non-projecting part 24b of the same to clamp the loose fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusion splicing method for an optical fiber and a fusion splicing machine, and more particularly, to a method for securely loosening a loose tube fiber in which a fiber is contained in a tube. TECHNICAL FIELD The present invention relates to a fusion splicing method and a fusion splicer capable of performing proper gripping and reliably preventing defective fusion splicing.

[0002]

2. Description of the Related Art Among optical fibers, the surface is made of a thin UV resin.
The wire coated with only (ultraviolet curing resin) may be used in a tube made of nylon or the like in order to prevent deterioration due to external force or the like. Such a fiber having a double structure is called a loose tube fiber (hereinafter, loose fiber).

Hereinafter, a conventional fusion splicing method of loose fibers will be described with reference to the drawings. FIG. 4 is an explanatory view for explaining a conventional fusion splicing method of loose fibers. FIG.
(A) is sectional drawing of the coating removal device in the state where the loose fiber was mounted on the coating guide. In this figure, a loose fiber 1 is composed of a tube 3 and a wire 2b contained in the tube, and the wire 2b further includes a glass core wire 5 inside.

[0004] The coating remover 11 is provided with a lower sandwiching plate 12.
a, upper sandwiching plate 12b, stopper 13, coating removal blade 1
4. It is composed of a lower coating guide 17a, an upper coating guide 17b, and a pivot 32. The lower sandwiching plate 12a is connected to the lower covering guide 17a, and likewise the upper sandwiching plate 1
2b is connected to the upper coating guide 17b. These coating guides can sandwich the loose fiber 1 between them. Lower sandwiching plate 12a and upper sandwiching plate 12b
Are connected by a pivot 32 and move about the pivot 32. The coating removing blade 14 is connected to both the lower sandwiching plate 12a and the upper sandwiching plate 12b. Stopper 13
Are connected to the lower sandwiching plate 12a, and are located behind the loose fiber 1 in this figure.

FIG. 4B will be described. FIG. 4 (b)
FIG. 4 is an elevational view, partially in section, of a gripping mechanism with a loose fiber attached. In FIG. 4B, the clamp chassis 27 is connected to the core clamp 21 by a core clamp spring 22 and is connected to the cover clamp 29 by a cover clamp spring 25. The loose fiber 1 is gripped by the covering clamp 29 and the chuck stage 26, and the glass core 5 is gripped by the core clamp and the V-groove 23.

FIG. 4C will be described. FIG. 4 (c)
FIG. 4 is a side view of a loose fiber fusion spliced portion covered with a reinforcing sleeve. The reinforcing sleeve 31 is provided to reinforce the fused portion of the optical fiber.

Next, the connection process will be described. First, the loose fiber 1 is placed on the lower coating guide 17a of the coating remover 11, and the distance between the tip of the fiber 1 and the coating removing blade 14 is adjusted according to the length of the exposed glass core wire 5. Subsequently, with the pivot 32 as an axis, the upper sandwiching plate 12b is pressed toward the lower sandwiching plate 12a until it hits the stopper 13, so that the coating removing blade 14 is cut so as to reach the glass core wire 5 (FIG. 4 (a)). And fiber 1
Is slowly pulled in the root direction to simultaneously remove the tube 3 and the wire coating 4 at the tip of the fiber 1.

Next, the processed fiber 1 is placed on the chuck stage 26 of the fusion machine, and the clamp chassis 27 is held so that the coating clamp 29 presses the tube 3 and the core clamp 21 presses the glass core 5. take down. Thereby, the loose fiber 1 is fixed to the chuck stage 26, and at the same time, the glass core wire 5 is accommodated in the V groove 23 (FIG. 4B).

Then, the V-groove 23 is moved in a plane perpendicular to the fiber axis (hereinafter, the vertical direction in this plane is represented by Y and the horizontal direction is represented by X) to align the fiber 1 and the other fiber. I do. Then, the discharge is started, and when the tips of both fibers are slightly melted, the chuck stage 26 is moved in the fiber axis direction (hereinafter, this direction is referred to as Z) to push the fibers together (the clamp chassis 27 is connected to the chuck stage 26). The discharge is terminated after a predetermined time has elapsed. Finally, put a reinforcing sleeve 31 on to protect the fused part,
This is contracted by heating (FIG. 4C).

In order to protect the wire from damage due to bending stress, it is necessary to store the tube 3 in the reinforcing sleeve 31 for a predetermined length or more (FIG. 4C). For this reason, the distance from the fusion point to the tip of the tube 1 is the length of the sleeve 31.
There is an upper limit according to the length of the welding machine and the reinforcing sleeve 3.
In one general dimensional specification, the position of the tube tip at the time of fusion cannot be retracted to a position outside the coating clamp 29. Therefore, when the loose fiber 1 is fused, it is general that the tube 3 is disposed and gripped by the coating clamp 29.

Japanese Patent Application Laid-Open Nos. 7-140343 and 7-140344 also disclose an optical fiber fusion splicing method and apparatus. However, here, only the fusion splicing method of plastic optical fibers and the device thereof are disclosed, and the fusion splicing method of loose fibers and the device thereof assumed by the present invention are not disclosed at all.

[0012]

As described above, in the conventional fusion splicing method, the loose fiber can be gripped only on the tube. For this reason, even if the fiber is pushed by moving the chuck stage in the Z direction during the discharge, the wire that is not directly gripped by the coating clamp does not follow this, and cannot be sufficiently pushed, resulting in poor fusion splicing. There is a problem that occurs.

The present invention has been devised in view of the above-mentioned problems, and provides a method and apparatus for reliably pressing a loose fiber by directly gripping the element wire of the loose fiber with a covering clamp and preventing defective fusion splicing. Is what you do.

[0014]

According to a first aspect of the present invention, there is provided a fusion splicing method for an optical fiber, comprising: In the case of connecting and connecting, the tube clamp is grasped simultaneously with the fiber strand exposed from the tube by using a covering clamp in which the protrusion and the non-protrusion are integrated.

According to the optical fiber fusion splicing method according to the first aspect of the present invention, in order to grasp the tube and at the same time grasp the fiber strand exposed from the tube, the loose fiber strand must be securely inserted. It can be gripped and fused.

In the method for fusion splicing an optical fiber according to the second aspect of the present invention, when the optical fiber is fusion spliced by the method according to the first aspect, only a tube is partially cut before being gripped. This removes the coating of the fiber so as to expose the fiber and leave a coating of a predetermined length at the root of the exposed fiber.

According to the optical fiber fusion splicing method according to the second aspect of the present invention, before grasping, only the tube is partially cut and removed, thereby exposing the bare fiber and exposing the bare fiber. Since the coating of the fiber strand is removed so that a predetermined length of coating is left at the root of the fiber strand, the length of the coating is too short, so that the protrusion of the coating clamp directly contacts the glass core wire. It is possible to prevent the problem that the tube is inserted into the reinforcing sleeve because the length of the tube is too short, and the length of the tube inserted into the reinforcing sleeve is insufficient.

A method for fusion splicing an optical fiber according to a third aspect of the present invention is to grip a tube when fusion splicing an optical fiber in the method according to the first or second aspect of the invention. The strength and the strength of gripping the bare fiber exposed from the tube are separately adjusted.

According to the optical fiber fusion splicing method according to the third aspect of the present invention, the strength of gripping the tube and the strength of gripping the bare fiber exposed from the tube are separately adjusted, whereby the fiber is spliced. Since the load applied to the wire and the tube can be easily changed, the load can be set according to the properties of the strand.

An optical fiber fusion splicer according to a fourth aspect of the present invention comprises: (a) an optical fiber fusion splicer in which a fiber element wire is accommodated in a tube; And (b) a chuck stage for placing the optical fiber on the chuck stage, wherein the non-projection portion holds down the optical fiber tube on the chuck stage, and The covering clamp forms a step between the protruding portion and the non-protruding portion so that the portion clamps the optical fiber by pressing the optical fiber exposed from the optical fiber tube on the chuck stage.

According to the optical fiber fusion splicer according to the fourth aspect of the present invention, the non-projecting portion holds down the optical fiber tube on the chuck stage, and at the same time, the projecting portion holds the optical fiber tube on the chuck stage. By holding the optical fiber by pressing the exposed fiber, the loose fiber can be securely fixed to the chuck stage and fusion-spliced. Also,
Since the tube is simultaneously gripped by the non-projecting portion of the covering clamp, the tube does not fall off the chuck stage, and the displacement of the strands associated therewith does not occur.

The optical fiber fusion splicer according to a fifth aspect of the present invention is the optical fiber fusion splicer according to the fourth aspect of the present invention, wherein the protruding portion and the non-protruding portion are each coated with a clamp spring. Is to be attached.

According to the optical fiber fusion splicer according to the fifth aspect of the present invention, the projections and the non-projections are exposed from the tube with the strength to grip the tube for mounting the covering clamp spring. The strength of gripping the fiber strand can be adjusted separately, and the load applied to the strand and the tube can be easily changed when gripping the loose fiber. it can.

According to a sixth aspect of the present invention, there is provided a method for removing a coating of an optical fiber, comprising:
In the method for removing coating of an optical fiber in which a fiber is exposed from a part of a tube, (a) placing the optical fiber in a lower guide groove having a guide groove for the fiber and a guide groove for the tube; The tip of the tube is brought into contact with the step at the boundary between the guide groove and the guide groove for the tube to position the optical fiber, and (c) the coating of the optical fiber is removed with a coating removing blade at a certain distance from the step. is there.

According to the optical fiber coating removing method of the sixth aspect of the present invention, the optical fiber is positioned by abutting the tip of the tube on the step at the boundary between the strand guide groove and the tube guide groove. Since the coating of the optical fiber is removed by the coating removing blade at a certain distance from the step, the length of the coating left at the root of the fiber is kept constant.

An optical fiber sheath remover according to a seventh aspect of the present invention is an optical fiber sheath remover in which a bare fiber is accommodated in a tube and a bare fiber is exposed from a part of the tube. a) a lower guide groove provided with a guide groove for an optical fiber corresponding to the diameter of the strand of the optical fiber, a guide groove for a tube corresponding to the diameter of the tube of the optical fiber, and (b) an end of the tube. (C) a step at a certain distance from the step, at the boundary between the guide groove for the wire and the guide groove for the tube for positioning the optical fiber, and removing the coating for removing the coating of the fiber wire And a blade.

According to the optical fiber sheath remover according to the seventh aspect of the present invention, a wire guide groove adapted to the diameter of the optical fiber wire and a tube guide groove adapted to the diameter of the optical fiber tube are provided. A lower guide groove having a guide groove, a step at the boundary of the tube guide groove for abutting the tip of the tube to position the optical fiber, and a certain distance from the step, and Since the apparatus has the coating removing blade for removing the coating, the length of the coating left at the root of the strand is kept constant.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIGS. 1 and 2 are diagrams illustrating Embodiment 1 of a fusion splicing method of an optical fiber according to the present invention. FIG. 1A is a side view of a loose fiber in which a strand is exposed by cutting a tube. In this figure, the loose fiber 1 is composed of a tube 3, a wire 2a exposed from the tube, and a wire 2b contained in the tube, and the wire 2a and the wire 2b are integrated.

FIG. 1B will be described. FIG. 1 (b)
FIG. 4 is a cross-sectional view of the coating remover with the loose fiber placed on the coating guide. The coating remover 11 is provided with the lower sandwich plate 1.
2a, upper sandwiching plate 12b, stopper 13, coating removal blade 1
4, a lower coating guide 15 and an upper coating guide 16.

Here, the lower sandwiching plate 12a is connected to the lower covering guide 15, and likewise the upper sandwiching plate 12b
Is connected to the upper coating guide 16. The lower coating guide 15 includes a wire guide groove 15a on which a wire is placed, and a tube guide groove 15b on which a tube is placed.
A step 15c is provided at a boundary between the wire guide groove 15a and the tube guide groove 15b. Lower sandwiching plate 12
a and the upper sandwiching plate 12b are connected by a pivot 32, and move around the pivot 32. The coating removal blade 14 is
It is connected to both the lower sandwiching plate 12a and the upper sandwiching plate 12b. The stopper 13 is connected to the lower sandwiching plate 12a, and is located at the back of the fiber strand 2a in FIG.

FIG. 1C will be described. FIG. 1 (c)
FIG. 4 is a side view of the loose fiber from which the wire coating has been removed.
The wire 2a exposed from the tube in FIG.
In FIG. 1 (c), it is composed of a glass core wire 5 and a portion in which the glass core wire is covered with a wire covering.

FIG. 2A will be described. FIG. 2 (a)
FIG. 5 is an elevational view, partially in section, of a gripping mechanism in a state where loose fibers are mounted. The clamp chassis 27 that supports the vertical movement of the clamp is connected to the core clamp 21 by a core clamp spring 22 and is connected to the coating clamp 24 by a coating clamp spring 25. The coating clamp 24 is configured such that a projection 24a provided on a part of the pressing surface of the coating clamp and a non-projection 24b of the pressing surface are integrated. The wire 2a is formed by the projection 24a and the chuck stage 26.
And the non-projecting portion 24b and the chuck stage 2
6 holds the tube 3. The glass core wire 5 is held by the core wire clamp and the V-groove 23.

FIG. 2B will be described. FIG. 2 (b)
FIG. 4 is a side view of a loose fiber fusion spliced portion covered with a reinforcing sleeve. The reinforcing sleeve 31 is covered to reinforce the fused portion of the optical fiber.

Next, a method for processing the loose fiber 1 will be described. First, the diameter of the tube 3 is 0.9 m
m, a loose fiber 1 having a diameter of a strand 2b of 0.25 mm
In the above, only the tube 3 was cut using a wire stripper (not shown) having a through hole having a diameter of 0.4 mm.
The wire 2a is exposed with a length of mm (FIG. 1A).

Next, the distance from the coating removing blade 14 is 0.5
A coating remover provided with a semi-cylindrical guide groove 15a having a radius of 0.15 mm for a wire in a range of ３3 mm and a semi-cylindrical guide groove 15b having a radius of 0.5 mm for a tube in a range of 3 to 10 mm. 11 is prepared, and the processed fiber is placed on the lower coating guide 15. At this time, two guide grooves 1
The fiber is positioned so that the tip of the tube 3 abuts on a step 15c (3 mm from the removal blade) provided at the boundary between 5a and 15b (FIG. 1 (b)).

Subsequently, with the pivot 32 as an axis, the lower sandwiching plate 12a is moved until the upper sandwiching plate 12b hits the stopper 13.
, So that the coating removing blade 14 is cut so as to reach the glass core wire 5. Then, the fiber 1 is slowly pulled in the root direction, and the wire coating 4 at the tip of the fiber 1 is removed. As a result, the wire 2a is in a state where the coating 4 having a length of 3 mm and the glass core wire 5 having a length of 30 mm are exposed. Then, use a fiber cutter (not shown) to set the glass core wire 5
Is cut to a length of 16 mm, and at the same time, an end face perpendicular to the axis is formed at the tip (FIG. 1 (c)).

Next, a method of fusion splicing the loose fiber processed as described above will be described. First, height 0.
A coating clamp 24 having a projection 24a of 6 mm and a length of 2 mm and a non-projection 24b of a length of 20 mm on a pressing surface is attached to the welding machine. Then, the processed loose fiber 1 is placed on the chuck stage 26 of the fusion splicer, and the projection 24a of the coating clamp has the wire coating 4 having a length of 3 mm, the non-projection 24b has the tube 3, and the core clamp 21 has the core. The clamp chassis 27 is lowered while holding down the glass core wires 5 respectively. As a result, both the wire coating 4 of the loose fiber 1 and the tube 3 are attached to the chuck stage 26.
At the same time, the glass core wire 5 is also housed in the V-groove 23 (FIG. 2A).

Then, the V-groove 23 is moved in the X and Y directions to align the held fiber with another held fiber in the same manner as the held fiber with a positioning accuracy of 0.2 μm. Thereafter, the discharge is started, and after 0.1 second, the chuck stage 26 is moved by 10 μm in the Z direction (the clamp chassis 27 is also connected to the chuck stage 26 and moves at the same time).
The fibers are pushed together, the discharge is stopped 1.5 seconds after the start, and the fusion is terminated. In this state, the light loss of the fused portion was measured and found to be as good as 0.02 dB. Finally, in order to protect the fused portion, a reinforcing sleeve 31 having a length of 60 mm is covered, and this is heated and shrunk, thereby completing the connection operation. When the length of the tube of the loose fiber 1 accommodated in the reinforcing sleeve 31 was measured, it was a sufficient value of 10 mm or more on both sides with respect to the standard of 8 mm or more on one side (FIG. 2B).

Therefore, according to the first embodiment of the present invention, since the wire 2a of the loose fiber 1 and the tube 3 are securely gripped by the coating clamp 24, the tube 3 does not fall off the chuck stage 26. Does not occur. Therefore, the pushing accuracy of the fiber during the discharge is improved, and the low-loss connection can be stably performed. In fact, the fusion splicing of the optical fibers according to the first embodiment reduces the yield by 15%.
Improved. In this way, there is no defective fusion splicing,
The work time can be shortened, and the length of the fiber to be attached to the product can be shortened to the length required for one fusion, so that human and material costs can be reduced.

Further, since the fiber 1 is positioned by the step provided in the guide of the coating removing device 11, the length of the wire coating 4 to be left at the root of the wire 2a can be always constant. Further, it is desirable that the length of the coating 4 is set to be equal to or slightly longer than the length of the projection 24a of the coating clamp 24. By setting the length to such a length, there is a problem that the projection 24a directly contacts the glass core wire 5 to cause damage because the length of the coating 4 is too short, or the tip of the tube 1 is It is possible to prevent a problem that the tube is too far from the fusion point and the length of the tube inserted into the reinforcing sleeve 31 is insufficient.

In FIG. 1 (b), a step 15c for positioning is provided by the upper coating guide 16 and the lower coating guide 1.
5 shows an example in which the fibers are provided, but it is also possible to first provide them on at least one of the coating guides on which the fibers are placed.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a diagram for explaining another embodiment of the optical fiber fusion splicing method according to the present invention, and FIG. 3A will be described. This figure is a partially sectional elevation view of the gripping mechanism in a state where the loose fiber is mounted. In this figure, a clamp chassis 27 that supports up and down movement of a clamp is coupled to a core clamp 21 by a core clamp spring 22, and a covering clamp spring 25.
a and 25b are connected to the coating clamp 28. The coating clamp 28 is configured such that a projection 28a provided on a part of the holding surface of the coating clamp and a non-projection 28b of the holding surface are integrated. Others are the same as FIG. 2 (a).

FIG. 3B will be described. FIG. 3 (b)
FIG. 3 is an elevational view, partially in cross section, of a gripping mechanism in a state where a filling fiber is mounted. The filling fiber 6 is covered with a coating 7 and contains a glass core wire 5 therein. Although the filling fiber 6 is gripped by the projection 28a and the chuck stage 26, the non-projection 28b does not touch anything. Others are the same as FIG.

Next, a method of holding the optical fiber will be described. First, a loose fiber 1 having a diameter of the strand 2b of 0.25 mm and a diameter of the tube 3 of 1 mm is processed by a terminal processing method similar to that of the first embodiment, and the glass core wire 5 is 16 mm, and the sheath 4 at the root of the strand is formed. 3 mm (Fig. 1
(C)).

Subsequently, a covering clamp 28 having a projection 28a having a height of 0.7 mm and a length of 2 mm and a non-projection 28b having a length of 20 mm on the pressing surface is prepared, and about 200 mN / cm (about 200 mN / cm) with respect to the projection 28a. About 20 g / cm) of the covering clamp spring 25a to the non-projecting portion 28b by about 780 mN.
/ Cm (approximately 80 g / cm) of the covering clamp spring 25b was attached to the clamp chassis 27. And
The processed loose fiber 1 is placed on the chuck stage 26 of the fusion machine, and the protruding portion 28a of the coating clamp 28 covers the wire covering 4 having a length of 3 mm,
The clamp chassis 27 was lowered so that the core wire clamps 21 pressed the glass core wires 5 respectively.
When the holding load applied to each part of the loose fiber 1 in this state was measured, the strand was approximately 200 mN (approximately 20 g).
It was about 780 mN (about 80 g) in the tube (FIG. 3).
(A)).

Next, in order to perform fusion of the filled fiber 6 having a coating diameter of 0.9 mm (a fiber having no tube and all coatings integrated with a glass core wire), a coating guide 17 is used.
A method similar to the conventional method (FIG. 4 (a)) using a coating remover 11 having a semi-cylindrical groove having a radius of 0.5 mm in a and 17b.
The coating was removed on the tip of the fiber at 30 mm to expose the glass core wire 5. Then, the glass core wire 5 was cut into 16 mm by a fiber cutter (not shown), and an end face perpendicular to the axis was formed at the end. Subsequently, this fiber is placed on the chuck stage 26 of the fusion machine, and
7 was lowered and gripped so that only the projection 28a of the coating clamp 28 pressed down the coating 7 of the fiber (FIG. 3B). When the pressing load applied to the filled fiber 6 in this state was measured, it was about 980 mN (about 100 g).

As shown in the present embodiment, according to the structure of the coated clamps 24 and 28 of the present invention, the loose fiber 1
There is an advantage that both the filling fiber 6 can be gripped. In this case, the coating clamps 24 and 28 not only have a function of simply pressing down the coating, but also have a function of changing the pressing load according to the properties of the fiber.

The function of changing the pressing load will be described below. Of the strands used for the loose fiber 1, those with a thin strand coating 4 are easily damaged by external force or the like, and it is necessary to reduce the holding load when gripping the strand. On the other hand, among the filled fibers 6 having a diameter of 0.4 mm or more, many have a thick coating and poor flexibility, especially when the fiber has a bending habit, in order to grasp the fiber with the bending habit corrected. It is necessary to increase the holding load to grip.

According to the coated clamps 24 and 28 of the present invention, in the case of the loose fiber 1, the pressing load can be dispersed by pressing the strand 2 a and the tube 3 at the same time. Only wire 2a
Can be added to On the other hand, in the case of the filling fiber 6, the entire load of the coating clamps 24 and 28 can be concentrated on this portion by pressing down only the protrusions 24a and 28a. Can be applied.

Also, as in the present embodiment, the protrusion 28
The load applied to the strand 2a and the tube 3 when the loose fiber 1 is gripped can be easily changed by adjusting the strength of the covering clamp springs 25a and 25b attached to each of the a and the non-projecting portion 28b. As a result, the load can be set according to the properties of the strand 2a. Further, even if only one coating clamp spring 25 can be mounted on the coating clamp 24 as shown in FIG. 2A, the height of the projection 24a with respect to the diameter of the wire 2a and the tube 3 and the projection The load distribution ratio can be arbitrarily set by changing the length ratio of the portion 24a and the non-projection portion 24b.

In the above embodiment, the projections 24a, 28a
Is provided integrally with the coating clamps 24, 28, but the projections 24a, 28a are made into independent parts, which are attached to and detached from the coating clamps 24, 28 using an adhesive sheet or a magnet (not shown). The structure which enables it may be sufficient. Thereby, the protrusions 24a, 2
The gripping method can be changed according to the type of the fiber, such as gripping by the method of attaching the fiber 8a, and gripping the filled fiber 6 by the conventional method shown in FIG. 4B. Also, when using loose fibers with different diameters of wires and tubes, prepare a projection with the appropriate height for each to ensure that the wires can be securely attached to any of the loose fibers. It is possible to grasp.

Furthermore, since an appropriate pressing load can be set for each of the loose fiber 1 and the filling fiber 6, the loose fiber 1 has no damage to the wire 2a, and the filling fiber 6 has a reliable even if it has a bending habit. In addition, it can be corrected and gripped, and fusion splicing excellent in tensile strength reliability and low loss is possible. Further, since these two types of fibers can be gripped by the same clamp, there is no need to replace the components of the gripping mechanism for each fiber type, which is effective in reducing the operating cost.

Also, when the conventional covering clamp is modified into the structure of the present invention, only the covering clamp needs to be replaced without changing the clamp chassis, and the modification cost is extremely low.

Further, in the above embodiment, the protrusion 24
Although the example in which the pressing surfaces of the a and 28a and the non-projecting portions 24b and 28b are smooth is shown, irregularities may be provided to make the fiber less likely to slip, for example, by making the surface a satin finish. In particular, in the loose fiber 1, since the load applied to the projections 24a and 28a is set small in order to prevent damage to the strand 2a, it is effective to prevent the strand from slipping due to such a surface shape.

In the above embodiment, the projections 24a,
Although the example in which the corner of 28a has a right angle shape has been described, an R process with a radius of about 0.5 to 1 mm may be performed in order to prevent a sharp angle bending stress from being applied to the strand of the loose fiber 1.

[0056]

As described above, the fusion splicing method for an optical fiber according to the first aspect of the present invention provides a method for grasping a tube and simultaneously grasping an optical fiber exposed from the tube. Pushing accuracy is improved, and low-loss connection can be performed stably. Therefore, the number of defective fusion splicing is reduced, so that the working time can be reduced, and the length of the fiber to be attached to the product can be reduced to the length required for one fusion, so that human and material costs can be reduced. This has the effect.

The optical fiber fusion splicing method according to the second aspect of the present invention has the same effects as the optical fiber fusion splicing method according to the first aspect. In addition, the fiber strand is exposed by cutting and removing only the tube before grasping. Further, the coating of the fiber is removed so as to leave a coating of a predetermined length at the exposed root portion of the fiber. As a result, the length of the coating is too short, causing the protrusion of the coating clamp to directly contact the glass core wire and causing damage. It is possible to prevent the cause of defective fusion splicing such as a problem that the length of the tube inserted into the sleeve is insufficient. Therefore, the number of defective fusion splices is reduced.
The same effect as that of the optical fiber fusion splicing method according to the above aspect is obtained.

The optical fiber fusion splicing method according to the third aspect of the present invention has the same effect as the optical fiber fusion splicing method according to the first or second aspect. In addition to it,
The load applied to the wire and the tube can be easily changed to separately adjust the strength of gripping the tube and the strength of gripping the fiber strand exposed from the tube. It also has the effect of being able to do it.

In the optical fiber fusion splicer according to the fourth aspect of the present invention, the tube is grasped by the chuck stage and the non-projection portion of the coating clamp, and at the same time, the fiber exposed from the tube by the chuck stage and the projection portion. Since the element wire is gripped, the accuracy of pushing the optical fiber is improved, and the low-loss connection can be stably performed. Therefore, the fusion splicing defect is reduced, so that the work time can be reduced, and the length of the fiber to be attached to the product can be reduced to a length required for one fusion, so that human and material costs can be reduced. It has the effect of being able to. In addition, since the projecting portion and the non-projecting portion of the covering clamp are integrated, there is an effect that the structure is simplified as compared with the case where each is a separate structure.

The optical fiber fusion splicer according to the fifth aspect of the present invention has the same effects as the optical fiber fusion splicer according to the fourth aspect. In addition, the protrusions and non-protrusions each have a covering clamp spring, so that the strength of gripping the tube and the strength of gripping the fiber strand exposed from the tube can be adjusted separately. Since the loads applied to the tubes can be changed separately, there is an effect that the load can be set according to the properties of the strands.

In the optical fiber coating removing method according to the sixth aspect of the present invention, the optical fiber is positioned by abutting the tip of the tube against a step at the boundary between the strand guide groove and the tube guide groove, In order to remove the coating of the optical fiber with the coating removal blade at a certain distance from the step, the length of the coating left at the root of the fiber is fixed, and this length can be kept constant regardless of the operator. it can. Therefore, if the loose fiber from which the coating has been removed by this coating removing method is fusion-spliced, for example, by the method according to the first aspect of the present invention, the length of the coating is too short. The effect of preventing damage such as damage caused by direct contact with the glass core wire and the problem that the length of the tube inserted into the reinforcing sleeve is insufficient because the tip of the tube is too far away from the fusion point because it is too long. Play.

The optical fiber sheath remover according to the seventh aspect of the present invention is at the boundary between the strand guide groove and the tube guide groove for positioning the optical fiber by abutting the tip of the tube. Because of the provision of the step and the coating removing blade at a fixed distance from the step, the length of the coating left at the root of the fiber strand is fixed, and this length can be kept constant regardless of the operator. Therefore, if the loose fiber from which the coating has been removed by the coating remover is fusion-spliced by, for example, the fusion splicer according to the fourth aspect of the present invention, the length of the coating is too short. There is a problem that the protrusion directly contacts the glass core wire and causes damage,
The tip of the tube is too far from the fusion point because it is too long,
This has the effect of preventing a problem that the length of the tube inserted into the reinforcing sleeve is insufficient.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a part of a process of a fusion splicing method of a loose fiber according to a first embodiment of the present invention;
(A) is a side view of a loose fiber in which a tube is cut to expose a strand, (b) is a cross-sectional view of a sheath remover in a state where the fiber is placed on a sheath guide, and (c) shows a sheath of the strand. It is a side view of the loose fiber removed.

FIG. 2 is a diagram illustrating a part of a process of a fusion splicing method of a loose fiber according to the first embodiment of the present invention;
(A) is a side view of the holding mechanism part with the fiber attached, and (b) is a side view of a loose fiber fusion spliced part covered with a reinforcing sleeve.

3A and 3B are diagrams illustrating a method for gripping an optical fiber according to a second embodiment of the present invention, wherein FIG. 3A is a partially sectional elevational view of a gripping mechanism with a loose fiber mounted thereon,
(B) is a partial cross-sectional elevation view of the gripping mechanism in a state where the filling fiber is mounted.

4A and 4B are diagrams for explaining a process of a conventional loose fiber fusion splicing method, wherein FIG. 4A is a cross-sectional view of a coating remover in a state where a loose fiber is placed on a coating guide, and FIG. FIG. 4 is an elevational view, partially in elevation, of a gripping mechanism in a mounted state, and FIG. 4C is a side view of a loose fiber fusion spliced portion covered with a reinforcing sleeve.

[Explanation of symbols]

1 loose fiber, 2a, 2b strand, 3 tube, 4 strand coating, 5 glass core, 6 filling fiber, 7 filling fiber coating, 11 coating remover, 12a, 12b sandwiching plate, 13 stopper,
14 coating removal blade, 15 lower coating guide, 15a
Guide groove for strand, 15b Guide groove for tube,
15c step, 16 upper coating guide, 17a lower coating guide, 17b upper coating guide, 21 core clamp, 22 core clamp spring, 23V
Groove, 24, 28 Coated clamp, 24a, 28a
Projection, 24b, 28b Non-projection, 25, 25
a, 25b coated clamp spring, 26 chuck stage, 27 clamp chassis, 29 coated clamp, 31 reinforcing sleeve, 32 pivot.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keitaro Yano 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 2H036 KA02 MA11 MA13 NA01 2H038 CA02

Claims (7)

[Claims] 1. A method for fusion splicing an optical fiber in which a fiber element wire is accommodated in a tube, wherein the tube is grasped simultaneously with the tube by using a coated clamp in which a projection and a non-projection are integrated. An optical fiber fusion splicing method characterized by gripping the fiber strand exposed from the optical fiber. 2. The optical fiber fusion splicing method according to claim 1, wherein the fiber strand is exposed by partially cutting and removing only the tube before gripping. A fusion splicing method for an optical fiber, comprising removing a coating of the fiber so as to leave a coating of a predetermined length at a root portion of the fiber. 3. The method for fusion splicing an optical fiber according to claim 1, wherein the strength for gripping the tube and the strength for gripping the fiber strand exposed from the tube are separately adjusted. Characteristic fusion splicing method of optical fiber. 4. A fusion splicer for an optical fiber in which a fiber element wire is accommodated in a tube, the fusion splicer comprising: (a) a covering clamp spring, and a projection and a non-projection are integrally formed. (B) a chuck stage for placing an optical fiber on the chuck stage, wherein the non-projecting portion presses the tube of the optical fiber on the chuck stage, and at the same time, the projecting portion is connected to the chuck stage. The coating clamp forms a step between the protruding portion and the non-protruding portion so as to grip the optical fiber by pressing a fiber strand exposed from the optical fiber tube above. Fiber fusion splicer. 5. The optical fiber fusion splicer according to claim 4, wherein the projection and the non-projection are each provided with a covering clamp spring. 6. The fiber strand fits within the tube,
A method for removing coating of an optical fiber in which a fiber element wire is exposed from a part of a tube, comprising: (a) placing the optical fiber in a lower guide groove including a guide groove for the element wire and a guide groove for the tube; Positioning the optical fiber by abutting the tip of the tube on a step at the boundary between the guide groove for the wire and the guide groove for the tube, and (c) coating the optical fiber with a coating removing blade at a fixed distance from the step. A method for removing a coating of an optical fiber, comprising removing the coating. 7. The fiber strand fits within the tube,
An optical fiber coating remover in which a fiber strand is exposed from a part of a tube, wherein: (a) a strand guide groove for placing the strand of the optical fiber; and a tube guide for placing the tube of the optical fiber. A lower guide groove having a guide groove; and (b) a step at a boundary between the strand guide groove and the tube guide groove for positioning the optical fiber by abutting the tip of the tube; c) An optical fiber coating remover, comprising: a coating removing blade at a predetermined distance from the step.