JPH10332976A - How to connect optical fiber - Google Patents

Abstract

(57) [Problem] To accurately connect an optical fiber core of an optical fiber core held in a connector and connect the optical fiber core. SOLUTION: Upper and lower holding members 16, 16 'in the upper and lower half portions of a connector are divided into two optical fiber cores 4A, 4B of two optical fiber core wires 1A, 1B to be connected to each other.
, But the V-groove 18 for axis alignment is
The lower holding member 16 ′ is provided only on the lower holding member 16 ′, and the upper holding member 16 connects the optical fiber cores 4 </ b> A and 4 </ b> B to the groove wall 1 of the V groove 18.
8a so as to be pressed into the V groove 18. Therefore, the alignment of the optical fiber cores 4A and 4B can be performed more accurately than when the V-grooves are provided in the upper and lower holding members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for connecting single-core or multi-core optical fibers.

[0002]

2. Description of the Related Art An optical fiber core used in a telephone office building or the like generally has a connector which is preliminarily processed and attached at both ends thereof. These optical fibers are
It is bundled and used as a cable. However, an extra length is always expected so as to always be able to cope with the determination of the line length. Therefore, when the cable is laid in the telephone office building, the optical cable becomes excessive.

[0003] The excess cable portion becomes an obstacle when adding cables due to an increase in telephone subscribers and the like. Therefore, the excess cable portion is cut and removed, and the cut optical fiber cores on both sides are cut off at the site. There have been various attempts to quickly connect to each other.

[0004] One prior art method of connecting two optical fiber core wires in this manner is a method of discharging the optical fiber core between a pair of discharge electrodes at a high voltage and fusing them together. . The fusion spliced optical fiber core is protected from the outside by reinforcing the fusion spliced portion with an appropriate reinforcing material. However, since this method uses a fusion splicer including a high-voltage power supply, it is not particularly suitable for on-site connection work.

Another prior art method is to insert an optical fiber core of an optical fiber core into a pair of upper and lower V-grooves provided on opposing surfaces of an upper and lower half of a connector, and to insert the V-groove into the V-groove. This is a non-fusion splicing method in which axes are aligned along a groove wall, and a small space between end faces of these optical fiber cores is filled with a refractive index matching medium and connected.

In this non-fusion splicing method, it is necessary to keep the gap between the end faces of the two optical fiber cores to be connected to a minimum. There is a disadvantage that the gap between them tends to be large, and the light transmission efficiency decreases. Further, it is necessary to manage the deviation of the optical axis of the optical fiber core in units of μm. However, such management is structurally impossible with a pair of upper and lower V-grooves. Could not improve.

[0007]

One object of the present invention is to easily manage the deviation of the optical axis of an optical fiber core of an optical fiber core held in a connector in units of μm. And a method for connecting an optical fiber core.

Another object to be solved by the present invention is to effectively prevent a gap from being generated at a butt joint even if tension is applied to the optical fiber after the optical fibers are butt-connected. It is an object of the present invention to provide a method for connecting an optical fiber to be processed.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is to hold two optical fiber core wires to be connected to each other in a connector, abut the optical fiber cores to each other, and connect the connector to the optical fiber core. In a method for connecting an optical fiber core wire to be fixed to the optical fiber core wire as a protective jacket of a wire connection portion,
The connector is composed of two upper and lower halves which are divided into upper and lower portions. The upper and lower halves are provided with a lower holding member having a V-groove for axially aligning the optical fiber cores to be connected to each other of the optical fiber cores, and An upper holding member for elastically pressing the optical fiber core in the V-groove of the lower holding member.
After aligning the optical fiber core with a predetermined surface pressure through a refractive index matching medium while aligning the grooves in the groove, the upper half of the connector having the upper clamping member is joined to the lower half of the connector to form an optical fiber. An object of the present invention is to provide a method for connecting an optical fiber core, wherein a fiber core is sandwiched between these upper and lower sandwiching members.

In the method for connecting an optical fiber cable according to the present invention, it is preferable that the upper and lower holding members are held by holding members provided at upper and lower half portions. The member may be formed integrally with the lower half part.

The upper and lower half portions may further include a coating holding portion for hooking and holding the coating of the optical fiber core from the periphery. In this case, when the upper and lower half portions are joined together, The sheath of the core wire can be hooked and held on the sheath holding portion.

Further, the V-groove of the lower holding member has a depth such that the optical fiber core is substantially buried, and the upper holding member is capable of cutting into the V-groove to press the optical fiber core against the groove wall of the V-groove. Preferably, it has flexibility.

The upper and lower half-split portions may further include a connector fixing means comprising a projecting portion having an engaging claw and a concave portion having an engaging claw engaged with the engaging claw of the projecting portion. The split parts can be joined and fixed to each other by the connection fixture fixing means.

As described above, if the means for aligning the optical fiber core is composed of the V-groove provided only in the holding member below the upper and lower holding members held by the connector, as in the prior art, In comparison with the case where a pair of V-grooves are provided, the dimensional control for the optical fiber core is easier, and therefore, if the dimensional accuracy in the axial direction of the V-groove of the lower holding member is good, the alignment of the optical fiber core is improved. Can be performed with high accuracy. As in the prior art, the method of axially aligning the optical fiber core with the upper and lower V-grooves involves not only the dimensional accuracy of the upper and lower V-grooves in the axial direction, but also the cross-sectional dimension of the space defined by the upper and lower V-grooves. Although the dimensional accuracy in the radial direction is required to match the outer diameter of the fiber core, the dimensional accuracy in the axial direction of the V-groove can be easily obtained only for the lower holding member.

In particular, the V-groove of the lower holding member has a depth such that the optical fiber core is substantially buried, and the upper holding member bites into the V-groove of the lower holding member to press the optical fiber core against the groove wall of the V-groove. With such flexibility, the optical fiber core can be more easily axially aligned along the groove wall of the V-groove.

After the optical fiber cores are abutted while maintaining a predetermined surface pressure, the optical fiber cores are elastically held by upper and lower holding members and are held by the frictional force of the holding members. It can be connected with high accuracy.

Further, when the coating of the optical fiber core is hooked and held by the coating holding portions of the upper and lower half portions of the connector (splice), the optical fiber cores can be abutted even if an axial tension is applied to the optical fiber core. It is possible to prevent a gap from being generated between the end faces, and thus it is possible to effectively prevent an increase in optical transmission loss at the connection portion of the optical fiber core.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. The optical fiber cores 1A, 1A to be connected by the optical fiber core connecting method according to the present invention are described below.
B consists of multi-core optical fiber cores (tape optical fiber cores) in the illustrated embodiment, and these optical fiber cores 1A, 1A,
As shown in FIG. 1 (A), each end of 1B is gradually peeled off the primary coatings (for example, ultraviolet curing resin) 2A, 2B and the secondary coatings (for example, PVC) 3A, 3B to form a multi-core light. The exposed optical fiber cores 1A, 1B are exposed to the fiber cores 4A, 4B, and a heat-shrinkable protective tube 5 for protecting the connection portion and a portion extending from the connection tool are provided on the optical fiber core wires 1A, 1B as described later. Protectors 6A, 6 for protecting the battery from bending
B from the end, and the protective tube 5 and the bend protectors 6A, 6B are arranged along the length direction in a direction away from the end so as not to hinder the connection work of the optical fiber cores 1A, 1B. (See FIG. 1B). FIG.
As can be seen from (B), since the protection tube 5 is put over the connecting portion between the two optical fiber cores 4A and 4B,
Only one protective tube 5 is one optical fiber core 1A
(Or 1B).

The method of the present invention, as shown in FIGS. 5 and 8, includes two multi-core optical fiber cores 1A to be interconnected in a connector 12 held on a butt splicer 10.
Insert the corresponding optical fiber cores 4A and 4B of 1B,
These optical fiber cores 4A, 4B are butt-connected to each other, and after the butt connection, the connecting tool 12 is used as it is as a protective jacket for the connection portion of the optical fiber cores 1A, 1B. explain.

As shown in FIGS. 2 to 4, the connecting device 12 is composed of two vertically divided halves 14, 14 ', and these upper and lower halves 14, 14' are multi-core. The upper and lower holding members 16, 16 for aligning the corresponding multi-core optical fiber cores 4A, 4B to be connected to each other of the optical fiber cores 1A, 1B, and holding these multi-core optical fiber cores 4A, 4B. ′, And a primary coating holding unit for inserting and holding the exposed portions of the primary coatings 2A and 2B of the multi-core optical fibers 1A and 1B. And a secondary coating holding section 24, 24 'for hooking and holding the secondary coatings 3A, 3B of the multi-core optical fiber core wires 1A, 1B from above and below.

As shown in FIGS. 3 and 4, the secondary coating holding portions 24 and 24 'cut into the secondary coatings 3A and 3B of the multi-core optical fiber cores 1A and 1B, respectively.
Are hooked from above and below. Therefore, even if a tensile tension is applied to the multi-core optical fiber core wires 1A and 1B from the outside, the optical fiber cores 4A and 4B inside the secondary coatings 3A and 3B are pulled by the hooking ridges 24a and 24'a. Therefore, it is possible to prevent a gap from being generated at the butted portion of the optical fiber cores 4A and 4B.

These upper and lower upper and lower halves 14, 14 '
Is molded from a thermoplastic resin such as vinyl chloride resin and polypropylene. The upper half 14 is shown in FIG.
(A) is shown with the inner surface facing up, FIG. 3 (A) is shown in vertical section, and the lower half 14 ′ is shown in FIG.
3B, the inner surface is shown up, and FIG. 3B is shown in a vertical cross section.
FIG. 3 (C) shows a longitudinal section of the connector fixing means described after 4 ′.
Is shown in The upper surface (inner surface) of the upper half portion 14 of FIGS. 2 (A) and 3 (A) is joined to the upper surface (inner surface) of the lower half portion 14 'of FIGS. 2 (B) and 3 (B). The connection tool 12 is formed in combination.

As shown in detail in FIG. 8, the lower holding member 16 axially aligns the corresponding multi-core optical fiber cores 4A, 4B to be connected to each other of the multi-core optical fiber cores 1A, 1B. As described above, the upper-side holding member 16 'is formed of a groove plate having a multi-row V-groove 18 provided on the upper surface independently of each other for each of the optical fiber cores 4A and 4B.
The respective optical fiber cores 4A and 4B are elastically engaged with the respective optical fiber cores 4A and 4B in the groove 18 so that the respective optical fiber cores 4A and 4B are correspondingly formed in the corresponding groove walls 18a.
Consists of a flat plate pressed against.

As shown in FIG. 8, the multi-row V-groove 18 of the lower holding member 16 'has a depth such that the optical fiber cores 4A and 4B are almost buried, and at least the lower surface 16a of the upper holding member 16 has a lower surface 16a. It is preferable that the optical fiber cores 4A and 4B are made of a flexible material having flexibility so as to bite into the multi-row V-groove 18 of the holding member 16 'and press the optical fiber cores 4A and 4B against the groove wall 18a of the multi-row V-groove 18.

Therefore, the upper holding member 16 is connected to the connecting member 12.
Unlike the materials described above, they are made of materials such as polyethylene, nylon, and synthetic rubber, which have relatively high elasticity and compressibility. On the other hand, the lower holding member 16 ′ is formed of a material having low compressive deformation and good workability, such as aluminum or hard plastic, so that the multi-row V-groove 18 is not distorted when the upper holding member 16 is pressed. . In this manner, when the upper and lower holding members 16 and 16 ′ are formed, when the upper holding member 16 ′ is pressed against the lower holding member 16, the multi-row V-grooves 18 of the lower holding member 16 are not distorted, and the upper holding member 16 16 ′ bites into the multi-row V-groove 18 of the lower holding member, and effectively presses the optical fiber cores 4A, 4B against the groove wall 18a, and pushes the optical fiber cores 4A, 4B along the groove wall 18a of the multi-row V-groove 18. Axis can be effectively aligned.

The upper holding member 16 has a plurality of ridges 16a extending in the vertical direction on opposite side surfaces thereof. The upper holding member 16 holds the upper half portion 14 together with the ridges 16a. The holding member 20 is elastically engaged with the member holding portion 20 and is held so as not to fall out of the holding member holding portion 20. On the other hand, the lower holding member 16 'has a plurality of ridges 16'a extending in the vertical direction on opposite side surfaces thereof, and the lower holding member 16' deforms these ridges 16'a while plastically deforming them. It is engaged with the holding member holding portion 20 of the half-split portion 14 and is held so as not to get out of the holding member holding portion 20. Of course, if the upper and lower holding members 16 and 16 'can be reliably held by the holding member holding portions 20 and 20', these ridges 16a and 16'a can be omitted.

As shown in FIGS. 2 to 4, the connecting device 12 has connecting device fixing means 26 for engaging and fixing the upper and lower half-split portions 14 and 14 'with each other. In the illustrated embodiment, the connector fixing means 26 is provided for each of the left and right connector portions 12A and 12B into which the optical fiber core wires 1A and 1B to be connected to each other are inserted, and the projections with the engaging claws 28a which mesh with each other. The protrusion 28 includes a concave portion 30 with a meshing claw 30a in which the protrusion 28 engages and the meshing claw 28a meshes. Part 14, 1
4 'are engaged with each other and fixed.

The engagement claw 28a of the projection 28 and the recess 30
Are provided in two stages, respectively, and as shown in FIG.
a includes a plurality of claw portions intermittently provided side by side, and the meshing claw 30a of each step on the concave portion 30 side is formed of a long and continuously provided ridge-shaped claw portion.

In the illustrated example, a projection 28 is provided on the left connector part 12A of the upper half part 14, a concave part 30 is provided on the right connector part 12B, and the lower half part 1
The recessed portion 30 is provided in the left connector portion 12A of 4 ′, and the protrusion 28 is provided in the right connector portion 12B (see FIG. 4).

Accordingly, these upper and lower half-split portions 1
4 and 14 ′, the projection 28 on the right side of the upper half 14 resiliently engages with the recess 30 on the right side of the lower half 14 ′, and the left side of the upper half 14. Recess 30
Resiliently meshes with the left protrusion 28 of the lower half 14 so that the upper and lower upper and lower halves 14, 14 'are fixed to each other. At this time, as shown in FIG. 9, the engaging claws 28a of the protruding portions 28 mesh with the engaging claws 30a of the concave portion 30, and these are locked with each other.

As shown in FIGS. 5 to 7, the butt connection device 10 includes a base 32 and left and right connection parts 12A and 12B provided on the base 32 and holding left and right connection parts 12A and 12B of the connection part 12, respectively. The connector holders 34A and 34B are provided. On the base 32, left and right connector holders 34A, 3
4B, the left and right connector parts 1 are respectively provided on the outside corresponding to 4B.
2A, optical fiber core wires 1A, 1B to be held by 12B
Fiber fixing devices 36A and 36B for fixing B are provided.
The fiber fixtures 36A and 36B are, as shown in FIG.
It comprises a pair of clamp members 40 and 42 supported by hinges 38 and the like so as to be openable and closable, however, these fiber fixing members 36A and 36B can have any other forms.

In the illustrated embodiment, one of the fiber fixtures 3
6A, as shown in FIG.
Preload applying means 4 for applying a preload to the optical fiber core 1B fixed and held by the optical fiber core 1B fixed and held by the other fiber fixture 36B.
4 is provided. This preload applying means 44 is provided as shown in FIG.
As shown in FIG. 7, the spring 4 spanned between a spring support piece 42a extending from the lower clamp member 42 of the fiber fixing device 36A into the base 32 and a side wall 32b on the opposite side of the base 32.
6 and the side wall 32 of the base 32 fixed to the spring support piece 42a.
a and a knob 48 which extends to the outside through a.

As shown in FIG.
5B, the optical fiber core 1A is fixed and held on the fiber fixing tool 36A in a state where it is pulled to the left side of FIG. Since the spring is biased toward the right side of (B), the optical fiber core 4A of the optical fiber core 1A is
Is abutted against the optical fiber core 4B of the optical fiber core 1B fixedly held on the other fiber fixing member 16B with a predetermined surface pressure.

As described above, since the optical fiber core 1A is fixed to the fiber fixture 36A while the knob 48 is pulled, the knob 48 can be locked in the pulled state as shown in FIG. It is preferable to provide the locking means 50 of FIG. The locking means 50 is, for example, a knob rod 4
8a and an engaging groove 54 provided in the side wall 32a of the base 32 so that the stopper 52 is engaged. When the knob 48 is pulled, the stopper 52 is moved to the side wall 32a. The knob 48 can be locked by locking the stopper 52 to the side wall 32a by angularly displacing the knob rod 48a. Therefore, in this case, the knob rod 48a must be rotatably attached to the spring support piece 42a.

Next, the operation in the case where the method of the present invention is carried out using the apparatus shown in the figure will be described in detail with reference to FIGS. As already described in detail with reference to FIG. 1, the primary coating 2 at each end of the optical fiber cores 1A and 1B.
A, 2B and the secondary coatings 3A, 3B are peeled off in a stepwise manner to expose the optical fiber cores 4A, 4B. The bending protection devices 6A and 6B for protecting the bending of the protection tube 5 and the optical fiber cores 1A and 1B are covered from the ends, and these protection tubes 5 and the bending protection devices 6A and 6B are connected to the optical fiber cores 1A and 1B. Along the length direction in a direction away from the connection end (see FIG. 1B).

Next, as shown in FIG. 6, the left and right connector holders 34A, 34B on the base 32 of the butt connector 1.
The left and right connecting part 12A, 12B of the lower half part 14 'of the connecting part 12 are respectively held by the lower half part 14'.
The lower holding member 16 ′ is held by the holding member holding portion 20 ′, and the optical fiber cores 4 of the multi-core optical fiber cores 1 </ b> A and 1 </ b> B are provided in each groove portion of the multi-row V-shaped groove 18 of the lower holding member 16 ′.
Insert A and 4B.

In this case, the optical fiber core 4B of the optical fiber core 1B is inserted into the multi-row V-groove 18 such that the tip is located substantially in the middle of the multi-row V-groove 18 in the longitudinal direction. The optical fiber core 4A is inserted into the multi-row V-groove 18 such that the distal end thereof faces the distal end of the optical fiber core 4B while maintaining a slight gap. If the wall surface of each groove of the multi-row V-groove 18 is accurately formed without being displaced in the longitudinal direction, the optical fiber core 1 along the multi-row V-groove 18
The optical fiber cores 4A and 4B of A and 1B are aligned.

Thereafter, the optical fiber cores 1A and 1B are fixed by fiber fixing tools 36A and 36B, respectively.
The optical fiber core 1B is fixed to the fiber fixture 36B and its tip is held at the initial position. However, the optical fiber core 1A has the knob 48 of the preload applying means 44 on the left side in FIG. When the fiber fixing device 36A is pulled and locked to the fiber fixing device 36A in a state locked in this state, and then the knob 48 is released, the fiber fixing device 36A is displaced rightward in FIG. The optical fiber core 4A of the optical fiber core 1A fixed and held by the fiber fixture 36A is abutted against the optical fiber core 4B of the optical fiber core 1B at a predetermined surface pressure.

In order to prevent the connection loss from being lost even if a small amount of gap is generated due to tension applied between the optical fiber cores 4A and 4B, a paste-like refractive index is previously provided on one or both of the optical fiber cores 4A and 4B. A matching medium is applied.

Thus, the optical fiber cores 4A, 4A
8B, while being held at a predetermined pressure by the spring 46 of the preload applying means 44 via the refractive index matching medium, and then, as shown in FIG. The held upper half part 14 is joined to the lower half part 14 '. At this time, as shown in FIG. 8B, the upper holding member 16 in the upper half part 14 is connected to the lower holding member 16'. The optical fiber cores 4A and 4B in the multi-row V-groove 18 are pressed against the groove wall 18a. Accordingly, these optical fiber cores 4A and 4B are
8 are mutually aligned along the groove wall 18a.

Thereafter, the optical fiber cores 1A and 1B together with the connector 12 are detached from the butt splicer 10, and finally, as shown in FIGS. 9 and 10, the optical fiber cores 1A and 1B are previously moved to the respective optical fiber cores 1A and 1B. Bending protector 6
A, 6B is returned to the outer end of the connector 12 and elastically latched by meshing. Further, the heat-shrinkable protective tube 5 brought to the one optical fiber core 1A is extended over the entire length of the connector 12. The heat-shrinkable protective tube 5 is heat-shrinked by a hot gun or the like (not shown) and closely adheres to the connector 12 to form a connection portion of the optical fiber core wires 1A and 1B.

In the embodiment shown in FIGS. 1 to 10, the upper and lower holding members 16 and 16 ′ are separate from the upper and lower halves 14 and 14 ′ of the connecting tool 12 and are separate from the upper and lower halves 14 and 14 ′. ,
The optical fiber core 4A is held by the holding member holding portions 20 and 20 'of 14', but is formed of a material which does not damage the optical fiber core 4A even when the lower half portion 14 'presses the optical fiber core 4A. If it is, lower holding member 1
6 'may be formed integrally with the lower half portion 14'. However, since the upper holding member 16 must be made of a material having elasticity and compressibility as shown in FIG. 8B, the upper holding member 16 cannot be formed integrally with the upper half part 14. Instead of being held by the holding member holding portion 20 of the split portion 14, the split portion 14 may be fixed and held to the upper half split portion 14 by bonding or other means. When the lower holding member 16 ′ is separate from the lower half portion 14 ′, the lower holding member 16 ′ is fixed and held to the lower half portion 14 ′ by bonding or other means in the same manner. Is also good.

In the above embodiment, the present invention is applied to the multi-core optical fiber cores 1A and 1B, but it goes without saying that the present invention can also be applied to a single-core optical fiber core. In this case, the V-groove 18 of the lower holding member 16 '
The structure and connection method of the connector 12 and the upper and lower sandwiching members 16, 16 'are substantially the same as those of the multi-core optical fiber core except that is a single row.

[0044]

According to the present invention, as described above, the means for aligning the optical fiber core consists of the V-groove provided only on the holding member below the upper and lower holding members held by the connector. Therefore, it is easier to control the dimensions of the optical fiber core than when a pair of upper and lower V-grooves are provided as in the prior art, and therefore, the optical fiber core extends along the groove wall of the V-groove of the lower holding member. Can be performed with high accuracy.

In particular, the V-groove of the lower holding member has a depth such that the optical fiber core is substantially buried, and the upper holding member bites into the V-groove of the lower holding member to press the optical fiber core against the groove wall of the V-groove. With such flexibility, the alignment of the optical fiber core can be performed more accurately and easily.

After the optical fiber cores are abutted while maintaining a predetermined surface pressure, the optical fiber cores are clamped between the upper and lower clamping members by utilizing the elasticity of the upper clamping member, and held by the frictional force of the clamping members. Therefore, the optical fiber core can be optically connected with high precision.

Further, when the coating of the optical fiber core is hooked and held by the coating holding portions of the upper and lower half portions of the connector (splice), the optical fiber cores can be abutted even when the axial tension is applied to the optical fiber core. It is possible to prevent a gap from being generated between the end faces, and thus it is possible to effectively prevent an increase in optical transmission loss at the connection portion of the optical fiber core.

[Brief description of the drawings]

FIG. 1 shows a processing state of a multi-core optical fiber cable to be connected by the connection method of the present invention, and FIG. 1A is a side view showing a state where a primary coating and a secondary coating are stepped off, and FIG. (B) is a side view of the optical fiber core wire of FIG.

FIGS. 2A and 2B show a disassembled and unfolded state of a two-piece type connector used in the method of the present invention, wherein FIG. 2A is a bottom view of an upper half part, and FIG. It is a top view of a part.

FIG. 3 is a sectional view showing an exploded state of the connecting device of FIG. 2; FIG. 3 (A) is a longitudinal sectional view thereof, and FIG.
It is a B sectional view.

FIG. 4 is an exploded perspective view of the two-piece connector of FIGS. 2 and 3;

5A and 5B show a butt splicer used in the method of the present invention. FIG. 5A is a perspective view of the butt splicer, and FIG. 5B is a partial cross-sectional view of a portion having a fiber fixing device having a preload applying means. .

FIG. 6 is a side view of a state in which the optical fiber core is held in the lower half portion of the connector held by the butt splicer.

FIG. 7 is a side view of a state in which the upper half portion of the connecting tool is joined from the state of FIG. 6;

8A and 8B sequentially show a state in which the optical fiber core is held between upper and lower holding members in the connector, and FIG. 8A is an enlarged cross-sectional view of the state before the upper holding member bites into the optical fiber core; (B) is an enlarged cross-sectional view in a state where the upper holding member has completely pressed the optical fiber core against the lower holding member.

FIG. 9 is an end view showing, in cross section, a part of a connection portion of an optical fiber cable formed by a method of the present invention and formed with a connector.

10 is a plan view showing a part of a state in which an upper half portion of a connecting portion of the optical fiber core of FIG. 9 is removed, in a cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1A Optical fiber core wire 1B Optical fiber core wire 2A Primary coating (for example, ultraviolet curing resin) 2B Primary coating (for example, ultraviolet curing resin) 3A Secondary coating (for example, PVC etc.) 3B Secondary coating (for example, PVC etc.) 4A Optical fiber core 4B Optical fiber core 5 Heat-shrinkable protective tube 6A Bend protector 6B Bend protector 10 Connector 12 Connector 12A Left connector 12B Right connector 14 Upper half 14 'Lower half 16 Upper Holding member 16a Ridge 16 'Lower holding member 16'a Ridge 18 Multi-row V-groove 18a Groove wall 20 Holding member holding part 20' Holding member holding part 22 Primary coating holding part 22 'Primary coating holding part 24 Secondary coating holding Portion 24 'Secondary coating holding portion 24a Hook ridge 24'a Hook ridge 26 Connector fixing means 28 Projection 28a Meshing 28a 30 recess 30a meshing claw 32 base 32a side wall 32b side wall 34A left connector holder 34B right connector holder 36A fiber fixture 36B fiber fixture 38 hinge 40 clamp member 42 clamp member 42a spring support piece 44 preload applying means 46 Spring 48 Knob 48a Knob rod 50 Locking means 52 Stopper 54 Engagement groove

Claims (6)

[Claims] 1. An optical fiber core to be connected to each other is held by a connector and their optical fiber cores are butted against each other, and the connector is used as a protective jacket for a connection portion of the optical fiber. In a method for connecting an optical fiber core fixed to an optical fiber core, the connecting tool includes two upper and lower half portions that are vertically divided, and the upper and lower half portions are connected to each other by the optical fiber core wire. A lower holding member having a V-groove for axially aligning an optical fiber core to be connected to the optical fiber core, and an upper holding member for elastically pressing the optical fiber core in the V-groove of the lower holding member; After aligning the optical fiber core with a predetermined surface pressure via a refractive index matching medium while aligning the core in the V-shaped groove of the lower holding member of the lower part of the connector, the upper holding member is provided. Said A method for connecting an optical fiber core, wherein an upper half portion of a connector is joined to a lower half portion of the connector, and the optical fiber core is sandwiched between the upper and lower holding members. 2. The method of connecting an optical fiber cable according to claim 1, wherein the upper and lower holding members are held by holding members provided on the upper and lower half portions. Characteristic optical fiber core wire connection method. 3. The optical fiber core wire connecting method according to claim 1, wherein the lower holding member is formed integrally with the lower half part. Connection method. 4. The method of connecting an optical fiber core according to claim 1, wherein the upper and lower half-split portions further include a coating holding portion that hooks and holds a coating of the optical fiber core, and the upper and lower half. A method for connecting an optical fiber core, wherein the coating of the optical fiber core is hooked and held on the coating holding part when the split part is joined. 5. The method of connecting an optical fiber core according to claim 1, wherein the V-groove of the lower holding member has a depth that the optical fiber core is substantially buried, and the upper holding member is provided. Is flexible so as to bite into the V-groove and press the optical fiber core against the groove wall of the V-groove. 6. The method for connecting an optical fiber core according to claim 1, wherein the upper and lower halves are:
Further, there is provided a connector fixing means comprising a projecting portion having a meshing claw and a concave portion having a meshing claw meshing with the meshing claw of the projecting portion, and the upper and lower half portions are joined and fixed to each other by the connector fixing means. A method for connecting an optical fiber core, comprising: