JP2526488B2 - Reinforcement structure and reinforcement method of optical fiber fusion splicing portion - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing structure and a reinforcing method for an optical fiber fusion splicing portion.

[0002]

2. Description of the Related Art Generally, for coating optical fiber connection, a coating removal portion from which a coating layer has been removed, that is, a so-called end portion of a core is abutted, and fusion is performed by discharge heating or laser heating. And in order to reinforce this fusion splicing part,
Various reinforcing structures and methods have been proposed. For example,
FIG. 4 is a diagram showing an example of a conventional reinforcing structure. In the optical fibers 1A and 1B, the ends of the cores 3A and 3B in the coating layers 2A and 2B are abutted and then fused to form the fusion spliced portion 4. Is forming. Then, the hot-melt films 13A and 13B are attached to the inner surfaces of the pair of straight glass-ceramic plates 12A and 12B as tensile members, and the glass-ceramic plates 12A and 12B are used so that these hot-melt films 13A and 13B are inside. The optical fiber fusion splicing part is sandwiched and the hot melt films 13A and 13B are heated and melted to form the adhesive layer 14, whereby the optical fibers 1A and 1B and the glass ceramic plates 12A and 12B are bonded to each other. Then, the optical fiber fusion splicing part 4 has two reinforcing glass ceramic plates 12A, 1
It is reinforced by 2B.

As another reinforcing structure, as shown in FIG. 5, a straight steel wire rod 16 as a tensile strength member in a heat-shrinkable tube 15 and an EVA tube 17 which melts when heated to form an adhesive. They are inserted side by side, and the fusion splicing part 4 of the optical fiber is inserted into the EVA tube 17 and then heated and melted to form the adhesive layer 18, and the heat shrinkable tube 15 is heated to shrink the optical fiber. The fusion splicing portion 4 is integrated with the steel wire rod 16 by the adhesive layer 17 and the heat shrinkable tube 15 to reinforce the periphery of the fusion splicing portion 4. Incidentally, as other reinforcing techniques, for example, JP-A-57-190915 and JP-A-59-3871.
No. 4, Japanese Unexamined Patent Publication No. 2-291508, and the like.

[0004]

As described above, the above-mentioned 2
In one example, and in the conventional reinforcing structure of the optical fiber fusion splicing portion described in each publication, both of the optical fiber fusion splicing portion and the strength member are integrated with an adhesive or the like. In either case, the tensile strength member is formed in a straight shape so that the optical fiber fusion splicing portion can be held in a straight state even when an external bending force is applied. For this reason, when the optical fiber thus reinforced is stored in the extra length container, the length L0 of the tensile strength member is set as shown in FIG.
A length L2, which is a length (60 mm) that is twice the minimum bending radius R (about 30 mm) of the optical fiber, is required. As a result, the accommodation space for the optical fiber in the extra length container is large. Therefore, there arises a problem that a large space is required for disposing the optical fiber. It is an object of the present invention to provide a reinforcing structure and a reinforcing method for an optical fiber fusion splicing part, which can reduce the accommodation space of the optical fiber in the extra length accommodation body and reduce the arrangement space of the optical fiber. .

[0005]

SUMMARY OF THE INVENTION A reinforcing structure for an optical fiber fusion splicing portion of the present invention is a pair of bent reinforcing substrates for sandwiching the optical fiber fusion splicing portion connected by heat fusion from both sides. And an adhesive layer disposed on the inner surface of these bending-strengthening substrate to hold the optical fiber fusion splicing portion, and the optical fiber fusion-splicing portion and the bending reinforcement substrate are bonded by this adhesive layer. The bending radius of the reinforcing substrate is the optical fiber.
The radius of curvature is set to the minimum bending radius . Further, a flexurally formed tensile strength member extending along the optical fiber fusion splicing portion, a heat-melting resin that holds the optical fiber fusion splicing portion, and a heat shrinkage that coats the tensile strength body and the thermal melting resin A tube, and the bending radius of the strength member is
The radius of curvature is set so that the optical fiber has the minimum bending radius.
Has been. Further, the reinforcing method of the optical fiber fusion splicing part of the present invention is such that the bending radius of the optical fiber is the minimum bending radius.
A hot melt film is attached to the inner surface of each of the pair of reinforcing substrates that are bent so that the optical fiber fusion splicing part is sandwiched between the two bending reinforcement substrates so that the optical fiber fusion splicing part is sandwiched between the hot melt films. And, while holding both of these bending reinforcement substrates, the hot melt film is melted to form an adhesive layer, and the optical fiber fusion splicing portion and both bending reinforcement substrates are bonded by this adhesive layer. Integrate these. Also, the bending radius is
A tensile strength member bent and formed so that the fiber has a minimum bending radius, and a tubular heat-melting resin that holds the optical fiber fusion splicing part are placed inside the heat-shrinkable tube, and the Insert the fiber fusion splicing part, heat to melt the hot melt resin to form an adhesive layer, and bond the optical fiber fusion splicing part and the bending strength member with this adhesive layer, and heat shrink The heat-shrinkable tube covers the fusion spliced portion of the optical fiber and the bending strength member.

[0006]

Next, the present invention will be described with reference to the drawings. 1A and 1B are perspective views showing a reinforcing structure according to a first embodiment of the present invention. FIG. 1A shows a state before reinforcement and FIG. 1B shows a state after reinforcement. In FIG.
The pair of coated optical fibers 1A and 1B to be fusion-spliced are respectively covered with a coating layer 2A including a coating layer and a primary coating.
2B from which the coating layer 2
The coating removal portions 3A and 3B (core wires) from which A and 2B have been removed are projected, and further, the distal ends of the respective core wires 3A and 3B are cut, and then the respective core wires 3A and 3B are butted to each other for discharge heating or The fusion splicing is performed by laser heating or the like to form the fusion splicing portion 4. Further, 5A and 5B are a pair of bent glass-ceramic plates that have been formed in advance according to the extra length container of the fiber, and the inner surfaces of these bent glass-ceramic plates 5A and 5B are melted and bonded when heated. Hot melt films 6A and 6B as agents are attached.

Then, as shown in FIG. 2B, the hot melt film 6 is applied from both sides of the fusion splicing portion 4 of the optical fiber.
The bent glass-ceramic plates 5A and 5B are pressed so that A and 6B are inside, and the portions of the optical fibers 1A and 1B including the fusion splicing part 4 are sandwiched between them, and the glass-ceramic plates 5A and 5A By heating while pressing 5B, both hot melt films 6A,
Melt 6B. As a result, both hot melt films 6A and 6B are melted to form an integrated adhesive layer 7, and the adhesive layer 7 adheres the optical fiber fusion splicing portion 4 to both bent glass ceramic plates 5A and 5B. As a result, the optical fiber fusion splicing portion 4 is integrated with the two bent glass-ceramic plates 5A and 5B in a state of being sandwiched between them, so that the fusion splicing portion 4 is not damaged even by an external force. Reinforced.

When the optical fibers 1A and 1B thus reinforced in a bent state by the bent glass ceramic plates 5A and 5B are housed in the extra length housing, as shown in FIG. 2, for example, the bent glass ceramics are used. Board 5A, 5
If the curvature at the intermediate position in the thickness direction of B is set to be approximately equal to the minimum bending radius R (about 30 mm) of the optical fiber, the length L1 (about 60 m) corresponding to the diameter of the bending radius R is set.
It will be possible to store in m). As a result, compared with the conventional structure shown in FIG. 6, the size can be reduced by exactly the length L0 of the reinforcing structure, the accommodation space of the optical fiber in the extra length accommodation body can be reduced, and the arrangement space of the optical fiber can be reduced. Reduction can be realized.

FIGS. 3A and 3B are views showing a second embodiment of the present invention. FIG. 3A shows the state before reinforcement and FIG. 3B shows the state after reinforcement. In this embodiment, the present invention is applied to a reinforcing sleeve. As shown in FIG. 3A, the heat-shrinkable polyethylene tube 8 is slightly bent.
A bent steel wire rod 9 serving as a tensile strength member that is bent with a predetermined curvature and an EVA tube 10 that melts when heated to serve as an adhesive are inserted side by side. Then, as shown in FIG. 3B, the fusion splicing part 4 of the optical fibers 1A and 1B is inserted into the EVA tube 10, and further inserted into the heat-shrinkable polyethylene tube 8 and then heated. , The EVA tube 10 is heated and melted to form the adhesive layer 11, and the heat-shrinkable polyethylene tube 8 is filled with the optical fibers 1A and 1B including the fusion splicing portion 4.
And the bent steel wire rod 9 are integrated. Further, at the same time, the heat-shrinkable polyethylene tube 8 is shrunk by heating, and the optical fiber fusion splicing part 4 and the bent steel wire rod 9 are
Are held together with the adhesive layer 7, and as a result, the optical fiber fusion splicing portion 4 is reinforced.

Also in this embodiment, since the bent steel wire rod 9 as the tensile strength member is bent and formed in advance with a predetermined curvature, the fusion splicing portion 4 of the optical fiber also follows the curvature of the bent steel wire rod 9. It will be reinforced in a bent state. Therefore, when the optical fibers 1A and 1B reinforced in the bent state are housed in the extra length container, if the curvature of the bent steel wire rod 9 is set to the minimum bending radius R of the optical fiber, FIG. As shown, the optical fiber can be accommodated in the length L1 (about 60 mm) corresponding to the diameter of the bending radius R. As a result, the space for accommodating the optical fiber in the extra length container can be reduced, and the space for disposing the optical fiber can be reduced. The curvature of the bent glass-ceramic plate or the bent steel wire rod in each of the above-described examples is an example, and the curvature can be set to an arbitrary value depending on the size of the extra length container and the installation space of the optical fiber. It goes without saying that it can be set to a value.

[0011]

As described above, in the reinforcing structure of the present invention, the optical fiber fusion splicing part is sandwiched between the pair of bending reinforcing substrates from both sides, and these are bonded by the adhesive layer , and supplemented.
The bending radius of the strong substrate is the bending radius of the optical fiber that is the minimum bending radius.
Since a structure in which set the rate radius, the optical fiber fusion spliced portion is to be reinforced in a state of being bent at the minimum bending radius, at the time of accommodating the optical fiber excess length accommodating body
The optical fiber can be bent with a minimum bending radius, the housing space can be reduced, and the arrangement space of the optical fiber can be reduced. Further, since the optical fiber fusion splicing part is held together with the bending strength member with the hot-melt resin and these are covered with the heat shrinkable tube, the optical fiber fusion splicing part is bent in the minimum bending radius. It will be reinforced, and this optical fiber is stored in the extra length container.
In this case, the optical fiber can be bent with the minimum bending radius,
There is an effect that the accommodation space can be reduced and the installation space of the optical fiber can be reduced.

Further, the reinforcing method of the present invention has a bending radius
Is attached to the inner surface of each of a pair of reinforcing substrates formed by bending the optical fiber with a radius of curvature that is the minimum bending radius, and the optical fiber fusion splicing part is sandwiched between the hot-melt films with both bending reinforcing substrates. By sandwiching the optical fiber fusion splicing part and heating while holding both of these bending and reinforcing substrates to melt the hot melt film to form an adhesive layer, the optical fiber fusion splicing part and the both bending and reinforcing substrate are formed. It is possible to obtain a reinforcing structure in which and are adhered and these are integrated in a bent state. Alternatively, a bent tensile strength member and a tubular heat-melting resin are arranged in a heat-shrinkable tube, the optical fiber fusion splicing part is inserted into the heat-melting resin, and the heat-melting resin is melted by heating. To form an adhesive layer, bond the optical fiber fusion splicing portion and the bending strength member with this adhesive layer, and bond the optical fiber fusion splicing portion and the bending strength member with a heat-shrinkable heat-shrinkable tube. By covering, a reinforcing structure integrated in a bent state can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention,
(A) is a figure which shows the state before reinforcement, (b) is a figure which shows the state after reinforcement, respectively.

FIG. 2 is a diagram showing a space for accommodating an optical fiber in an extra length container.

FIG. 3 is a perspective view showing a second embodiment of the present invention,
(A) is a figure which shows the state before reinforcement, (b) is a figure which shows the state after reinforcement, respectively.

FIG. 4 is a perspective view showing an example of a conventional reinforcing structure.

FIG. 5 is a perspective view showing another example of a conventional reinforcing structure.

FIG. 6 is a view showing a space for accommodating an optical fiber fusion splicing portion having a conventional reinforcing structure in an extra length accommodating body.

[Explanation of symbols]

 1A, 1B Optical fiber 3A, 3B Core wire 4 Fusion splicing part 5A, 5B Bending glass ceramic plate 6A, 6B Hot melt film 7 Adhesive layer 8 Heat shrinkable polyethylene tube 9 Bending steel wire rod 10 EVA tube 11 Adhesive layer

Claims (4)

(57) [Claims] 1. A structure for reinforcing an optical fiber fusion splicing portion connected by heat fusion, and a pair of bending substrates that are bent to sandwich the optical fiber fusion splicing portion from both side surfaces, and these bending reinforcements. The adhesive layer is disposed on the inner surface of the substrate and holds the optical fiber fusion splicing portion, and the optical fiber fusion splicing portion and the bending reinforcing substrate are bonded by this adhesive layer, and the reinforcement is provided. The bending radius of the substrate is
A reinforcing structure for an optical fiber fusion splicing part, wherein the fiber is set to a radius of curvature which is a minimum bending radius . 2. In a structure for reinforcing an optical fiber fusion splicing portion connected by heat fusion, a bent tensile strength member extending along the optical fiber fusion splicing portion, and the optical fiber fusion splicing. A heat-melting resin that holds the connection portion, and a heat-shrinkable tube that covers the strength member and the heat-melting resin are provided, and the bending radius of the strength member is the smallest in the optical fiber.
It is characterized in that it is set to a radius of curvature that is the bending radius
Reinforcing structure of the optical fiber fusion splicing part of. 3. When reinforcing an optical fiber fusion spliced portion connected by heat fusion, the bending radius of the optical fiber fusion splicing portion is the optical fiber.
A hot-melt film is attached to each of the inner surfaces of a pair of reinforcing substrates that are bent to have a minimum bending radius, and the optical fiber fusion splicing part is sandwiched between the hot-melt films in the both bending reinforcing substrates. An optical fiber fusion splicing part is formed by sandwiching the optical fiber fusion splicing part, and heating while holding both of these bending and reinforcing substrates to melt the hot melt film to form an adhesive layer. A method for reinforcing an optical fiber fusion splicing part, characterized by adhering both bending reinforcing substrates and integrating them. 4. When reinforcing an optical fiber fusion spliced portion connected by thermal fusion, the bending radius of the optical fiber fusion splicing portion is the optical fiber.
A tensile strength member bent to have a minimum bending radius and a tubular heat-melting resin that holds the optical fiber fusion splicing portion are arranged in a heat-shrinkable tube. Insert the optical fiber fusion splicing part into the, and heat to melt the hot-melt resin, to bond the optical fiber fusion splicing part and the bending strength member with the hot-melt resin, and heat-shrink heat shrink A method for reinforcing an optical fiber fusion splicing portion, which comprises coating the optical fiber fusion splicing portion and a bending strength member with a tube.