JP2000193860A - Optical closure, and submarine optical cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a metallic parts from being corroded so as to be durable for a long service in an optical closure to be applied to a submarine optical cable etc. SOLUTION: The optical closure comprises a connection part storage body 5 of pressure-proof and water-tight structure in which a protective tube 9 exposed from an end of an optical fiber 2 is inserted, and an optical connection part of optical fibers 2a drawn out of the protective tube 9 is stored together with excessive portions, and the protective tube 9 which are formed of a corrosion-resistant metal of the same composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical closure and a submarine optical cable, and more particularly to an optical closure and a submarine optical cable that can be used for a long time.

[0002]

2. Description of the Related Art A closure provided at a connection portion of a submarine optical cable is required to withstand a long-term use under a high-pressure environment. For example, a highly durable closure sleeve has been developed. I have. In addition, in view of ensuring high waterproofness for a long period of time, the connection portion (fusion-bonded portion, optical connector, etc.) of the optical fibers drawn from the optical cable is stored in a metal sealable storage body. Further, a structure has been proposed in which a watertight material made of a resin foaming agent or the like is filled in a closure sleeve containing the storage body.

[0003]

By the way, the optical cable for laying the sea floor itself has been provided using a metal tube so as to protect the optical fiber inside in response to water pressure or damage caused by sharks or the like. I have. However, in the case where the closure applied to the processing of the connection portion of the optical cable has a metal housing, if the housing and the metal tube on the optical cable side are dissimilar metals, the metal If there is a contact portion with seawater in a tube or the like, an electric circuit is formed by the dissimilar metal and seawater that are in contact with each other, and corrosion is accelerated at the contact portion with seawater (so-called electrolytic corrosion), which may shorten the life. there were. In other words, if the tube of the optical cable and the housing on the optical closure side are each formed of a metal having excellent corrosion resistance, the optical closure will have a sufficient life, but due to aging and shark damage, If a metal portion (not limited to either the cable side or the closure side) and a contact portion with seawater occur, corrosion is promoted by electrolytic corrosion, and the life is shortened. Particularly in the sea, the corrosion progresses rapidly due to the electrolytic corrosion, and therefore, there is an urgent need to develop a technology capable of preventing the corrosion.

The present invention has been made in view of the above-mentioned problems, and has as its object to provide an optical closure and a submarine optical cable which are hardly corroded even when left in the sea or the like for a long period of time and can improve durability. It is assumed that.

[0005]

The present invention has the following features to attain the object mentioned above. That is, in the invention according to claim 1, an optical closure for storing an optical connection portion between optical fibers drawn out from an optical cable in a closure sleeve while securing water stoppage, wherein the optical cable is an optical fiber. A protection tube which is exposed by removing the outer sheath of the optical cable is inserted into a watertight structure connection portion housing body housed in the closure sleeve, and a tip end of the protection tube. The optical connection portions of the optical fibers drawn out from the optical fiber are configured to be stored together with the extra length, and the protective tube and the connection portion storage body are made of a metal having the same composition and corrosion resistance. An optical closure is a means for solving the above problem. Between metals of the same composition,
Even if one of the metal parts comes into contact with seawater or the like, electrolytic corrosion due to the formation of an electric circuit can be prevented. Therefore, the protective tube and the connection part housing are made of a metal having the same composition and excellent in corrosion resistance. Accordingly, even if the connection portion storage body in the optical closure or the protective tube with the built-in optical cable comes into contact with seawater or the like, it is possible to prevent the corrosion due to electrolytic corrosion and to obtain excellent durability. As the optical closure, various configurations can be adopted, but the point is that all the metal parts in contact with the protective tube on the optical cable side are formed of the same metal as the protective tube, as in the case of the connection portion housing. Preferably, this makes it possible to more reliably prevent electrolytic corrosion.

According to a second aspect of the present invention, there is provided a submarine optical cable in which optical cables are connected to each other via the optical closure according to the first aspect. In any of the optical cables connected via the optical closure, the protection tube is inserted into the connection portion housing in the optical closure. Therefore, the protection tubes of different optical cables are electrically connected to each other via the connection portion housing. In this submarine optical cable, it is possible to prevent the protective tube on the optical cable side from having a contact portion between dissimilar metals between the metal component on the optical closure side and the corrosion prevention due to electrolytic corrosion over the entire length of the submarine optical cable.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front sectional view showing a state where an optical closure 1 according to the present embodiment is assembled.
3 is a plan view, FIG. 3 is a view showing the appearance of the optical closure 1, (a) is a front view, and (b) is a side view. Figure 1,
As shown in FIGS. 2, 3 (a) and 3 (b), the optical closure 1 is applied to a submarine optical cable, and includes a connecting part 4, a connecting part storage body 5, and a closure sleeve 6.
And is provided. In these figures, reference numeral 2 denotes
Optical cable. The connecting part 4 includes a pair of fixed parts 4.
a, 4b (fixed plate), three connecting rods 4c are fixed in parallel to each other with their longitudinal directions aligned.
The frame as a whole has a rigid structure. At both ends of the three connecting rods 4c, the cable holding parts 3 are attached via the fixing parts 4a and 4b, and the connection part storage body 5 is arranged between the two cable holding parts 3.
An optical fiber 2a of the optical cable 2 is provided in the connection portion housing 5.
The optical connection portions 2b and the extra length 2c are stored. The closure sleeve 6 accommodates the connecting component 4 and the connecting portion housing 5 from the outside to secure water stoppage.

As shown in FIGS. 3 (a) and 3 (b), the closure sleeve 6 is disposed at the axially opposite ends of the two-part cylindrical resin sleeve bodies 6a and 6b. End plates 6c and 6d are provided. The end plates 6c and 6d have a split structure similar to that of the closure sleeve 6, and are bound by a fixing bracket 6f to fix the disc-shaped sealing plate 6g fitted in the center and secure watertightness. In the sealing plate 6g, a cable hole 7 inserted into the optical cable 2 is opened at the center, and the inner surface of the cable hole 7 is tightly attached to the outer surface of the optical cable 2 by being fixed by the end plates 6c and 6d. Sufficient watertightness that can withstand is secured. The sleeve bodies 6a and 6b are bound with a band 6e from the outside to ensure sufficient watertightness to withstand high water pressure. In addition, the band fixing part 6
When the band 6e is loosened by operating d (buckle bracket),
Can be disassembled and released.

As shown in FIG. 1, the closure sleeve 6
When the is assembled, the entire connecting component 4 is accommodated so as to extend along the axial direction of the sleeve main bodies 6a and 6b, including the cable gripping components 3 supported at both ends thereof. In FIG. 1, the cable gripping component 3 is
c, 6d are integrally incorporated and fixed, but are not limited to this. The end plates 6c, 6d are separate from each other, and are supported by fixed components 4a, 4b in the vicinity of the end plates 6c, 6d. Configurations can also be employed. In addition, the cable grip part 3
Is integrated with the end plates 6c and 6d, the holding position of the optical cable 2 in the cable holding component 3 and the cable hole 7 in the sealing plate 6g at the center of the end plates 6c and 6d.
Positioning between the optical closure 1 and the like becomes easy, the workability of assembling the optical closure 1 is improved, and after assembling the optical closure 1,
Since the connecting rod 4c in the closure sleeve 6 is stably supported without being displaced, the connecting part storage body 5 supported by the connecting rod 4c (the supporting structure of the connecting part storing body 5 for the connecting rod 4c will be described later), etc. Is also supported stably, and the connection part storage body 5
The optical connection portion 2b and the extra length 2c housed therein can be stably housed without vibrating. In addition, the fact that the coupling component 4 can be stably stored in the closure sleeve 6 without vibrating also prevents the optical connection portion 2b and the extra length 2c from being adversely affected by vibration, and contributes to stable storage.

As shown in FIG. 1, an optical cable 2 penetrating a cable hole 7 opened at the center of the end plates 6c and 6d is drawn into the optical closure 1 from both sides, and these are drawn. The optical cable 2 is connected to the end plate 6.
In the vicinity of c and 6d, the cable is gripped and fixed by the cable gripping component 3. FIG. 4 is a view taken along line AA of FIG. FIG.
, The cable gripping component 3 includes a ring 3a provided along the periphery of the end plates 6c and 6d,
and a total of three gripping component main bodies 3b screwed at three locations in the circumferential direction of FIG. The optical cable 2 can be gripped and fixed from three directions by the detent plate 3c attached to the tip of each gripping component body 3b by rotating each gripping component body 3b in and out of the ring 3a by a rotating operation. It has become.
The cable gripping component 3 is not limited to the structure shown in FIG. 4, and various configurations such as a configuration in which the optical cable 2 is sandwiched between a pair of opposing gripping component main bodies can be adopted. As shown in FIGS. 1 and 2, the cable holes 7 of the end plates 6c and 6d on both sides of the optical closure 1 are located on the same straight line, and the optical cable 2 drawn in from these cable holes 7 Positioned on the same straight line by the cable gripping parts 3 on both sides. The three connection rods 4c of the connection part 4 are equally arranged around a straight line where the optical cable 2 is positioned.

FIG. 9 is a sectional view showing the optical cable 2. As shown in FIG. 9, the optical cable 2 covers the outside of a protective tube 9 containing a single-core or multi-core optical fiber 2 a (mainly an optical fiber core) with an inner sheath 10.
Further, similarly, a structure is adopted in which the wire 11, the waterproof tape 12, and the outer skin 8, which are strength members, are sequentially laminated outward. Although the wire 11 is mainly an iron wire, it is more preferable to use a wire made of a material that is resistant to rust, such as stainless steel. The protection tube 9 is made of the optical fiber 2
Since a is reliably protected, it is formed of metal also in terms of withstand voltage. It is more preferable that the metal forming the protective tube 9 is also a metal that does not easily rust against seawater or the like. Examples of the metal forming the protection tube 9 include:
For example, Incoloy 825 manufactured by Daido Incoloy Alloy
Etc. are preferred. This material is Ni 38.0-46.0
%, Cr 19.5 to 23.5%, Fe22.0% or more, and is excellent in corrosion resistance to seawater. The protective tube 9 made of the alloy having the exemplified composition has a tensile strength of 60 to 80 kg / mm ² and a hardness (HB) of 140.
２２０220, which has sufficient rigidity.

FIG. 5 is a perspective view showing the connection portion housing 5. The connection portion housing 5 includes a disk-shaped closed lid 13 and a cylindrical pipe section 14 having a bottom that can be opened and closed with respect to the closed lid 13.
By affixing a flange portion 14b provided around the opening portion 14a of the pipe portion 14 with a bolt to a, a hermetic seal can be achieved. That is, the connection part storage body 5 is
Can be divided into two parts by the
3 and the pipe portion 14 are each a divided body of the connection portion housing 5.

As shown in FIGS. 1 and 2, the distal end of the optical cable 2 drawn into the optical closure 1 has its outer sheath 8 removed and the protective tube 9 is exposed. 11 is withdrawn. The protection tube 9 exposed at the end of the optical cable 2 drawn in from the one end face plate 6c side is inserted into the connection portion housing 5 via a waterproof joint 13b which is a tube insertion port provided at the center of the sealing lid 13. The protective tube 9 inserted and exposed at the tip of the optical cable 2 pulled in from the other end face plate 6d side,
The connector housing 5 is connected via a waterproof joint 14e, which is a tube insertion port provided at the center of the bottom 14c of the pipe portion 14.
It is inserted into. As shown in FIG. 5, the waterproof joint 14e
When the nut 14f is rotated and tightened, the built-in rubber packing or the like closely adheres to the periphery of the protection tube 9 to waterproof, and when the nut 14f is loosened, the protection tube 9 is allowed to move in the insertion direction. The waterproof joint 13b is also a waterproof joint 14e.
Similarly to the above, by tightening or loosening the nut, it is possible to switch between fixing and waterproofing of the protection tube 9 and a state in which the movement of the protection tube 9 is allowed.

The outer peripheral flange portion 13a of the sealing lid 13 of the connection portion housing 5, the flange portion 14b of the pipe portion 14,
The connecting rod 4c is inserted into the connecting rod insertion holes 5a, 5b, and 5c formed at three places in the bottom flange part 14d protruding around the bottom part 14c of the pipe part 14, and the waterproof joint 13b. , 14e, the sealing lid 13 and the pipe section 14 can move smoothly along the connecting rod 4c. Seal lid 13
The pipe section 14 can move independently along the three connecting rods 4c in a state where it is not bolted to each other, so that the connection section housing 5 can be easily opened and closed. When closing the opened connection part storage body 5,
Since the sealing lid 13 and the pipe portion 14 that are in contact with each other are positioned by the connecting rod 4c, the bolts between the flange portions 13a and 14b can be easily fixed.

The protective tube 9 of the optical cable 2 has a thickness of several meters.
m, the protective tubes 9 are connected to the connecting rod 4c when the sealing lid 13 and the pipe portion 14 are moved along the connecting rod 4c by loosening the nuts of the waterproof joints 13b and 14e. In the same manner as described above, the sealing lid 13 and the pipe section 14 function as a guide for slidably moving in substantially the same straight line, and the movement accompanying the opening / closing operation of the sealing lid 13 and the pipe section 14 can be performed more smoothly. Things. That is, when the sealing lid 13 and the pipe part 14 are opened and closed, the connecting rod 4c and the protection tube 9 are opened.
Does not move, and the sealing lid 13 and the pipe portion 14 move using these as guides.

Opening and closing of the connecting portion housing 5 is possible by moving either the sealing lid 13 or the pipe portion 14.
The sealing lid 13 is fixed by the fixing portion 13c (see FIGS. 1 and 2).
It is preferable that the pipe part 14 is fixed to the connecting rod 4c near the fixing part 4a, and the pipe part 14 is moved toward and away from the sealing lid 13. Thus, when the connection part storage body 5 is opened and closed, the sealing lid 13 does not move, and the trays 15a and 15b supported by the sealing lid 13 do not move, so that the trays 15a and 15b are subjected to vibration or impact. It is possible to prevent adverse effects on the optical connection portions accommodated in the trays 15a and 15b and the extra-long optical signal transmission performance. Since the fixing portion 13c can be fixed and released by screws or the like, if the fixing force of the fixing portion 13c is loosened, the fixing position of the sealing lid 13 with respect to the connecting rod 4c can be changed. A movable region L of the pipe portion 14 is secured between the sealing lid 13 and the fixed component 4b. By retracting the pipe portion 14 separated from the sealing lid 13 into the movable region L, the tray 15a , 15b can be exposed.

The sealing cover 13 and the pipe section 14 are
The whole, including 3b and 14e, is formed of a metal having the same composition as the protective tube 9. As a result, the same kind of metal is brought into contact between the sealing lid 13 or the pipe portion 14 and the protection tube 9, and even if there is a contact portion with seawater in the inside of the closure or in the protection tube 9 or the like. In addition, an electric circuit that causes electrolytic corrosion is not formed, so that the promotion of corrosion due to electrolytic corrosion can be prevented, and the corrosion resistance in seawater can be greatly improved. Various metals other than the above-mentioned Ni-based alloy can be used as the metal forming the sealing lid 13, the pipe portion 14, and the protective tube 9. However, in any case, the metal having the same composition prevents electrolytic corrosion. And improve corrosion resistance.

As shown in FIGS. 8 (a) and 8 (b), the distal end of the protective tube 9 is inserted into a tray 15a previously stored in the connecting portion storage body 5, and is fixed by a fixture 16. As shown in FIG. 7, a tube insertion hole 15c into which the protection tube 9 is inserted is formed in the tray 15a. Returning to FIGS. 8A and 8B, in the tray 15a, the optical fiber 2a is pulled out from the protective tube 9, and
Another tray 15b stacked on the tray 15a
The optical connection portion 2b between the optical fibers 2a and the extra length 2c are accommodated therein. The extra length 2c is also stored in the tray 15a in a curved state. Various configurations such as a fusion splicing portion and an optical connector can be adopted as the optical connection portion 2b.

As shown in FIGS. 1 and 6, wires 11 drawn out from both sides to the tip of the optical cable 2 drawn into the optical closure 1 are fixed components 4a, 4b, respectively.
Is clamped and fixed between the fixed base 17a provided in the above and the ring-shaped wire fixing member 17 to be bolted thereto. As a result, the tensile force acting between the two optical cables 2 is supported by the connecting rod 4c, and the connecting portion housing 5
Does not work. Further, since no tensile force acts on the protective tube 9 between the connecting portion housing 5 and the cable gripping component 3, the tensile force between the optical cables 2 does not affect the state of fixing to the tray 15a.

The fixing parts 4a, 4b, the connecting rod 4c, and the wire fixing member 17 are made of, for example, stainless steel. The wire fixing member 17 and the fixing base 17a are fixed by sandwiching the wire 11 made of iron via an insulating material (insulating bushing) (not shown). This allows
In the event that seawater comes into contact with the wire 11 or the like, an electric circuit is prevented from being formed between the seawater and the connection portion housing 5 via the wire 11, and also in this case, the corrosion due to electrolytic corrosion is promoted. Can be prevented.

The light closure 1 is assembled on the ground or on a ship, and then sunk in a target sea area. In assembling the optical closure 1, work in the connection portion housing 5 is as follows.
This is performed by opening the sealing lid 13 and the pipe portion 14. Tray 1
The work of fixing the protection tube 9 to the 5a is performed by moving the pipe portion 14 into the movable area L to open the connecting portion storage body 5, and moving or removing the tray 15b to place the tray 15a in the opened and exposed tray 15a. Do it. When the fixing of each protection tube 9 to the tray 15a is completed, the optical fibers 2a drawn from each protection tube 9 are fusion-spliced to each other, and the optical connection portion 2b (fusion portion) is connected to the connection portion holder in the tray 15b. 15d
And the extra length 2c is stored in the tray 15b in a curved state.
Next, the pipe portion 14 is brought into contact with the sealing lid 13, the flange portions 13a and 14b are bolted together, the connection portion storage body 5 is sealed, and the trays 15a and 15b are stored and protected. At this time, in the operation of contacting the pipe portion 14 with the sealing lid 13 and sealing the same, the waterproof joints 13b and 14e of the protection tube 9 are used.
When the pipe section 14 is moved in the direction of the sealing lid 13, the protection tube 9 does not follow the movement of the pipe section 14, and the pipe section 14 is allowed to move freely.
Is smoothly moved using the three connecting rods 4c and the protection tube 9 as guides. These operations are performed on the optical cable 2
By fixing the wire 11 drawn out from the wire fixing member 17 in advance, the wire 11 can be efficiently formed without being affected by the tensile force between the optical cables 2.

Next, the entire closure sleeve 6 is assembled, and a filling port 6h opened in the sleeve main bodies 6a and 6b.
As shown in FIG. 3, a filler having a water-blocking property, such as a resin foaming agent, is injected and filled into the closure sleeve 6.
Thus, the optical closure 1 is completed. The completed light closure 1 is dropped and installed in a target sea area. At this time, as shown in FIGS. 1 and 2, both optical cables 2 connected via the optical closure 1
In addition, since the wire 11 is also fixed to the wire fixing member 17, the connecting component 4 bears the tensile force acting between the two optical cables 2, and the connected state is maintained.

In the closure sleeve 6, a movable area L
Is filled with a large amount of filler for embedding, so that sufficient waterproofness can be ensured. Moreover, since the optical connection portion 2b between the optical fibers 2a is stored in the sealed connection portion storage body 5, high waterproofness can be reliably obtained. This light closure 1
Now, the movable area L is secured, so the size is increased.
An optical closure applied to a submarine optical cable hardly causes a problem in its installation space, but has a great advantage because durability is emphasized.

According to the optical closure 1, the optical connection part 2b between the optical fibers 2a can be reliably protected and stored, and the protection tube 9 and the connection part storage body 5 on the optical cable 2 side can be securely stored.
Are formed from a metal having the same composition to prevent the electrolytic corrosion of the protective tube 9 and the connecting portion housing 5 at the time of contact with seawater, so that excellent durability that can be used for a long time is obtained, The optical connection portion 2b can be stably and reliably protected and stored for a long time. Further, with this, even in the case of a submarine optical cable configured by connecting the optical cables 2, the corrosion resistance and durability of the optical closure 1, which is the connection portion thereof, can be ensured, and the life can be greatly extended. it can. That is, by forming the metal parts such as the connection part storage body 5 in the optical closure 1 from a material having excellent corrosion resistance, the optical closure 1 can have sufficient corrosion resistance. In the unlikely event that a contact portion with seawater occurs in the metal parts in 1 or the metal exterior material in the optical cable 2 and an electrical circuit is formed between the metal component and the seawater due to the presence of the contact portion of a dissimilar metal, the optical closure There is a concern of shortening the life of No. 1. However, in the optical closure 1 according to the present invention, even if a metal part in the optical closure 1 or a metal exterior material in the optical cable 2 has a contact portion with seawater, there is no contact between dissimilar metals. Therefore, the promotion of corrosion due to electrolytic corrosion can be prevented, and the life can be extended. Therefore, in the submarine optical cable formed by connecting the optical cable 2 via the optical closure 1, even if any of the optical cable 2 or the optical closure 1 is flooded, a contact portion between the metal portion and the seawater is generated. Since there is no contact portion between dissimilar metals as a whole, the formation of an electric circuit is prevented, and there is no fear that the corrosion will be adversely affected by electrolytic corrosion. In a submarine optical cable in which the optical cables 2 are connected to each other via the optical closure 1, the protective tubes 9 of the optical cables 2 are electrically connected to each other via the connection portion housing 5 in the optical closure 1. In this way, it is possible to avoid the occurrence of a contact portion between dissimilar metals between the protective tube 9 and the metal component on the optical closure 1 side in the protective tube 9.
Even if a metal part in the optical closure 1 or a metal exterior material in the optical cable 2 comes into contact with seawater, it is possible to prevent the corrosion from being accelerated by electrolytic corrosion. Moreover, in the light closure 1,
By simply sliding the pipe portion 14 along the connecting rod 4c, the connecting portion housing 5 can be easily opened and closed, so that the optical connecting portion 2b can be stored in the connecting portion housing 5 and the extra length 2c can be processed. Work can be performed efficiently, and assembly can be performed easily in a short time.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the optical closure of this embodiment, instead of the connection housing 5 of the first embodiment, FIG.
The connection part storage body 19 in FIG. 11 is employed. FIG.
0, the connecting portion housing 19 includes a box-shaped housing main body 20 and a detachable lid 21 capable of sealing the upper opening 20a of the housing main body 20. Housing body 20
On the other hand, when the lid 21 is fixed with the fixing brackets 22a and 22b to close the upper opening 20a, a sealed state is obtained by the O-ring 20b and the like provided in the housing body 20 around the upper opening 20a, Water tightness inside the storage body 19 is ensured. The housing body 20 and the lid 21 are
Is formed of the same corrosion-resistant metal as the protective tube 9 (for example, Incoloy 825 manufactured by Daido Incoloy Alloy), so that electrolytic corrosion can be prevented. Fixing bracket 22
Preferably, a and 22b are also formed from the same material.

An optical cable 2 is provided inside the connection portion housing 19.
Is inserted via waterproof joints 23 provided on both sides of the housing body 20 facing each other, and the optical connection between the optical fibers 2a drawn out from the tip of the protection tube 9 in the housing body 20 is performed. The portions 2b are stored together with the extra length in the trays 24 arranged and stored in a plurality in the housing body 20 vertically. The waterproof joint 23 has a variable tightening force. When the tightening force is reduced, the protection tube 9 is allowed to move, and when the tightening force is increased, the periphery of the protection tube 9 is sealed watertight.

As shown in FIG. 11, the tray 24 can be taken out of the housing main body 20 and can be stored again. When the optical connecting portion 2b is to be taken out or housed, the tray 24 is taken out of the housing body 20. The lid 24a of the tray 24 is opened. When the lid 21 is removed to open the connection housing 19, the extra lengths of the optical fibers 2a and the optical connection parts 2b are arranged and stored by the plurality of trays 24 in the arrangement state. The optical fiber 2a can be easily taken out and can be easily stored again.

Also in this embodiment, since the protection tube 9 of the optical cable 2 is inserted through the waterproof joint 23 provided on the housing body 20, the connection portion housing 19 is inserted.
Excellent water tightness can be ensured at the insertion opening at the inlet. In addition, the fixing position of the waterproof joint 23 is not between the housing body 20 and the lid 21 but on the side of the housing body 20. 20c
Without affecting the water tightness between the
As a result, excellent watertightness can be stably secured in the connection portion housing 19.

The optical closure and the submarine optical cable of the present invention are not limited to the above-described embodiment, and it goes without saying that various modifications are possible. For example, the connection portion storage body is not limited to the configuration including the closed lid and the pipe portion as in the above-described embodiment, and may be a connection portion that is opened and closed in a direction perpendicular to the connecting rod, or a drawer type tray. It is possible to adopt various configurations such as those having the same. Even in such a case, by forming the protective tube on the optical cable side and the connecting portion housing from the same composition of metal, it is possible to prevent electrolytic corrosion and achieve excellent corrosion resistance. Obtainable. Further, in the optical closure according to the present invention, a configuration in which a plurality of optical cables are connected to one or an optical cable for separately dropping / dropping an optical cable can be adopted. In these cases, the number of installed cable gripping parts,
The shape of the closure sleeve, the configuration of the connection portion housing, and the like are also changed. In the above-described embodiment, the application to the submarine optical cable has been described as an example. However, the application is not limited to this, and application to a low wet ground, a lake, a river, a river, or the like is also possible.

[0030]

As described above, according to the optical closure of the first aspect, the protection tube exposed from the optical cable is inserted, and the optical connection portion between the optical fibers pulled out from the tip of the protection tube is left. Since the connection tube housing having a pressure-resistant and water-tight structure to be stored together with the length and the protective tube are formed of the same metal, the contact portion of the connection container housing or the protection tube with seawater or the like should be used. In the case of occurrence of electrical contact, it is possible to prevent electrolytic corrosion caused by the contact of dissimilar metals and improve corrosion resistance, so that optical connection parts and extra length can be stably protected and stored over a long period of time, greatly improving durability. It has excellent effects such as improvement.

In the submarine optical cable according to the second aspect, the optical cables are connected to each other via the optical closure according to the first aspect. In this case, it is possible to avoid the occurrence of a contact portion between dissimilar metals between the metal component and the metal component, and to prevent corrosion promotion due to electrolytic corrosion.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment of an optical closure of the present invention.

FIG. 2 is a plan view of the optical closure of FIG.

3A and 3B are views showing a closure sleeve of the optical closure of FIG. 1, wherein FIG. 3A is a front view and FIG. 3B is a side view showing an end plate.

FIG. 4 is a view showing a cable gripping component provided on a connecting rod of the optical closure of FIG. 1;

FIG. 5 is a perspective view showing the vicinity of a connection portion housing of the optical closure of FIG. 1;

FIG. 6 is a perspective view showing the vicinity of a wire fixing member of the optical closure of FIG. 1;

FIG. 7 is a cross-sectional view showing a pipe part constituting the connection part storage body of FIG. 5;

8 is a view showing a tray stored in the connection portion storage body of FIG. 5, wherein (a) is a plan view showing the tray,
(B) is a side view showing a fixture for fixing the protective tube exposed at the tip of the optical cable to a tray.

FIG. 9 is a sectional view showing a sectional structure of the optical cable.

FIG. 10 is a view showing a second embodiment of the optical closure of the present invention, and is a perspective view showing a state where a connection portion housing is opened.

FIG. 11 is a cross-sectional view showing an operation of taking out a tray from the connection portion storage body of FIG. 10;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical closure, 2 ... Optical cable, 2a ... Optical fiber (optical fiber core wire), 2b ... Optical connection part (fusion connection part),
2c: extra length, 5, 19: connection part storage body, 6: closure sleeve, 9: protection tube.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Naoki Hagino 1440, Misaki, Sakura-shi, Chiba F-term in Fujikura Sakura Plant Co., Ltd. (Reference) 2H038 CA49 CA67 5K002 AA06 AA07 BA33 FA01 GA10

Claims (2)

[Claims] 1. An optical closure for storing an optical connection part (2b) between optical fibers (2a) drawn out of an optical cable (2) in a closure sleeve (6) while ensuring water-stopping, The optical cable has a protection tube (9) for housing the optical fiber therein, and the outer sheath of the optical cable is removed from the watertight connection housing (5, 19) housed in the closure sleeve. The exposed protective tube is inserted, and the optical connection portions of the optical fibers drawn out from the distal end of the protection tube are stored together with the extra length (2c). The optical closure (1), wherein the body is made of a corrosion-resistant metal having the same composition. 2. An undersea optical cable, wherein optical cables are connected to each other via the optical closure according to claim 1.