JP2001174644A - Optical fiber cable junction box and transmission line fault detection method using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When an obstructive stress occurs in a transmission line of an optical fiber cable, the influence range of the stress is locally suppressed, and the position where the stress occurs is quickly found. And a transmission line fault detecting method using the same. SOLUTION: The optical fiber cable connection box has a mechanism for releasing the fixing of the optical fiber cable when a stress exceeding a predetermined limit value is applied to the optical fiber cable connected to the optical fiber cable connection box. And a mechanism in which the fiber core is deformed and cut at the same time as the release, and a transmission abnormal state is established.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable connection box for connecting optical fiber cables to each other and a transmission line fault detecting method using the same.

[0002]

2. Description of the Related Art To connect optical fiber cables, an optical fiber cable connection box fixes an end portion of the optical fiber cable, and accommodates a connection portion between the fiber cores of the two optical fiber cables and an extra connection length. And protect the whole.

[0003] In the conventional optical fiber cable junction box, the lower limit is restricted so that the fixing (tensile) strength of the optical fiber cable does not easily come off. The upper limit is not specified.

[0004] In the optical cable transmission line using the optical fiber cable junction box, the effect of the stress when an obstructive stress is applied to the optical fiber cable will be described with reference to FIG.

Reference numeral 60 denotes an optical cable transmission line using an optical fiber cable connection box 61. An optical fiber cable 62 is connected to the optical fiber cable connection box 61 to form an optical cable transmission line 60.

In the optical cable transmission line 60, when an obstructive stress P is applied to the optical fiber cable 62, the left and right optical fiber cables 62 at the location where the stress P is applied are pulled in the direction of arrow T, and the influence of the stress is reduced. Spread right and left.

In this optical fiber cable connection box 61,
Since the optical fiber cable 62 is firmly fixed so as not to come off, stress propagates to the other optical fiber cable 62 through the optical fiber cable connection box 61, and the influence of the stress is transmitted to a farther range E.

[0008]

As described above, in the conventional optical fiber cable connection box, since the limit value of the fixing (tensile) strength of the optical fiber cable is not restricted, a large stress is applied to the optical fiber cable. When it is
The effect of stress may spread not only to the connection section between the optical fiber cable at that part and the optical fiber cable connection box at both ends, but also to the connection sections before and after the section, and there is a possibility of damage, resulting in widespread damage to the transmission line. was there.

In addition, there is a problem that it takes time to specify the position where the obstructive stress is applied and the range affected by the stress.

[0010] Therefore, an object of the present invention is to solve the above-mentioned problems, and when a stress causing an obstacle occurs in a transmission line of an optical fiber cable, locally restrict the influence range of the stress, and An object of the present invention is to provide an optical fiber cable junction box capable of quickly finding a position where a stress is generated, and a transmission line fault detection method using the same.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, an optical fiber cable to be connected is introduced and fixed, and an optical fiber for connecting fiber cores of both optical fiber cables is connected. In the fiber cable connection box, fixing / releasing means for releasing the fixing of the optical fiber cable when a stress exceeding a preset limit value is applied to the optical fiber cable, and the optical fiber cable released by the fixing / releasing means. An optical fiber cable connection box comprising a fiber core cutting means for cutting a fiber core to make a transmission abnormal state with movement.

According to a second aspect of the present invention, the fixing / releasing means is provided on a connection fitting provided in the connection box main body, and a support fitting for fixing a tension member of the optical fiber cable, and one end thereof is supported. Attached to the bracket, the other end,
2. A breaking member which is attached to a tension member extending from an optical fiber cable terminal introduced into a junction box body, fixes the tension member to a support bracket, and breaks when a predetermined load is applied. It is an optical fiber cable connection box of the statement.

According to a third aspect of the present invention, the tension member and the breaking member of the optical fiber cable are connected by a tension member clamp, and the supporting member has a slack for drawing the optical fiber cable into the connection box body via the breaking member. 3. The optical fiber cable connection box according to claim 1, further comprising an adjusting unit.

According to a fourth aspect of the present invention, the fiber core cutting means is provided on the connection fitting and provided with a wiring groove for accommodating an extra connection length of the fiber core extending from the optical fiber cable terminal. An optical fiber cutting jig, a cutting member movably provided so as to intersect with the wiring groove of the fiber optical fiber cutting jig and cutting the optical fiber, and fixing of the optical fiber cable by the fixing / releasing means. The optical cable connection box according to any one of claims 1 to 3, further comprising cutting member operating means for operating the cutting member to cut the fiber core housed in the wiring groove when released.

According to a fifth aspect of the present invention, the cutting member comprises a cutter movably provided in a cutting groove formed in a fiber core cutting jig, and an optical fiber having the cutter housed in a wiring groove. A spring that constantly urges the core wire in the cutting direction, the cutting member operating means includes a stopper that holds the cutter at a normal storage position in the cutting groove,
5. When the fixing of the optical fiber cable is released by the fixing / releasing means, the tension member is moved to release the holding of the stopper to form a release wire for operating the cutting member. Optical fiber cable connection box.

According to a sixth aspect of the present invention, there is provided a fiber core deforming portion for wiring and storing the extra length of the fiber core on the connecting fitting, and the fiber core having a predetermined diameter is provided in the fiber core deforming portion. The optical fiber cable connection box according to claim 1, wherein the optical fiber cable connection box is bundled and stored.

The invention according to claim 7 uses an optical fiber cable connection box which releases the fixation of the optical fiber cable when a stress exceeding a preset limit value is applied to the optical fiber cable and causes an abnormal transmission state. By constructing an optical cable transmission line with optical fiber cable connection boxes installed at predetermined regular intervals, when a failure occurs in the optical cable transmission line due to earth and sand, fallen trees, etc., the transmission loss monitoring device will use This is a transmission path failure detection method characterized by detecting a transmission path failure.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a plan sectional view, FIG. 2 is a front sectional view, FIG. 3 is a side view, and FIG. 4 is an enlarged view of a fiber core cutting means.

First, the optical fiber cable connection box of the present invention will be described.

The outer structure of the optical fiber cable connection box 1 is such that the main body 2 and the cover 4 are tightened with the bolts 42 with the end face rubber packings 43a and 43b, the rubber packing 44, and the sealing material 45 interposed therebetween for ensuring airtightness. With the structure, the airtight state can be checked by the gas valve 46.

At both ends of the main body 2 and the cover 4, an inlet 14 for introducing the optical fiber cable terminal 5 to be connected is formed, and the inlet 14 is provided with the optical fiber cable terminal 5 to be introduced. A sleeve 9 for protection is provided.

The internal structure of the optical fiber cable connection box 1 is such that a connection fitting 3 is provided on the main body 2, and the connection fitting 3 has an optical fiber cable terminal portion 5 to be connected and extends from the optical fiber cable terminal portion 5. Fixing / releasing means 20 for fixing the tension member 6 and releasing the fixing when a predetermined stress is applied to the optical cable;
Optical fiber cable terminal 5 and tension member 6
When the tension member 6 is disengaged and the tension member 6 moves, a fiber core cutting means 25 for cutting the fiber core 50 and a connection part 21 for accommodating the fiber cores 50 and an extra connection length are stored. A storage tray 22 is provided.

First, the structure of the fixing / releasing means 20 of the optical fiber cable terminal 5 will be described.

As shown in FIG. 1, the fixing / releasing means 20 for the optical fiber cable terminal 5 is provided on the connection metal fitting 3 and is a support fitting for fixing the tension member 6 extending from the optical fiber cable terminal 5. 10 and one end thereof is attached to the support fitting 10 and is processed into a cross-sectional area which is broken by a predetermined load to release the fixing of the optical fiber cable end portion 5 when a predetermined stress is applied to the optical fiber cable. And a tension member clamp 7 for connecting the other end of the breaking member 8 and the tension member 6 to each other.
And formed.

When stress is applied to the optical fiber cable and the optical fiber cable end 5 is pulled and a predetermined load is applied to the breaking member 8, the breaking member 8 breaks and is supported on the connecting fitting 3 by the support fitting 10. The fixing of the optical fiber cable terminal portion 5, the tension member 6, and the tension member clamp 7, which have been fixed to the above, is released, and the optical fiber cable can be moved in the lateral direction in FIG.

The support fitting 10 includes a fixing fitting 11 and
Threading portion 13 for adjusting the degree of looseness connected to the breaking member 8
And a sag adjusting nut 12 screwed with the sag adjusting threaded portion 13, and the sag adjusting means comprises a sag adjusting nut threaded with the sag adjusting threaded portion 13. Nut 12
By changing the positions of the breaking member 8 fixed by the support fitting 10, the tension member clamp 7 and the optical fiber cable terminal portion 5, the looseness of the optical fiber cable to be connected can be adjusted. I have.

Next, the fiber core 50 is laid between the optical fiber cable terminal 5 and the storage tray 22, and the fiber core 50 is cut with the movement of the tension member 6. The structure of the fiber core cutting means 25 will be described.

As shown in FIG. 2, at both ends of the connection fitting 3, a fiber core deformation part 15 is provided, and a fiber core cutting jig 16 is provided on the upper part thereof by a hinge 17 and a fixing screw 18. It is provided so as to be rotatable and fixed in a closed state with respect to the fiber core deforming portion 15.

A circular wiring groove 19 for accommodating the fiber core 50 to be cut is provided above the fiber core cutting jig 16, and a cutting jig cover 23 is mounted above the wiring groove 19. Have been.

As shown in FIG. 4, the fiber core wire cutting jig 16 is provided with a cutting groove 26 in the vertical direction in FIG.
The cutting member 51 is movably accommodated in the cutting groove 26.

The cutting member 51 includes the cutter 27, the shaft 28 connected to the cutter 27, and the coil spring 2.
9 and the spring retainer 30, and the direction in which the cutter 27 cuts the fiber core 50 a wired at the intersection of the wiring groove 19 and the cutting groove 26 by the coil spring 29 (the lower side in the figure). Is always energized.

The cutting member operating means 40 for operating the cutting member 51 is formed of a Matsuba pin 34, a pin holder 35, a release wire 36, and the like.
8 into the hole 33 provided, and with the pin holder 35,
By holding down the inserted Matsuba pin 34, the coil spring 29 is normally compressed and the cutting member 51 is pressed.
At the upper end of the cutting groove 26.

One end of the release wire 36 has the Matsuba pin 3
4 and are wired in a U-shape along wire guides 38 provided at two locations across the tension member 6 extending from the optical fiber cable terminal portion 5.
The other end is fixed to the connection fitting 3 by a wire clamp 37.

Further, the release wire 36 and the tension member 6 from the introduced optical fiber cable terminal 5 are provided.
Are fixed by a wire fixing bracket 39 in the middle of the two wire guides 38.

The connection of the optical fiber cable in the optical fiber cable connection box 1 will be described.

First, the optical fiber cable terminal 5 to be connected is introduced from the sleeve 9, and the tension member 6 extending from the optical fiber cable terminal 5 is fixed to the release wire 36 by the wire fixing bracket 39. To the tension member clamp 7.

The fiber core 50 extending from the optical fiber cable terminal part 5 is bundled for one turn with a diameter of φ60 and stored in the fiber core deformation part 15.

At the time of storage, after the fixing screw 18 for fixing the fiber core wire cutting jig 16 is turned to release the fixing,
The fiber core cutting jig 16 is rotated to expose the fiber core deforming part 15. After the storage is completed, the fiber core cutting jig 16 is closed, and the fiber core deforming part 15 is fixed by a fixing screw 18. 15 on.

After being housed in the fiber core deforming portion 15, the remaining length of the remaining fiber core 50 is taken out of the fiber core deforming portion 15 through the fiber core hole 46, and the fiber core cutting jig 16 is used. The cutting jig cover 23 is accommodated along the provided circular wiring groove 19, fixed at two places in the wiring groove 19 with a silicone adhesive 47, and the cutting jig cover 23 is mounted on the wiring groove 19.

Fiber core 50 extending from wiring groove 19
The extra length is introduced into the storage tray 22 and connected to the fiber core of the optical fiber cable introduced from the left end of the optical fiber cable connection box 1, and the connection portion 21 and the extra connection length are stored in the storage tray 22. I do.

The operation of the optical fiber cable junction box according to the present invention will be described.

First, when an obstructive stress is generated on the right side of the optical fiber cable connection box in FIG. 1, the optical fiber cable terminal 5 is pulled rightward in FIG. 1, that is, the optical fiber cable terminal 5, the tension member. 6 and the tension member clamp 7 are pulled rightward, and a load is applied to the breaking member 8.

When a load equal to or greater than a predetermined limit value is applied to the breaking member 8, the breaking member 8 breaks, and the optical fiber cable end portion 5, the tension member 6, and the tension member clamp 7 are released from being fixed. Move to the right, and move to the right.

When the fixing of the optical fiber cable terminal 5 is released and the optical fiber cable terminal 5 moves rightward, the fiber core 50 extending from the optical fiber cable terminal 5 is pulled rightward, and the fiber core is pulled. Line deformation part 1
The bundle diameter of the fiber core wires 50 bundled and stored at φ60 in the wire 5 becomes small, and the transmission loss increases.

Further, as shown in FIG. 4B, when the tension member 6 moves to the right (arrow A in the figure), the release wire 36 fixed to the tension member 6 by the wire fixing metal 39 is released. Pulled right.

Since one end of the release wire 36 is fixed on the connection fitting 3 by the wire clamp 37, one end connected to the Matsuba pin 34 is pulled along the wire guide 38, and the shaft 28 and the cutting The Matsuba pin 34 holding the member 51 at the upper end of the cutting groove 26 comes out of the hole 33 of the shaft 28.

When the Matsuba pin 34 comes off, the fixing of the shaft 28 is released, and the coil spring 29 released from the compression is extended, so that the cutter 27,
The shaft 28 and the cutter holder 30 move down the cutting groove 26 (arrow B in the figure) to cut the fiber core 50 wired in the cutting groove 26, and the transmission becomes abnormal.

As described above, when a predetermined stress is applied to the optical fiber cable, the fixing of the optical fiber cable end portion 5 is released and the optical fiber cable can be moved in the lateral direction. It will not be transmitted to the optical fiber cable fixed to the left end of the box 1.

Next, in the optical cable transmission line using the optical fiber cable junction box of the present invention, when the optical fiber cable is subjected to stress that causes an obstacle, the influence of the stress and the method of detecting the transmission line failure will be described with reference to FIG. This will be described with reference to FIG.

Reference numeral 55 denotes an optical cable transmission line using the optical fiber cable connection box of the present invention. The optical fiber cable 57 is connected to the optical fiber cable connection box 1 of the present invention.
a, 1b, and 1c are connected to form an optical cable transmission line 55.

When an obstructive stress P is applied to the optical fiber cable 57 in the optical cable transmission line 55, the left and right optical fiber cables 57 at the location where the stress P is applied are pulled, the stress spreads right and left, and stress is generated. The broken portion of the optical fiber cable connection box 1b closest to the location is broken, and the fixing of the optical fiber cable terminal portion 58 is released.

For this reason, the influence of the stress depends on the optical fiber cable connection box 1 from which the optical fiber cable 57 is released.
b, the range of E is affected by the stress,
The range of N is not affected by stress.

By detecting the optical fiber cable connection box 1b in which the transmission is abnormal due to the deformation and cutting of the optical fiber core, the transmission monitoring device can quickly detect the stress generation position.

Further, an optical cable transmission line using an optical cable as a detection line and an optical fiber cable junction box as a detector is constructed at a place where a failure such as fallen tree or landslide is expected to occur.
The present invention can be applied to a system for monitoring whether or not a failure has occurred due to deterioration of a transmission state when tension is applied to an optical cable.

[0056]

In summary, according to the present invention, when stress is applied to the optical fiber cable, the fixing of the optical fiber cable connected to the optical fiber cable connection box is released, so that the influence of the stress is further increased. Prevent spreading,
In addition to being able to locally suppress the effects of stress, deforming and cutting the optical fiber core to bring the transmission to an abnormal state, the transmission monitoring device can quickly detect the location of the failure and the range of the stress By performing the optical fiber cable break connection, the recovery work can be made economical in a short time.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of one embodiment of an optical fiber cable connection box of the present invention.

FIG. 2 is a front sectional view of one embodiment of the optical fiber cable connection box of the present invention.

FIG. 3 is a side view of one embodiment of the optical fiber cable connection box of the present invention.

FIG. 4 is an enlarged view of a fiber core wire cutting means according to one embodiment of the present invention.

FIG. 5 is a diagram showing an example of a transmission line using the optical fiber cable connection box of the present invention.

FIG. 6 is a diagram showing an example of a transmission line using a conventional optical fiber cable connection box.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber cable connection box 5 Optical fiber cable terminal part 8 Breaking part 20 Fixing / releasing means 25 Fiber core wire cutting means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 10/12 (72) Inventor Takemitsu Hanami 880, Sunazawa-cho, Hitachi City, Ibaraki Prefecture Inside the Takasago Plant of Hitachi Cable, Ltd. (72) Inventor Takashi Nagayama 1060 Horowa, Ogizu-cho, Hitachi City, Ibaraki Prefecture Within Wakko Engineering Co., Ltd. Terms (reference) 2H036 RA14 2H038 CA38 5K002 AA06 BA33 EA07 FA01

Claims (7)

[Claims] An optical fiber cable connection box for introducing and fixing an optical fiber cable to be connected and connecting fiber cores of both optical fiber cables,
Fixing / releasing means for releasing the fixing of the optical fiber cable when a stress equal to or greater than a preset limit value is applied to the optical fiber cable, with the movement of the optical fiber cable released by the fixing / releasing means, An optical fiber cable connection box, comprising: a fiber core cutting means for cutting a fiber core to set a transmission abnormal state. 2. The fixing and releasing means is provided on a connection fitting provided in the connection box main body, a support fitting for fixing a tension member of the optical fiber cable, and one end is attached to the support fitting, The other end is attached to a tension member extending from the optical fiber cable terminal introduced into the connection box main body, fixing the tension member to the support bracket, and a breaking member that breaks when a predetermined load is applied. The optical fiber cable connection box according to claim 1. 3. A tension member of an optical fiber cable and a breaking member are connected by a tension member clamp, and the support fitting has a slack adjusting means for drawing the optical fiber cable into the connection box body via the breaking member. The optical fiber cable connection box according to claim 1. 4. A fiber core cutting jig provided on a connection fitting and provided with a wiring groove for accommodating an extra connection length of a fiber core extending from an optical fiber cable terminal. And a cutting member movably provided to intersect with the wiring groove of the fiber core cutting jig and cutting the fiber core, and when the fixing of the optical fiber cable is released by the fixing / releasing means, The optical cable connection box according to any one of claims 1 to 3, further comprising a cutting member operating means for operating the cutting member to cut the fiber core wire stored in the wiring groove. 5. A cutting member, comprising: a cutter movably provided in a cutting groove formed in a fiber core wire cutting jig;
A spring that constantly urges the cutter in a direction of cutting the optical fiber core wire housed in the wiring groove,
The cutting member operating means includes a stopper for holding the cutter in a normal storage position in the cutting groove, and holding of the stopper by moving the tension member when the fixing of the optical fiber cable is released by the fixing / releasing means. The optical fiber cable junction box according to any one of claims 1 to 4, wherein the optical fiber cable junction box is formed by a release wire for releasing the cutting member and operating the cutting member. 6. A fiber core deforming portion for wiring and housing the extra length of the fiber core on the connection fitting, and the fiber core is bundled with a predetermined diameter and stored in the fiber core deforming portion. The optical fiber cable connection box according to claim 1. 7. An optical fiber cable connection box which releases the fixation of the optical fiber cable when a stress exceeding a preset limit value is applied to the optical fiber cable and causes an abnormal transmission state. When an optical cable transmission line is installed at predetermined regular intervals and a failure occurs in the optical cable transmission line due to earth, sand, fallen trees, etc., the fault occurrence position of the optical cable transmission line is detected by a transmission loss monitoring device. Transmission line failure detection method characterized by the following.