JP4163035B2 - Method for fixing the connecting portion of an optical fiber cable and its fixing structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an FTTH (Fiber To The Home) which installs an optical fiber cable laid in a sewer pipe to each household, particularly in a branch pipe branched from a sewer main. The present invention relates to a method of installing a connecting portion of a branched optical fiber cable laid in a public fence and a fixing structure thereof.
[0002]
[Prior art]
Laying fiber optic cables in sewer pipes has been a key feature since the late 1980s. Po It is implemented for the purpose of remote monitoring and remote control of the pump station. They are used to connect optical fiber cables between two points such as sewer facilities, so the number of optical fiber cables is from several tens to several hundreds. There is no need to branch to. However, since workability deteriorates with a long optical fiber cable, an optical fiber cable of about several hundred meters is connected by a manhole, and a connection branch box is used for the connection.
[0003]
Currently, high-speed / ultra-high-speed communication networks are being constructed, and there are two methods for laying optical fiber cables, which are the medium, aerial and underground. Optical fiber cable laying in the underground burial method has characteristics of protecting the spatial environment (aesthetics of the ground landscape, etc.) and being resistant to disasters such as earthquakes and typhoons, compared to laying in the aerial method. In particular, the sewer pipes in the underground pipes have branch pipes (mounting pipes) connected to the main pipes already leading to the homes, and the upper part of the pipes is an empty space. It is attracting attention as an important infrastructure for the FTTH project that draws in cables.
[0004]
When laying optical fiber cables in each house using sewer pipes in this way, branch cables (fiber optic cables) of about 24 to 200 cores are laid from the communication base into the sewer mains, and the sewer mains are connected to each other. In connected manholes, etc., branch to 2 to 4 cores (more than that for housing complex) for laying to each house by connecting branch boxes. It is installed from the pipe through the branch pipe to the branch pipe pole at the end of the branch pipe (pointing to the public fence, in the residential land or on the road). From there, the drawing optical fiber cable and the branching optical fiber cable are connected by a junction box and led to each house.
[0005]
In many cases, the construction work of the optical fiber cable in the sewer pipe is ordered as a public work, so the construction work is ordered in order to convert the entire area into FTTH. In such a case, it is desirable to clarify the boundary line of the optical fiber cable laying with a public fence as construction or property classification on the public side. Therefore, the demarcation point, that is, the connection point of the branching optical fiber cable is provided in the public fence, and the connection branch box is installed in the public fence.
[0006]
For example, Patent Document 1 describes an optical fiber connection box for connecting optical fibers to each other. This has a main body and a lid attached to the main body in a watertight state, and connects the optical fibers constituting the optical fiber cable to each other and is filled with a soft or moisture-proof filler. Yes. After connecting the optical fiber in this way, if it is covered with a lid, it will be watertight, and the internal softness or moisture proofness will be maintained by the soft filling material, so it will be installed in the sewer facility basin. In such a case, it becomes possible to prevent moisture and moisture from entering.
[0007]
Further, Patent Document 2 describes an optical fiber cable termination box related to a connection box for connecting an optical fiber cable installed overhead to a house. The optical fiber cable termination box has a base on a flat plate supported by the floor or wall of the building, and a fusion splicing as an optical connection part that connects the optical fiber core led out of the optical fiber cable to another optical fiber core And an optical connection portion storage tray for storing the connection length and the connection surplus length. Such optical fiber cable termination boxes connect the optical fiber cables.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-5593
[Patent Document 2]
JP-A-8-320418
[0009]
[Problems to be solved by the invention]
However, the configurations of the optical fiber connection box and the optical fiber cable termination box described in Patent Document 1 and Patent Document 2 have a large number of parts and work when the optical fiber cores of the optical fiber cables are connected and assembled. There is a problem with the characteristics, and when assembled, the dimensions become large, making it unsuitable for installation on public fences.
[0010]
In consideration of the above-described problems, the present invention can maintain the connection portion between the optical fiber cables in a waterproof and moisture-proof state, and can fix the connection portion of the optical fiber cable that can be easily assembled and installed. It is an object to provide a method and a fixing structure thereof.
[0011]
[Means for Solving the Problems]
The method of fixing the connection part of the optical fiber cable according to claim 1 of the present invention is the connection part of the optical fiber cable in which the optical fiber cables are connected to a public fence provided at the end of the branch pipe branched from the sewer main. A protective member is placed on the fused portion of the optical fiber core at the connection portion of the optical fiber cable, a sealing member is fitted between the both ends of the protective member and the optical fiber cable, and both ends of the protective member are fixed. A protective case assembled by attaching an end fixing member to the part is fixed to the inner wall of the public fence.
[0012]
According to such a method, the fused portion of the optical fiber core wire in the connection portion between the optical fiber cable introduced through the sewer main by the protective case and the optical fiber cable guided to the house can be maintained in a waterproof and moisture-proof state. . Further, in a sewage environment, hydrogen sulfide may be generated to cause a strong acid state, but the fused portion of the optical fiber core can be protected from the strong acid state by a protective case. Further, since the number of parts of the protective case is small, it can be easily assembled and workability is improved.
[0013]
The method of fixing the connection part of the optical fiber cable according to claim 2 fixes the connection part of the optical fiber cable in which the optical fiber cables are connected to a public pole provided at the end of the branch pipe branched from the sewer main. In the method, the fusion part of the optical fiber core wire in the connection part of the optical fiber cable is placed on the fixing member, and the tension member exposed from the end part of each optical fiber cable in the vicinity of the fusion part is provided. Fix to both ends of the fixing member, cover the fixing member with a protection member, fit a sealing member between the both ends of the protection member and the optical fiber cable, and attach end fixing members to both ends of the protection member. The assembled protective case is fixed to the inner wall of the public fence.
[0014]
According to such a method, the fusion part of the optical fiber core wire is protected by the protective case, and the tension member between the optical fiber cables to be connected is connected via the fixing member. The tensile force is not applied, and breakage of the fused portion of the optical fiber core wire can be prevented.
[0015]
The method for fixing the connection portion of the optical fiber cable according to claim 3 is the method according to claim 1 or 2, wherein the fusion portion of the optical fiber core wire and the optical fiber cable around the fusion portion are pulled out of the public fence. After assembling the protective case, the optical fiber cable drawn out of the public fence is inserted and arranged while being wound along the inner wall of the public fence, and then the protective case is attached to the inner wall of the public fence. It is characterized by being fixed to.
[0016]
According to such a method, by inserting the optical fiber cable while being wound along the inner wall of the public fence, the optical fiber cable can be arranged on the inner wall of the public fence without bending the optical fiber cable beyond the allowable bending radius. Can do.
[0017]
The method for fixing the connection portion of the optical fiber cable according to claim 4 includes a gripping member when fixing the protective case to the inner wall of the public fence in any one of claims 1 to 3. The plate member is fixed to the inner wall of the public fence with the protective case attached to the plate member.
[0018]
According to such a method, by installing the plate-like member to which the protective case is attached on the inner wall of the public fence, the connection portion of the optical fiber cable can be easily fixed to the inner wall of the public fence as one unit.
[0019]
The fixing structure of the connection part of the optical fiber cable according to claim 5 is a fixing structure of the connection part of the optical fiber cable in which the optical fiber cables are connected to a public pipe provided at the end of the branch pipe branched from the sewer main. A protective member is placed on the fused portion of the optical fiber core wire in the connection portion of the optical fiber cable, and a cylindrical sealing member is fitted between both ends of the protective member and the optical fiber cable, and both ends of the protective member A protective case assembled by attaching a cylindrical end fixing member to the outer surface of the part is fixed to the inner wall of the public fence.
[0020]
According to such a configuration, the fused portion of the optical fiber core wire at the connection portion between the optical fiber cable introduced through the sewer main by the protective case and the optical fiber cable guided to the house can be maintained in a waterproof and moisture-proof state. . Further, in a sewage environment, hydrogen sulfide may be generated to cause a strong acid state, but the fused portion of the optical fiber core can be protected from the strong acid state by a protective case. Further, since the number of parts of the protective case is small, it can be easily assembled and workability is improved.
[0021]
The fixing structure of the connecting portion of the optical fiber cable according to claim 6 is a fixing structure of the connecting portion of the optical fiber cable in which the optical fiber cables are connected to a public pipe provided at the end of the branch pipe branched from the sewer main. The optical fiber core wire fusion portion at the connection portion of the optical fiber cable is placed on a fixing member having a substantially U-shaped cross section, from the end portion of each optical fiber cable in the vicinity of the fusion portion. While the exposed tension member is fixed to both ends of the fixing member, the fixing member is covered with a cylindrical protective member, and a cylindrical sealing member is provided between the both ends of the protective member and the optical fiber cable. The protective case assembled with the cylindrical end fixing members attached to the outer surfaces of both ends of the protective member is fixed to the inner wall of the public fence. It is characterized by that.
[0022]
According to such a configuration, the fusion part of the optical fiber core wire is protected by the protective case, and the tension member between the optical fiber cables to be connected is connected via the fixing member. The tensile force is not applied, and breakage of the fused portion of the optical fiber core wire can be prevented.
[0023]
The fixing structure of the connecting portion of the optical fiber cable according to claim 7 is the structure of the optical fiber cable according to claim 5 or 6, wherein the optical fiber cable in the vicinity of the protective case storing the fused portion of the optical fiber cable is spirally wound. It is arrange | positioned along the inner wall of a public fence, The said protective case is fixed to the inner wall of the said public fence.
[0024]
According to such a configuration, the optical fiber cable is arranged in a spiral state along the inner wall of the public fence, so that the optical fiber cable can be connected to the inner wall of the public fence without bending the optical fiber cable beyond the allowable bending radius. Can be arranged.
[0025]
An optical fiber cable connecting portion fixing structure according to an eighth aspect of the present invention is the optical fiber cable connecting structure according to any one of the fifth to seventh aspects, wherein the protective case is a gripping member having a substantially U shape attached to a plate-like member. It is fitted, The said plate-shaped member is installed in the inner wall of the said public fence in the state bent along the inner wall of the said public fence.
[0026]
According to such a configuration, the optical fiber cable can be obtained by installing the plate-like member on the inner wall of the public fence while fitting the protective case to the gripping member having a substantially U-shaped cross section attached to the plate-like member. Can be easily fixed to the inner wall of a public fence as one unit.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.
[0028]
FIG. 1 is a cross-sectional view showing an example of an outline of a sewer pipe. In FIG. 1, reference numeral 1 denotes a main pipe of a sewer pipe, which is piped between a manhole 2 and another manhole 3. The branch pipes 4 and 5 branch from the upper side of the main pipe 1 at the branch pipe ports 6 and 7, and the branch pipes 4 and 5 are branch pipe troughs (hereinafter referred to as “public pipes”). 8 and 9).
[0029]
In general, the main pipe 1 is laid at a depth of several meters along the road. As shown in FIG. 2, branch pipe ports 6 and 7 are formed on the upper side of the main pipe 1 on the oblique side. 5 is connected to public fences 8 and 9 from the branch pipe ports 6 and 7 at different angles.
[0030]
FIG. 3 shows the situation of each ridge as an example of sewerage. From the drainage pipe 35 connected to the drainage pipe 30 of the bathroom, toilet, kitchen, etc. of the house 20 or the joining pipe 34 that joins the drainage pipe 31 from the drainage pipe 35, the drainage pipe 32, and the public poles 8 and 9 In many cases, a connecting rod 33 for connecting the drainage pipe 10 is installed as a sewage tank for inspection in a residential land. The boundary line shown in FIG. 3 is a public / private boundary line that distinguishes public and private property, and in this embodiment, an optical fiber cable described later in the public fences 8 and 9 distinguished by the public / private boundary line. The connecting part is fixed and becomes the demarcation point. In addition, it is possible to provide a connection part of an optical fiber cable also in these inspection sewage tanks.
[0031]
First, when laying an optical fiber cable in the main pipe 1, using a TV camera or the like in the main pipe 1, the distance between the manholes 2 and 3, the branch pipes 4 in the main pipe 1 from the manhole 2 and 5 branches tube The distance to the mouths 6 and 7, the distance from the branch pipes 4 and 5 to the public fences 8 and 9, the depth of the public fences 8 and 9, etc. are accurately measured (see FIG. 1).
[0032]
Then, based on the measurement result, as shown in FIG. 4, about 24 to 200 optical fiber cables 12 are laid from the communication base (not shown) to the upper part of the main pipe 1 in the sewer pipe. In the manholes 2 and 3 connecting the tubes 1 to each other, branch optical fiber cables 13 of about 2 to 4 cores (more than the housing complex) for laying from the connection branch box 15 to the public fences 8 and 9 are branched. At the same time, the branching optical fiber cable 13 is inserted into the protective sheath tube 40 and is laid from the main pipe 1 to the public fences 8 and 9 through the branch pipes 4 and 5.
[0033]
In addition, an example of a method for laying optical fiber cables up to public fences 8 and 9 as shown in FIG. 4 will be described. A hollow guide pipe 41 for laying an optical fiber cable and a sheath pipe 40 branched from the guide pipe 41 are inserted into the main pipe 1 of the underground conduit 29, and the guide pipe is located near the branch pipe ports 6 and 7. 41 and the branch portion 41a of the sheath tube 40 are positioned, the sheath tube 40 is pulled up into the branch tubes 4 and 5, and is fixed to the upper side of the branch tubes 4 and 5 by the fixing member 46. Then, both ends of the tension wire rope 42 inserted into the guide tube 41 are tensioned by a tension mechanism 43 provided in the manholes 2 and 3, and the guide tube 41 is installed at a substantially upper portion in the main tube 1. The slack preventing material 45 is arranged at a predetermined interval to prevent the guide tube 41 from slacking downward. Further, the optical fiber cable 12 and the branching optical fiber cable 13 are inserted into the guide tube 41, and the branching optical fiber cable 13 is laid from the branching portion 41a to the public fences 8 and 9 through the sheath tube 40. The method for laying the optical fiber cable 12 and the branching optical fiber cable 13 is not particularly limited.
[0034]
Although there are many types of optical fiber cables, SM (single mode) in which the core diameter is 10 μm or less and the distortion of the transmitted signal is reduced is generally used. In this embodiment, the branching optical fiber is used. An SM (single mode) type is applied to the cable 13. For example, an SM type optical fiber cable having a configuration of φ0.25 mm UV strand × 1, 2 core tape core wire × 1, 4 core tape core wire × 1, 8 core tape core wire × 1, etc. is applicable. Moreover, even if it is a rose core wire, it is applicable.
[0035]
An example of the branching optical fiber cable 13 is shown. As shown in FIG. 5, two optical fiber cores 51 disposed substantially at the center, an aramid fiber 54 disposed (vertically attached) around the optical fiber core 51, and the periphery of the aramid fiber 54 are covered. An optical fiber cord 59 including a thermoplastic resin coating 57, a tension member 52 made of steel wire disposed on the left and right of the optical fiber cord 59, and an inner coating formed on the outer periphery of the optical fiber cord 59 and the tension member 52. A material 53, a tear string 55 disposed at the upper center of the inner covering material 53, an aluminum / polyester laminate tape 56 covering the inner covering material 53 and the tear string 55, and an aluminum / polyester laminate tape 56. And an outer covering material 58 for covering the outer periphery of the outer periphery. As shown in FIG. 5, the branching optical fiber cable 13 has a rectangular cross section. The inner covering material 53 and the outer covering material 58 are made of polyethylene resin. An adhesive layer is formed on at least one of the inner surface and the outer surface of the aluminum / polyester laminate tape 56. As described above, since the aramid fiber 54 as the tensile fiber is disposed inside the optical fiber cord 59 of the optical fiber cable 13, the tensile strength of the optical fiber cable 13 as a whole is improved, and the optical fiber cord is only an optical fiber cord. Compared with the optical fiber cord, the optical fiber cord has an appropriate thickness and tensile strength, so that it is easy to handle when the optical fiber cables are connected to each other, and is hard to break.
[0036]
Further, the sheath tube 40 into which the branching optical fiber cable 13 is inserted has a spiral shape made of stainless steel, which is applied in the present embodiment, but is not particularly limited. A non-spiral shape is also applicable.
[0037]
As described above, the sheath tube 40 through which the branch optical fiber cable 13 laid down to the public fences 8 and 9 is inserted is provided with saddle-like clamps 40a on the inner walls 8a and 9a of the public fences 8 and 9, as shown in FIG. It is fixed with. Then, as shown in FIG. 4, the pull-in optical fiber cable 14 connected to the termination box 20a provided on the outer wall of each house 20 and the branch optical fiber cable 13 in the sheath tube 40 are connected as described later. By forming the connecting portion and fixing the connecting portion to the inner walls 8a and 9a of the public fences 8 and 9, each house 20 can communicate with the communication base with an optical fiber cable, and high-speed communication can be realized. The pull-in optical fiber cable 14 is the same as the branching optical fiber cable 13 described above. Na The explanation is omitted.
[0038]
A connection portion between the branching optical fiber cable 13 and the drawing-in optical fiber cable 14 will be described below. FIG. 7 is a perspective view showing a schematic configuration of a protective case in a connection portion between optical fiber cables according to the present embodiment.
[0039]
As shown in FIG. 7, a protective case 70 is provided at a connection portion where the branching optical fiber cable 13 and the drawing-in optical fiber cable 14 are connected. The protective case 70 includes a fusion protective sleeve 71 having therein a fusion part 71a to which the optical fiber core 51 of the branching optical fiber cable 13 and the optical fiber core 61 of the drawing optical fiber cable 14 are fused and connected. The tension members 52 and 62 exposed from the end portions of the optical fiber cables 13 and 14 in the vicinity of the fused portion of the branching optical fiber cable 13 and the drawing optical fiber cable 14 are mounted while the fusion protection sleeve 71 is placed. A fixing member 72 to be fixed, a protective member 73 that accommodates the fixing member 72 therein, a sealing member 74 that is disposed in both ends of the protective member 73, and an outer surface of both ends of the protective member 73, The sealing member 74, the protective member 73, the branching optical fiber cable 13, and the drawing optical fiber cable Comprising an end portion fixing member 75 is tightened between the outer surface of the Le 14.
[0040]
In the present embodiment, a heat-shrinkable tube having a length of about 30 mm, which is generally used for fusion bonding between optical fiber cores and mechanical connection, is applied to the fusion protection sleeve 71. It is also possible to apply a hollow tube or the like.
[0041]
As shown in FIG. 7, the fixing member 72 is formed by forming a substantially rectangular opening 72 a over the entire length in the upper surface of a cylindrical pipe, and has a substantially U-shaped cross section. Therefore, the fixing member 72 has a shape in which the fused portion 71a of the optical fiber cores 51 and 61 and the fusion protection sleeve 71 are easily placed. In the present embodiment, a stainless steel pipe having an outer diameter of about 6 mm and a length of about 40 mm provided with the opening 72 a as described above is applied to the fixing member 72.
[0042]
Moreover, the cylindrical member which has the thread part 73a at both ends is used for the protection member 73, and the notch part 73b which divides | segments a thread part is provided in both ends. The length of the notch 73 b in the longitudinal direction is substantially the same as the length of the threaded portion 73 a formed at both ends of the protective member 73. In the present embodiment, a stainless steel pipe having an outer diameter of about 10 mm and a length of about 70 mm is applied to the protection member 73. However, the cross section may be a square shape instead of a circle. Moreover, it is also possible to apply what was divided | segmented into multiple in the circumferential direction. When applying a square-shaped protective member, the end fixing members provided at both ends are shaped to be attached to the end of the protective member, and the sealing member branches off from the protective member when the end fixing member is attached. It is preferable that the optical fiber cable 13 and the pull-in optical fiber cable 14 be tightened between the outer surfaces of the optical fiber cable 13 and the pull-in optical fiber cable 14. Moreover, when applying the protection member divided into a plurality, the fixing member is arranged so as to cover it, and the outer surface of the protection member divided into a plurality of portions is tightened with a metal band or the like and positioned at both ends of the protection member. It is preferable that the sealing member be clamped between the outer surfaces of the branching optical fiber cable 13 and the drawing optical fiber cable 14.
[0043]
Further, the sealing member 74 is formed with a through hole 74a having a cross-sectional shape slightly smaller than the cross-sectional shape of the branching optical fiber cable 13 or the drawing-in optical fiber cable 14 at a substantially central portion. The sealing member 74 has a cylindrical shape, and the outer peripheral portion 74b has a tapered shape that is inclined in the longitudinal direction. The material of the sealing member 74 is only required to be able to withstand the environment of sewage. For example, a material made of rubber such as NBR (nitrile rubber) or SBR (styrene butadiene rubber) is preferable.
[0044]
The end fixing member 75 has a cylindrical pipe shape, and an end surface having a circular opening 75a having a diameter larger than the outer diameter of the branching optical fiber cable 13 and the drawing optical fiber cable 14 at one end thereof. 75b is formed. The opening 75a is preferably sized so as not to contact the outer surfaces of the branching optical fiber cable 13 and the drawing optical fiber cable 14 when the end fixing member 75 is rotated. Further, on the inner peripheral surface of the end fixing member 75, a screw portion 75 c that matches the screw portion 73 a formed at both ends of the protection member 73 is formed.
[0045]
The material of the end fixing member 75 is made of stainless steel similar to the material of the protection member 73 described above, and when the end fixing member 75 is attached to the protection member 73 by using the same material, the end fixing member 75 is mutually connected. Screw part 73a, 75c becomes difficult to be damaged. That is, if the material of the end fixing member is made of resin, the screw portion of the end fixing member is immediately damaged and is not fixed when attached to the protective member 73 and tightened. Further, when the end fixing member 75 is attached to the protection member 73, the end surface 75 b having the opening 75 a is formed on one end side of the end fixing member 75, thereby preventing the sealing member 74 from falling off. be able to.
[0046]
A filler is injected into the protective member 73 of the protective case 70. The filler may be any soft material that prevents drainage from the outside from entering the protective case 70 and has moisture resistance. In the present embodiment, a silicone resin or the like may be applied. Is possible.
[0047]
A plate-like member for fixing the protective case 70 provided at the connecting portion between the branching optical fiber cable 13 and the drawing optical fiber cable 14 to the inner walls 8a and 9a of the public fences 8 and 9 will be described below. FIG. 8 is a perspective view showing a schematic configuration of a plate-like member that fixes a protective case of the connection portion of the optical fiber cable according to the present embodiment.
[0048]
A plate-like member 80 shown in FIG. 8 includes a thin plate 81 attached to the inner walls 8a and 9a of the public fences 8 and 9, and two gripping members 82 attached to the central upper and lower parts of the thin plate. The gripping member 82 has a substantially U shape, and has a shape in which an intermediate part of the protective case 70 (part corresponding to the protective member 73) can be fitted. Further, a thin plate-like mounting member 82a for attaching the gripping member 82 is provided on the thin plate 81 side. Further, the distance between the two gripping members 82 attached to the thin plate 81 is shorter than the length of the protective member 73. Further, a protrusion 82b is formed on the inner side of the tip portion of the gripping member 82 opposite to the thin plate 81 side, and when the intermediate portion of the protective case 70 is fitted, the protective case 70 is The protrusion 82b makes it difficult to come off. That is, the gripping member 82 is not particularly limited as long as it has a function of a substantially U-shaped holder for holding an electric cable or the like. Further, the material of the gripping member 82 can withstand the environment of sewage, and when the intermediate portion of the protective case 70 is fitted, the vicinity of the tip portion where the projection 82b is formed can be bent and reliably held. Any material can be used.
[0049]
The thin plate 81 shown in FIG. 8 is made of stainless steel, and circular through holes 81a are provided at the four corners. A plate-like member 80 (thin plate 81) is attached to the inner walls 8a, 9a of the public fences 8, 9 using anchor bolts or the like from these through holes 81a. Moreover, the plate-shaped member 80 will not be specifically limited if it can process or deform | transform into the shape along the inner walls 8a and 9a of the public fences 8 and 9. FIG. For example, as shown in FIG. 9, the above-described thin plate 81 may be a plate-like member 84 that is a net member 85 having a plurality of holes 85a. Thus, by comprising the plate-shaped member 84 from the net | network material 85, it becomes easily deformable to the shape in alignment with the inner walls 8a and 9a of the public fences 8 and 9. When hooks are attached to the inner walls 8a and 9a of the public fences 8 and 9, it is easy to hook the hooks to the appropriate holes 85a in the case of the thin plate 81 and in the case of the net member 85. Attach to and remove from. Since the gripping member shown in FIG. 9 is the same as the gripping member 82 described above, the same reference numerals are used and description thereof is omitted.
[0050]
By using the plate member 80 configured as described above, it is possible to fix the connecting portion between the branching optical fiber cable 13 and the drawing optical fiber cable 14 to the public fences 8 and 9.
[0051]
Next, a fixing structure for fixing the connecting portion between the branching optical fiber cable 13 and the drawing optical fiber cable 14 to the inner walls 8a, 9a of the public fences 8, 9 will be described below.
[0052]
6 are made up of risers up to the ground where branch pipes 4 and 5 branched from main pipe 1 and drain pipe 10 shown in FIG. 3 are connected. As described above, the sheath tube 40 is fixed to the inner walls 8a and 9a of the rising tubes (public fences) 8 and 9 by the saddle-shaped clamp 40a or the like. The extra length of the branching optical fiber cable 13 inserted into the sheath tube 40 is arranged in a spirally wound state along the inner walls 8a, 9a of the public fences 8, 9, and the branching optical fiber cable. In the state where the protective case 70 provided at the connection portion between the optical fiber cable 13 and the drawing optical fiber cable 14 is fitted to the two gripping members 82 of the plate-like member 80, the plates are attached to the inner walls 8a, 9a of the public fences 8, 9. It is fixed via the shaped member 80. In addition, the plate-like member 80 holding the protective case 70 is installed on the inner wall by an anchor bolt or the like in a state bent along the inner walls 8a, 9a of the public fences 8, 9.
[0053]
Thus, by arranging the extra length of the branching optical fiber cable 13 spirally along the inner walls 8a, 9a of the public fences 8, 9, the allowable bending radius of the branching optical fiber cable 13 is exceeded. Therefore, the branching optical fiber cable 13 can be prevented from being damaged. In addition, the plate-like member 80 is attached to the public fence 8 while fitting the protective case 70 of the connecting portion between the branching optical fiber cable 13 and the drawing-in optical fiber cable 14 to the two gripping members 82 attached to the plate-like member 80. , 9 can be easily fixed to the inner walls 8a, 9a of the public fences 8, 9 as a single unit with the connecting portion between the branching optical fiber cable 13 and the drawing optical fiber cable 14 installed on the inner walls 8a, 9a. it can.
[0054]
Next, a method for assembling the protective case 70 at the connecting portion between the branching optical fiber cable 13 and the drawing-in optical fiber cable 14 will be described below. FIG. 10 shows the assembly state of the protective case of the connection portion between the optical fiber cables according to the present embodiment, (a) is an explanatory view showing the attachment state of the fusion protection sleeve, (b) It is explanatory drawing which shows the condition which mounted | worn the fusion protection sleeve on the fixing member, (c) is explanatory drawing which shows the condition which fixed the tension member of each optical fiber cable to the fixing member, (d) is a protective case. It is explanatory drawing which shows the assembled state.
[0055]
First, as shown in FIG. 10A, the optical fiber cores 51 and 61 and the tension members 52 and 62 are exposed from the ends of the branching optical fiber cable 13 and the drawing optical fiber cable 14, respectively. And the front-end | tip parts of each optical fiber core wire 51 and 61 are faced | matched. At this time, the end fixing member 75 and the sealing member 74 are previously placed on the branching optical fiber cable 13 and the drawing optical fiber cable 14 side, and the protective member 73 is placed on one of the branching optical fiber cable 13 or the drawing optical fiber cable 14. Put it on. Further, one of the optical fiber cores 51 and 61 is covered with a fusion protection sleeve 71. Thus, the end portions of the optical fiber cores 51 and 61 are abutted with each other, and the fusion protection sleeve 71 is put on the abutted portions. Then, a fusing process is performed by a known fusing method to form a fusing part 71a to be connected.
[0056]
Next, the fused portion 71a of the optical fiber core wires 51 and 61 covered with the fusion protection sleeve 70 is placed on the fixing member 72 as shown in FIG. 10B, and each optical fiber cable in the vicinity of the fused portion. The tension members 52 and 62 exposed from the ends of 13 and 14 are bent along the outer surface of the fixing member 72. Then, as shown in FIG. 10 (c), the tape 78 is wound around and fixed from the respective tension members 52 and 62 at both ends of the fixing member 72. At this time, the optical fiber cores 51 and 61 are kept slightly slackened between both ends of the fixing member 72 so that no tension is applied. Since the end portions of the respective optical fiber cables 13 and 14 exist in both end portions of the fixing member 72, the openings 72 a at both end portions of the fixing member 72 are narrowed by winding the tape 78, and the tension members 52 and 62. The fixing member 72 and the respective optical fiber cables 13 and 14 are connected. As a method for fixing the tension members 52 and 62 to the fixing member 72, for example, a metal ring may be fitted and fixed.
[0057]
Next, as shown in FIG. 10 (d), the fixing member 72 is covered with the protective member 73, and the sealing member 74 previously covered with the respective optical fiber cables 13 and 14 is fitted into both end portions of the protective member 73. Then, the end fixing member 75 is screwed into both end portions of the protection member 73. The end fixing member 75 is screwed into both end portions of the protection member 73 in this way, and the notches 73b provided at both end portions of the protection member 73 make the diameters of both end portions of the protection member 73 slightly smaller, and the sealing member 73 is sealed. A member 74 is clamped between the protective member 73 and the outer surface of each optical fiber cable 13, 14. Note that the filler is injected after the sealing member 74 is fitted into one end of the protective member 73. Further, when the end fixing member 75 is screwed into the end portion of the protective member 73, the force for pressing the optical fiber cables 13 and 14 toward the fused portion 71a by the frictional force of the sealing member 74 works. Since the end portions 13 and 14 are connected by a rigid fixing member 72, no force is applied to the fused portion 71a, and the fused portion 71a is not damaged.
[0058]
Thus, by assembling the protective case 70 at the connection portion between the branching optical fiber cable 13 and the drawing-in optical fiber cable 14, the fused portions 71a of the optical fiber cores 51 and 61 at the connection portion are maintained in a waterproof and moistureproof state. can do. Further, in the sewage environment, a strong acid state may be caused by the generation of hydrogen sulfide, which is also protected by the protective case 70. Further, since the protective case 70 has a small number of parts, it can be easily assembled, and workability is improved. Further, since the tension members 52 and 62 of the optical fiber cables 13 and 14 are fixed to both ends of the fixing member 72, the optical fiber cables 13 and 14 are connected via the fixing member 72, respectively. Tensile force is not applied to the fused portion 71a of the optical fiber cores 51 and 61, and the fracture of the fused portion 71a can be prevented.
[0059]
Next, a method of fixing the protective case 70 to the public fences 8 and 9 at the connection portion between the branching optical fiber cable 13 and the drawing optical fiber cable 14 will be described below.
[0060]
The branching optical fiber cable 13 is pulled out of the public fences 8 and 9 from the sheath tube 40 fixed to the inner walls 8a and 9a of the public fences 8 and 9 by a saddle-shaped clamp 40a. Then, the protective case 70 described above is assembled while the pulling optical fiber cable 14 from the house 20 and the branching optical fiber cable 13 are connected. Then, the assembled protective case 70 is fitted to the gripping member 82 of the plate member 80 described above, and the branching optical fiber cable 13 drawn from the public fences 8 and 9 is connected to the inner walls 8a and 9a of the public fences 8 and 9. Is inserted and arranged while spirally winding along Since the branching optical fiber cable 13 has a certain degree of rigidity, the branching optical fiber cable 13 is arranged along the inner walls 8a, 9a of the public fences 8, 9.
[0061]
Then, the branching optical fiber cables 13 disposed on the public fences 8 and 9 are fixed to the inner walls 8a and 9a of the public fences 8 and 9 using a saddle-shaped clamp or the like as appropriate. Thus, after fixing the extra length of the branching optical fiber cable 13 to the public fences 8 and 9, a plate-like member fitted with the protective case 70 of the connecting portion between the branching optical fiber cable 13 and the drawing optical fiber cable 14 is fitted. 80 is directly fixed to the inner walls 8a, 9a of the public fences 8, 9 with anchor bolts or the like.
[0062]
Alternatively, a hook or the like may be attached to the inner walls 8a and 9a of the public fences 8 and 9 in advance, and the plate member 84 may be hung on the hook using the through hole 81a. In the case of this form, even when it becomes necessary to take out the protective case 80 from the public fences 8 and 9 for some reason, the whole plate-like member 84 can be easily removed. The same applies when the net member 85 is used instead of the thin plate 81.
[0063]
As described above, the connecting portion to which the branching optical fiber cable 13 and the drawing optical fiber cable 14 are connected uses the protective case 70 provided at the connecting portion and the plate member 80 to which the gripping member 82 is attached. Thus, it becomes possible to easily fix to the inner walls 8a, 9a of the public fences 8, 9. In addition, by arranging the branching optical fiber cable 13 along the inner walls 8a and 9a of the public fences 8 and 9, and fixing the unitized optical fiber cable connection on the upper side thereof, the flow of drainage from the house 20, etc. Can be prevented.
[0064]
【The invention's effect】
As described above, the present invention can maintain a waterproof and moisture-proof state by providing a protective case at the connection portion between the optical fiber cables, and can easily assemble the protective case and install it in a public fence. It becomes.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an outline of a sewer pipe.
FIG. 2 is a cross-sectional view showing an arrangement state of branch pipes.
FIG. 3 is a diagram showing the situation of each culvert as an example of sewerage.
FIG. 4 is an explanatory diagram showing a situation in which an optical fiber cable is laid in a sewer pipe.
FIG. 5 is a cross-sectional view of a branched optical fiber cable according to the present embodiment.
FIG. 6 is an explanatory diagram showing a fixing state of a connecting portion between a branched optical fiber cable and a lead-in optical fiber cable according to the present embodiment.
FIG. 7 is a perspective view showing a schematic configuration of a protective case in a connection portion between optical fiber cables according to the present embodiment.
FIG. 8 is a perspective view showing a schematic configuration of a plate-like member that fixes a protective case of a connection portion of an optical fiber cable according to the present embodiment.
FIG. 9 is a perspective view showing a schematic configuration of an example of a plate-shaped member according to the present embodiment.
FIGS. 10A and 10B show an assembly state of a protective case of a connection portion between optical fiber cables according to the present embodiment, FIG. 10A is an explanatory view showing an attachment state of a fusion protection sleeve, and FIG. It is explanatory drawing which shows the condition which mounted | worn the fusion protection sleeve on the fixing member, (c) is explanatory drawing which shows the condition which fixed the tension member of each optical fiber cable to the fixing member, (d) is a protective case. It is explanatory drawing which shows the assembled state.
[Explanation of symbols]
1 Main (Sewer main)
4,5 branch pipe
8,9 Public fence (branch pipe, rise pipe)
13 Optical fiber cable (Branch optical fiber cable)
14 Optical fiber cable (fiber optic cable for lead-in)
51, 61 Optical fiber core wire
52, 62 Tension member
70 protective case
72 Fixing member
73 Protection member
74 Sealing member
75 End fixing member
80,84 plate member
82 Grasping member

Claims (8)

A method of fixing a connection portion of an optical fiber cable in which optical fiber cables are connected to a public fence provided at an end of a branch pipe branched from a sewer main,
Cover the fused portion of the optical fiber core at the connection portion of the optical fiber cable, fit a sealing member between both ends of the protective member and the optical fiber cable, and attach end fixing members to both ends of the protective member A method of fixing a connecting portion of an optical fiber cable, wherein the protective case assembled in this manner is fixed to the inner wall of the public fence. A method of fixing a connection portion of an optical fiber cable in which optical fiber cables are connected to a public fence provided at an end of a branch pipe branched from a sewer main,
The fused portion of the optical fiber core wire in the connection portion of the optical fiber cable is placed on the fixing member, and the tension members exposed from the end portions of the respective optical fiber cables in the vicinity of the fused portion are arranged at both end portions of the fixing member. A protective case that is assembled by attaching a protective member to the fixing member, fitting a sealing member between both ends of the protective member and an optical fiber cable, and attaching end fixing members to both ends of the protective member. A method for fixing a connection portion of an optical fiber cable, wherein the connection portion is fixed to an inner wall of the public fence. After assembling the protective case by pulling out the fused portion of the optical fiber core and the optical fiber cable around the fused portion to assemble the protective case, the fiber optic cable drawn out of the public cage is connected to the public cage. The optical fiber cable connection part according to claim 1 or 2, wherein the protective case is fixed to the inner wall of the public fence after being inserted and arranged while being wound along the inner wall. Method. When the protective case is fixed to the inner wall of the public fence, the plate member is fixed to the inner wall of the public fence in a state where the protective case is attached to a plate-like member provided with a gripping member. The method of fixing the connection part of the optical fiber of any one of Claim 1 thru | or 3. It is a fixing structure of the connecting portion of the optical fiber cable in which the optical fiber cables are connected to a public fence provided at the end of the branch pipe branched from the sewer main,
A protective member is put on the fused portion of the optical fiber core wire in the connection portion of the optical fiber cable, and a cylindrical sealing member is fitted between the both ends of the protective member and the optical fiber cable, and the outer surfaces of the both ends of the protective member A fixing structure for a connecting portion of an optical fiber cable, wherein a protective case assembled with a cylindrical end fixing member attached thereto is fixed to an inner wall of the public fence. It is a fixing structure of the connecting portion of the optical fiber cable in which the optical fiber cables are connected to a public fence provided at the end of the branch pipe branched from the sewer main,
The fused portion of the optical fiber core wire in the connection portion of the optical fiber cable is placed on a fixing member having a substantially U-shaped cross section, and is exposed from the end portion of each optical fiber cable in the vicinity of the fused portion. While the tension member is fixed to both ends of the fixing member, the fixing member is covered with a cylindrical protection member, and a cylindrical sealing member is fitted between the both ends of the protection member and the optical fiber cable. Securing the connecting portion of the optical fiber cable, wherein a protective case assembled by attaching cylindrical end fixing members to the outer surfaces of both ends of the protective member is fixed to the inner wall of the public fence Construction. An optical fiber cable in the vicinity of the protective case containing the fused portion of the optical fiber cable is arranged along the inner wall of the public fence in a spirally wound state, and the protective case is fixed to the inner wall of the public fence 7. The structure for fixing a connecting portion of an optical fiber cable according to claim 5 or 6, wherein the structure is fixed. The protective case is fitted to a gripping member having a substantially U shape attached to a plate-like member, and the public fence is bent in a state where the plate-like member is bent along the inner wall of the public fence. The fixing structure of the connecting portion of the optical fiber cable according to any one of claims 5 to 7, wherein the fixing structure is provided on an inner wall of the optical fiber cable.

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