JP2009294470A - Branch structure of multicore optical fiber cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a branch structure of a multicore optical fiber cable, which branches a plurality of secondary coated optical fibers. <P>SOLUTION: The branch structure of a multicore optical fiber cable includes: an optical fiber cable having a plurality of secondary coated optical fibers; a housing that houses one end of the optical fiber cable; a plurality of branch tubes each having a protective tube made of metal, a tension member laid along the outside of the protective tube, and a jacket covering the protective tube and the tension member, with one end of the tube housed in the housing and protecting the branched plurality of secondary coated optical fibers; a fixing member having an approximately cylindrical first part and a first surface being the outer circumference surface of the first part, to which the plurality of branch tubes are arranged and fixed; and a pinching member disposed as the inner face opposing to the first surface, enclosing the plurality of branch tubes and mechanically pinching the plurality of branch tubes between itself and the fixing member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a branch structure of a multi-core optical fiber cable that branches a plurality of optical fiber core wires.

  A multi-core optical fiber cable in which a plurality of optical fiber cores are collectively formed into a cable is frequently used for efficiently laying a plurality of optical fiber cores. Each of the optical fiber cores is housed in a multi-core optical fiber cable as an independent single core wire or as a tape core wire in which a plurality of optical fiber core wires are arranged side by side. The laid multi-core optical fiber cable is connected to a wiring board, device or the like by attaching a connector or the like to one end thereof. At this time, each optical fiber built into the multi-core optical cable must be converted into a branch cord that incorporates a smaller number of core wires than the multi-core optical cable, and a connector is attached to the tip to connect to various devices and other cables. There is. In such a case, a branch portion is provided at a portion where the cable is branched into a cord, and a branch cord is attached thereto.

  For example, Patent Document 1 states that “a single-core optical fiber core separated from an optical tape fiber in an optical tape fiber core branching portion for branching each optical fiber of an optical tape fiber into a single-core optical fiber core. An optical fiber ribbon core wire branching section is described in which a wire is held by a guide member that aligns the wires without applying a twisting force. Patent Document 2 discloses an optical fiber branching device “configured so that compressive stress is applied to the branch spacer when tension is applied to the reinforcing fiber of the branch pipe and the reinforcing fiber of the cable”. Are listed.

  On the other hand, when a pressure from the side is applied or a sharp bend is applied to the optical fiber, an optical loss occurs at that portion. In order to prevent such a loss, an optical fiber cord incorporating a metal protective tube is known. Patent Document 3 states that “an optical fiber, a spring cover that covers the outer periphery of the optical fiber, a net-like blade cover that covers the outer periphery of the spring cover, and an outer cover that covers the outer periphery of the blade cover. A "optical fiber cord is described.

JP 2002-221646 A Special Table 2004-526209 WO2005 / 091037

  In an equipment room where a multi-core optical fiber cable is terminated, there is a risk that a loss due to a lateral pressure or a sharp bend may be applied to the cable or cord during handling or after laying. Therefore, it is desired to terminate the optical fiber accommodated in the multi-core optical fiber cable using an optical fiber cord having a metal protective tube having excellent strength. However, a cable branch portion that branches to such an optical fiber cord and is easy to manufacture has not been provided.

  According to one aspect of the present invention, an optical fiber cable having a plurality of optical fiber core wires, a housing that accommodates one end of the optical fiber cable, a metal protective tube, and the outside of the protective tube A plurality of branch tubes having a tensile strength material, a jacket covering the protective tube and the tensile strength material, one end of which is accommodated in the housing and protecting the branched optical fiber cores; and a substantially columnar first portion A fixing member that places and fixes a plurality of branch tubes on the first surface that is the outer peripheral surface of the first portion, and surrounds the plurality of branch tubes, and the inner surface is disposed to face the first surface, A branch structure of a multi-core optical fiber cable is provided that includes a holding member that mechanically holds a plurality of branch tubes with a fixing member.

  According to the multi-core cable branch structure according to one aspect of the present invention, a branch structure that is easy to manufacture is provided.

  Hereinafter, the present invention will be described according to each embodiment. FIG. 1 is an exploded perspective view of a branch portion 1 according to an embodiment of the present invention, FIG. 2 is a sectional view of the branch portion, and FIG. 3 is a perspective view showing a fixing member 20 used in the branch portion. The branch part 1 of the multi-core optical fiber cable according to an embodiment of the present invention includes a multi-core optical fiber cable 70 containing a plurality of optical fiber core wires 72 and a plurality of optical fiber core wires 72 accommodated therein. This is a branching portion that branches into the branching tube 50. The branch tube 50 is a protective tube 52 formed in a tube shape by winding a thin metal plate in a spiral shape, a tensile strength material 54 disposed on the outer periphery thereof, and a jacket that collectively covers the protective tube 52 and the tensile strength material 54. 56. The branch tube 50 is mechanically fixed to the fixing member 20 by the first clamping member 40, and is led out from one end of the housing 10 that houses the fixing member 20. The multi-core optical fiber cable 70 is clamped at the other end of the housing 10, and the built-in optical fiber core wire 72 is distributed in the space inside the housing 10, and each is introduced into the protection tube 52 of a desired branch tube. ing.

  Next, details of the branching portion of this embodiment will be described. A multi-core optical fiber cable 70 is introduced into the branching portion 1 from one end, and a plurality of branching tubes 50 are introduced from the other end. The branch portion 1 is positioned with respect to the housing 10, the fixing member 20 having a plurality of branch tubes 50 arranged on the surface thereof, and a plurality of holding members that hold the branch tube 50 between the fixing members 20. 40, 42, 44.

  As shown in FIG. 3, the fixing member 20 is formed by arranging a plurality of substantially cylindrical portions each having a different outer diameter in series and concentrically. The fixing member 20 includes a substantially cylindrical first portion 22a, a substantially cylindrical second portion 22b that is disposed adjacent to one end of the first portion 22a, and has a larger outer diameter than the first portion 22a. A substantially cylindrical third portion disposed at one end of the second portion 22b and adjacent to the end opposite to the end adjacent to the first portion 22a and having an outer diameter smaller than that of the second portion 22b. And a portion 22c. The first portion 22a, the second portion 22b, and the third portion 22c respectively include a first surface 24a, a second surface 24b, and a third surface 24c that are outer peripheral surfaces corresponding to a cylindrical curved surface.

  In the first portion 22a, a plurality of alignment grooves 26a having a substantially semicircular cross section are arranged on the first surface 24a at substantially equal intervals. The alignment groove 26 is approximately the same size as the outer diameter of the branch tube 50, and extends from one end of the first portion 22a to the other end. The branch tubes 50 are respectively disposed in the alignment grooves 26a. Thereby, the some branch tube 50 can be arrange | positioned in desired space | interval in the column-shaped 1st part 22a. Fine irregularities may be provided on the surface of the alignment groove 26a in a direction intersecting with the extending direction of the groove. Providing such irregularities increases the friction between the branch tube 50 and the fixing member 20 when the branch tube 50 is held in cooperation with a clamping member, which will be described later, and more effectively the branch tube. 50 can be held.

  The second portion 22b is adjacent to one end of the first portion 22a in the axial direction and is arranged substantially coaxially with the first portion 22a. The 2nd part 22b is provided with the 2nd surface 24b which can clamp the tensile strength material 54 of the protection tube 50 between the clamping members 42 mentioned later. The second surface 24b can be provided with a plurality of fine grooves in a direction intersecting the axial direction of the second portion 22b so that the tensile strength material 54 can be more effectively sandwiched. The second portion 22b includes a plurality of receiving holes 28 having a circular cross section aligned with the alignment groove 26a through the second portion 22b from one end to the other end in the radial direction. The receiving holes 28 are disposed on substantially the same circumference with respect to the axial direction of the second portion 22b. The receiving hole 28 has an inner diameter that is substantially the same as or slightly larger than the outer diameter of the branch tube 50, and can have the same radius as the inner surface of the alignment groove 26a. The end of the receiving hole 28 covered with the jacket 56 of the branch tube 50 disposed in the alignment groove 26a is inserted. The second portion 22 b further includes a flange portion 30 that can be engaged with the inner surface of the housing 10. The flange portion 30 is disposed at one end of the second portion 22b adjacent to the first portion 22a, and protrudes radially outward from the second surface 24b. The width of the flange portion 30 is configured to be narrower than the width of the second surface 24b. In order to reduce the size of the branch portion 1, it is preferable to reduce the width of the flange portion 30 as long as a desired fixing strength is obtained.

  The fixing member 20 further includes a substantially cylindrical third portion 22c adjacent to the second portion 22b. The third portion 22c includes a plurality of alignment grooves 26b extending from the second portion 22b side on the third surface 24c. The alignment groove 26 b has the same curvature as the inner diameter of the receiving hole 28 and is aligned with the receiving hole 28. That is, it is also arranged in alignment with the alignment groove 26a. Therefore, the branch tube 50 inserted from the alignment groove 26 a side can reach the alignment groove 26 b through the receiving hole 28. The third portion 22c includes an alignment groove 26c on the third surface 24c, which is continuous with the alignment groove 26b. The alignment groove 26 c is a groove having a size corresponding to the protective tube 52 of the branch tube 50, and receives the protective tube 52 exposed at the end of the branch tube 50. The alignment groove 26c has a groove width (curvature radius) smaller than that of the alignment groove 26b. A step portion 27 is provided at a boundary portion between the alignment groove 26c and the alignment groove 26b, and the end portion of the jacket 56 of the branch tube 50 can be prevented from being inserted into the alignment groove 26c side beyond the step portion 27. Fine grooves that intersect the extending direction of the grooves can be provided on the surfaces of the alignment grooves 26b and 26c as necessary.

  A central through hole 32 extending from one end to the other end in the axial direction can be provided at the center of the fixing member 20. The tension member 74 of the multi-core optical fiber cable 70 is inserted into the center through hole 32, and the tension member 74 is led out from the end portion of the branch portion 1 on the side where the branch tube 50 is attached. In the present embodiment, the tension member 74 is not fixed to the fixing member 20, but can be fixed using a known method such as a screw, caulking, adhesive, or the like. The fixing member 20 can be made of any material having a required strength, and can be made of various resins, metals such as brass, for example.

  The first clamping member 40 is a ring-shaped member made of a thin plate. The branch tube 50 is clamped between the inner surface 40 a of the first clamping member 40 and the fixing member 20, and is fixed to the fixing member 20. The inner diameter is set larger than the outer diameter of the first portion 22 a of the fixing member 20. After the branch tube 50 subjected to predetermined end treatment is arranged in the alignment grooves 26 a to 26 c of the fixing member 20, the other end of the branch tube 50 is passed through the first clamping member 40, and the inner surface 40 a is the first surface of the fixing member 20. The 1st clamping member 40 is moved to the position facing 22a, and the diameter of the 1st clamping member 40 is reduced with the crimping tool which is not shown in figure. Since the protective tube 52 of the branch tube 50 used in the present embodiment is made of metal, the protective tube 52 is mechanically sandwiched between the first clamping member 40 and the fixing member 20 without being largely crushed. For this reason, the protective tube 52 of the branch tube, the tensile strength material 54, and the jacket 56 can be fixed collectively. Further, since the protective tube 52 is spiral, the tensile strength material 52 can be more firmly fixed at the edge portion of the protective tube 52. The 1st clamping member 40 can be produced from the metal which has malleability, for example, aluminum.

  Depending on the required fixing strength between the branch tube 50 and the branch portion 1, the tensile material 54 may be further fixed to the second surface 22 b of the fixing member 20 by the second clamping member 42. The tensile strength material 52 is cut at a predetermined length from the end portion of the jacket 56, and is folded and disposed on the second surface 22b. The second clamping member 42 is arranged coaxially with the second portion 24b so that the inner surface 42a faces the second surface 22b, and by reducing the diameter of the second sandwiching member 42, the tensile strength material 52 is connected to the inner surface 42a and the second surface 24b. Hold between. As the 2nd clamping member 42, the thing similar to the 1st clamping member 40 can be used, and it should just have the internal diameter matched with the outer diameter of the 2nd part.

  The branch portion 1 can further include a third clamping member 44. The third clamping member 44 covers the plurality of protective tubes 52 arranged on the alignment groove 26c arranged on the third surface 24c of the third portion 22c, and is arranged coaxially with the fixing member 20. The protective tube 52 is sandwiched between the inner surface 44a of the third sandwiching member 44 and the third surface 24c by being reduced in diameter in the same manner as the first sandwiching member 40 and the second sandwiching member 42. Note that it is particularly preferable for the branch portion 1 used in an environment in which vibration is applied to hold the protective tube 52 between the third portions. If the protective tube 52 moves due to vibration, the end of the protective tube 52 may come into contact with the optical fiber core 72 depending on the position of the optical fiber core 72 inserted into the protective tube 52 and the degree of bending. There is a risk that. When the vicinity of the end portion of the protective tube 52 is held by the third holding member 44, the movement of the protective tube 52 due to vibration can be suppressed, so that the optical fiber core wire 72 can be prevented from being damaged. Further, since the protective tube 52 protrudes from the end portion of the jacket 56, the end portion of the protective tube 52 can be visually recognized when the optical fiber core wire 72 is inserted, and the operation of inserting the optical fiber core wire 72 into the protective tube 52 is performed. It becomes easy.

  As shown in FIG. 1, the housing 10 includes a fixing member 20 to protect it from the external environment, and mechanically connects the multi-core optical fiber cable 70 and the branch tube 50. In the present embodiment, the housing 10 includes a pair of cover members 10 a and 10 b each having a shape obtained by dividing a cylinder by a plane parallel to the axial direction thereof, and the cover members 10 a and 10 b are aligned by the divided surface 11. Thereby, the cylinder which has the space which can accommodate the fixing member 20 inside can be comprised. The cover members 10a and 10b are provided with grooves 12 having a rectangular cross section extending in the circumferential direction on the inner surfaces thereof. The groove 12 can be engaged with the flange portion 30 of the fixing member 20, whereby the fixing member 20 is positioned with respect to the housing 10. Further, the tension applied to the branch tube 50 is transmitted to the housing 10 via the fixing member 20, thereby preventing an excessive tension from being applied to the optical fiber core wire 72.

  Each of the cover members 10a and 10b has a cable gripping portion 13 on the inner surface on one end side thereof, and a plurality of protrusions 14 whose sections extending in the circumferential direction of the cover members 10a and 10b are truncated triangles. is doing. The top surface 14 a of the ridge 14 forms a substantially cylindrical curved surface, and the radius of curvature of the curved surface is configured to be smaller than the outer diameter of the multi-core optical fiber cable 70. Therefore, when the multi-core optical fiber cable 70 is arranged on the cable gripping portion 13 and the two cover members 10a and 10b are closed, the tip end (top surface 14a) of the ridge 14 bites into the jacket 76 and the multi-core optical fiber cable. The branch part 1 is mechanically fixed to 70.

  Each of the cover members 10a and 10b further includes two through holes 16 and two spiral holes 18 provided substantially perpendicular to the dividing surface 11 thereof. When the cover members 10a and 10b are combined, the center axis of the through-hole 16 of the cover member 10a and the center axis of the cover member 10b spiral hole 18 coincide, and the center axis of the spiral hole 18 of the cover member 10a and the cover member The central axis of the 10b through hole 16 coincides. A recess 16 a having a larger diameter than the through hole 16 is provided on the outer peripheral surface side of the cover members 10 a and 10 b of the through hole 16, and the head of the spiral member 19 is secured when the cover members 10 a and 10 b are fixed by the spiral member 19. The portion 19 a is configured not to protrude outward from the outer peripheral surface of the housing 10. The cover members 10a and 10b can be made of various materials having a required strength, and can be made of, for example, a resin or a metal.

  Next, the branch tube 50 will be described in detail with reference to FIG. The branch tube 50 includes a protective tube 52, a tensile material 54 disposed on the outer periphery thereof, and a jacket 56 that collectively covers the protective tube 52 and the tensile material 54. The protective tube 52 is formed in a tube shape by winding a thin metal plate in a spiral shape, and can accommodate one or a plurality of optical fiber core wires 72 in its internal space. In other words, the protective tube 52 is formed by forming a spiral groove in a metal tube. The thin plate wound spirally has a gap between adjacent thin plates. Since the thin plate is spirally wound to form the protective tube 52, the edge of the thin plate acts on the tensile strength material 52 when sandwiched between the first portions 22a of the fixing member 20 as described above, and the strength of the tensile strength material 52 is increased. It can be improved. Moreover, since there is a gap between adjacent thin plates, it can have high lateral pressure resistance and high flexibility. The protective tube 52 is not limited to a thin plate spiraled, and a tube having no spiral groove may be used as the protective tube 52. In order to improve the fixing strength of the tensile strength material 54, a plurality of fine grooves and irregularities that intersect the axial direction of the protective tube 52 may be provided on the outer surface of the protective tube 52.

  The tensile strength material 54 is a member that resists the tension applied to the branch tube 50 and prevents the optical fiber core wire 72 from being broken due to the applied tension. A known member can be used as the tensile material, and for example, an aramid fiber can be preferably used. The jacket 56 covers the tensile strength material 54 and the protective tube 52 and forms the outer shape of the branch tube 50. The jacket 56 can be manufactured from a known material, for example, a resin material such as polyvinyl chloride (PVC) or polyethylene (PE), and is coated on the protective tube 52 and the tensile strength material 54 by a known method such as extrusion. can do.

  The branch part 1 of this embodiment can be applied to various known multi-core optical fiber cables 70. The multi-core optical fiber cable 70 has a plurality of optical fiber core wires 72 in a coating 76 formed in a tube shape. The multi-core optical fiber cable 70 may incorporate a plurality of independent optical fiber cores 72, or may have one or a plurality of tape core wires in which a plurality of optical fiber cores 70 are arranged in parallel and covered together. Also good. A known optical fiber such as a plastic optical fiber (POF) or a quartz optical fiber can be used for the optical fiber core 70. Such an optical fiber core wire 70 includes a core through which light passes and a clad concentrically provided in the core and confining light in the core. The optical fiber core 70 is typically provided with a coating made of one or a plurality of resin layers concentrically with the cladding on the outer periphery of the cladding. The core and clad are typically composed of a light-transmitting substance, transparent plastic, quartz glass, and the like. For the coating, a UV curable resin, a polyamide resin, or the like can be used. The multi-core optical fiber cable 70 can have a tension member 74 inside the cable as required. The tension member 74 is a wire-like member, receives a tension applied to the multi-core optical fiber cable 70, and prevents an excessive tension from being applied to the optical fiber core wire 72. A known material can be used for the tension member 74, and steel, stainless steel, FRP, or the like can be used. The coating 76 is typically made of a resin material such as PVC or PE, and protects the optical fiber core wire 72 from the external environment.

Next, the assembly process of this embodiment will be described with reference to FIGS. 4 to 7 as necessary.
a: The jacket 56 is removed from the tip of the branch tube 50 by a predetermined length, and the tensile strength material 54 is cut at a predetermined length from the end of the jacket 56 that has been cut off.

  b: The tip of the branch tube 50 is arranged in the alignment groove 26a of the fixing member 20, and the branch tube 50 is moved along the alignment groove 26a until the end of the jacket 56 abuts on the stepped portion 27. At this time, the protective tube 52 exposed from the branch tube 50 is disposed on the alignment groove 26c. This operation is repeated for a desired number of branch tubes 50 (FIG. 4).

  c: The first clamping member 40 is arranged on the first portion 22a of the fixing member 20 so that the inner surface 40a faces the first surface 24a, and is placed on the fixing member 20 and the branch tube 50 by a caulking tool (not shown). Reduce diameter. Thereby, the branch tube 50 is fixed to the fixing member 20 (FIG. 5).

  d: The tensile strength material 54 protruding from the end of the jacket 56 is folded back onto the second surface 24b, and the second tensile strength material 54 is positioned between the second surface 24b and the inner surface 42a of the second clamping member 42. The clamping member 42 is disposed concentrically with the fixing member 20. A caulking tool (not shown) is used to reduce the diameter of the second clamping member 40b onto the second surface 24b. Thereby, the tensile strength material 54 is fixed to the fixing member 20 (FIG. 6).

  e: The third clamping member 44 is coaxially disposed on the third portion 22c of the fixing member 20 such that the vicinity of the end of the protective tube 52c is located between the inner surface 44a and the third surface of the third clamping member 44. To do. The caulking tool (not shown) is used to reduce the diameter of the third clamping member 44 on the third surface 24c. Thereby, the protective tube 52 is fixed to the fixing member 20 (FIG. 7).

  f: The outer sheath 76 of the multi-core optical fiber cable 70 is removed by a predetermined length, and the optical fiber core wire 72 and the tension member 74 are exposed from the end portion of the outer sheath 76. Each optical fiber core wire 72 is inserted into the corresponding protective tube 52, and the tension member 74 is inserted into the central through hole 32.

  g: The flange portion 30 of the fixing member 20 to which the branch tube 50 is fixed is fitted in the groove 12 of the cover member 10a, and the vicinity of the end portion 76 of the multi-core optical fiber cable 70 is placed on the cable gripping portion 13 of the cover member 10a. To place. The cover member 10b is aligned with the cover member 10a, and both the cover members 10a and 10b are fastened and fixed by the spiral member 19.

  The branch part 1 concerning this embodiment can be assembled as mentioned above. Thus, in this embodiment, since the branch tube 50 can be fixed to the fixing member 20 in advance, the operation of passing the optical fiber core wire 72 to the protective tube 52 and the operation of assembling the branch tube 50 into the housing 10 are simplified. Become. Moreover, since no adhesive is used, the assembly workability is improved. Steps d and e are optional steps and may be performed as necessary. The order of steps c, d, and e can be arbitrarily changed.

  Although the above description has been given for one embodiment, the present invention is not limited to this embodiment. FIG. 8 shows a second embodiment of the fixing member 120 to which the branch tube 50 is fixed, and FIG. 9 shows a third embodiment of the fixing member 220 to which the branch tube 50 is fixed.

  The fixing member 120 is greatly different from the fixing member 20 with respect to the position of the flange portion 130. In the present embodiment, the flange portion 130 is disposed at one end of the second portion 122b on the third portion 122c side. Further, the stepped portion 127 is provided in the first portion 122a, and the tensile strength material 54 extends from the first portion 122a to the second portion 122b. As a modification of this embodiment, the stepped portion 127 can be disposed in the third portion 122c, and the tensile strength material 54 can be laid from the third portion 122c to the second portion 122b. In this case, a groove can be provided to pass the tensile material 54 through the flange portion 130.

  In the fixing member 220 according to the third embodiment, the third portion 222c is disposed between the first portion 222a and the second portion 222b, and the flange portion 230 is located on the third portion 222c side of the first portion 222a. It is arranged at one end. The tensile strength material 54 is fixed by the second portion 222b, and the second portion 222b has an outer diameter smaller than that of the third portion 222c in order to prevent interference between the optical fiber core wire 72 and the second clamping member 42. Yes.

  Although the pinching members 40, 42, and 44 have been described by exemplifying ring-shaped so-called caulking, any other members that can hold the branch tube 50 between the fixing member 20 can be used. As such, for example, a loop may be made of a belt-like member such as a hose clamp, and the fixing member 20 and the branch tube 50 may be sandwiched in the loop. Alternatively, two rectangular parallelepiped members having a sandwiching surface (inner surface) roughly corresponding to the curvature of the surface of the fixing member 20 can be prepared, and the fixing member 20 and the branch tube 50 can be sandwiched between the sandwiching surfaces of these members. .

  Each portion of the above-described fixing member has a substantially cylindrical shape, but may have another shape such as a polygonal column. The fixing member 20 and the housing 10 can also be locked by disposing a flange-like protrusion on the inner surface of the housing 10 and providing a groove for locking the protrusion on the fixing member.

It is a disassembled perspective view of the branch part by the 1st Embodiment of this invention. It is sectional drawing of the branch part by the 1st Embodiment of this invention. It is an external appearance perspective view of the fixing member by the 1st Embodiment of this invention. It is a figure which shows the assembly process of the branch part by the 1st Embodiment of this invention. It is a figure which shows the assembly process of the branch part by the 1st Embodiment of this invention. It is a figure which shows the assembly process of the branch part by the 1st Embodiment of this invention. It is a figure which shows the assembly process of the branch part by the 1st Embodiment of this invention. It is sectional drawing of the fixing member by the 2nd Embodiment of this invention. It is sectional drawing of the fixing member by the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Branch part 10 Housing 12 Groove 13 Cable gripping part 14 Projection 20 Fixing member 22 Part 24 Surface 26 Alignment groove 28 Receiving hole 30 Flange part 32 Center through-hole 40 1st clamping member 40a Inner surface 42 2nd clamping member 44 3rd clamping Member 50 Branch tube 52 Protective tube 54 Tensile material 56 Jacket 70 Multi-core optical fiber cable 72 Optical fiber core wire

Claims (6)

An optical fiber cable having a plurality of optical fiber cores;
A housing for accommodating one end of the optical fiber cable;
A plurality of metal pipes, a tensile material attached to the outside of the protective pipe, and a jacket covering the protective pipe and the tensile material, one end of which is accommodated in the housing and branched. A plurality of branch tubes for protecting the optical fiber core wire,
A fixing member having a substantially columnar first portion, and arranging and fixing the plurality of branch tubes on a first surface which is an outer peripheral surface of the first portion;
A sandwiching member that surrounds the plurality of branch tubes, an inner surface thereof is disposed to face the first surface, and mechanically sandwiches the plurality of branch tubes with the fixing member;
A multi-fiber optical fiber cable branch structure comprising:   The multi-fiber optical fiber cable branch structure according to claim 1, wherein the protective tube is a spiral tube. The fixing member includes a substantially columnar second portion and a second surface which is an outer peripheral surface thereof;
3. The multi-fiber optical fiber cable branching structure according to claim 1, further comprising a second holding member that mechanically holds the tensile material between an inner surface and the second surface. The fixing member includes a substantially columnar third portion and a third surface which is an outer peripheral surface thereof,
The multi-fiber optical fiber cable branching structure according to claim 3, further comprising a third clamping member that mechanically clamps the protective tube between an inner surface and the third surface.   The multi-fiber optical fiber cable branching structure according to any one of claims 1 to 4, wherein the fixing member further includes an engaging portion that engages with the housing.   6. The multi-fiber optical fiber according to claim 5, wherein the first surface has a plurality of first grooves corresponding to the branch tube, and a plurality of through holes communicating with the first grooves are formed in the second portion. Cable branch structure.

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