JP2007148121A - Optical fiber cable holder, optical fiber cable holding structure, and method for holding optical fiber cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cable holder that can surely hold a support wire part of an optical fiber cable, even though the tool has a simple structure, and to provide an optical fiber cable holding structure and a method for holding optical fiber cable. <P>SOLUTION: The optical fiber cable holder 12 comprises a holding grip member 14A for fastening a support wire part 5 of an optical drop cable and a dummy wire 15 for reinforcing the fastening force of the retaining grip member 14A on the support wire part 5. The retaining grip member 14A comprises a folded portion 17 of two metal wires 16, bent together to fold back and two winding portions 18, comprising two metal wires 16 spirally wound together, each disposed on both sides of the folded portion 17. While the support wire part 5 and the dummy wire 15 are lined up linearly, the support wire part 5 and the dummy wire 15 are wound up collectively by the winding portions 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical fiber cable holder, an optical fiber cable retaining structure, and an optical fiber cable retaining method for retaining an optical fiber cable having a cable main body portion and a support wire portion on an aerial wire or the like.

  In recent years, with the development of optical access networks such as FTTH, optical fibers have been wired to subscriber homes. As an optical fiber wiring method, for example, a messenger wire is laid so as to span between utility poles, the optical fiber cable is held along the messenger wire, and the optical fiber cable is drawn into each subscriber's house at an appropriate position. I am doing so. At this time, as an optical fiber cable, it has a cable main body formed by covering an optical fiber, and a support line formed by covering the support wire that is integrated with the cable main body and extends along the optical fiber. So-called optical drop cables are often used.

When drawing such an optical drop cable into each subscriber's house, it is necessary to keep the optical drop cable on a messenger wire or the like. As a conventional optical drop cable retaining structure, for example, as described in Patent Document 1, a structure using an optical drop cable retaining tool for retaining an optical fiber cable is known.
JP 2000-41325 A

  However, in the above-described prior art holder, an optical cable holding portion that holds an optical fiber cable in which the cable main body portion and the support wire portion are integrated, a cable main body holding portion that holds the cable main body portion, and a support wire The support line holding part that holds the support part and the anchor around which the support line part is wound are provided, and the holding part and the anchor are provided on one substrate. For this reason, the structure for retaining the optical drop cable has to be large and complicated as a whole.

  An object of the present invention is to provide an optical fiber cable holder, an optical fiber cable retaining structure, and an optical fiber cable retaining method capable of reliably retaining a support line portion of an optical fiber cable while having a simple structure. is there.

  The present invention relates to an optical fiber having a cable main body formed by coating an optical fiber with a resin, and a support line formed by resin coating a metal support wire that is integrated with the cable main body and extends along the optical fiber. An optical fiber cable holder for holding a support line part separated from a cable body part when the cable is fastened to an aerial wire or a fixed installation, a holding grip member for tightening the support line part, and a metal And a dummy wire for reinforcing the clamping force of the holding grip member with respect to the support wire portion, and the holding grip member winds two metal strands in a spiral shape It is formed as described above, and has two winding portions that are collectively wound in a state where the support wire portion and the dummy wire are arranged.

  Using such holding grip members and dummy wires, for example, when securing an optical fiber cable to an aerial wire, the dummy wires are arranged in parallel with respect to the support wire portion separated from the cable body portion, The support line portion and the dummy line are collectively wound by the two winding portions of the holding grip member, thereby holding the support line portion and the dummy line. Then, in this state, the holding grip member and the imaginary wire are connected to each other by the fastening tool. As described above, the optical fiber cable holder is composed of only a simple component such as a holding grip member having two winding portions and a dummy wire. As a result, the structure of the optical fiber cable holder need not be enlarged or complicated.

  Here, it is also conceivable that only the support wire portion is wound and held by the two winding portions of the holding grip member without using the dummy wire. However, when the present inventors adopt such a method, the holding layer is softened when the temperature of the coating layer provided on the surface of the support wire portion becomes high in summer or the like. A new fact was found that the winding portion of the holding member becomes slippery with respect to the support wire portion, and the tightening force of the holding grip member to the support wire portion is reduced. The cause is as follows.

  That is, the support wire portion is sandwiched between the two winding portions, but since the cross-sectional shape of the support wire portion is a relatively small-diameter circle, the support wire portion is supported when the support wire portion is tightened by the two winding portions. There is a problem that the wire layer is only wrapped and the coating layer is hardly crushed. In addition, if the outer diameter of each metal wire constituting the holding grip member is made too thick so as to sufficiently crush the coating layer of the supporting wire portion by the holding grip member, the cross section is cut by the spirally formed winding portion. The circular support line cannot be tightened well. Accordingly, it is difficult to sufficiently crush the covering layer of the support line portion by the holding grip member, and the clamping force of the holding grip member to the support line portion is insufficient.

  Therefore, as described above, with the dummy lines arranged in parallel to the support line part, the support line part and the dummy line are collectively wound by the two winding parts of the holding grip member, and the support line part and The dummy line is sandwiched between the two winding portions in a state where the dummy line has a shape of a cross section 8. For this reason, when the supporting wire portion and the dummy wire are tightened by the two winding portions, both the covering layers escape to the region between the covering layer of the supporting wire portion and the covering layer of the dummy wire. A layer becomes easy to be crushed in the juxtaposition direction of a support line part and a dummy line. As a result, the temperature of the covering layer of the support wire portion becomes high in summer or the like, so that the tightening force of the holding grip member with respect to the support wire portion is ensured even when the covering layer is softened.

  Preferably, the holding grip member further includes a folded portion that is bent so as to fold two metal strands, and the winding portions are provided on both sides of the folded portion of the holding grip member. In this case, for example, the folded portion can be used as a portion to be connected to the holding tool for connecting the holding grip member and the overhead wire, so that the optical fiber cable can be easily held. Moreover, since two winding parts are obtained from one holding grip member, the number of holding grip members to be used can be minimized.

  Preferably, the outer diameter of each metal wire constituting the holding grip member is equal to or greater than the outer diameter of the support wire portion and the dummy wire. As described above, the support wire portion and the dummy wire are sandwiched between the two winding portions of the holding grip member in a state where the cross section is in the shape of 8. Therefore, unlike the case where only the support wire portion having a circular cross section is tightened by the two winding portions, the winding formed in a spiral shape even if the outer diameter of each metal wire constituting the holding grip member is increased to some extent. The support wire portion and the dummy wire can be sufficiently tightened by the portion. Further, by increasing the outer diameter of each metal wire constituting the holding grip member, when the support wire portion and the dummy wire are tightened by the holding grip member, a large pressure is applied to the support wire portion and the dummy wire. Will start. Thereby, since each coating layer of a support line part and a dummy wire becomes easier to be crushed, the clamping force of the holding grip member with respect to a support line part becomes still higher.

  Further, preferably, the dummy line has substantially the same structure as the support line portion. In this case, for example, the remaining support line portion in the work or the like can be used as a dummy line as it is, so that it is not necessary to make a new dummy line. This eliminates unnecessary costs. The substantially identical structure includes not only the completely identical structure but also almost the same structure.

  The present invention also includes a cable main body formed by resin-covering an optical fiber, and a support line formed by resin-covering a metal support wire that is integrated with the cable main body and extends along the optical fiber. An optical fiber cable holding structure for holding an optical fiber cable to an aerial wire or a fixed installation, and the above-mentioned optical fiber cable holder, and a holding tool for connecting the optical fiber cable holder and the aerial wire or a fixed installation. And the fastening tool includes a connecting wire formed by coating a metal wire with a resin, and a connecting grip member for fastening the connecting wire in two rows. The connecting grip member includes two metals. The wire is formed so as to be spirally wound, and has two winding portions that collectively wind the connecting wires in two rows.

  When the optical fiber cable is fastened to, for example, an aerial wire using such an optical fiber cable holder and a fastening tool, the support grip part and the dummy wire separated from the cable body part as described above are used as grip members for holding. Tighten all at once. Then, in this state, the holding grip member and the imaginary wire are connected to each other by the fastening tool. As described above, the optical fiber cable holder includes only a simple part such as a holding grip member having two winding portions and a dummy wire. Further, similarly to the holding grip member, the pulling fastener is constituted by only a simple part such as a connecting grip member having two winding portions and a connecting line. Thereby, it is not necessary to enlarge or complicate the structure of the optical fiber cable holder and the pulling fastener.

  In addition, since the holding grip member and the connecting grip member can have the same structure, the types of parts for holding the optical fiber cable can be reduced, which is advantageous in terms of cost.

  Further, in the optical fiber cable holder, when the support wire portion and the dummy wire are collectively tightened by the two winding portions of the holding grip member, the support wire portion covering layer and the dummy wire covering layer are as described above. Both covering layers escape to the area between the two, so that both covering layers are easily crushed. Thereby, even if the temperature of the coating layer of the support line part becomes high in summer or the like, the clamping force of the holding grip member to the support line part is ensured. Also, the pulling fastener is similar to the optical fiber cable holder described above, in which the connecting lines are arranged in two rows and the connecting wires in each row are collectively tightened by the two winding portions of the connecting grip member. It has a holding structure. That is, since the connecting lines are in two rows, the connecting lines are sandwiched between the two winding portions in the shape of the shape of the cross section 8, and therefore, a relief portion of the covering layer is formed between the covering layers of each connecting line. The Rukoto. Therefore, even if the temperature of the covering layer of the connecting wire increases, the tightening force of the connecting grip member with respect to the connecting wire is ensured.

  Preferably, the connecting grip member further includes a folded portion formed by bending two metal wires so that the winding portions of the connecting grip member are provided on both sides of the folded portion of the connecting grip member. It has been. In this case, the folded portion can be used as a portion connected to the holding grip member, the overhead wire, or the like, so that the optical fiber cable can be easily retained. Moreover, since two winding parts are obtained from one connection grip member, the number of connection grip members to be used can be minimized.

  At this time, there is a pair of connecting grip members, and each pair of connecting grip members is arranged so that each folded portion is positioned on the side opposite to the side facing each other. It is preferable to wind the both ends of the connecting wire by the winding part. In this case, by connecting one folded portion of the pair of coupling grip members to the holding grip member and coupling the other folded portion of the pair of coupling grip members to an aerial wire or the like, The operation of securing the optical fiber cable can be performed more easily.

  Preferably, the outer diameter of each metal wire constituting the connecting grip member is equal to or greater than the outer diameter of the connecting wire. As described above, the connecting line is sandwiched between the two winding portions of the connecting grip member in a state where the cross section is in the shape of a letter 8. For this reason, even if the outer diameter of each metal wire constituting the connecting grip member is increased to some extent, the two-row connecting wires can be sufficiently tightened by the spirally formed winding portion. Further, by increasing the outer diameter of each metal wire constituting the connecting grip member, a large pressure is applied to the connecting line when the connecting wire is tightened by the connecting grip member. As a result, the covering layer of the connecting wire is more easily crushed, and the tightening force of the connecting grip member with respect to the connecting wire is further increased.

  Further, preferably, the connecting line has substantially the same structure as the support line portion. In this case, for example, the remaining support line portion in the work or the like can be used as a connection line as it is, so that it is not necessary to make a new connection line. This eliminates unnecessary costs. The substantially identical structure includes not only the completely identical structure but also almost the same structure.

  The present invention also includes a cable main body formed by resin-covering an optical fiber, and a support line formed by resin-covering a metal support wire that is integrated with the cable main body and extends along the optical fiber. An optical fiber cable retaining method for securing an optical fiber cable to an aerial wire or a fixed installation, the step of preparing the above-mentioned optical fiber cable holder, the step of preparing the above-mentioned retaining device, and the cable body part. In the state in which the support wire portion thus formed and the dummy wire of the optical fiber cable holder are arranged, a step of tightening the support wire portion and the dummy wire together with a holding grip member of the optical fiber cable holder, And a step of connecting the fiber cable holder and the overhead wire or fixed installation.

  Thus, by using the above-described optical fiber cable holder and the retainer, the structure for retaining the optical fiber cable is not enlarged or complicated by retaining the optical fiber cable on an aerial wire or a fixed installation. That's it.

  Moreover, even if the temperature of the coating layer of the support wire portion becomes high in summer or the like, it is possible to ensure the tightening force of the holding grip member with respect to the support wire portion. Furthermore, even if the temperature of the covering layer of the connecting wire that is a part of the clasp becomes high, it is possible to ensure the tightening force of the connecting grip member with respect to the connecting wire.

  Furthermore, even in a place where no overhead wire is installed, by adjusting the length of the connecting line in the fastener, the optical fiber cable can be reliably secured to a fixed installation such as a utility pole.

  According to the present invention, the support line portion of the optical fiber cable can be reliably held while having a simple structure. As a result, it is possible to improve workability and cost reduction related to the retention of the optical fiber cable while preventing adverse effects on the characteristics of the optical fiber.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an optical fiber cable holder, an optical fiber cable retaining structure, and an optical fiber cable retaining method according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration diagram showing an embodiment of an optical fiber cable retaining structure according to the present invention. In the figure, the optical fiber cable retaining structure 1 of this embodiment is configured such that when the optical drop cable 2 which is one of the optical fiber cables is pulled into each home, the optical drop cable 2 is connected to a messenger wire (aerial wire) 3 or a utility pole. Etc.

  As shown in FIG. 2, the optical drop cable 2 includes a cable main body 4 and a support wire portion 5 integrated with the cable main body 4. The cable body 4 includes one or two (one in the figure) optical fibers 6, a pair of tensile strength wires 7 that are disposed on both sides of the optical fibers 6 and are made of metal wires, and the like. 6 and a sheath (covering layer) 8 formed by covering the tensile strength wire 7 together. The support wire portion 5 extends along the axial direction of the optical fiber 6 and includes a support wire 9 made of, for example, a Zn-plated steel wire, and a sheath 10 covering the support wire 9. The sheaths 8 and 10 are made of a thermoplastic resin such as PE. The sheaths 8 and 10 are integrated with each other through the neck portion 11.

  The optical fiber cable retaining structure 1 includes an optical fiber cable holder 12 for retaining the support wire portion 5 separated from the cable body portion 4 when the optical drop cable 2 is retained on the messenger wire 3 or the like. The optical fiber cable holder 12 is provided with a fastening tool 13 for connecting the messenger wire 3 and the like.

  The optical fiber cable holder 12 reinforces the two holding grip members 14A and 14B for tightening the support wire portion 5 and the tightening force (gripping force) of the holding grip members 14A and 14B with respect to the support wire portion 5. And a dummy line 15 (see FIG. 3).

  As shown in FIG. 3, the holding grip members 14 </ b> A and 14 </ b> B are formed by bending together two metal strands 16 having a circular cross section. At this time, the two metal strands 16 may be bent in a twisted state (see FIG. 3), or the two metal strands 16 may be bent in a line. In addition, as the metal strand 16, for example, a Zn plating wire or the like is used.

  The holding grip members 14A and 14B are respectively provided on a folded portion 17 formed by bending two metal strands 16 together so as to be folded in a U shape, and on both sides of the folded portion 17, respectively. It has two winding portions 18 formed by winding the wire 16 together in a spiral. The holding grip members 14A and 14B are formed by winding the support wire portion 5 and the dummy wire 15 together by the winding portions 18 in a state where the support wire portion 5 and the dummy wire 15 are arranged in a line. The part 5 and the dummy wire 15 are configured to be tightened together.

  The dummy line 15 has the same structure as the support line portion 5. As shown in FIG. 4, the support wire portion 5 has a circular cross section in which the outer diameter A of the support wire 9 is about 1.2 mm and the outer diameter B of the sheath 10 is about 2.0 mm. In addition, about 1.2 mm is within a range of an allowable error of 1.2 mm (for example, ± 0.05 mm), and about 2.0 mm is a range of an allowable error of 2.0 mm (for example, ± 0.05 mm). Is within.

  The support line portion 5 of the optical drop cable 2 is often left behind in wiring work or the like. Therefore, by effectively using the wasted support line portion 5 as the dummy line 15, it is not necessary to separately prepare the dummy line 15, so that the cost can be reduced accordingly.

  Further, as shown in FIG. 4, the outer diameter C of the metal strand 16 constituting the holding grip members 14 </ b> A and 14 </ b> B is equal to the outer diameter B of the support wire portion 5, or the outer diameter of the support wire portion 5. It is larger than B. For this reason, the outer diameter C of the metal strand 16 is larger than the outer diameter A of the support wire 9 of the support wire portion 5.

  When holding the supporting wire portion 5 separated from the cable body portion 4 using the holding grip members 14A and 14B and the dummy wire 15, the holding grip member 14A is used as shown in FIG. The one end portion of the dummy wire 15 and the corresponding portion of the support wire portion 5 are tightened, the other end portion of the dummy wire 15 and the corresponding portion of the support wire portion 5 are tightened by the holding grip member 14B, and the holding wire is held. The folded portions 17 of the grip members 14A and 14B are connected to each other.

  Specifically, as shown in FIGS. 5 (a) and 5 (b), one of the holding grip members 14A is arranged in a state in which the support wire portion 5 and the dummy wire 15 separated from the cable body portion 4 are arranged. The support wire portion 5 and the dummy wire 15 are collectively wound by the winding portion 18. At this time, the winding portion 18 is fitted into the support wire portion 5 and the dummy wire 15 from the center side (folded portion 17 side) to the end portion side of the holding grip member 14A.

  Subsequently, as shown in FIGS. 5C and 5D, the support wire portion 5 and the dummy wire 15 are collectively wound by the other winding portion 18 of the holding grip member 14A. At this time, the other winding portion 18 is moved from the center side of the holding grip member 14A to the end side so that the support wire portion 5 and the dummy wire 15 are wound adjacent to the one winding portion 18 wound earlier. The support wire portion 5 and the dummy wire 15 are fitted into the head.

  Subsequently, in this state, the holding grip member 14A is pulled to both sides so as to extend, so that the spiral inner diameter D (see FIG. 4) of each winding portion 18 is slightly reduced, and the support wire portion 5 and the dummy wire 15 are Tightened and held. Then, both end portions of the holding grip member 14A are fixed to the optical drop cable 2 by a fixing member 19 such as a vinyl tape (see FIG. 1).

  For the holding grip member 14B, the support wire portion 5 and the dummy wire 15 are held and fixed in the same manner as described above. When the winding portion 18 is fitted into the support wire portion 5 and the dummy wire 15, the support wire portion 5 and the dummy wire 15 are provided on the inner surface of the winding portion 18 (the surface that contacts the support wire portion 5 and the dummy wire 15). It is desirable to apply an abrasive (for example, alumina or the like) for increasing the frictional force with the material. Thereby, in the state where the support wire portion 5 and the dummy wire 15 are held by the holding grip members 14A and 14B, the winding portion 18 is difficult to come off.

  Returning to FIG. 1, the pulling fastener 13 connected to the optical fiber cable holder 12 as described above has a connecting wire 20 and two connecting grip members 21 </ b> A and 21 </ b> B for fastening the connecting wire 20. . The connecting wire 20 has the same structure as the support wire portion 5 of the optical drop cable 2. As a result, similarly to the above-described dummy line 15, it is not necessary to separately prepare the connection line 20 by effectively using the support line portion 5 remaining in the wiring work or the like as the connection line 20.

  The connecting grip members 21A and 21B have the same structure as the holding grip members 14A and 14B. That is, the connecting grip members 21 </ b> A and 21 </ b> B have a folded portion 22 and two winding portions 23 provided on both sides of the folded portion 22. As shown in FIG. 6, the connecting grip members 21 </ b> A and 21 </ b> B are formed by winding the connecting wires 20 together by the winding portions 23 in a state where the two connecting wires 20 are arranged in a row. 20 is tightened and held together. The both ends of the connecting grip members 21A and 21B are fixed to the connecting wire 20 by a fixing member 24 such as a vinyl tape (see FIG. 1).

  At this time, the connecting grip member 21A collectively tightens one end side portions of the two connecting wires 20, and the connecting grip member 21B collectively fixes the other end portion of the two connecting wires 20. Tightened. Further, the connecting grip members 21A and 21B are arranged so that the folded portions 22 face the opposite side to the side facing each other. In addition, the winding method of the winding part 23 is the same as that of the winding part 18 of said holding grip members 14A and 14B.

  FIG. 7 is a schematic view showing a wiring state in which the optical drop cable 2 is drawn into each home in an urban area where the messenger wire 3 is laid.

  In the same figure, the messenger wire 3 is comprised, for example with a copper strand etc., and is laid so that each utility pole P may be spanned. The optical drop cable 2 is laid so as to extend along the messenger wire 3. The optical drop cable 2 is wired so as to be drawn into the subscriber's home Q at an arbitrary retaining position. At the holding position of the optical drop cable 2, the cable main body 4 and the support wire portion 5 of the optical drop cable 2 are separated. The separated support wire portion 5 is fastened to the messenger wire 3 by the optical fiber cable fastening structure 1 described above.

  When actually holding the optical drop cable 2, the holding grip members 14 </ b> A and 14 </ b> B and the dummy wire 15 constituting the optical fiber cable holder 12 and the holding tool 13 are prepared. Note that the clasp 13 may be made in advance or may be made at a work site.

  First, the connecting grip member 21A and the holding grip member 14A are respectively engaged with the turning back portion 22 of the holding grip member 14A, 14B through the turning back portion 22 of the connecting grip member 21A of the pulling fastener 13 and locked. 14B is connected. And in the state which arranged the dummy wire 15 with respect to the support line part 5 isolate | separated from the cable main-body part 4, 14 G of holding members hold | maintain part of the support line part 5 and the one end side part of the dummy line 15. The other part of the support wire portion 5 and the other end side portion of the dummy wire 15 are fastened by the fastening and holding grip member 14B. Then, the folded portion 22 of the connecting grip member 21 </ b> B in the fastener 13 is hooked on the hook F provided on the messenger wire 3.

  Thus, by pulling the optical drop cable 2 to the messenger wire 3, the cable main body portion 4 of the optical drop cable 2 can be reliably detoured with respect to the support wire portion 5. Thereby, since the optical fiber 6 incorporated in the cable main body part 4 is prevented from being bent suddenly, an increase in optical transmission loss can be suppressed. If necessary, the cable body 4 detoured with respect to the support wire 5 may be fastened to the winding portion 18 of the holding grip members 14A and 14B with a vinyl tape or the like.

  The procedure for holding the optical drop cable 2 is not particularly limited to the above. For example, the folded portion 22 of the connecting grip member 21 </ b> B in the clasp 13 may be hooked on the hook F first.

  Further, the fastening tool 13 may be manufactured while the optical drop cable 2 is being fastened. In this case, first, a part of the support line part 5 and one end side part of the dummy line 15 are fastened by the holding grip member 14A, and the other part of the support line part 5 and the dummy line 15 are fastened by the holding grip member 14B. Tighten the other end of the part. Then, in a state where the folded portion 22 of the connecting grip member 21A and the folded portions 17 of the holding grip members 14A and 14B are connected to each other in the fastener 13, the one end side portion of each connecting line 20 is connected by the connecting grip member 21A. The other end portion of each connecting wire 20 is fastened by the fastening and connecting grip member 21B. Then, the folded portion 22 of the connecting grip member 21 </ b> B in the fastener 13 is hooked on the hook F.

  FIG. 8 is a schematic view showing a wiring state in which the optical drop cable 2 is drawn into each home in a suburb where no messenger wire 3 is laid.

  In the figure, the optical drop cable 2 is laid so as to span the respective power poles P, and is wired so as to be drawn into the subscriber's home Q at an arbitrary retaining position. At the holding position of the optical drop cable 2, the support wire portion 5 separated from the cable main body portion 4 is held to one of the utility poles P by the optical fiber cable holding structure 1. The method of securing the optical drop cable 2 is the same as that when the messenger wire 3 is provided. At this time, the folded portion 22 of the connecting grip member 21 </ b> B in the pulling fastener 13 is hooked on a hook F provided on the utility pole P.

  In this case, the optical drop cable 2 can be fastened to the utility pole P without changing the length of the connecting wire 20 in the fastening tool 13 as appropriate, without installing the messenger wire 3 in particular. Thereby, it becomes possible to reduce the cost for newly stretching a messenger wire.

  Here, as a comparative example, when only the support wire portion 5 is tightened by the holding grip members 14A and 14B, the support wire portion 5 includes two holding grip members 14A and 14B as shown in FIG. It will be in the state of being pinched by the winding part 18. At this time, since the support wire portion 5 has a circular cross section, there is no effective escape portion of the sheath 10 of the support wire portion 5 when the support wire portion 5 is tightened by the holding grip members 14A and 14B. 10 becomes difficult to be crushed. Further, if the metal wire 16 constituting the holding grip members 14A and 14B is made thicker than the support wire portion 5, the support wire portion 5 having a circular cross section cannot be tightened well by the spiral winding portion 18. For this reason, the metal strand 16 must be made thin with respect to the support wire portion 5, and in this case, it becomes difficult to apply a large force to the support wire portion 5.

  For this reason, even if the support wire portion 5 is tightened by the holding grip members 14A and 14B, the sheath 10 of the support wire portion 5 cannot be sufficiently crushed. Is not sufficiently small, and the sheath 10 having a large thickness is interposed between the support wire 9 of the support wire portion 5 and the metal wire 16. Actually, when the support wire portion having an outer diameter of the support wire of 1.2 mm and the outer diameter of the sheath of 2 mm is tightened by a holding grip member formed of a metal wire having an outer diameter of 1.2 mm, the spiral of the winding portion is obtained. The inner diameter was about 1.8 to 2.0 mm and was not so small.

  In such a case, when the temperature of the sheath 10 of the support wire portion 5 is increased to 40 ° C. or higher, for example, in summer, the sheath 10 is softened, and the winding portion 18 of the holding grip members 14A and 14B is connected to the support wire portion 5. Therefore, the clamping force of the holding grip members 14 </ b> A and 14 </ b> B against the support line portion 5 is reduced. As a result, the support wire portion 5 cannot be sufficiently held by the holding grip members 14A and 14B, so that it is difficult to securely hold the optical drop cable 2 to the messenger wire 3 or the like. In this case, for example, at the position where the optical drop cable 2 is held, the optical drop cable 2 may be greatly shaken or dropped due to strong wind or the like, which may adversely affect the characteristics of the optical fiber 6.

  On the other hand, in the present embodiment, a dummy wire 15 having the same structure as that of the support wire portion 5 is prepared, and the support wire portion 5 and the dummy wire 15 are tightened together by holding grip members 14A and 14B. . For this reason, the two winding portions 18 of the holding grip members 14A and 14B sandwich the support wire portion 5 and the dummy wire 15 which are arranged so as to have a shape of a cross section 8 as shown in FIG. . At this time, in a state before tightening, a clearance groove portion 25 having a substantially V-shaped cross section is formed between the support wire portion 5 and the dummy wire 15 (see FIG. 4A). Accordingly, when the support wire portion 5 and the dummy wire 15 are tightened by the winding portion 18, the sheath 10 of the support wire portion 5 and the dummy wire 15 escapes (deforms) to the escape groove portion 25 side. The sheath 10 is easily crushed in the direction in which the lines 15 are arranged (see FIG. 4B).

  Further, by arranging the support line part 5 and the dummy line 15, the two winding parts 18 are not only the support line part 5 having a circular cross section but also the support line part formed in the shape of the cross section 8 as described above. 5 and the dummy line 15 are sandwiched. For this reason, even if the outer diameter C of the metal wire 16 constituting the holding grip members 14A and 14B is increased to some extent, the support wire portion 5 and the dummy wire 15 can be tightened together by the winding portion 18 and can be well tightened. There is no particular problem. Accordingly, by making the outer diameter C of the metal strand 16 equal to or greater than the outer diameter B of the support wire portion 5, a large force can be applied to the support wire portion 5 by the winding portion 18. Therefore, the sheath 10 is further easily crushed in the direction in which the support wire portion 5 and the dummy wire 15 are arranged side by side.

  As a result, the spiral inner diameter D of the wound portion 18 after tightening becomes sufficiently small, and the sheath 10 is hardly interposed between the support wire 9 of the support wire portion 5 and the metal strand 16. That is, the winding part 18 will be in the state which clamps the support line part 5 and the support line 9 of the dummy wire 15 directly (refer FIG.4 (b)).

  Therefore, even when the temperature of the sheath 10 of the optical drop cable 2 becomes high and the sheath 10 is softened in summer, etc., it is possible to prevent the winding portions 18 of the holding grip members 14A and 14B from sliding with respect to the support wire portion 5. Therefore, the clamping force of the holding grip members 14A and 14B with respect to the support line portion 5 is sufficiently ensured. As a result, the optical drop cable 2 can be reliably secured to the messenger wire 3 or the utility pole P.

  Here, when the support wire portion 5 and the dummy wire 15 having an outer diameter A of the support wire 9 of about 1.2 mm are used, the support wire portion 5 and the dummy wire 15 are tightened by the holding grip members 14A and 14B. In the obtained state, it is preferable that the spiral inner diameter D of the winding portion 18 is 2.40 to 3.05 mm. With such a configuration, even if the temperature of the sheath 10 of the support wire portion 5 rises, the clamping force of the holding grip members 14A and 14B with respect to the support wire portion 5 can be sufficiently secured.

  Further, the holding structure of the connecting wire 20 by the connecting grip members 21 </ b> A and 21 </ b> B in the pulling fastener 13 is exactly the same as that of the optical fiber cable holder 12. For this reason, as in the case of the optical fiber cable holder 12 described above, it is possible to sufficiently secure the fastening force of the connecting grip members 21A and 21B with respect to the connecting wire 20 even when the temperature of the clasp 13 becomes high. it can.

  Here, when the support line part and the dummy line were tightened together with the grip member and the support line part was tightened together with the grip member, a high-temperature tightening force test was actually performed. explain.

  First, a sample in a state where only the support line portion was tightened by the grip member and a sample in which the support line portion and the dummy line were collectively tightened by the grip member were prepared. The length of these samples is about 50 cm. As a test method, the sample was placed in a test apparatus (high temperature layer), the inside of the test apparatus was heated with a black light, and the sample was pulled from both sides to apply a load. In addition, about the sample of the state which clamped together the support line part and the dummy line with the grip member, the abrasive | polishing agent was apply | coated to the inner surface of the winding part of a grip member.

  In the sample in which only the support line portion was tightened by the grip member, when the inside of the test apparatus reached 40 ° C. or higher and a tensile load of 700 N was applied to both sides of the sample, the grip member was insufficiently tightened. . On the other hand, in the sample in which the support wire part and the dummy wire are collectively tightened by the grip member, when the inside of the test apparatus reaches 60 ° C., even if a tensile load of 1200 N is applied to both sides of the sample, the grip There was no occurrence of insufficient tightening force of the members.

  As described above, in the present embodiment, since the optical fiber cable holder 12 is configured by the holding grip members 14A and 14B and the dummy wires 15, the optical fiber cable holder 12 is reduced in size and simplified. be able to. Moreover, since the fastening tool 13 is configured by the connecting wire 20 and the connecting grip members 21A and 21B, the fastening tool 13 can be reduced in size and simplified. Thereby, cost reduction of the optical fiber cable retaining structure 1 can be realized.

  Further, in the optical fiber cable holder 12, since the support wire portion 5 and the dummy wire 15 are tightened together by the holding grip members 14A and 14B, the support wire portion 5 is supported even when the temperature of the support wire portion 5 becomes high as described above. The line part 5 can be reliably held. Moreover, in the fastener 13, since the two connecting wires 20 are tightened together by the connecting grip members 21A and 21B, the connecting wire 20 is securely held even when the temperature of the connecting wire 20 becomes high as described above. can do. For this reason, even if environmental temperature becomes high, the optical drop cable 2 can be reliably fastened to the messenger wire 3 or the utility pole P. FIG. Thereby, it can be avoided that the optical drop cable 2 is greatly shaken at the holding position of the optical drop cable 2 to adversely affect the characteristics of the optical fiber 6.

  Further, the holding grip members 14A and 14B are provided with a folded portion 17, and the connecting grip members 21A and 21B are provided with a folded portion 22. The folded portions 17 and 22 are used to make an optical fiber cable. The optical drop cable 2 can be easily fastened to the messenger wire 3 and the utility pole P by connecting the holder 12 and the hook F to the fastener 13. In addition, when the support wire portion 5 is held by the optical fiber cable holder 12, it is not necessary to peel off the sheath 10 of the support wire portion 5 one by one, so that the workability at the time of holding the optical drop cable 2 can be improved. .

  Moreover, since the hardware etc. which wrap around the support wire part 5 become unnecessary, it can prevent that a bird makes a nest on the optical fiber cable holder 12 or the clasp 13, for example. This makes it possible to avoid damage to the optical drop cable 2 caused by bird's nest.

  Further, when the support line portion 5 of the optical drop cable 2 is held, if the support line portion 5 is wound around a hardware or the like as in the prior art, the support line portion 5 is naturally bent. However, since the support wire part 5 once bent is difficult to process so as to extend straight, it cannot be reused. In the present embodiment, since the support line portion 5 is held in a state of extending substantially straight, the support line portion 5 can be reused.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the outer diameter C of the metal wire 16 constituting the holding grip members 14A and 14B is equal to or greater than the outer diameter B of the support wire portion 5, but the holding wire is supported by the holding grip members 14A and 14B. If the clamping force of the holding grip members 14 </ b> A and 14 </ b> B against the support wire portion 5 is sufficiently obtained when the portion 5 and the dummy wire 15 are fastened together, the metal strand 16 is more than the support wire portion 5. You may make it thinner.

  Moreover, in the said embodiment, although the dummy wire 15 and the connection line 20 shall have the same structure as the support line part 5 of the drop cable 2, as the dummy line 15 and the connection line 20 to be used, it is not restricted to this, Any metal wire may be used as long as it is formed by resin coating.

  Furthermore, in the said embodiment, although the connecting wire 20 was made into 2 rows state by arranging the two connecting wires 20 as a structure of the clasp 13, as shown in FIG. The connecting line 20 may be in a two-row state by folding back in a letter shape.

It is a block diagram which shows one Embodiment of the optical fiber cable holding structure which concerns on this invention. It is sectional drawing of the optical drop cable shown in FIG. It is a component block diagram of the optical fiber cable holder shown in FIG. It is sectional drawing which shows the state in which the support line part and dummy wire of an optical drop cable are clamped by the holding | grip grip member shown in FIG. It is a figure which shows the procedure which winds the support line part and dummy line of an optical drop cable collectively by the winding part of the holding | grip grip member shown in FIG. It is a partial block diagram of the pulling fastener shown in FIG. It is the schematic which shows the wiring state which led the optical drop cable shown in FIG. 2 in each household in the urban area with a messenger wire. It is the schematic which shows the wiring state which led the optical drop cable shown in FIG. 2 in each household in the suburbs without a messenger wire. As a comparative example, it is sectional drawing which shows the state in which only a support line part is clamp | tightened with the holding | grip grip member shown in FIG. It is a partial block diagram of the modification of the fastening tool shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical fiber cable retention structure, 2 ... Optical drop cable (optical fiber cable), 3 ... Messenger wire (aerial wire), 4 ... Cable main-body part, 5 ... Support line part, 6 ... Optical fiber, 7 ... Tensile wire, DESCRIPTION OF SYMBOLS 8 ... Sheath, 9 ... Support wire, 10 ... Sheath, 11 ... Neck part, 12 ... Optical fiber cable holder, 13 ... Fastening tool, 14A, 14B ... Holding grip member, 15 ... Dummy wire, 16 ... Metal strand, DESCRIPTION OF SYMBOLS 17 ... Folding part, 18 ... Winding part, 19 ... Fixing member, 20 ... Connecting wire, 21A, 21B ... Grip member for connection, 22 ... Folding part, 23 ... Winding part, 24 ... Fixing member, P ... Electric pole (fixed installation) object).

Claims (10)

An optical fiber cable comprising: a cable main body formed by resin coating an optical fiber; and a support line unit formed by resin coating a metal support wire that is integrated with the cable main body and extends along the optical fiber. A fiber optic cable holder for holding the support wire portion separated from the cable body portion when being fastened to an aerial wire or a fixed installation,
A holding grip member for fastening the support wire portion;
A metal wire that is resin-coated, and a dummy wire for reinforcing the clamping force of the holding grip member with respect to the support wire portion,
The holding grip member is formed so as to wind two metal strands in a spiral shape, and has two winding portions for collectively winding the support wire portion and the dummy wire in a lined state. An optical fiber cable holder. The holding grip member further includes a folded portion formed by bending the two metal strands,
The optical fiber cable holder according to claim 1, wherein the winding portion is provided on each side of the folded portion of the holding grip member.   3. The optical fiber cable holder according to claim 1, wherein an outer diameter of each metal wire constituting the holding grip member is equal to or greater than an outer diameter of the support wire portion and the dummy wire. .   The optical fiber cable holder according to any one of claims 1 to 3, wherein the dummy wire has substantially the same structure as the support wire portion. An optical fiber cable comprising: a cable main body formed by resin coating an optical fiber; and a support line unit formed by resin coating a metal support wire that is integrated with the cable main body and extends along the optical fiber. An optical fiber cable retaining structure that is secured to an aerial wire or a fixed installation,
An optical fiber cable holder according to any one of claims 1 to 4,
A tensioning tool for connecting the optical fiber cable holder and the overhead wire or the fixed installation;
The clasp has a connecting wire formed by coating a metal wire with a resin, and a connecting grip member for fastening the connecting wire in a state of being arranged in two rows,
The connecting grip member is formed so as to spiral two metal strands in a spiral shape, and has two winding portions that collectively wind the connecting wires in two rows. Characteristic optical fiber cable retention structure. The connection grip member further includes a folded portion that is bent so as to fold the two metal wires.
6. The optical fiber cable holding structure according to claim 5, wherein the winding portion of the connecting grip member is provided on both sides of the folded portion of the connecting grip member. The connection grip member has a pair,
The pair of connecting grip members are arranged so that each of the folded portions is positioned on a side opposite to the side facing each other, and each of the two winding portions is connected to both ends of the connecting line. The optical fiber cable retaining structure according to claim 6, wherein each of the optical fiber cable is wound.   The optical fiber cable retaining structure according to any one of claims 5 to 7, wherein an outer diameter of each of the metal wires constituting the connecting grip member is equal to or greater than an outer diameter of the connecting wire. .   The optical fiber cable retaining structure according to any one of claims 5 to 8, wherein the connecting line has substantially the same structure as the support line portion. An optical fiber cable comprising: a cable main body formed by resin coating an optical fiber; and a support line unit formed by resin coating a metal support wire that is integrated with the cable main body and extends along the optical fiber. , A fiber optic cable retention method that is secured to an overhead wire or fixed installation,
Preparing the optical fiber cable holder according to any one of claims 1 to 4,
A step of preparing the clasp according to any one of claims 5 to 9,
The support line portion and the dummy are held by the holding grip member of the optical fiber cable holder in a state where the support line portion separated from the cable main body portion and the dummy wire of the optical fiber cable holder are arranged. The process of tightening the wires together;
A method of retaining an optical fiber cable, comprising the step of connecting the optical fiber cable holder and the overhead wire or the fixed installation by the retainer.

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