JP5895596B2 - Cable pulling jig and cable connection structure - Google Patents

Description

  The present invention relates to a cable pulling jig used when laying a cable such as an optical cable.

  In order to construct an optical communication network such as FTTH using an optical fiber, an optical cable is laid over the ground or underground. The structure of the installed optical cable is roughly divided into a slot type and a slotless type. In the slot type, a plurality of optical fiber single core wires or tape core wires are assembled in a groove of a spacer having a tension member (mainly steel wire) at the center, and a presser winding tape is wound around the outer periphery of the optical fiber. A cover is formed. The slotless type has a structure in which the inside is hollow, a plurality of optical fiber single core wires or tape core wires are assembled in the hollow portion, and a tension member (mainly steel wire) is embedded in the jacket. The slotless type cable does not use a slot and has fewer components than the slot type cable, and therefore can be manufactured at a low cost.

  When laying an optical cable in an aerial space such as between utility poles, the tip of the optical cable is held with a simple jig and pulled. When laying an optical cable in an underground pipe, a larger tension is required compared to laying in an aerial, so a pulling jig is attached to the tip of the optical cable and pulled. There are several types of pulling jigs depending on the construction method, and one of them is the pooling eye method.

  The pulling eye type pulling jig used for the slot type cable inserts a tension member into the hole of the sleeve to fix the tension member in the center of the slot, The tension member can be integrated.

  As the cable pulling terminal structure used for the slotless type cable, an optical fiber insertion hole into which the optical fiber lead-out portion can be inserted into the holder, and a tension member insertion hole into which the tension member lead-out portion can be inserted are formed. A thin-walled portion is formed outside the tension member insertion hole on the outer peripheral surface of the holder to crimp the lead-out portion of the tension member. A protective tube is screwed to the distal end of the holder, and the towed end is attached to the distal end of the protective tube. A device in which a tool is screwed is known (for example, see Patent Document 1).

JP 2010-217316 A

  The pulling eye type pulling jig used for slot type cables can be applied to cables in which the tension member is arranged in the center of the cable because the hole for inserting the tension member is arranged in the center of the sleeve. However, it could not be applied to a slotless cable in which a tension member is not arranged in the center of the cable.

  In the cable pulling terminal structure described in Patent Document 1 used for the slotless cable, the number of parts is large and expensive as compared with the pulling jig for the slot type cable, and the number of work steps is also increased.

  In addition, the demand for laying optical cables in underground pipelines is increasing year by year, and a simple and inexpensive jig is required as a traction jig for laying slotless cables that are easy to lay in underground pipelines. Yes.

  An object of the present invention is to provide an inexpensive cable pulling jig that can be applied to a cable in which a tension member is not arranged in the center and has a simple configuration.

The cable pulling jig and cable connecting structure of the present invention that can solve the above-described problems is that the tension member is fixed by inserting a cable tension member and crimping it in the radial direction to plastically deform it. A plurality of fixing holes are formed in the sleeve, and each of the plurality of fixing holes extends in a direction along the axial direction of the sleeve and opens at one end surface of the sleeve at a predetermined interval .
The plurality of fixing holes corresponding to the respective tension members to be inserted are positioned closer to the center axis of the cable than the positions of the tension members, and tapered surfaces are provided at the inlets of the plurality of fixing holes. and said that you are.

In the connection structure between the cable pulling jig and the cable according to the present invention, it is preferable that the plurality of fixing holes are arranged in a point-symmetric manner on the one end surface in a combination of a plurality of pairs having different intervals.

In the connection structure between the cable pulling jig and the cable of the present invention, it is preferable that the fixing hole is also formed at the center position of the one end face.

In the connection structure between the cable pulling jig and the cable according to the present invention, it is preferable that an identification portion capable of identifying the circumferential direction of the sleeve is provided on the outer peripheral surface of the sleeve.

In the connection structure between the cable pulling jig and the cable according to the present invention, it is preferable that an eye nut having an annular portion is attached to the other end of the sleeve.

In the cable pulling jig and cable connection structure of the present invention, it is preferable that a cap that covers at least one end surface of the sleeve and extends along the axial direction of the sleeve is attached to the sleeve.

According to the connection structure between the cable releasing jig and the cable of the invention, a plurality of fixing holes for inserting and fixing the tension member has an opening at a predetermined distance from one another at one end surface of the sleeve, the insertion The plurality of fixing holes corresponding to each of the tension members to be formed are positioned closer to the center axis of the cable than the positions of the tension members, and tapered surfaces are provided at the inlets of the plurality of fixing holes. Therefore, even in a slotless type cable in which no tension member is arranged in the center, the tension member can be fixed to the sleeve by inserting the tension member and crimping the sleeve. That is, the slotless type cable can be pulled with a simple configuration with a small number of parts.

It is a figure which shows one Embodiment of the jig | tool for cable pulling (sleeve), Comprising: (a) is a side view, (b) is a figure of the end surface seen from the arrow A direction of (a). It is a fragmentary sectional view of the pooling eye using the sleeve of FIG. It is sectional drawing which shows an example of the cross-sectional structure of the slotless type | mold optical cable pulled. FIG. 2 is a schematic view when a tension member of a slotless optical cable is inserted into the fixing hole of the sleeve of FIG. 1. FIG. 5 is a schematic diagram when a tension member is caulked in a fixing hole of a sleeve from the state of FIG. 4. It is a schematic diagram which shows the example of arrangement | positioning of the fixing hole formed in a sleeve. It is a schematic diagram which shows the suitable shape at the time of crimping a sleeve.

Hereinafter, an example of an embodiment of a cable pulling jig according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, a sleeve 2 which is one form of a cable pulling jig is a rod-like member having a substantially circular cross section, and is formed of a metal such as stainless steel. On one end side of the sleeve 2 (on the right side in FIG. 1A), a pair of fixing holes 7 opened in one end surface 6 of the main body 3 is provided. The pair of fixing holes 7 extend in a direction along the axial direction of the sleeve 2 and are formed in parallel with a predetermined interval (for example, about 5 mm to 10 mm). The pair of fixing holes 7 are arranged at point-symmetrical positions with respect to the center point O of the one end face 6.

  The fixing hole 7 is capable of inserting the tension member of the cable to be pulled, and preferably has a diameter slightly larger than the tension member to be inserted. In addition, a tapered surface 8 having a hole diameter enlarged toward the outside is formed at a portion opened to one end surface 6 of the fixing hole 7. When the tension member is inserted into the fixing hole 7, the tapered surface 8 functions as a guide that contacts the tip of the tension member and guides it into the fixing hole 7. With the tension member inserted in the fixing hole 7, the tension member can be fixed to the sleeve 2 by plastic deformation by caulking the main body 3 from the outside in the radial direction.

  Near the center of the sleeve 2 in the axial direction, a flange portion 4 having a diameter slightly larger than that of the main body portion 3 is formed. From the flange portion 4 to the other end side (the left side in FIG. 1A). Is provided with a screw portion 5 to which a nut or the like can be attached.

FIG. 2 shows a pulling eye type cable pulling jig 1 having the sleeve 2 of FIG.
The cable pulling jig 1 includes a sleeve 2, an eye nut 9 attached to the screw portion 5 on the other end side of the sleeve 2, a cap 11 fixed at a position on the other end side of the flange portion 4 in the sleeve 2, It has. The eye nut 9 has a structure having an annular portion, and a tow rope or the like can be connected to the annular portion to pull the sleeve 2 with a strong force. The cap 11 is a substantially cylindrical member that covers the periphery of the one end surface 6 while being attached to the sleeve 2 and extends along the axial direction of the sleeve 2. The cap 11 is made of a metal material such as aluminum. It is preferable that the inner diameter of the cap 11 is slightly larger than the outer diameter of the cable to be pulled.

  A cylindrical gasket 13 made of an elastic member such as rubber is mounted at a position on the other end side of the flange portion 4 in the sleeve 2. A cap 11 is attached so as to cover the gasket 13 and the flange portion 4, and a cap cover 12 is attached so as to cover a fixed end of the cap 11. The cap 11 and the cap cover 12 are fixed to the sleeve 2 by screwing the hexagon nut 10 into the screw portion 5.

  Between the flange portion 4 of the sleeve 2 and the hexagon nut 10, the cap 11, the cap cover 12, and the gasket 13 are pressed in the axial direction of the sleeve 2. The gasket 13 is expanded in the radial direction by being compressed in the axial direction, whereby the space between the sleeve 2 and the cap 11 is sealed in a watertight manner.

Next, as an example of a cable pulled by the cable pulling jig 1, the slotless optical cable 30 shown in FIG. 3 will be described.
The optical cable 30 has a plurality (two in this example) of optical fiber ribbons 31 at the center as viewed in the cross section. The optical fiber ribbon 31 is formed by integrating a plurality (eight in this example) of optical fibers in parallel on a plane and integrating them in a tape shape with a coating resin. An inclusion 32 such as nylon fiber is disposed around the optical fiber ribbon 31, and the periphery thereof is covered with an outer jacket 35.

  At two locations in the circumferential direction in the vicinity of the inner circumference of the outer jacket 35, tear strings 34 for tearing the outer jacket 35 and taking out the optical fiber tape core wire 31 are embedded. The tear string 34 of this example is arranged at a position orthogonal to the parallel direction of the optical fibers in the optical fiber ribbon 31 (the width direction of the optical fiber ribbon 31).

  Further, two tension members 33 for undertaking the tension applied to the optical cable 30 are embedded on the extension line in the parallel direction of the optical fiber inside the jacket 35. The pair of tension members 33 are provided at positions separated by a predetermined distance from the center of the optical cable 30 as viewed in a cross section. The tension member 33 is made of steel wire, FRP wire or the like and has a tensile strength function. When the optical cable 30 is laid, the tension member 33 is pulled mainly under tension.

Next, a procedure for fixing the optical cable 30 to the cable pulling jig 1 when laying the optical cable 30 will be described.
First, at the terminal portion of the optical cable 30, the outer jacket 35 is removed by a predetermined length, and a pair of tension members 33 are protruded from the ends of the outer jacket 35. As shown in FIG. 4, the pair of fixing holes 7 of the sleeve 2 are preferably slightly narrower than the distance between the pair of tension members 33 of the optical cable 30. Then, as indicated by an arrow B, the shafts 33 a of the pair of tension members 33 are slightly moved toward the center axis of the sleeve 2 (for example, 1 mm to 2 mm) and inserted into the fixing holes 7. Thereby, the fixed state of the optical cable 30 with respect to the sleeve 2 is easy to be stabilized.

  If the displacement between the fixing hole 7 and the tension member 33 is large, the tension member 33 may bend and be damaged at the inlet of the fixing hole 7, but the tapered surface 8 is provided at the inlet of the fixing hole 7. Therefore, this positional deviation can be sufficiently allowed up to about 2 mm.

  Further, for example, the outer diameter of the optical cable 30 is 7 mm to 13 mm, and the diameter of the main body 3 of the sleeve 2 is slightly smaller than that. When the diameter of the tension member 33 is about 1 mm, the diameter of the fixing hole 7 is preferably about 1.2 mm. If the diameter of the tension member 33 is changed, the diameter of the fixing hole 7 may be changed accordingly.

  When the pair of tension members 33 are inserted into the fixing holes 7 respectively, the main body 3 of the sleeve 2 is crimped in the radial direction. When caulking, a pair of caulking jigs having a semi-cylindrical inner peripheral surface is used. When the direction in which the sleeve 2 is compressed is different, the fixing force of the tension member 33 is also different. In order to increase the fixing force of the tension member 33, it is preferable to crimp the sleeve 2 so as to compress it from both sides in the direction along the parallel direction of the fixing holes 7 (vertical direction in FIG. 4). FIG. 5 shows a caulking direction (arrow C) when the sleeve 2 is caulked to fix the tension member 33. In this state, the sleeve 2 is compressed in the radial direction and plastically deformed. At the same time, the fixing hole 7 is also plastically deformed, and the tension member 33 is fixed inside the fixing hole 7.

  After the tension member 33 is fixed to the sleeve 2, as shown in FIG. 2, the gasket 13, the cap 11, and the cap cover 12 are attached from the other end side of the sleeve 2, and the hexagon nut 10 is fixed with screws. By screwing the hexagon nut 10, the gasket 13 is compressed in the axial direction to seal the space between the sleeve 2 and the cap 11 in a watertight manner.

  Next, the eye nut 9 is screwed into the threaded portion 5 and attached. The eye nut 9 may have a structure in which a small bolt can be inserted and fixed to the portion to be screwed into the screw portion 5 from the outside in the radial direction. In that case, the eye nut 9 can be firmly fixed to the screw portion 5 by the small bolt.

  The optical cable 30 is fixed to the cable pulling jig 1 by the above procedure. Since the watertight structure is formed between the sleeve 2 and the cap 11, it is possible to prevent water from entering from the other end side of the sleeve 2 and entering the optical cable 30. Further, it is more preferable that a waterproof tape is wound around the outer periphery of the outer cover 35 of the portion of the optical cable 30 accommodated in the cap 11 so that a watertight structure is formed between the cap 11 and the outer cover 35.

  In addition, it is also possible to use only the sleeve 2 as a cable pulling jig and lay a drop cable having a pair of tension members or the like in the air.

  As described above, according to the sleeve 2 or the cable pulling jig 1, the plurality of fixing holes 7 for inserting and fixing the tension member 33 are opened at one end face 6 of the sleeve 2 at a predetermined interval. Therefore, even in the case of the slotless type optical cable 30 in which the tension member 33 is not arranged in the center, the tension member 33 is inserted and the sleeve 2 is crimped, whereby the tension is applied to the sleeve 2. The member 33 can be fixed. That is, the slotless type optical cable 30 can be pulled with a simple configuration with a small number of components.

Next, another structural example (modified example) of the sleeve 2 will be described.
In the slotless type cable, since the distance between the pair of tension members differs depending on the type of cable, it is conceivable to prepare a different sleeve for each type of cable. However, since this requires the cost of arranging a plurality of types of sleeves, it is preferable that the sleeve be applicable to a plurality of types of cables.

  As shown in FIG. 6, the fixing holes 7 a to 7 e that are formed to open in the one end surface 6 of the sleeve 2 can be provided in various numbers and arrangements. The letters A to E in the fixing holes 7a to 7e in the drawing are schematically displayed so that the combination of the respective fixing holes can be easily identified. The example of FIG. 6A has the same configuration as the example shown in FIG. 1B, and a pair of fixing holes 7 a are formed at equal intervals with respect to the center O of the one end face 6. The configuration shown in FIGS. 6B, 6 </ b> C, and 6 </ b> D is a configuration that can be applied to a cable having tension members with other intervals while having the configuration including the fixing hole 7 a of this example.

The example of FIG. 6B further includes a pair of fixing holes 7b that are wider than the pair of fixing holes 7a, and can accommodate two types of intervals of the tension member.
6C, in addition to the example of FIG. 6B, a pair of fixing holes 7c that are wider than the pair of fixing holes 7b, and a pair of fixing holes 7d that are wider than the pair of fixing holes 7c, And a pair of fixing holes 7e that are wider than the pair of fixing holes 7d, and can accommodate the five types of intervals of the tension member.
The example of FIG. 6 (d) has a configuration in which a fixing hole 7x is further provided at the center of one end face 6 in addition to the example of FIG. It is.
As described above, the plurality of fixing holes 7 a to 7 e are a combination of a plurality of pairs with different intervals, and are arranged point-symmetrically on the one end face 6. In addition, what is necessary is just to set the hole diameter of fixing hole 7a-7e, 7x suitably to the diameter of the tension member of the assumed cable.

  Moreover, the force with which the sleeve 2 fixes the tension member 33 varies depending on the direction of caulking as described above. Therefore, an identification portion that can identify the circumferential direction of the sleeve 2 is provided on the outer peripheral surface of the main body portion 3 so that the circumferential position when the sleeve 2 is caulked in the radial direction can be understood. preferable. An example in which an identification unit is provided is shown in FIGS. In the example of FIG. 7A, a pair of identification protrusions 3 a is formed on the extension of the pair of fixing holes 7 in the parallel direction. In the example of FIG. 7B, a pair of identification recesses 3 b is formed on the extension of the pair of fixing holes 7 in the parallel direction. These identification parts (identification protrusion 3a, identification concave part 3b) make it easy for the operator to recognize that the sleeve 2 should be crimped so as to compress in the direction of arrow C. In addition, you may display an identification part by a mark instead of a protrusion and a recessed part.

  In addition, the slotless type optical cable having a pair of tension members has a direction in which it is easily bent due to the rigidity of the pair of tension members. Therefore, when the optical cable is pulled out from the bobbin and laid on the ground at the time of laying, the parallel direction of the pair of tension members tends to be in the horizontal direction. When a sleeve having an identification portion as shown in FIG. 7 is used when attaching the sleeve to the end portion of such an optical cable, the identification portion can serve as a mark for aligning the pair of fixing holes with the pair of tension members. Function.

DESCRIPTION OF SYMBOLS 1: Cable pulling jig | tool, 2: Sleeve, 5: Thread part, 6: One end surface, 7: Fixing hole, 9: Eye nut, 10: Hex nut, 11: Cap, 30: Optical cable, 33: Tension member

Claims (6)

A plurality of fixing holes are formed in the sleeve to which the tension member is fixed by inserting a cable tension member and crimping in a radial direction and plastically deforming. The plurality of fixing holes are respectively formed on the sleeve. Extending in a direction along the axial direction and opening at a predetermined interval on one end face of the sleeve ,
The plurality of fixing holes corresponding to the respective tension members to be inserted are positioned closer to the center axis of the cable than the positions of the tension members, and tapered surfaces are provided at the inlets of the plurality of fixing holes. connection structure between the cable releasing jig and cables, characterized in that there. A connection structure between the cable pulling jig and the cable according to claim 1,
A structure for connecting a cable pulling jig and a cable, wherein the plurality of fixing holes are a combination of a plurality of pairs having different intervals and are arranged point-symmetrically on the one end surface. A connection structure between a cable pulling jig and a cable according to claim 1 or 2,
The cable pulling jig and the cable connection structure , wherein the fixing hole is also formed at a center position of the one end face. A connection structure between a cable pulling jig and a cable according to any one of claims 1 to 3,
A structure for connecting a cable pulling jig and a cable, wherein the outer peripheral surface of the sleeve is provided with an identification portion capable of identifying the circumferential direction of the sleeve. A connection structure between the cable pulling jig and the cable according to any one of claims 1 to 4,
A cable pulling jig and a cable connection structure, wherein an eye nut having an annular portion is attached to the other end of the sleeve. A connection structure between a cable pulling jig and a cable according to any one of claims 1 to 5,
A cable pulling jig and cable connection structure , wherein a cap covering at least one end surface of the sleeve and extending along the axial direction of the sleeve is attached to the sleeve.

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