JP2005266391A - Optical drop wire, and its manufacturing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical drop wire in which an optical fiber can be efficiently and easily extended by eliminating or suppressing its distortion, and to provide its manufacturing method and apparatus. <P>SOLUTION: An optical drop wire 1 is integrally formed by covering an optical fiber 2 and a support wire 3 which are arranged side by side, with a sheath 4, wherein a plurality of slits 10 are formed at a neck part 8 between the optical fiber 2 and the support wire 3, at equal intervals along with an axial direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical drop wire for drawing an optical fiber into a subscriber's house and the like, a manufacturing method and a manufacturing apparatus therefor.

  When an optical fiber is branched and drawn from an optical fiber cable wired overhead to a subscriber's house or the like, an optical drop wire 50 having a support line 3 that supports the optical fiber 2 is used as shown in FIG.

  The optical drop wire 50 includes a core wire portion 6 in which the optical fiber 2 and the tension member 5 are integrally covered with the sheath material 4, a suspension wire portion 7 in which the support wire 3 is covered with the sheath material 4, A neck portion 51 that integrally connects the portion 6 and the hanging wire portion 7 with the sheath material 4 is provided. The neck portion 51 is formed so as to be constricted between the core wire portion 6 and the suspension wire portion 7, and has joined the core wire portion 6 and the suspension wire portion 7 at a constant rate in the axial direction. This is because the core wire portion 6 needs to be separated from the support wire 3 when the support wire 3 is fastened to a utility pole or the like.

JP 2003-90941 A

  In the conventional optical drop wire 50, the hanging wire portion 7 and the core wire portion 6 are integrated, and the extension of the hanging wire portion 7 is directly applied to the core wire portion (optical fiber) 6, so that excessive tension is applied to the hanging wire portion 7. There is a problem that distortion occurs in the optical fiber. Similarly, as a cause of distortion, there is twisting that occurs when a cable is fed out from the center of a bundle to which tension is applied. The tension is applied directly to the core portion 6 by twisting, and as a result, distortion occurs in the optical fiber.

  Moreover, since the cutting operation of the neck portion 51 is performed on site, a simple cutter is used. However, since the length of cutting the neck portion 51 is relatively long as a standard of 360 mm, there is a problem that skill is required. If the cutting of the neck portion 51 fails and the core wire portion 6 and the suspended wire portion 7 are cut, not only the basic characteristics of the optical fiber core wire itself are impaired, but also the support wire 3 and the tension member 5 are corroded. There was a fear of doing. In this case, it is necessary to replace the optical drop wire 50 with a new one and perform the wire drawing work again. Therefore, there is a problem that the optical drop wire 50 is wasted, extra work is generated, and work efficiency is lowered. It was.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical drop wire that can solve the above-described problems, can suppress distortion of the optical fiber, and can efficiently and easily extend the optical drop wire, and a manufacturing method and manufacturing apparatus therefor. .

  In order to solve the above-mentioned problems, the present invention provides an optical drop wire integrally formed by covering with an optical fiber and a support wire in a state where the optical fiber and the support wire are arranged, and in the axial direction at the neck between the optical fiber and the support wire. A plurality of slits are formed at equal intervals along.

  The length of the slit is 100 to 360 mm, and the interval between the slits is preferably 20 to 40 mm.

  It is preferable to form the optical fiber long at a predetermined ratio with respect to the suspended portion.

  In addition, while manufacturing the optical drop wire by drawing the optical fiber and the support wire through the sheathing chamber of the sheath material and making the optical drop wire in the vicinity of the die, the blade is made to be able to appear and disappear freely. It is pulled out to form a slit in the axial direction of the neck.

  A coating chamber through which the optical fiber and the support wire are inserted to flow in one direction; an extruder connected to the coating chamber for supplying a melted sheath material; and a downstream side of the coating chamber. An optical drop wire manufacturing apparatus provided with a die for molding the sheath material into a predetermined cross-sectional shape is provided with a blade that can be moved into and out of the optical drop wire fed out of the die.

  A guide hole for guiding the blade may be formed in the die, and the blade may be projected and retracted with respect to the optical drop wire being molded in the die.

  The distortion of the optical fiber can be eliminated or suppressed, and the optical drop wire can be efficiently and easily drawn.

  FIG. 1 is a perspective view of an optical drop wire showing a preferred embodiment of the present invention, and FIG. 2 is a front sectional view of the optical drop wire.

  As shown in FIGS. 1 and 2, the optical drop wire 1 is formed by covering and integrally forming an optical fiber 2 and a support member 3 with a sheath material 4, and the optical fiber 2 and the tension member 5. Is comprised of a core wire portion 6 that encloses the support wire 3, a suspension wire portion 7 that encloses the support wire 3, and a neck portion 8 that integrally connects the core wire portion 6 and the suspension wire portion 7.

  The core part 6 is formed in a substantially rectangular cross section, and has grooves 9 for facilitating the stripping of the optical fiber 2 on both sides. Two optical fibers 2 are arranged in the approximate center of the core 6 and sandwiched between the grooves 9 on both sides. The tension member 5 is for protecting the optical fiber 2 from axial tension, and is disposed along the optical fiber 2. The tension member 5 is formed of a steel wire or FRP (Fiber Reinforced Plastics) that is sufficiently thinner than the support wire 3.

  The suspension wire portion 7 is formed by covering the outer periphery of the support wire 3 with the sheath material 4 to a substantially uniform thickness. The support wire 3 is stretched between structures (not shown) such as intermediate pillars and lead-in pillars, and is made of steel wire or FRP.

  The neck portion 8 is formed of the sheath material 4 and is formed between the core wire portion 6 and the suspension wire portion 7 in the width direction. In addition, a plurality of slits 10 for facilitating cutting of the neck portion 8 are formed in the neck portion 8 at equal intervals along the axial direction. The lengths of the slits 10 are all 360 mm, and the interval between the slits 10, that is, the axial length of the connecting portion 11 formed between the slits 10 is 30 mm. The reason why the length of the slit 10 is determined to be 360 mm is that when the optical drop wire 1 is fastened to the intermediate column or the pull-in column, the standard length that separates the hanging portion 7 and the core portion 6 is 360 mm. . The reason why the axial length of the connecting portion 11 is determined to be 30 mm is that the length capable of supporting the core wire portion 6 with sufficient strength is about 30 mm.

  Further, the core wire portion 6 is formed to be slightly longer than the hanging wire portion 7 and is not directly subjected to the tension applied to the hanging wire portion 7. That is, the length of the core wire portion 6 between the adjacent connection portions 11 is slightly longer than that of the suspension wire portion 7, and even if the suspension wire portion 7 extends slightly due to tension, the tension reaches the core wire portion 6. There is no such thing.

  The operation of this embodiment will be described.

  As shown in FIG. 3, when the optical drop wire 1 is fastened to the intermediate column 12, the connecting portion 11 is extended so as to be substantially at the center of the intermediate column 12, and the hanging portion 7 separated from the core portion 6 is provided. It hangs around the fastener 13 and holds it. Even if the neck portion 8 is not cut, it can be fastened to the intermediate pillar 12, and the optical drop wire 1 can be efficiently and easily extended.

  Since the suspended suspending portion 7 is shortened, the core wire portion 6 is appropriately slackened to bypass the retaining position. And since the core wire portion 6 is formed longer than the suspension wire portion 7 and the cord wire portion 6 has an extra length, the tension of the suspended suspension wire portion 7 does not directly act on the core wire portion 6. It is possible to prevent the optical fiber 2 from being distorted.

  Further, when the optical drop wire 1 is drawn out from the center of the bundle around which the optical drop wire 1 is wound, the core wire portion 6 moves relatively freely with respect to the hanging wire portion 7, so that twisting of the optical drop wire 1 can be prevented. It is possible, and the distortion of the fiber core wire, which is a measure of long-term reliability, can be eliminated or suppressed.

  In addition, when a separating part of 360 mm or more is unavoidable between the hanging wire part 7 and the core wire part 6, it can be formed by cutting the neck part 8 along the axial direction, and the core wire can be used when cutting the neck part 8. It becomes possible to prevent the part 6 and the suspension part 7 from being damaged, and the optical drop wire 1 can be efficiently and easily extended.

  Next, the manufacturing method and manufacturing apparatus of the optical drop wire 1 will be described.

  4 is a schematic plan sectional view of the optical drop wire manufacturing apparatus 20, FIG. 5 is a view taken along the line AA in FIG. 4, and FIG. 6 is a view taken along the line BB in FIG.

  As shown in FIG. 4, the optical drop wire manufacturing apparatus 20 includes a coating chamber 21 into which the optical fiber 2, the support wire 3, and the tension member 5 are inserted to flow in one direction, and the coating chamber 21 connected to the coating chamber 21. An extruder 22 for supplying the sheath material 4 melted to the core, a die 23 provided on the downstream side of the coating chamber 21 for molding the sheath material 4 into a predetermined cross-sectional shape, and an optical drop wire fed out from the die 23 1 and a blade 24 that can freely move in and out.

  The covering chamber 21 is formed between an outer cylinder 26 and a base 27 of the head 25 described later. The head 25 includes an outer cylinder 26 that constitutes an outer shell of the coating chamber 21, and a cylindrical base 27 that is provided coaxially within the outer cylinder 26. The outer cylinder 26 is connected to an extruder 22 which will be described later, and the sheath material 4 melted from the extruder 22 is supplied thereto.

  The base 27 is inserted through the optical fiber 2, the tension member 5, and the support wire 3 to guide the die 23, and is formed by narrowing the end facing the die 23, and the opposite end is formed. The outer cylinder 26 is fixed in a liquid-tight manner. Accordingly, the head 25 is configured so that the sheath material 4 supplied from the extruder 22 flows only to the die 23 side and does not flow backward into the die 27.

  The optical fiber 2, the support wire 3, and the tension member 5 flow from the head 25 side to the die 23 side, and are wound by a winder (not shown) provided on the downstream side. 23 is pulled out.

  The extruder 22 includes a screw 29 that is connected to a driving device 28 and is rotatable, a transfer pipe 30 that surrounds the outer periphery of the screw 29 and guides the sheath material 4, and a heater (not shown). The extruder 22 is connected to a hopper 31 for receiving pellets as a raw material of the sheath material 4, and the extruder 22 is supplied with pellets from the hopper 31.

  The die 23 has a molding hole 32 for joining the optical fiber 2, the tension member 5, the support wire 3, and the sheath material 4 drawn from the base 27 into a predetermined cross-sectional shape. The molding hole 32 is formed on the upstream side of the die 23 and is reduced in diameter toward the downstream side, and the molding portion 34 is formed in the cross-sectional shape of the optical drop wire 1 to be formed and hardens the outer shape of the sheath material 4. Consists of.

  The blade 24 is provided integrally with a movable iron core of a solenoid 35 provided in a fixed system (not shown) such as a frame of the extruder 22, and the diameter is increased along the end face of the die 23 by operating the solenoid 35. It is configured to slide in the direction. Further, the tip of the blade 24 is disposed so as to face the neck portion 8 of the optical drop wire 1 drawn out from the die 23, and is configured to penetrate the neck portion 8 by extending the solenoid 35. The blade 24 is formed in an elliptical cross section, and the slit 10 is formed in a shape having no corners.

  The manufacturing method and operation of the optical drop wire 1 using the optical drop wire manufacturing apparatus 20 will be described.

  First, the pellets are accommodated in the hopper 31 and the extruder 22 is operated. The pellets supplied from the hopper 31 to the extruder 22 are melted by the heat in the extruder 22 and extruded toward the coating chamber 21 by the rotating screw 29. As a result, the coating chamber 21 is filled with the melted sheath material 4, and the sheath material 4 starts to flow toward the die 23.

  Further, the winder is also operated simultaneously with the operation of the extruder 22. As a result, the optical fiber 2, the tension member 5 and the support wire 3 are passed through the coating chamber 21 and pulled out from the die 23. The optical fiber 2, the tension member 5, and the support wire 3 are entangled while being joined to the sheath material 4 at the assembly portion 33 of the die 23 and are integrally covered. The sheath material 4 is solidified into a predetermined shape by passing through the molding part 34. At this time, the winding speed of the optical fiber 2 and the tension member 5 is slightly higher than the winding speed of the support wire 3, and the optical fiber 2 is formed longer than the support wire 3.

  When the properties of the sheath material 4 are stabilized and the optical fiber 2 and the like are stably coated in a predetermined shape, the solenoid 35 is expanded and contracted at predetermined time intervals. Thereby, the blade 24 can be made to appear and disappear in the neck portion 8 formed between the optical fiber 2 and the support wire 3. Since the neck portion 8 flows together with the optical fiber 2 and the support line 3, the blade 24 is immersed in the neck portion 8, so that a slit 10 extending in the axial direction is formed in the neck portion 8, and the blade 24 is extracted from the neck portion 8. The connection part 11 is formed in the. The axial lengths of the slit 10 and the neck portion 8 can be easily determined by adjusting the time interval for extending or retracting the solenoid 35.

  As described above, when the optical drop wire 1 is manufactured by passing the optical fiber 2 and the support wire 3 through the sheathing chamber 21 of the sheath material 4 and drawing out from the die 23, the optical fiber 2 and the support wire 3 are disposed in the vicinity of the die 23. Since the blade 24 is pulled out of the neck 8 to be formed while being freely retracted to form the slit 10 in the axial direction of the neck 8, a plurality of slits 10 along the axial direction can be easily formed in the neck 8 at equal intervals.

  In addition, since the optical drop wire manufacturing apparatus 20 is configured by including the blade 24 that can be protruded and retracted with respect to the optical drop wire 1 fed out from the die 23, a plurality of slits 10 along the axial direction can be easily formed in the neck portion 8 with a simple mechanism. It can be formed at equal intervals.

  Another embodiment in which the above-described embodiment is partially changed will be described. The description of the same configuration as described above will be omitted, and the changed configuration will be described.

  FIG. 7 is an enlarged side cross-sectional view of the main part of the optical drop wire manufacturing apparatus 40, and particularly shows the vicinity of the die 41. FIG.

  As shown in FIG. 7, the die 41 has a guide hole 42 for guiding the blade 24, and is configured so that the blade 24 protrudes and retracts with respect to the neck portion 8 of the optical drop wire 1 being molded in the die 41. Has been. And especially the guide hole 42 is formed so that it may be connected to the upstream end of the molding part 34 of the die | dye 41, and when determining the outer periphery shape of the optical drop wire 1, it is comprised so that the slit 10 may be formed simultaneously. Yes. Further, an insertion hole 44 communicating with the guide hole 42 is formed in the head 43 surrounding the outer periphery of the die 41, so that the blade 24 can be inserted into the die 41 from the outer periphery side of the head 43.

  When the solenoid 35 is expanded and contracted by the optical drop wire manufacturing apparatus 40 configured as described above, and the blade 24 is inserted into and extracted from the die 41, the blade 24 appears and disappears in the soft sheath material 4 being molded. For this reason, even if the outer surface of the sheath material 4 becomes rough when the blade 24 moves in and out of the sheath material 4, this roughness is buried while flowing in the die 41 and does not remain on the optical drop wire 1 drawn out from the die 41. . On the other hand, since the blade 24 is projected and retracted in the sheath material 4 after passing through the assembly portion 33 that greatly deforms the sheath material 4, the deformation of the sheath material 4 that occurs after the formation of the slit 10 is slight and passes through the die 41. In the meantime, the slit 10 is not filled.

  As described above, the guide hole 42 for guiding the blade 24 is formed in the die 41, and the blade 24 is projected and retracted with respect to the optical drop wire 1 being molded in the die 41. Therefore, it is possible to easily manufacture a beautiful optical drop wire 1 without rough skin.

  In addition, although the optical drop wire 1 having the two optical fibers 2 has been described, as shown in FIG. 8, the optical drop wire 45 having three or more optical fibers 2 may be used. 2 may be included.

  Moreover, although the length of the slit 10 shall be 360 mm, what is necessary is just about 100 mm or more and 360 mm or less. And although the length of the axial direction of the connection part 11 was 30 mm, it should just be about 20 mm or more and 40 mm or less.

  The core portion 6 includes the tension member 5, but may be omitted when an optical drop wire that does not require the tension member 5 is manufactured.

  Further, although the blade 34 is provided in the solenoid 35, it is not limited to this. For example, instead of the solenoid 35, a retractable drive device such as a hydraulic cylinder or an air cylinder may be used.

It is a perspective view of the optical drop wire which shows suitable embodiment of the present invention. It is front sectional drawing of an optical drop wire. It is a side view of the optical drop wire fastened to the utility pole. It is a schematic plane sectional view of an optical drop wire manufacturing device. It is an AA arrow directional view of FIG. It is a BB line arrow directional view of FIG. It is a principal part expanded side sectional view of the optical drop wire manufacturing apparatus which shows other embodiment. It is front sectional drawing of the optical drop wire which shows other embodiment. It is a perspective view of the conventional optical drop wire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical drop wire 2 Optical fiber 3 Support line 4 Sheath material 8 Neck part 10 Slit 20 Optical drop wire manufacturing apparatus 21 Coating chamber 22 Extruder 23 Die 24 Blade 42 Guide hole

Claims (6)

  In an optical drop wire integrally formed by covering with an optical fiber and a support line in a state where the optical fiber and the support line are arranged, a plurality of slits are formed at equal intervals along the axial direction at the neck between the optical fiber and the support line. An optical drop wire characterized by that.   2. The optical drop wire according to claim 1, wherein the slit has a length of 100 to 360 mm and a slit interval of 20 to 40 mm.   The optical drop wire according to claim 1 or 2, wherein the optical fiber is formed long at a predetermined ratio with respect to the suspended portion.   The optical fiber and the support wire are passed through the sheathing chamber of the sheath material, and when the optical drop wire is manufactured by pulling it out from the die, it is pulled out while allowing the blade to freely move in and out of the neck formed between the optical fiber and the support wire. A method for producing an optical drop wire, comprising forming a slit in an axial direction of a neck portion.   A coating chamber for inserting the optical fiber and the support wire to flow in one direction, an extruder connected to the coating chamber for supplying a sheath material melted into the coating chamber, and provided on the downstream side of the coating chamber An optical drop wire manufacturing apparatus provided with a die for molding a sheath material into a predetermined cross-sectional shape, comprising: a blade that can be moved in and out of the optical drop wire fed out of the die. manufacturing device. 6. The optical drop wire manufacturing apparatus according to claim 5, wherein a guide hole for guiding the blade is formed in the die, and the blade is caused to appear and disappear with respect to the optical drop wire being molded in the die.

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