JPH09145974A - Manufacturing device for cable for laying optical fiber and fiber insertion pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pass an optical fiber through a pipe a long distance while maintaining the flexibility of the pipe when the optical fiber is passed through the pipe by an air flowing-in method. SOLUTION: A fiber insertion pipe 10 for inserting the optical fiber and conductive cables 11 are both put together and the fiber insertion pipe 10 is constituted in a corrugated shape to increase the pressure resistance. A towing wire is previously passed through the fiber insertion pipe and made to have extra-length parts, and both the ends of the towing wire are drawn to extend the towing wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable equipped with a fiber insertion pipe for inserting an optical fiber.

[0002]

2. Description of the Related Art In recent years, a LAN using optical communication has been constructed, and for that purpose, a cable having a combination of an ordinary electric wire and a fiber insertion pipe for passing an optical fiber has been developed. This cable has been laid in advance in the required locations in the building, and when passing optical fibers,
An air pouring method is adopted in which an optical fiber is poured into the fiber insertion pipe of the cable together with the pressure air.

[0003]

However, when the optical fiber is inserted by the above-mentioned air casting method, it is necessary to supply a sufficient amount of air for floating and transferring the optical fiber. If it is long, a considerably high pressure of air will be sent into the pipe.

This means that the fiber insertion pipe is required to have a sufficient pressure resistance, and therefore a plastic pipe having a large wall thickness cannot be avoided. As a result,
The flexibility of the fiber insertion pipe is lost, the cable laying work becomes difficult, and the bending radius of the cable becomes large, so that the wiring space increases.

The present invention has been made in view of the above circumstances, and allows a long optical fiber to be inserted into a fiber insertion pipe while maintaining the flexibility of the pipe to facilitate cable laying work and to provide a wiring space. It is an object of the present invention to provide a cable for laying an optical fiber, which can reduce the size. Another object is to provide a fiber insertion pipe manufacturing apparatus suitable for such an optical fiber laying cable.

[0006]

[Means for solving the problem and its action / effect]

<Invention of Claim 1> An optical fiber laying cable according to the invention of Claim 1 is an optical fiber laying cable obtained by assembling a fiber insertion pipe for inserting an optical fiber together with another cable. Is characterized in that it has a wavy shape that undulates along the extension direction of the cable.

According to this structure, since the fiber insertion pipe has a corrugated shape and the circumferential wall thereof has a portion extending in the radial direction, the resistance to the internal pressure becomes larger than that of a simple cylindrical pipe having the same thickness. , The breakdown voltage is increased. Further, since it has a corrugated shape, it is easy to bend, the cable laying work is easy, and the bending radius of the cable can be made small so that it can be wired in a narrow place.

<Invention of Claim 2> The optical fiber laying cable according to the invention of Claim 2 is characterized in that in Claim 1, the inner peripheral side of the fiber insertion pipe has a smooth cylindrical surface.

[0009] With this configuration, air smoothly flows on the inner surface of the fiber insertion pipe, and the optical fiber moves smoothly without being caught, so that a longer optical fiber can be inserted.

<Invention of Claim 3> An optical fiber laying cable according to the invention of Claim 3 is Claim 1 or Claim 2.
The optical fiber laying cable of (1) is characterized in that a pulling line for pulling the optical fiber is further provided in the fiber insertion pipe.

With this configuration, when inserting the optical fiber into the fiber insertion pipe, the tip of the optical fiber may be connected to the pulling line and pulled into the insertion pipe. This may be done by injecting pressured air from the inlet side of the fiber insertion pipe at the same time, or without injecting it.
The optical fiber may be inserted using only the pull line, and in any case, the optical fiber insertion work can be performed more easily.

<Invention of Claim 4> The cable for laying an optical fiber according to the invention of Claim 4 is characterized in that an extra length portion which is extended by applying tension to both ends of the traction line is provided in advance.

In order to draw the optical fiber into the fiber insertion pipe using the traction line, it is necessary to connect one end of the traction line to the optical fiber and pull the other end to draw it in. Therefore, the traction line has a certain margin. is necessary. However, if you simply manufacture the fiber insertion pipe with the traction wire passing through it, the above margin length will be secured when the fiber insertion pipe is continuously manufactured and cut into the required length to be supplied. Can not do it.

On the other hand, according to the above configuration, when the continuously produced optical fiber laying cable is cut to the required length and then both ends of the traction line in the fiber insertion pipe are pulled to apply tension, The extra length of the traction line is stretched, and the traction line having a sufficient margin length is passed through the fiber insertion pipe. This has the effect of facilitating the work of connecting the optical fiber to the pull line and pulling it in.

<Invention of claim 5> An apparatus for producing a fiber insertion pipe according to the invention of claim 5 is a pipe forming device for extruding and molding a fiber insertion pipe for inserting an optical fiber, and a traction line of the optical fiber at both ends. A surplus portion forming device that intermittently forms a surplus portion that is stretched by applying tension and is characterized in that the traction line with the surplus portion formed is supplied into the nipple of the pipe molding device. Have.

According to this structure, the fiber insertion pipe is continuously extruded and molded by the pipe molding device. On the other hand, the extra length forming device intermittently forms an extra length in the traction line of the optical fiber, and the traction line is blown into the nipple of the pipe molding device by the air flow, whereby the traction line is inserted into the fiber insertion pipe. Will be inserted.

Therefore, according to this structure, it is possible to continuously produce the fiber insertion pipe in which the traction line having the extra length portion intermittently is inserted.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> A first embodiment of the present invention will be described below with reference to FIGS.

1 and 2 show an optical fiber laying cable according to this embodiment. In the figure, 10 is a fiber insertion pipe, and 11 is a plurality of conductive cables for transmitting electric power or electric signals. Conductive cable 1
1 is arranged around the fiber insertion pipe 10 in a spiral twisted state, and the outer circumference is a jacket tube 12
And is integrated with the fiber insertion pipe 10.

The fiber insertion pipe 10 is made of polyethylene resin, for example, and has a rectangular corrugated shape that undulates along the extension direction of the cable as shown in FIGS. As for this fiber insertion pipe 10, a simple cylindrical pipe is first molded by an extrusion molding machine, and then,
It may be formed into a corrugated shape by using a forming device having a continuous moving die in the softened state.

The optical fiber laying cable having the above-described structure is laid in advance at a required place in a building, for example. When the optical fiber is passed through here, the optical fiber (not shown) may be poured into the fiber insertion pipe 10 of the cable together with the pressure air.

In this case, since the fiber insertion pipe 10 has a corrugated shape that undulates along the extension direction of the cable, there is a portion extending in the radial direction on the peripheral wall thereof, and for this reason, a simple cylindrical shape having the same thickness It has a higher resistance to internal pressure than pipes. Moreover, since the outside of the fiber insertion pipe 10 is suppressed by the conductive cable 11, the resistance to the internal pressure is further increased. As a result, high-pressure air can be blown into the fiber insertion pipe 10, and a long optical fiber can be easily inserted.

Moreover, since the fiber insertion pipe 10 has a corrugated shape, it is easy to bend and the cable laying work is facilitated. Further, since the bending radius of the cable can be reduced, it is possible to wire in a narrow place.

<Second Embodiment> FIGS. 5 and 6 show a fiber insertion pipe 20 according to a second embodiment of the present invention. The outer peripheral surface 20a of the pipe 20 has a corrugated shape that smoothly undulates along the extension direction of the cable, and the inner peripheral surface 20b has a straight cylindrical shape and is smooth. The configuration other than this fiber insertion pipe 20 is the same as that of the first embodiment, and the duplicated description will be omitted.

In this way, the inner wall surface 2 of the pipe 20
Since the fluid frictional resistance at 0b decreases, the pipe 20
Since the pressurized air supplied therein smoothly flows and the optical fiber is floated and transferred without being caught, the effect that the longer optical fiber can be inserted is obtained in addition to the effect of the first embodiment.

<Third Embodiment> FIGS. 7 and 8 show a fiber insertion pipe 30 according to a third embodiment of the present invention. Similarly to the second embodiment, the pipe 30 has an outer peripheral surface 30a having a corrugated shape that smoothly undulates along the extension direction of the cable, and an inner peripheral surface 30b has a straight cylindrical shape. Further, a smooth thin cylindrical layer 31 is formed inside the pipe 30 to further reduce friction. This smooth thin-walled cylindrical layer 31 is preferably made of a resin having high smoothness such as high-density polyethylene, polypropylene, polyester resin or nylon, and more preferably mixed with a lubricating material such as silicone resin. . Since the configuration other than the fiber insertion pipe 30 is the same as that of the first embodiment, the duplicated description will be omitted.

By doing so, the fluid frictional resistance on the inner wall surface of the pipe 30 is further reduced, so that the pressure air supplied into the pipe 30 flows smoothly and the optical fiber is floated and transferred without being caught. In addition to the effect of the first embodiment, an effect that a longer optical fiber can be inserted can be obtained.

<Fourth Embodiment> FIG. 9 shows a fourth embodiment of the present invention. The difference from the first embodiment is that
Similar to the first embodiment, the traction line 43 is inserted through the fiber insertion pipe 40 in advance, the conductive cable 41 is located on the outer circumference of the fiber insertion pipe 40, and the periphery thereof is covered with the jacket tube 42. Is.

The pulling wire 43 has an end connected to the optical fiber during the insertion operation of the optical fiber, and the other end of the pulling wire 43 is pulled out from the fiber insertion pipe 40 when the pressurized air is supplied to float the optical fiber. This makes it possible to compensate for the shortage of the feeding force of the optical fiber due to the pneumatic feeding method, so that an effect that a longer optical fiber can be inserted is obtained.

<Fifth Embodiment> FIGS. 10 and 11 show a fifth embodiment of the present invention. The difference from the fourth embodiment is that the traction line 53 inserted in the fiber insertion pipe 50 is loosened. There is a point I set aside. In this way, the traction line 53 is formed with a corrugated extra length portion 53a that is stretched by applying tension to both ends.

According to this construction, when the continuously produced optical fiber laying cable is cut to a required length and then both ends of the traction line 53 in the fiber insertion pipe 50 are pulled to apply tension, the traction line The extra length portion 53a of 53 is stretched, and the traction line 53 having a sufficient margin length is passed through the fiber insertion pipe 50. Therefore, if one end of the pull line 53 is connected to the optical fiber and the other end is pinched and pulled out, the work of inserting the optical fiber can be easily performed.

<Sixth Embodiment> FIGS. 12 and 13 show a sixth embodiment of the present invention. The difference from the fifth embodiment lies in the method of forming the extra length portion 63a of the traction line 63. Here, the extra length portion 63a is formed by intermittently sagging the traction line 63 and fixing it with an adhesive.
This adhesive is set to have a strength such that the bonded portion will come off when tension is applied to both ends of the traction line 63, and the traction line 63 may be stretched before the optical fiber insertion work.

<Seventh Embodiment> FIGS. 14 and 15 show a seventh embodiment of the present invention. The difference from the fifth embodiment lies in the method of forming the extra length portion 73a of the traction line 73. Here, the extra length portion 73a is formed by intermittently forming a knot on the traction line 63. When strong tension is applied to both ends of the traction line 63, the knot is released and the traction line 63 is stretched.

Even with such a structure, the traction line 73 having a sufficient margin for inserting the optical fiber can be inserted into the fiber insertion pipe 70, and therefore the continuous operation is still possible. It is possible to obtain the effect that the optical fiber laying cable produced in (1) is cut to a required length, and then the traction line 73 in the fiber insertion pipe 70 is extended to easily perform the optical fiber insertion work.

<Eighth Embodiment> FIG. 16 shows an apparatus for manufacturing a fiber insertion pipe 70 used in the seventh embodiment.

In the figure, reference numeral 81 is a drum around which a traction line 73 is wound, and a traction line 73 drawn from this drum.
In this case, the extra length portion 73a is formed by intermittently binding in the length direction by the binding machine 82 corresponding to the extra length portion forming device. 83 is a well-known extrusion molding machine, and a hopper 84
The resin raw material supplied from the above is melted and heated, and the cylindrical primary pipe 86 is extruded from the extrusion head 85 having a nipple and a die. The primary pipe 86 is formed into a corrugated shape by the molding device 87 having a continuously moving mold (not shown) in a softened state, and the corrugated fiber insertion pipe 70 is molded. Then, after that, the cooling water tank 88
It is cooled and solidified by passing through the inside, and is wound on the winding drum 89.

The traction line 73 is fed into the primary pipe 86 from the rear into the nipple of the extrusion head 85, and therefore, the fiber insertion pipe 70 continuously produced.
Is inserted through.

Therefore, if this fiber insertion pipe 70 is cut to a required length and both ends of the traction line 73 at the cut end are pulled, the knot of the extra length portion 73a is unraveled and the traction line 73 is stretched. As described in the above embodiment, the effect of easily inserting the optical fiber can be obtained.

In order to insert the traction line 53 having the corrugated extra length portion 53a shown in the fifth embodiment, air is blown from the rear of the nipple of the extrusion molding machine to make the traction line 53 redundant. It should be supplied. Further, in the case of the traction line 63 having the adhesive type extra length portion 63a shown in the sixth embodiment, the traction line 6 is replaced with the binding machine of FIG.
It is sufficient to form an intermittent folded-back portion in 3 and provide a device for applying an adhesive here.

[Brief description of the drawings]

FIG. 1 is a partial perspective view of an optical fiber laying cable showing a first embodiment of the present invention.

[FIG. 2] Similarly, a cross-sectional view

FIG. 3 is a vertical sectional view of the fiber insertion pipe.

FIG. 4 is a cross-sectional view of the fiber insertion pipe.

FIG. 5 is a vertical sectional view showing a fiber insertion pipe according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a fiber insertion pipe of the same.

FIG. 7 is a vertical sectional view showing a fiber insertion pipe according to a third embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a fiber insertion pipe of the same.

FIG. 9 is a partial perspective view of a cable for laying an optical fiber according to a fourth embodiment of the present invention.

FIG. 10 is a vertical sectional view showing a fiber insertion pipe according to a fifth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the fiber insertion pipe of the same.

FIG. 12 is a vertical sectional view showing a fiber insertion pipe according to a sixth embodiment of the present invention.

FIG. 13 is a transverse cross-sectional view showing the same fiber insertion pipe.

FIG. 14 is a vertical sectional view showing a fiber insertion pipe according to a seventh embodiment of the present invention.

FIG. 15 is a cross-sectional view showing the same fiber insertion pipe.

FIG. 16 is a schematic side view showing an apparatus for manufacturing a fiber insertion pipe according to an eighth embodiment of the present invention.

[Explanation of symbols]

10, 20, 30, 40, 50, 60, 70 ... Fiber insertion pipe 11 ... Conductive cable 12 ... Outer tube 31 ... Smooth thin cylindrical layer 53, 63, 73 ... Traction lines 53a, 63a, 73a ... Extra length part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Noriaki Yamano 1-14 Nishisuehirocho, Yokkaichi-shi, Mie Sumitomo Wiring Systems, Ltd.

Claims (5)

[Claims] 1. A cable for laying an optical fiber, which is formed by assembling a fiber insertion pipe for inserting an optical fiber together with another cable, wherein an outer peripheral surface of the fiber insertion pipe has a wavy shape along the extension direction of the cable. A cable for laying optical fibers. 2. The optical fiber laying cable according to claim 1, wherein an inner peripheral side of the fiber insertion pipe has a smooth cylindrical surface. 3. The optical fiber laying cable according to claim 1 or 2, wherein a traction line for traction of the optical fiber is provided in the fiber insertion pipe. 4. The optical fiber laying cable according to claim 1, wherein the traction line is provided with extra length portions that are extended by applying tension to both ends. . 5. A pipe molding apparatus for extruding a fiber insertion pipe for inserting an optical fiber,
An extra length forming device that intermittently forms an extra length extending by applying tension to both ends of the optical fiber traction line, and the traction line in which the extra length is formed is inside the nipple of the pipe molding device. A device for manufacturing a fiber insertion pipe that is supplied to the.