JPH06300927A - Air current laying method for communication wire rod - Google Patents

Abstract

PURPOSE:To provide a method for laying the long-sized communication wire rod in a duct with an air flow while preventing static electricity from being generated. CONSTITUTION:The communication wire rod 1 is supplied from a reel 2 and sent to the duct 3 through a force sending head 4. The compressed air from a compressor 5 is also sent to the duct 3 by the force sending head 4. A throw cylinder 7 is fitted to a T branch 6 halfway on the duct 3 and a conductive material 9 put therein is supplied into the duct 3, little by little. On the exit side of the duct 3, a recovery bottle 10 is fitted to discharge the air current jetted from the exit side through a filter 11 and also collect the conductive material. The conductive material 9 is sent in the duct 3 together with the air current to remove generated static electricity and the communication wire rod 1 can be prevented from coming into contact with the duct 3 electrostatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow laying method for a communication wire rod, such as an optical fiber cable, in which a communication wire rod covered with an insulating material is laid in a pipe by an air flow. The present invention relates to an air flow laying method for communication wires with reduced resistance.

[0002]

2. Description of the Related Art It is important to reduce the friction coefficient between the communication wire and the inner wall of the conduit in the method of laying the communication wire by the air flow while blowing the pressurized gas into the existing conduit. For example, in the optical fiber cable described in Japanese Patent Application Laid-Open No. 2-50111, a group lubricant is added to the outermost layer of the coating layer, which is the contact surface with the inner wall of the conduit, to reduce the friction coefficient. Is. Japanese Patent Publication No. 22922/1990 describes that powder talc is blown as a lubricant in a method of laying an optical fiber cable.

By the way, the conduit for laying the communication wire is usually made of an insulating resin. Also, the covering layer of the communication wire is usually an insulating resin. For example, regarding an optical fiber cable, it is common to use an optical fiber cable that is covered with foamed polyethylene and press it into a polyethylene pipe line. In order to avoid an increase in frictional resistance due to humidity, the gas to be pressure-fed is generally dried by using dry air or nitrogen.

Therefore, when the communication wire is pressure-fed into the conduit by an air flow, static electricity due to friction is easily generated. When static electricity is generated, it appears as a resistance force due to the electrostatic force, and it is as if the frictional resistance increased. The method described above is effective in reducing the coefficient of friction, but is ineffective against static electricity. We also tried a method of applying an antistatic material, such as diethanolamine, to the surface of the coating layer of the communication wire, but the effect was reduced when the antistatic material was scraped due to friction with the pipeline and the laying distance was extended. It has become clear from experiments by the inventors that this is done.

Regarding the cause, since the antistatic material uses a mechanism for adsorbing moisture to form a semiconductor film on the surface of the material and discharging static electricity which has been charged, the laying distance is extended and a dry gas is generated. When the delivery time is long, the conductivity is impaired. The antistatic material layer is scraped off by the communication wire and the antistatic effect is reduced. When the wire laying distance becomes long, the frequency of friction between the conduit and the communication wire increases, and the possibility of generation of static electricity also increases. Various points are estimated.

As described above, in the airflow laying method of the communication wire, the electrostatic attraction causes an increase in the attractive force between the conduit and the communication wire and an increase in the friction resistance during the long-time pressure feeding, resulting in a decrease in the pressure feeding speed. There was a problem that the laying length was limited.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and prevents the generation of static electricity,
An object of the present invention is to provide an airflow laying method capable of laying a long communication wire.

[0008]

According to the present invention, there is provided an air flow laying method for a communication wire rod, in which a communication wire rod is laid in a pipe by an air flow, wherein a conductive fine solid is sent into the air flow. It is a thing.

It is also characterized in that the conductive fine solid is a scaly thin film made of a conductive material and having a smooth surface, and that the scaly thin film is made of a graphite or a metal such as copper or aluminum. It is what

It is also characterized in that the electrically conductive fine solid is a small diameter particle made of a conductive material, and the small diameter particle is made of a graphite or a metal such as copper or aluminum.

The present invention is also characterized in that the conductive fine solid is fed in slightly from the feeding position of the wire.

[0012]

According to the present invention, a conductive fine solid such as a scale-like thin film made of a conductive material and having a smooth surface or small-diameter particles made of a conductive material is sent into a conduit together with a communication wire or compressed air. , Take the air current and send it through the pipeline. On this occasion,
Since the communication wire has a long length and contacts with various parts of the conduit to generate contact resistance, the moving speed is slow, whereas the conductive fine solid is separated from the pipe wall and the communication wire. Since it is in a state, it moves at a speed according to the speed of the air flow.

As described above, the conductive fine solids such as thin films and particles pass between the pipe wall and the communication wire, pass, and are discharged from the outlet of the pipe. During this time, the conductive fine solids also come into contact with the charged portions on the conduit and the communication wire. When the conductive fine solid is cross-linked to the places charged with positive and negative charges respectively, the positive and negative charges are short-circuited to reduce the charges. In addition, when it comes into contact with either one of the potentials,
Take away that charge. The charge state of a conductive fine solid charged by the robbed charge is not localized and charged like an insulator, and the charge is distributed throughout the solid due to its conductivity. It is charged in the state. The charged conductive fine solids are moved by an air flow, and when they move to a site having an opposite potential, they discharge the carried charges.

Even if the charged electrically conductive fine solid line cannot be discharged by the time it moves to the outlet, the electrically conductive fine solid takes away a large amount of electric charge, and due to the electrically conductive property, a thin film or small-diameter particles are obtained. Since the electric charge is distributed over the entire solid, it is possible to remove the electric charge that is charged in a laying system by being charged in a very low voltage state.

As the conductive fine solid, for example, 0.
When a scale-shaped thin film material such as a 5 mm square and 0.05 mm thick graphite film is used, the potential gradient at the edge portion becomes large, and the effect of discharging static electricity and removing it like the principle of the lightning rod is large and effective. Is. Further, since the surface area per weight is large, there is an effect that a large amount of charges can be removed with a material having a small weight.

When small-diameter particles made of a conductive material are used as the conductive fine solid, even if the small-diameter particles are sandwiched between the communication wire and the conduit, static electricity is removed and at the same time the particles are rolled. Like the principle of bearings, the frictional resistance between the communication wire and the conduit is reduced to increase the lubricity.

As a material for producing the above-mentioned action, a material capable of conducting and distributing a high-potential electrostatic charge can be freely selected from graphite, metals such as copper and aluminum.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an embodiment of a method for laying an air flow of a communication wire according to the present invention. In the figure, 1 is a communication wire rod, 2 is a reel, 3 is a conduit, 4 is a pressure feed head, 5 is a compressor,
6 is a T-branch, 7 is a dropping cylinder, 8 is an airtight stopper, 9 is a conductive material,
Reference numeral 10 is a collection bottle, and 11 is a filter. Communication wire 1
It is supplied from the reel 2 and sent to the conduit 3 via the pressure feed head 4. Compressed air is sent from the compressor 5 to the pressure feed head 4 toward the conduit 3. Also, the communication wire 1 is
It is introduced into the pumping head 4 via an airtight seal and is inserted into the conduit 3 by means of a drive reel. T in the middle of pipeline 3
A branch 6 is provided and a dropping cylinder 7 is attached. The dropping cylinder 7 has a small hole on the T-branch 6 side, and a small amount of the stored conductive material 9 is supplied from the T-branch 6 into the conduit 3. An airtight stopper 8 is provided on the upper end of the dropping cylinder 7, and the conduit 3
The compressed air introduced therein is prevented from flowing backward in the dropping cylinder 7. A recovery bottle 10 is attached to the outlet side of the pipeline 3, and the air flow ejected from the outlet side of the pipeline 3 is discharged through the filter 11. Therefore, the conductive material that has exited from the end of the conduit 3 together with the air flow is recovered in the recovery bottle 10.

The embodiment described with reference to FIG. 1 will be described by a concrete example. The communication wire 1 has an outer diameter of 250 μ, as shown in FIG.
A wire rod was used in which seven m optical communication lines 12 were used, one was arranged in the center and six were arranged around the optical communication line 12 and the outer diameter was 2 mm with a foamed polyethylene coating 13 on the outside. As the pipe line 3, a pipe made of a polyethylene material having an inner diameter of 6 mm and an outer diameter of 8 mm was used, and the pipe was sent to a pipe line having a length of 1500 mm.

The pressure feed head 4 has the same configuration as that described in Japanese Patent Publication No. 22922/1990, and includes a drive roller for drawing the communication wire 1 into the conduit 3 filled with compressed air,
It has a nozzle that guides the compressed air supplied from the compressor to the pipeline. Further, after that, a dropping cylinder 7 for dropping the conductive material 9 into the conduit 3 is provided. The pipe 3 side of the dropping cylinder 7 is a T-branch 6, and an airtight plug 8 is provided on the upper portion. Inside the dropping tube 7, the conduit 2 is passed through the gap of the conductive material 9.
The pressure is almost equal to the internal pressure, and the conductive material 9 is dropped into the conduit 3 by gravity. The dropping amount can be changed depending on the mounting angle of the dropping cylinder 7.

The experimental results will be described. --- Comparative Example 1-- When compressed air having a pressure of 6 kg / cm < ² > was used to send the communication wire without dropping the conductive material, the length of pumping was 7
It was possible to satisfactorily send the ink up to 00 m at a speed of 10 m / min or more. However, after 700 m, the transmission speed of the communication wire clearly decreased and became about 1 m / min at 850 m. In this state, the communication wire was in close contact with the conduit, and when a large amount of the communication wire was fed from the entrance of the conduit, it was meandering in the conduit and impaired the transmission characteristics of the communication wire. This state is a laying speed which cannot be practically used.

--Example 1-- From the time when the feeding speed was reduced in Comparative Example 1, a scale of graphite having a size of 0.5 mm square and a thickness of about 0.05 mm was introduced into the conduit at a rate of about 2 g / min. When it was fed from the T-branch into the pipe in a certain amount, the speed of the wire rod gradually increased and was recovered to reach a delivery speed of 10 m / min in 20 minutes. As a result of feeding the conductive material as it was, it was possible to feed the material to the conduit of 1500 m. The change in the wire feeding speed during this period is shown in FIG.

--Example 2-- As a result of feeding the conductive material in Example 1 in the same manner from the start of feeding, a feeding speed of 10 m / min or more can be maintained over the entire length of the pipeline, and in 97 minutes. The transmission of 1500 m was completed.

--Example 3-- As a conductive material, a small ball made of aluminum having an outer diameter of 0.3 mm was introduced and the same feeding as in Examples 1 and 2 was carried out. The wire speed was 10 m. / Min or less,
It was possible to send 1500m in 102 minutes.

--Comparative Example 2 --- The graphite scale used in Example 1 was fed into the conduit for 5 minutes at a rate of 2 g / min for 20 minutes, and then the dropping was stopped to feed the communication wire. When the communication was performed, the transmission distance was 750 m and the transmission speed was 1
It has fallen below 0 m / min. It is considered that static electricity was generated between the communication wire and the inner wall of the conduit as described above by stopping the dropping of the graphite scales. It was confirmed that it was necessary to eliminate static electricity during transportation.

--Comparative Example 3 --- Talc particles (size: several μm to 30 μm) which are insulating materials
As a result of sending the communication wire rod while dropping (about m) into the pipe, the speed decreased to 10 m / min or less at 600 m. At this time, static electricity was also felt on the outer surface of the conduit.

From Comparative Examples 2 and 3, the necessity of removing static electricity was confirmed. The effect of removing static electricity is effective even with a short conduit. When the method of the present invention is used and when the communication line is not used, the pipe after the communication is cut, and the powder of the insulating material such as talc is sprinkled on the line and the communication line. It could be confirmed. When the method of the present invention is used, the amount of the conductive material attached to the inner surface of the conduit and the outer surface of the communication wire is small, and does not affect the operation of the communication wire after installation. By using this conductive material, the adhesion phenomenon due to static electricity between the communication wire and the conduit can be eliminated, and good communication can be achieved even when the installation distance is long.

When particles having a high bulk density such as metal particles are used as the conductive material introduced into the conduit, the shape thereof is spherical or spheroidal so as not to damage the communication wire or the conduit. It is preferable that it has no corners, such as a body, and that it has a large specific gravity and is effective in pipelines with many downwards.

On the other hand, the scale-like material has a low bulk density,
Since it is highly mobile due to the air flow, it works effectively even in pipelines with many climbs. Among such scale-like materials, graphite is a useful material for the present invention because it is a light material and at the same time exhibits excellent slidability.

[0030]

As is clear from the above description, according to the present invention, it is possible to stably lay a communication wire on a longer pipe.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a method for laying an air flow of a communication wire according to the present invention.

FIG. 2 is a cross-sectional view of a communication wire used in an example of the present invention.

FIG. 3 is an explanatory diagram of experimental results.

[Explanation of symbols]

 1 Communication Wire 2 Reel 3 Pipeline 4 Pressure Feeding Head 5 Compressor 6 T Branch 7 Drop Tube 8 Airtight Plug 9 Conductive Material 10 Recovery Bottle 11 Filter

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[Procedure amendment]

[Submission date] March 23, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a method for laying an air flow of a communication wire according to the present invention.

FIG. 2 is an explanatory diagram of experimental results.

FIG. 3 is a sectional view of a communication wire used in an example of the present invention.

[Explanation of symbols] 1 communication wire 2 reel 3 conduit 4 pressure feed head 5 compressor 6 T branch 7 drop cylinder 8 airtight stopper 9 conductive material 10 recovery bottle 11 filter

Claims (6)

[Claims] 1. An air flow laying method for a communication wire rod, wherein a communication wire rod is laid in a pipe by an air flow, wherein a conductive fine solid is fed into the air flow. 2. The method for arranging an air flow of a communication wire according to claim 1, wherein the conductive fine solid is a thin film made of a conductive material and having a smooth surface. 3. The method for air flow laying of a communication wire according to claim 2, wherein the scale-like thin film is made of a graphit or a metal such as copper or aluminum. 4. The method for laying an air flow of a communication wire according to claim 1, wherein the conductive fine solid is a small particle made of a conductive material. 5. The small particle is a graphite or
The airflow laying method for a communication wire according to claim 4, wherein the airflow laying method is made of a metal such as copper or aluminum. 6. The conductive fine solid is fed from a position slightly ahead of a wire feeding position.
6. An air flow laying method for a communication wire rod according to any one of items 1 to 5.