JPH05224031A - Communication line and laying method therefor - Google Patents

Abstract

PURPOSE:To reduce the friction between the communication line and the internal wall of a tubular member when pressure air is sent in a conduit. CONSTITUTION:The communication line is transferred from a 1st tubular member wherein the communication line is stored to a 2nd tubular member where no communication line is stored. A wind reception part 3 is fitted to the rear end part which is viewed in the movement direction of the communication line 2. When the communication line is sent with the air, the driving force is produced at the wind reception part 3, so the rear end part tends to move earlier than any other part and the slacking of the communication line is formed in the vicinity of the rear end part of the communication line 2 and then propagated to separate the communication line 2 from the internal wall of the tubular member 1. Consequently, the friction is reduced to increase the sending speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a communication line for transferring a communication line stored in a conduit to another conduit by a flow of a pressure gas and laying the same, and a method of laying the communication line. ..

[0002]

2. Description of the Related Art Conventionally, as a technique for laying and collecting communication lines, there is a method described in JP-A-2-72723. This method will be described with reference to FIG. In the figure, 11 is a cable, 12 and 13 are tubular members, 14 and 15 are joints, 16
Is a compressor, 17 is a communication line, 18 is an optical fiber element wire, and 19 is a jacket.

FIG. 1A is an explanatory view of a method of laying a communication line in an existing pipeline. The cable 11 is a bundle of a plurality of tubular members 12. The tubular member 12 is previously laid as a cable in a state where the communication line is not housed therein, and the tubular member 12 is provided with the communication line 1
7 is laid. In the communication line 17, in this example, as shown in FIG.
It is covered with a lightweight jacket 19 such as foamed polyethylene. In the tubular member 13, a communication wire to be laid on the tubular member 12 is stored in advance, and is wound in a coil shape for easy loading. This tubular member 13 is carried into a site where a communication line is to be laid, and one end of the tubular member 13 is joined to an existing tubular member 12 that has been laid in advance at the laying site at a joining portion 14, and at the joining portion 15 at the other end. , Connect the compressor 16 and let pressure gas flow,
The communication line is laid by introducing the communication line from the tubular member 13 which is not provided to the tubular member 12 which is already provided.

FIG. 1B is an explanatory view of a method of collecting the communication line laid on the existing tubular member 12. The communication line joins the tubular member 13 which is not provided to one end of the tubular member 12 at the joining portion 14, and joins the joining portion 15 to the other end of the tubular member 12.
At, the compressor 16 is connected. Tubular member 13
Is empty. By introducing the pressure gas from the compressor 16 to the tubular member 12, the communication line accommodated in the tubular member 12 is moved to and accommodated in the tubular member 13, and the communication line can be collected.

According to such a conventional method of laying and collecting communication lines, there is a problem that the transmission speed is very slow especially at the start of transmission.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and includes a first tubular member accommodating a communication line and a second tubular member not accommodating the communication line.
Of the first tubular member, and a pressure fluid is supplied from the opposite side of the first tubular member to the second tubular member to carry the communication line on the pressure gas flow. It is an object of the present invention to provide a method of laying a communication line, by which the communication line and the inner wall of the conduit can be peeled off from each other and friction can be reduced, and a communication line suitable for the method.

[0007]

SUMMARY OF THE INVENTION The present invention is a communication wire housed in a tubular member and communicated by pressure gas flow to another tubular member joined to the tubular member, the moving rear end of the wire being a communication line. Is provided with a wind receiver smaller than the inner diameter of the tubular member and larger than the outer diameter of the communication line, and one end of the first tubular member accommodating the communication line is Connecting to another second tubular member and connecting the other end of the first tubular member to a pressure gas supply device to transfer from the first tubular member to the second tubular member by pressure gas flow. A method of laying a communication line, comprising:
A wind receiver smaller than the inner diameter of each of the tubular members and larger than the outer diameter of the communication line is attached and transferred.

[0008]

As a result of examining the cause of the decrease in the transmission speed by the conventional method, the inventors presumed that the main cause thereof is as follows.

First, when the state of the communication line in the pipeline during the transmission was observed, it was observed that the communication line was in close contact with the inner wall at the curved portion of the pipeline. The cause of the decrease in transmission speed is
It is thought that the frictional force is increasing due to the close contact of the communication line with this inner wall. That is, looking at the situation in the pipeline, the pressure gradient of the pressure gas in the pipeline is large at the inlet of the pressure gas and small at the exit of the existing pipeline, as shown in FIG. Gases such as nitrogen and air that are generally used are compressible gases, so the flow velocity at the pressure gas inlet is very slow, and the volume expands as the pressure decreases toward the outlet, so the flow velocity becomes faster. Therefore, when the communication line is conveyed by using the pressure fluid, it means that the fluid velocity around the communication line becomes faster toward the tip during the installation.
Therefore, it is considered that the tip of the communication line tends to be moved more quickly, so that the communication line is closely attached to the inner wall of the conduit.

According to the present invention, a wind receiver is provided so that the rear end of the communication line produces a large propulsive force as compared with the other portion, and this portion receives the pressurized gas flow and is earlier than the other portions. As the slack of the communication line is generated near the rear end of the communication line and propagates due to this slack, the communication line and the inner wall of the pipeline are peeled off from each other, friction can be reduced, and the transmission speed can be increased. Of.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of an embodiment of the present invention.
It can be considered as a cross section of a part of the tubular member described in FIG. In the figure, 1 is a tubular member, 2 is a communication line, 3 is a wind receiver, and 4 is a pressurized gas flow. The wind receiving portion 3 is detachably attached to the rear end portion when viewed from the traveling direction of the communication line 2, and in this embodiment, it has a substantially spindle shape. The outer diameter thereof is considerably smaller than the inner diameter of the conduit 1 and larger than the outer diameter of the communication line 2. When the communication line 2 is pressure-fed by the pressure gas flow 4, a propulsive force is generated in the wind receiving part 3, so that the rear end portion tries to advance faster than other parts, and the vicinity of the rear end portion of the communication line 2 is reached. The slack of the communication line is generated and the slack is propagated, so that the communication line 2 and the inner wall of the tubular member 1 are separated from each other, friction is reduced, and the transmission speed is increased.
The shape of the wind receiving portion 3 is not limited to the spindle shape. Appropriate shapes such as a spherical shape and a conical shape with the rear part as the bottom surface can be adopted.

Specific experimental results will be described. The configuration of the evaluated pipeline is 100 m in length, 6 mm in inner diameter,
A polyethylene pipe having an outer diameter of 8 mm was bundled into a circle having a diameter of 1 m, and two bundles were connected. That is, FIG.
The two tubular members 3 of (A) are in a connected state. In one of them, seven cores of optical fiber having a diameter of 250 μm are arranged as shown in FIG. 4 (C), and light having a length of 100 m, which is coated with foamed polyethylene and has an outer diameter of 2 mm, is formed. A fiber cable was inserted as a communication line. Then, pressure 5 is applied from the end on the side opposite to the connection end of the conduit in which the communication line is inserted.
A compressed air of kg / cm ² was blown in, and an experiment of transferring a communication line was conducted.

First, as a comparative example, one in which the rear end of the communication line was simply cut was used. In this case, the first 5
It took 4 minutes and 30 seconds to send 0m, and 3 minutes and 2 minutes to 50m in the latter half.
Since it took 0 seconds, it took 7 minutes and 50 seconds to send 100 m. Throughout the laying experiment, it was confirmed that the communication line adhered to the inner wall of the pipe line wrapped in a bundle and was sliding and moving, causing a large amount of friction over the entire length.

Next, as an embodiment of the present invention, a spindle-shaped wind receiver having a diameter of 4 mm and a length of 6 mm as shown in FIG. 1 is attached to the rear end of the communication line, and the same communication as above is performed. As a result, the 100 m full length transmission was completed in 3 minutes and 40 seconds. It was confirmed that the communication line during the laying intermittently moved around the rear end like a worm, and at this time, the communication line floated up from the inner wall of the conduit.

Further, the optimum value of the size of this wind receiver was obtained. The inner diameter of the conduit was changed, and a 100 m transmission time was measured and evaluated for a communication wire having a diameter of 2 mm. FIG. 3 shows the results, and the hatched area in the figure represents the range of the diameter of the wind receiving portion that can reduce the sending time to 75% or less of the sending time required in the conventional technique. There is. From this result, the diameter of the wind receiving part is smaller than 70% of the inner diameter of the conduit and larger than the diameter of the communication wire outer diameter obtained by adding 30% of the difference between the inner diameter of the conduit and the outer diameter of the communication wire. It turns out to be effective. This relationship was recognized when the diameter of the communication line was 1 to 8 mm and the inner diameter of the conduit was 3 to 20 mm. On the other hand, regarding the length of the wind receiver, no difference in characteristics was observed in the range of 3 to 20 mm. Even with other shapes, the dimensional relationship of the wind receiving portion is effective within the range described above.

The reason why the upper limit of the outer diameter of the wind receiving portion is determined is considered to be that a proper amount of gas passes through the gap between the wind receiving portion and the inner wall of the conduit to give a propulsive force to the communication line.

Further, according to the method of the present invention, even in a pipeline having a curved portion, the contact between the communication line and the inner wall of the pipeline can be peeled off and friction can be reduced. Therefore, the method is particularly effective in a laying route with many bends. This is also effective when the tubular members that store the communication lines and are carried into the installation site are used in a bundled state, or when the tubular members to be installed are installed with many bends. For this reason, it is effective to use it for installation work places with large restrictions, for example, wiring in buildings and premises.

[0018]

As is apparent from the above description, according to the present invention, in the method of transferring the communication line accommodated in one pipeline to the other pipeline joined thereto, the communication line Since the contact with the inner wall of the conduit can be removed and the friction can be reduced, the communication line can be transferred in a shorter time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing a pressure gradient in a pipeline.

FIG. 3 is a diagram showing an experimental result for determining an effective diameter of a wind receiving part.

FIG. 4 is an explanatory diagram of a conventional method of laying and collecting communication lines.

[Explanation of symbols]

 1 Tubular member 2 Communication line 3 Wind receiver 4 Pressure gas flow

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shigeru Tanaka 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Takenori Morimitsu 1-6, Uchisaiwai-cho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A communication line which is housed in a tubular member and is sent by pressure gas flow to another tubular member joined to the tubular member, wherein the moving rear end has an inner diameter larger than that of the tubular member. A communication line characterized in that it is provided with a wind receiver that is small and larger than the outer diameter of the communication line. 2. One end of a first tubular member accommodating a communication line is connected to another second tubular member, and the other end of the first tubular member is connected to a pressure gas supply device to obtain a pressure. A method of laying a communication wire for transferring from the first tubular member to the second tubular member by a gas flow, wherein the communication wire is provided at a rear end of the communication wire and is smaller than an inner diameter of each of the tubular members. A method of laying a communication line, characterized in that a wind receiver larger than the outer diameter of the cable is attached and transferred.