JPH0682202A - Pipe length measurement method - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a method for measuring the length of a pipeline before inserting a cable with connectors attached at both ends into an existing pipeline and laying the cable. [Structure] Float 1-1 containing gas lighter than air
Is a method of measuring the pipe length from the length of the float ream 1 by supplying the driving device 2 or the air flow from one end of the pipe 3 to insert the float ream 1 formed by connecting the two.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the length of a cable when it is installed in a buried conduit.

[0002]

2. Description of the Related Art As an infrastructure of a communication network in an advanced information society, a full-scale construction of a subscriber optical line is under way in order to fully light up even a general household. Conventionally, when laying an optical cable underground, a method has been adopted in which the cable is once inserted into a conduit and then the optical fibers between the cables are fusion-spliced. By the way, in order to realize the construction of a huge amount of equipment for drawing the optical fiber from the station to each home, it is necessary to thoroughly simplify the work at the site,
In particular, instead of the fusion splicing method, which requires a long time, a method has been tried in which all the connection points are attached to the both ends of the cable in advance, and all the connection points are made into connectors (1990 Joint Conference of The Institute of Electrical and Information Engineers: P1-6). .

[0003]

By the way, when a cable having connectors at both ends is laid in a pipeline having a length of 100 to 300 m, it cannot be used if the cable is shorter than the pipeline length. If it is too long, the extra length must be processed in the manhole, and the cable is wasted. For this reason, it was necessary to accurately measure the pipe length between manholes in advance, but the technique has not yet been developed.

[0004]

SUMMARY OF THE INVENTION The present invention is a method for measuring a pipe length for solving this problem, which is characterized in that it is formed by connecting floats filled with a gas lighter than air. It is a method of supplying a float ream from one end of the conduit to advance the inside of the conduit, and after the tip of the float ream reaches the other end of the conduit, the conduit length is measured from the length of the float ream.

Here, a float ream formed by intermittently attaching a float to the outer circumference of a light weight wire or a float ream formed by attaching a float to the outer circumference of a light weight rod and connecting the lots to a conduit. Can be supplied.

As a method of feeding the float ream into the pipe line or collecting the float ream, it can be performed by a driving means or by using an air flow means.

Further, in order to smoothly insert the float station, a sensor or an oscillating element is attached to the tip of the float station and a signal from the tip is detected to confirm the position.

[0008]

The float chain of the present invention moves along the upper wall of the inner surface of the pipeline, and since the floats of unit length are connected to each other, a small driving force is required even if the pipeline is bent. It can be easily inserted. Further, the float ream is lightweight and can be quickly inserted by utilizing the air flow. By attaching a sensor or oscillating element to the tip of the float series and detecting the signal from the tip,
It can be inserted smoothly even in narrow and long pipelines. By measuring the pipe length in this way, it is possible to manufacture a cable with connectors attached to both ends without waste, and to lay it in the pipe.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) is an explanatory view of an embodiment of the method for measuring the pipe length of the present invention, FIG. 1 (b) is an enlarged view of a float ream, and FIG. 1 (c) is an enlarged connection portion. FIG. 1 and FIG. 2D are explanatory views of the float continuous drive device. In the figure, 1 is a float ream formed by connecting floats 1-1 filled with a gas lighter than air, 2 is a float drive device for supplying the float ream into the conduit 3, 4 is a manhole, 5 is An existing cable laid in the pipeline, 6 is a drum around which a float string is wound. Here, the pipe line 3 is a hard vinyl circular pipe having an inner diameter of 83 mm and buried at a distance of 200 m between manholes 4 and 1.2 m underground. A communication cable 5 having a polyethylene outer diameter of 400 mm is laid therein, and the case where the length of this conduit is measured by the method of the present invention will be described.

Helium gas was injected into a natural rubber balloon to form a float 1-1 having a length of 98 cm, a width of 50 mm and a height of 35 mm. The buoyancy of one float is 1.
It was 5 g. This float has an oval cross section in order to effectively use the gap between the pipe and the existing cable. Both ends of the float 1-1 were connected by a connector 7 having a limited movable range as shown in FIG.

In order to feed the float ream into the pipe line, a driving device 2 is used in which rotating blades press the float connection portion between them as shown in FIG. Since the float ream 1 is fed along the upper surface of the inner wall of the pipe in the space above the existing cable 5, the transmission resistance is small, and the float ream 1 is the float 1
Since it is divided into -1, it can be easily inserted even if there is a bent portion. The driving device can be fed outside the rotary blade by using a track or a roller. A transponder manufactured by Texas Instruments was attached to the tip of the float ream 1, a radio signal was sent to the transponder at the manhole at the exit, and a response wave from the transponder was received to confirm the insertion condition of the float ream 1. The conduit length was measured from the number of floats 1-1 inserted in the conduit in this way.

FIG. 2A is a perspective view of another embodiment different from the above-mentioned float station. A float 1-1 is attached to the outer circumference of a lightweight plastic rod 8 and is connected to the float station 1. It is composed. In addition, FIG. 2B shows the float 1 at a regular interval on the outer circumference of the lightweight nylon wire 9.
Float ream with -1 attached. Furthermore, FIG. 2 (C)
Is a float series in which fin-like protrusions 1-2 are provided on the outer periphery of the float 1-1, and when the fins are inserted into the pipeline by ventilation, the floats vibrate and move forward by receiving wind on the protrusions. This has the effect of preventing the float run between the pipe and the existing cable.

FIG. 3 is an explanatory view of an apparatus for creating an air flow in the pipe line 3 and inserting the float ream 1. The air is sent to the inlet of the pipe line 3 by the compressor 10 and covered with the sealing material 11. To prevent backflow of air. When air having a wind speed of 60 m / min was sent to the conduit 3 shown in FIG. 1 by the device shown in FIG. 3 and the float series shown in FIG.
I was able to insert it in 15 minutes.

When inserting the float station into the conduit, it is necessary to confirm the condition of the float because the distance is long and narrow. Therefore, a photoelectric sensor is attached to the tip of the float station, and two conductive wires are fixed to the float station. When the tip of the float station approaches the manhole, current flows through the sensor, so that the position can be detected. it can.
Also, by attaching a small microphone to the tip,
When it approaches the manhole, the noise on the ground can be heard, and by installing a microphone and a whistle,
In the pipe, the whistle sounds due to the air flow, and you can hear it through the microphone, but as you approach the manhole, the air flow weakens and you cannot hear the whistle. It is also possible to monitor the position of the float station by supplying radio waves from the entrance to the two conductors fixed to the float station and receiving them at the manhole on the exit side.

[0015]

As described above, the float ream of the present invention moves along the inner upper wall of the pipeline, and since the floats of unit length are connected and constructed, the pipeline is bent. However, it can be easily inserted with a small driving force. Further, the float ream is lightweight and can be quickly inserted by utilizing the air flow. By attaching a sensor or an oscillating element to the tip of the float series and detecting a signal from the tip, it is possible to smoothly insert even a narrow and long conduit. By measuring the pipe length in this manner, a cable with connectors attached to both ends can be manufactured without waste, and the pipe line can be installed.

[Brief description of drawings]

FIG. 1 (a) is an explanatory view of an embodiment of the method for measuring a pipe length of the present invention, FIG. 1 (b) is an enlarged view of a float ream, and FIG. 1 (c) is an enlarged connection portion. FIG. 1 and FIG. 2D are explanatory views of the float continuous drive device.

2 (A), (B), and (C) are perspective views of other embodiments of the float series, respectively.

FIG. 3 is an explanatory diagram of an apparatus for creating an air flow in a pipe and inserting a float connection.

[Explanation of symbols]

 1: Float ream 1-1: Float 2: Float ream drive device 3 Pipe line 4: Manhole 5: Existing cable 6: Drum 7: Connection part 8: Rod 9: Wire 10: Compressor 11: Sealant

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Yabuta 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Ken Tsujimura 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (6)

[Claims] 1. A float ream formed by connecting floats filled with a gas lighter than air is supplied from one end of the conduit to advance in the conduit so that the tip of the float ream reaches the other end of the conduit. After that, the pipeline length is measured from the length of the float ream, and the pipeline length is measured. 2. A float ream formed by intermittently attaching a float to the outer circumference of a light weight wire, or a float ream formed by attaching a float to the outer circumference of a light weight rod and connecting the lots into a pipeline. Claim 1 characterized by the above.
The method for measuring the line length described. 3. The float ream is pushed into the conduit or pulled by the drive means.
The method for measuring the line length described. 4. The method for measuring the pipeline length according to claim 1, wherein the float ream is fed into the pipeline or collected by the air flow means. 5. The method for measuring the pipeline length according to claim 1, wherein a sensor is attached to the tip of the float run and the position of the float run is confirmed by receiving a signal from the sensor. 6. An oscillation element is attached to the tip of the float chain,
The method for measuring a pipe length according to claim 1, wherein the position of the float station is confirmed by receiving an oscillation signal.