JPH09179000A - Slack detection method for optical fiber unit feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect abnormal slack generated in the pipe at the time of feeding an optical fiber unit into the pipe by an air flow by a simple device. SOLUTION: In an air flow supply means for feeding the air flow inside the pipe to install the optical fiber unit and an optical fiber unit feeding device for feeding the optical fiber unit to the inside of the pipe, a transparent pipe 10 provided with a bent part connected in a sealed state is provided in a part of the pipe or between the exit of the feeding device and the entrance of the pipe, a photosensor 2 is installed near the center of the outer side circular arc of the bent part and the slack of the optical fiber unit L is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for feeding an optical fiber unit into a conduit by an air flow, and in particular, when the optical fiber unit is fed into the conduit, an abnormal optical fiber unit in the conduit is detected. The present invention relates to a slack detecting method for surely detecting slack and controlling a feeding device.

[0002]

2. Description of the Related Art There is known a method in which an optical fiber unit is fed into a pipeline by using an air flow and installed.

FIG. 5 is an external view of a feeding device for an optical fiber unit used in this method. As shown in the figure, this device has a structure in which a pressure feed head 33 is connected to a conduit 31 via a slack detecting section 32. An optical fiber unit 35 is supplied from the supply 34 to the pressure feeding head 33, and the roll 36 is driven to fix the optical fiber unit 35 to the pressure feeding head 33 with an air seal 37.
And is fed by the air flow of the pressure feeding head 33. A compressor 39 for supplying an air flow is connected to the pressure feeding head 33, and a control device 38 is provided for controlling the feeding of the air.

On the surface of the optical fiber unit placed in the conduit, a carrier force due to shear is generated due to the viscosity of the air flowing in the conduit. When the conveying force due to shear overcomes the frictional force generated between the optical fiber unit and the inner wall of the conduit, the optical fiber unit propels in the air flow direction.

[0005]

In the above apparatus,
When the delivery speed of the pinch roll 36 is higher than the traveling speed of the optical fiber unit 35 or when the pinch roll 36 approaches the pressure-feeding limit distance of the optical fiber unit 35, the optical fiber unit causes abnormal slack in the conduit. If such an abnormal travel occurs, the optical fiber unit may be damaged or the transmission loss may increase, so that it is attempted by an operator to visually monitor, or to monitor with an optical slack detector. ing.

[0006] The applicant of the present invention has already shown that the pipeline 1 as shown in FIG.
4 is provided with an abnormality detection sensor C for detecting undulations of the optical fiber L, and the detection data is sent from the sensor C to the data processing unit 22, and the control unit 24 uses this processing data.
Filed a method for controlling the drive motor 23 of the pinch roll 16 (Japanese Patent Laid-Open No. 4-118603).

The above-mentioned method requires a plurality of optical detecting devices, and the optical fiber unit in the linear conduit is pumped while being transmitted in the direction in which vibration is pumped like a wave. Has been clarified. Therefore, complicated data processing is required to determine whether or not the slack is actually a problem.

The present invention has been made in view of such circumstances.

[0009]

The features of the present invention include an air flow supply means for sending an air flow into a pipe in which an optical fiber unit is to be laid, and an optical fiber for sending the optical fiber unit into the pipe. In an optical fiber unit feeding device provided with a unit supply means, a transparent pipe having a bent portion which is hermetically connected to a part of the pipe or between an outlet of the optical fiber unit feeding device and an inlet of the pipe. And a sensor for detecting the optical fiber unit is installed in the vicinity of the center of the outermost circular arc of the transparent pipe having the bent portion, and the slack is detected by the transparent pipe portion having the bent portion.

Due to the bent transparent pipe, the optical fiber unit tries to pass through the inside (shortest distance) of the bent portion of the transparent pipe when it is not slack. When it sags, the optical fiber unit pops out of the bend of the transparent pipe. This can be used to detect slack. Further, since normal wave vibration does not occur in the bent pipe, it is possible to reliably detect slack.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 to 3 show an embodiment of the present invention. The apparatus shown in FIG. 1 is obtained by applying the present invention to the optical fiber unit feeding apparatus shown in FIG.
The same parts as those in FIG. 4 are denoted by the same reference numerals. The feature of the apparatus of FIG. 1 is that a transparent pipe having a bent portion is provided between the outlet of the optical fiber unit feeding device and the inlet of the pipe to be laid, and a photo is provided near the center of the outer arc of the bent portion of the transparent pipe. A slack detector 1 provided with a sensor 2 is provided to detect slack of the optical fiber unit L passing through the transparent pipe 10 to control the drive motor 3 of the pinch roll 16 or to supply air to the pressure feed head 11. The purpose is to control the air flow control valve 4.

As shown in FIG. 2, the slack detector 1 has a pipe-shaped optical fiber unit passage 10 formed in a transparent cubic member 100 and bent in a substantially U shape in the horizontal direction. Then, the U-shaped photomicrosensor 2 is provided in the outer arc portion of the U-shaped bent portion. The photomicrosensor 2 has a light emitting element at one end and a light receiving element at the other end, and is commercially available.

Another form of the slack detector 1 is, as shown in FIG. 3, a pipe-shaped optical fiber unit passage 10 which is bent in a transparent cube member 100 in a horizontal direction with an arc in a substantially L-shape. Is formed. Then, the U-shaped photomicrosensor 2 similar to the above is provided on the outer arc portion of the L-shaped bent portion.

In the present invention using the above-mentioned apparatus system, the optical fiber unit L is sequentially sent out to the pipe 14 and run by the sending force of the pinch roll 16 and the carrying force by the air flow from the pressure sending head 11. In Although,
At that time, the transparent pipe of the slack detector 1 usually passes inside the curved portion, that is, the shortest distance.

When the optical fiber unit L is slackened for some reason, the optical fiber unit L pops out along the inner wall outside the bent portion of the transparent pipe as shown by the dotted line in FIG.

In such a state, the photo sensor 2 detects the signal, and the signal is sent to the control unit 5 to control the drive motor 3 of the pinch roll 16 to decelerate or approach the pressure feed limit distance. When it is determined that the air flow is controlled, the air flow control valve 4 is controlled to increase the air flow carrying force.

Further, in the present invention, since the transparent pipe is bent in the horizontal plane direction, the vibration amount of the optical fiber unit in the slack detector 1 during normal pressure feeding can be suppressed more effectively.

The radius of curvature of the bent portion of the transparent pipe is
It goes without saying that the radius of curvature must be equal to or greater than the allowable curvature radius when laying the optical fiber cable.

In the above embodiment, the transparent pipe is formed in the transparent cubic member, but the transparent pipe itself may be fixed to the substrate.

In the case of the embodiment shown in FIG. 3, the feeding device and the pipe to be laid have a positional relationship orthogonal to each other.

[0021]

As described above, according to the present invention, the following effects can be obtained.

(1) It is possible to detect accurately whether the optical fiber unit is in normal wave vibration or slack due to abnormal traveling.

(2) The above-mentioned slack can be detected with a simple detector using a transparent pipe having a simple bend and one commercially available photosensor.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an example of an optical fiber unit feeding device according to the present invention.

2A and 2B show an example of a slack detector according to the present invention, in which FIG. 2A is a plan sectional view, and FIG. 2B is a side sectional view taken along line II-II.

3A and 3B are other examples of the slack detector according to the present invention, in which (A) is a plan sectional view and (B) is III-II.
It is a side sectional view taken on the line I.

FIG. 4 is a vertical sectional side view showing an example of a conventional optical fiber unit feeding device.

FIG. 5 is an external view of a conventional general optical fiber automatic feeding device.

[Explanation of symbols]

 1 slack detector 2 photo sensor 3 pinch roll drive motor 4 air flow control valve 5 control unit 10 transparent pipe 11 pressure feed head 12 optical fiber unit through line 13 air supply line 14 installation pipe 15 air leak prevention unit 16 pinch roll L light Fiber unit

Claims (3)

[Claims] 1. An optical fiber unit feeding device comprising an air flow supply means for feeding an air flow into a pipe in which an optical fiber unit is to be laid and an optical fiber unit supply means for feeding the optical fiber unit into the pipe. A transparent pipe having a bent portion that is hermetically connected to a part of the pipe or between the outlet of the optical fiber unit feeding device and the inlet of the pipe,
A sensor for detecting an optical fiber unit is installed in the vicinity of the center of an arc having the maximum curvature of a transparent pipe having the bent portion, and slack is detected by the transparent pipe portion having the bent portion. Sagging detection method. 2. The slack detecting method according to claim 1, wherein the bent transparent pipe for detecting the slack is substantially U in a horizontal plane direction.
A method for detecting slack in an optical fiber unit feeding device, wherein the slack is bent in a letter shape. 3. The slack detecting method according to claim 1, wherein the bent transparent pipe for detecting the slack is substantially L in a horizontal plane direction.
A method for detecting slack in an optical fiber unit feeding device, characterized in that the optical fiber unit is bent in an arc shape.