JP3195210B2 - Optical fiber installation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber laying apparatus for inserting an optical fiber for optical communication into a pipe laid in advance.

[0002]

2. Description of the Related Art Conventionally, this type of device has been disclosed in
An optical fiber laying device disclosed in Japanese Patent No. 22921 is known. As shown in FIG. 4, when an optical fiber 2 is inserted into a pipe 1 previously laid, an optical fiber inlet 4 having a sealing means 3 at one end is provided and the other end of the optical fiber 2 is connected to the pipe 1 at the other end. A hollow tubular path 6 having a connection port 5 and an optical fiber holding means (feeding means) for moving a part of the hollow tubular path 6 along the hollow tubular path 6 to advance the optical fiber 2 with a force that overcomes a hydrostatic force. Roller) 7 and a feed head 8 having an air supply port 9
A high-speed air flow is formed inside the pipe line 1 by air supplied from the optical fiber 2, and the optical fiber 2 can be pumped over the air flow.

[0003]

However, in the prior art described above, an external air compressor is connected to the feed head 8 to supply compressed air. The pressure is, for example, about several hundred meters in the pipe 1 having an inner diameter of 6 mm. In this case, air pressure of about 5 kg / cm ² or more is required.

Therefore, the feed head 8 must have an airtight structure so that the air pressure does not escape to the outside. For this reason, the apparatus shown in FIG. 4 is provided with a lip seal as the sealing means 3 for preventing the air pressure in the feed head 8 from leaking from the optical fiber inlet 4. In this apparatus, since the left and right tubular paths communicate with each other through the gap around the feed roller 7, the air seal at the optical fiber inlet 4 is indispensable.

The sealing means 3 has an advantage that a high sealing property can be obtained because air pressure acts from the right side in the drawing and acts in the direction of tightening the seal. On the other hand, the optical fiber 2 is tightened to give a strong frictional force. There was an inconvenience.

The optical fiber 2 is pulled by a feed roller 7 or a supply reel (not shown).
Since it was necessary to push in from the side, it was unavoidable that an unnecessary large stress was applied to the optical fiber.

[0007] The present invention has been made in view of the above problems, and has as its object to provide an optical fiber laying apparatus capable of reducing the stress applied to an optical fiber.

[0008]

In order to achieve the above object, an optical fiber laying apparatus according to the present invention has a connection portion with a pipe line previously laid at one end and an optical fiber inlet at the other end. An air head comprising a tubular path having a compressed air inlet communicating with the tubular path, and an elastic member provided at an optical fiber inlet of the air head and capable of adjusting a gap amount between the outer diameter of the optical fiber and the air head. and <br/> air seal means having a gas-tight ring of a feeding means for feeding toward the optical fiber in the insertion direction, the optical fiber and the airtight ring
And an actuator for adjusting a gap between the actuator and the actuator .

In this case, as described in claim 2, an outer diameter measuring means for measuring the outer diameter of the optical fiber and a control means for adjusting the gap amount according to the outer diameter may be provided. .

[0010]

In the optical fiber laying apparatus of the present invention having the above configuration, the amount of gap between the air sealing means and the outer diameter of the optical fiber is optimized while preventing an excessive frictional force from being applied to the optical fiber. , Effectively prevent air leakage.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical fiber laying apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view schematically showing an optical fiber installation device.

In FIG. 1, reference numeral 10 denotes a pipe having a circular cross section which is laid in advance along an optical communication path and is made of a synthetic resin such as polyethylene, and has an inner diameter of about 5 to 6 mm and an outer diameter of about 7 to 9 mm. Thick. Reference numeral 11 denotes an optical fiber inserted into the pipe passage 10, which is a unit formed by bundling several core optical fibers made of quartz including a core and a clad and covering the outer periphery with a protective member such as foamed polyethylene. Having an outer diameter of about 2 mm.

Reference numeral 12 denotes an air head provided with a connection portion 13 connected to an end of the pipe line 10.
It is made by processing a steel round pipe having the same inner diameter as 0 and has a hollow tubular passage 14 inside. A branch portion 15 is formed to project outward from a central portion in the longitudinal direction, and a compressed air introduction port 16 communicating with the tubular passage 14 is provided at an end of the branch portion 15. ing. Reference numeral 17 denotes an optical fiber introduction port provided at an end of the air head opposite to the connection portion 13.

Reference numeral 18 denotes a driving roller as a feeding means for feeding the optical fiber 11 toward the optical fiber inlet 17, and is driven to rotate by a motor 19, and a driven roller 20 which is freely rotatable on its side is moderately rotated. The optical fibers 11 are in contact with each other with an appropriate pressing force, and the optical fiber 11 is sandwiched between them. The outer peripheral surfaces of the driving roller 18 and the driven roller 20 are covered with a rubber layer having a thickness of several mm. The driving roller 18 and the driven roller 20 are arranged to be separated to the left of the air head 12.
Together with a single frame (not shown) so that the relative positions of the two do not change. Reference numeral 21 denotes a supply reel for the optical fiber 11.

Next, the air sealing means 22 will be described with reference to the enlarged view of FIG. 2. Reference numeral 23 denotes an annular hermetic ring which is in close contact with the end face of the optical fiber inlet 17 and has a low friction coefficient. In addition, in the present embodiment, an O-ring made of Teflon is used. The diameter of the center hole of the airtight ring 23 is selected to be slightly larger than the outer diameter of the optical fiber 11. Reference numeral 24 denotes a pair of tightening members which are disposed opposite to each other with the airtight ring 23 interposed therebetween, and the airtight ring 23 is completely fitted in a concave groove formed on the opposing surface thereof. When the 24 are moved toward and away from each other, the diameter of the central hole of the hermetic ring 23 increases or decreases. The fastening member 24 includes two upper and lower solenoids,
A suitable actuator 25 such as a cylinder, a motor, etc.
Are respectively fixed to the tips of the shafts 26, and are driven in the directions of contact and separation by operating the actuator 25.

Reference numeral 27 denotes a projector for projecting a parallel light beam having a built-in light source such as a laser diode, and reference numeral 28 denotes a light receiver comprising a CCD line sensor or the like, which constitutes an outer diameter measuring means. 11 is measured in real time. 29 is a microprocessor (C
PU) built-in control means,
The measured value of the outer diameter of the optical fiber 11 measured at step (1) is input, and the output side of the solenoid 25 is connected via a D / A converter and a drive amplifier circuit (both not shown).
Is connected.

Incidentally, the outer diameter measuring means is not limited to the optical sensor as described above, and the optical fiber 11 may be sandwiched between a pair of pinch rollers to detect the interval between the pinch rollers. It is.

Next, a method of using the optical fiber laying apparatus according to the present embodiment having the above-described configuration will be described.

First, the driven roller 20 is pulled upward in the drawing to form a gap between the driven roller 20 and the driving roller 18, and the airtight ring 23, the optical fiber inlet 17, the tubular path 14, and the connection are sequentially passed through the optical fiber 11. After passing through the section 13, it is manually fed into the pipe 10 until it can be inserted.

Next, after the driven roller 20 is returned, the air compressor (not shown) is operated to supply the compressed air to the compressed air inlet 16. As a result, a high-speed air flow is generated in the pipe 10, and the shear force of the air acting between the air flow and the outer surface of the optical fiber 11 causes the optical fiber 11 to travel in the same direction as the air flow. Power is given. In such a pumping state, the optical fiber 11
Due to the turbulence of the air flow in the pipe 10, it is constantly pushed and oscillated from random directions in up, down, left, and right directions, and travels in a state in which it floats halfway in the pipe 10. Also, if the optical fiber 11 in the pipe 10 is partially loosened, the air pressure applied to that part becomes higher than the other parts, so that the loosened part is naturally sent forward, and is straightened along the pipe 10. Sent.

If the motor 19 is rotated in this state,
The optical fiber 11 is gradually fed in and can be inserted to the opposite end of the pipe line 10.

The operation of the air sealing means 22 at this time will be described. In this embodiment, the ROM 30 incorporated in the control means 29 stores the outer diameter value of the optical fiber 11 based on the results of an experiment conducted in advance. And the operation amount of the actuator 25 corresponding thereto are stored in a data table format. Then, the control means 29 immediately controls the driving of the actuator 25 in accordance with the measured outer diameter inputted from the light receiver 28 in real time. Thereby, the gap amount between the airtight ring 23 and the optical fiber 11 is controlled to an optimum value, and it is possible to effectively prevent air leakage while preventing an excessive frictional force from being applied to the optical fiber 11.

As a special effect of this embodiment, since the feeding means such as the feeding roller is disposed outside the air head, the above-described prior art requires airtight parts at various places such as the bearing of the feeding roller. In comparison, the number of parts is reduced, the structure is simplified, and the air head on which air pressure acts is only required to be a simple pipe-shaped structural member. Therefore, the cost is low and there is almost no need for maintenance.

The present invention is not limited to the above embodiment, but can be modified as follows, for example.

In the above-described embodiment, the outer diameter of the optical fiber is measured and the gap amount is adjusted accordingly. However, instead of this, the air flow between the airtight ring 23 and the optical fiber 11 is changed. The degree of leakage may be directly measured, and the gap amount may be adjusted accordingly. Specifically, for example, an air flow rate measuring means for detecting a leak speed by detecting a wind speed, a wind pressure or the like is provided in the vicinity of the gap in order to detect an air flow ejected to the outside from the gap in the seal portion. Alternatively, an air flow rate measuring means may be provided near the optical fiber inlet inside the air head, and the gap amount may be adjusted so that the detected flow rate is always constant.

[0027]

As described above, according to the optical fiber laying apparatus of the present invention, the drive of the actuator can be controlled.
By this, the amount of clearance between the airtight ring of the air sealing means and the outer diameter of the optical fiber can be freely adjusted to an optimum value, so that excessive frictional force is not applied to the optical fiber and air leakage is prevented. It can be effectively prevented.

Accordingly, damage to the optical fiber due to unnecessary tensile / compressive stress can be effectively prevented, and the friction braking force generated at the seal portion is reduced, so that the feed speed can be improved accordingly.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing an optical fiber installation device according to an embodiment of the present invention.

FIG. 2 is an enlarged front view showing an air sealing means in the optical fiber laying device of FIG.

FIG. 3 is a view showing a main part of the air sealing means of FIG. 2;

FIG. 4 is a sectional view showing a main part of a conventional optical fiber laying device.

[Explanation of symbols]

 Reference Signs List 10 piping path 11 optical fiber 12 air head 13 connecting part 14 tubular path 15 branch part 16 compressed air inlet 17 optical fiber inlet 18 drive roller 19 motor 20 driven roller 21 supply reel 22 air sealing means 23 airtight ring 24 fastening member 25 actuator 27 Emitter 28 Receiver (outer diameter measuring means) 29 Control means

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-59-104607 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/46 H02G 1/08

Claims (2)

(57) [Claims] 1. An air head having a connection portion with a pre-installed piping passage at one end and a tubular passage having an optical fiber inlet at the other end and a compressed air introduction port communicating with the tubular passage. If, adjustable bullet the amount of clearance between the outer diameter of the provided optical fiber to the optical fiber inlet port of the Eaheddo
Air sealing means having an airtight ring made of a conductive member ,
A feeding unit for feeding the optical fiber in the insertion direction, and adjusting a gap amount between the airtight ring and the optical fiber.
An optical fiber laying device, comprising: 2. The optical fiber installation apparatus according to claim 1, further comprising an outer diameter measuring means for measuring an outer diameter of the optical fiber, and a control means for adjusting the gap amount according to the outer diameter.