JPS62856B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spinning control system for manufacturing optical fibers used in the communications sector and the like.

As is known, when manufacturing optical fibers for communication, optical fibers with a fiber diameter of approximately 100 to 200 μm are produced by stretching a silica glass preform rod made by CVD, VAD, etc. under heating. Usually, such manufacturing or processing is simply referred to as spinning, or also referred to as spinning processing, since the resulting optical fiber is in the form of fibers.

Below is a brief explanation of this spinning process.
With the upper end of the preform rod clamped to a vertically movable mount, the rod is slowly moved from its lower end into a spinning furnace (cylindrical).
The lower end of the preform rod, which is inserted into the fiber and heated and melted here, is taken off by a take-off machine via a capstan, whereby the preform rod is spun into an optical fiber having a desired fiber diameter.

Also, during this spinning process, the optical fiber is passed into a coating bath located between the spinning furnace and the capstan, and a plastic coating film called a primary coat is formed on the outer periphery of the optical fiber. surface reinforcement).

In the above example, the straight line connecting the center of the mount and the circumferential surface of the capstan is the basic axis line, and the spinning furnace, coating tank, etc. are centered to match this basic axis line, and the optical fiber also passes along this basic axis line. However, there is a problem in practice.

In other words, the optical fiber may become misaligned with the axis due to various causes such as bending of the preform rod due to manufacturing, defects when setting the preform rod on the mounting base, and accidents during spinning the optical fiber under dynamic conditions. It often deviates from the

Although each of the above-mentioned causes is a minute amount, the combined total amount of these is large, and even when viewed as a relative value of the optical fiber (extremely small diameter), the value is large.

If the optical fiber deviates from the base axis in this way, the optical fiber will no longer pass through the center of the die in the coating bath, and as a result, the thickness of the coating film will be uneven relative to the optical fiber, and in extreme cases, the optical fiber will be damaged. In addition to being damaged by contact with the inner surface of the die, consideration for this situation also makes it impossible to increase the thread protection speed.

In order to solve the above-mentioned problems, the present invention aims to control the optical fiber during spinning so that it is always maintained at a predetermined position, thereby producing high-quality optical fiber with high efficiency.

In explaining the control system of the present invention, the illustrated device will be explained first.

In the figure, 1 is a preform rod;
This preform rod 1 has an upper end in the longitudinal direction as a gripping end 1a, and a lower end in the longitudinal direction as an extending end 1b.

2 is the gripping end 1a of the preform rod 1
This universal catcher 2 is a cylindrical rotating member 2a that clamps the end of the rod 1.
and another rotating member 2b that pivotally supports the member 2a, and one rotating member 2a supports the other rotating member 2b.
The other rotary member 2b is pivotally supported by a mounting base 3 so as to be rotatable back and forth.

Therefore, when the gripping end 1a of the preform rod 1 is clamped by the universal catcher 2, by combining the left and right rotation of one rotary member 2a with the back and forth rotation of the other rotary member 2b, The extending end 1b of the rod 1 is the gripping portion 1a.
It becomes possible to swing freely in the horizontal plane using the side as a fulcrum.

4 is a board supporting the mounting base 3;
The substrate 4 is provided so as to be able to move up and down along a guide rod 5 by feeding a screw shaft 6 which can freely rotate in forward and reverse directions.

Therefore, the mounting base 3 can also move up and down together with the board 4.

Reference numerals 7a and 7b are a pair of guide rollers arranged to hold (hold) the outer periphery of the preform rod 1 on the extended end 1b side. The movable base 8a is supported by a movable base 8a which is movable left and right, and the movable base 8a is driven by a motor 9a in the front and rear direction. The drive in the left and right directions by the motor 9b is as follows.

Therefore, the extended end of the preform rod 1 held by the guide rollers 7a and 7b can be moved in both the front and back direction and the left and right direction on the horizontal plane via the above-mentioned mechanism.

Reference numeral 10 denotes a spinning furnace consisting of a cylindrical electric heating furnace, and this spinning furnace 10 has guide rollers 7a and 7b so that the stretched end 1b of the preform rod 1 supported as described above can be inserted therein. placed at the bottom.

11 is a cylindrical, U-shaped, etc. position detector;
This detector 11 has an optical position detection system using a laser beam or the like, and an electrical measurement position signal transmission system. The optical fiber 1c spun from 1b passes through.

Further, a controller 12 is connected to the position detector 11, which analyzes the measured position signal from the detector 11 and transmits a control signal based on this. Converters 13a and 13b are connected to each of the motors 9a and 9b to supply electric power with a predetermined output based on a control signal from the motors 9a and 9b.

Therefore, based on the optical fiber position detected within the position detector 11, the controller 12 and the converter 13
a, 13b, and the guide rollers 7a, 7b are moved in the front-rear direction, left-right direction, etc. via the motors 9a, 9b.

In this case, the controller 12, converters 13a, 13
b, motors 9a, 9b, etc. are connected to both guide rollers 7
This is the movement operation system for a and 7b.

14 is a coating tank in which a plastic solution or the like is placed, and this coating tank 14 has a small diameter die 15 at the center of its lower surface.
It is arranged below the position detector 11 mentioned above.

Reference numeral 16 denotes a cylindrical drying oven disposed below the coating bath 14, and this drying oven 16 has an electric heater inside.

Reference numeral 17 denotes a capstan disposed below the drying oven 16, and in the direction in which the optical fiber is guided by this capstan 17, an optical fiber take-up mechanism and a winding mechanism (not shown) are disposed.

In the present invention, as shown in the figure, the gripping end 1b of the preform rod 1 is clamped on the mount 3 side, and by slowly lowering the mount 3, the drawn end 1b of the rod 1 is attached to the spinning furnace. 10 and heated and melted here.
b is taken at a predetermined speed to spin an optical fiber 1c of a desired fiber diameter from the same end 1b.Hereinafter, the optical fiber 1c obtained by this spinning will be
The material is passed through a coating bath 14 and a drying oven 16, and then taken through a capstan 17 in a predetermined direction.

At this time, the gripping end 1a of the preform rod 1
The side of the rod 1 is supported by a universal catcher 2 on a mounting base 3, and the stretched end 1b side of the rod 1 is held by guide rollers 7a, 7b, and the spun optical fiber 1c is connected to a position detector. It will pass through 11.

In this state, if a situation occurs in which the optical fiber 1c deviates from a predetermined position, for example, if a situation occurs in which the optical fiber 1c deviates from the center of the die 15 using the coating bath 14 as a reference, the position detector 11 This is detected and the measured position signal is sent to the controller 12, and based on this signal, the controller 12 moves the motor 9 from the converters 13a and 13b.
A predetermined electric power is supplied to motors 9a and 9b, and each motor 9a and 9b is driven at a predetermined number of rotations.

This causes the movable base 8a to move forward and backward.
b moves in the left-right direction by the respective designated distances, and accordingly, both guide rollers 7a and 7b move similarly, and through these movements, the position of the stretched end 1b of the preform rod 1 is corrected, The optical fiber 1c is returned to its proper position.

Depending on the positional deviation of the optical fiber 1c, only one of the motors 9a and 9b may be driven, and the position of the optical fiber 1c may be corrected only in the front-rear direction or in the left-right direction.

Of course, the above position control is performed every time the optical fiber 1c is displaced, so that the proper position of the optical fiber 1c is always ensured.

Since the position of the optical fiber during spinning is controlled as described above, uneven thickness and damage during optical fiber coating, which is performed in conjunction with spinning, are prevented, and a high-quality optical fiber can be obtained. Since these situations do not occur, high-speed spinning of optical fibers can be achieved.

As explained above, according to the present invention, optical fibers of good quality can be manufactured with high efficiency.

[Brief explanation of the drawing]

The drawing is a schematic illustration of an optical fiber spinning apparatus according to the control system of the present invention. 1...Preform rod, 1a...Gripping end, 1b...Stretching end, 1c...Optical fiber, 2
...Universal catcher, 7a, 7b...Guide roller, 9a, 9b...Motor (moving operation system), 10...Spinning furnace, 11...Position detector, 1
2...Controller (mobile operation system), 13a, 13b...
...Converter (mobile operation system), 14...Coating tank, 17...Capstan.

Claims (1)

[Claims] 1. Inserting a preform rod, whose upper end in the longitudinal direction is a gripping end and the lower end in the same direction is a stretching end, into a spinning furnace sequentially from the stretching end side, and
The molten drawn end is warped to a take-up capstan located below the spinning furnace to form an optical fiber of a desired fiber diameter, and as the optical fiber travels between the spinning furnace and the capstan, In an optical fiber spinning method in which a coating film is formed on the outer periphery of the optical fiber by passing the optical fiber through a coating tank disposed between them, the supporting end side of the preform rod is formed in a free direction on a horizontal plane. The preform rod is supported by a universal catcher so that it can swing freely, and the stretched end side of the preform rod is held by guide rollers that are movable in two directions intersecting at right angles in a horizontal plane. An optical fiber position detector is arranged between the take-up side capstan and when the optical fiber spun as described above comes out of a predetermined position, this is detected by the position detector and the detection signal is emitted. An optical fiber spinning control system, characterized in that the movement operation system of the guide roller is operated based on the above, and thereby the stretching end of the preform rod is moved and the optical fiber is returned to a predetermined position.