JP3301204B2 - Optical fiber drawing method and drawing apparatus - 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 drawing method and apparatus for manufacturing an optical fiber by drawing an optical fiber preform.

[0002]

2. Description of the Related Art The construction of a conventionally known optical fiber drawing apparatus will be described with reference to FIG. Above the heating device 8 for drawing and drawing the optical fiber preform, two upper and lower holding devices 3 and 4 for suspending and holding the optical fiber preforms 12 and 11 respectively are provided. On the sides of the holding devices 3 and 4, feed mechanisms 5 and 6 for raising and lowering the holding devices 3 and 4 independently are provided.
There is provided a welding device 7 for connecting the optical fiber preforms 12 and 11 held by the optical fiber preform 4, and the optical fiber preforms 11 and 12 are integrated by welding and supplied into the heating device 8. I have. Holding devices 3, 4
A sensor 9 for detecting the outer diameters and positions of the optical fiber preforms 11 and 12 is provided below the optical fiber preforms 11 and 12, and the driving of the holding devices 3 and 4 is controlled based on a signal from the sensor 9.

[0003] The optical fiber preforms 11 and 12 supplied to the heating device 8 are heated and melted in the heating device 8 and drawn out as optical fibers 14. The optical fiber 14 drawn out of the heating device 8 passes through the pre-coating device 15 to be coated on the surface, and then is wound up by the winding device 17 via the drawing device 16.

[0004] Reference numeral 10 denotes a sensor for detecting the outer diameter and position of the optical fiber 14 immediately after being pulled out from the heating device 8. The outer diameter control of the optical fiber 14 is performed by controlling the speed of the take-off device 16 by the outer diameter control circuit 18 based on the signal from the sensor 10.

FIG. 10 is a view showing a series of operations of the optical fiber drawing method, particularly, a series of operations when the optical fiber preforms 11 and 12 are continuously supplied to the heating device 8.

First, as shown in (1), the optical fiber preform 11 on which welding has been performed is held by the upper holding device 3, and in this state, the holding device 3 is lowered at a constant speed.
The optical fiber preform 11 is fed into the heating device 8 and drawn by melting. During this drawing, when the welded part of the optical fiber preform 11 is detected by the sensor 9, as shown in (2), the optical fiber preform 11 is gripped by the lower holding device 4, and then ( As shown in 3), the holding device 3 on the upper side of 11 is separated from the optical fiber preform.

[0007] The upper holding device 3 is then raised to a predetermined position as shown in (4) to grip a new optical fiber preform 12 to be supplied next. When the holding device 3 is lowered while holding the optical fiber preform 12 and the lower end of the optical fiber preform 12 contacts the upper end of the optical fiber preform 11 with a constant force, as shown in FIG. Welding device 7 between preforms 11 and 12
By welding. Here, the optical fiber preform 1
The pressure contact force between the optical fiber preforms 11 and 12 is determined in consideration of the fact that the optical fiber preform 11 does not slip off from the lower holding device 4 and that the optical fiber preforms 11 and 12 are not damaged in quality. .

When the welding is completed, the lower holding device 4 is separated from the optical fiber preform 13 integrated by welding as shown in (6). Thereby, the (1)
And a series of operations is completed.

[0009]

However, the holding devices 3 and 4 in the above-described drawing apparatus are conventionally provided with a pair of arms that can be opened and closed on a vertically movable platform that moves vertically.
In this configuration, only chucks (claws) are attached inside these arms. Therefore, as shown in FIG.
When the optical fiber preform 11 already gripped by the upper holding device 3 is further gripped by the lower holding device 4, the optical fiber preform 11 is slightly bent or undulated due to the optical fiber preform 11. There is a possibility that various vibrations and axis deviations occur in 11 and cause various adverse effects. For example,
The optical fiber preform 11 collides with the upper seal cup 8a, which is the insertion opening of the heating device 8, or the position of the optical fiber 14 being drawn deviates from the measurable area of the sensor 10,
Control of the outer diameter of the optical fiber 14 may be impossible.

[0010] The above-described vibration and axis deviation of the optical fiber preform can be caused by not only holding the optical fiber preform 11 with the lower holding device 4 but also moving the upper holding device 3 from the optical fiber preform 11. When they are separated (Fig. 1
0 (3)) also occurs when the lower holding device 4 is separated from the optical fiber preform 13 after welding (FIG. 10 (6)).

When the optical fiber preforms 11 and 12 are integrated by welding using a conventional optical fiber drawing apparatus, the optical fiber preforms 11 and 12 are welded due to delicate bending, undulation, distortion due to welding, and the like. An axis shift occurs in the optical fiber preform 13 later, and the optical fiber preform 13 is moved to the upper seal cup 8 a of the heating device 8.
And the optical fiber 14 may come into contact with the lower seal cup 8b and be disconnected.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide an optical fiber that can continuously supply a plurality of optical fiber preforms smoothly into a heating device without causing vibration or axial displacement. An object of the present invention is to provide a drawing method and a drawing apparatus.

[0013]

In order to achieve the above object, an optical fiber drawing method according to the present invention uses an upper holding device.
The optical fiber preform held by
Is sent to the heating device by the lowering of the
The optical fiber preform being melted is held in the upper holding device.
Grip with the lower holding device provided on the lower side of the
Hold another optical fiber preform with the upper holding device.
Hold the lower end of the other optical fiber preform
Weld to the upper end of the optical fiber preform being drawn and
After, the optical fiber preform by the lower holding device
And release the gripping up and down by the upper holding device.
Holds optical fiber preform welded to
Optical fiber drawing to supply to the heating device and draw by melting
In the method, the upper holding device and the lower holding device
Opens and closes around a predetermined position and is smooth in the horizontal direction.
A pair of arms that can be moved
It can be swung up and down and horizontally installed inside the
A pair of claw portions, and a movement preventing hand for restraining the movement of the arm.
A step and a swing prevention means for restraining the swing of the claw portion.
Holding the optical fiber preform,
Move the arm with the claw part swingable.
The optical fiber preform was sandwiched between the claws.
Later, the movement preventing means and the swing preventing means move forward.
Restraining the movement of the arm and the swing of the claw.
Release of gripping of the optical fiber preform
The front by the movement prevention means and the swing prevention means
The movement of the arm and the restraint of the swing of the claw were released.
After that, the arm is moved so that the claw portion is connected to the optical fiber.
This is performed by separating from the preform .

Further, the optical fiber drawing apparatus of the present invention, the upper
The optical fiber preform held by the side holding device
When the upper holding device is lowered, it is sent to the heating device and melted.
The optical fiber preform is drawn by melting and drawing.
Grip with the lower holding device provided below the upper holding device
Then, another optical fiber is newly added to the upper holding device.
Hold the preform and hold the other optical fiber preform
The lower end of the optical fiber preform during the melt drawing.
Welded to the upper end, then the optical filter by the lower holding device
Release the grip of the iva preform and hold the upper
Optical fiber preform welded up and down by holding device
And supply it continuously to the heating device to draw a melting line
In the optical fiber drawing device, the upper holding device and
The lower holding device opens and closes around a predetermined position,
A pair of arms that can move smoothly in the horizontal direction
The vertical and horizontal directions provided inside each arm
A pair of claws that can swing in the directions
Movement preventing means for bundling, and a neck for restraining swing of the claw portion
Swing prevention means, the swing of the claw part is possible
The arm in such a state that the
After sandwiching the fiber preform,
And the movement of the arm and the
By restricting the swing of the claw, the optical fiber pre-
The foam is gripped, and the movement preventing means and the neck
Movement of the arm by swing prevention means and neck of the claw portion
After releasing the swing restraint, move the arm to
Separating the claws from the optical fiber preform
Release of the grip of the optical fiber preform is performed by
It is intended to be.

[0015]

[0016]

According to the present invention, a pair of arms that open and close around a predetermined position are made movable horizontally by an XY free table, and the arms are opened and closed in this state. Even if the arm is displaced from its original position due to undulation, the arm moves to that position and opens and closes, so that the optical fiber preform can always be gripped and released at an optimal position. In addition, since the claw portion is swingably provided inside the two arms by the support mechanism, the optical fiber preform can be gripped and released according to its inclination and surface shape. Therefore,
The shock at the time of holding and opening the optical fiber preform is relieved, and the vibration and the axial deviation of the optical fiber preform can be suppressed.

Here, an elastic member is provided on the support mechanism, and the head is swung vertically and horizontally inside the arm.
If you support it with the possible claw part urged forward,
The impact at the time of holding and opening the optical fiber preform can be further absorbed by the elastic member, so that the vibration and the axial deviation can be further suppressed.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the entire configuration of an optical fiber drawing apparatus 1 according to the present invention. In FIG. 1, reference numeral 8 denotes a heating device for melting and drawing an optical fiber preform. Above the heating device 8, two upper and lower holding devices 3, 4 for suspending and holding the optical fiber preforms 12, 11 respectively are provided. These holding devices 3 and 4 are provided on guide bars 2 and 2 arranged along the vertical direction so as to be able to move up and down, and can be moved up and down independently of each other by feed mechanisms 5 and 6 as in the conventional case. It has become.

A welding device 7 for butt-welding the ends of the optical fiber preforms 12 and 11 to each other is provided on the side of the lifting area of the holding devices 3 and 4. A sensor 9 for detecting the outer diameter and the position of the optical fiber preforms 11 and 12 is provided directly below the elevating area of the holding devices 3 and 4.

Reference numeral 19 denotes a control device for controlling the driving of the upper and lower holding devices 3 and 4 based on the signal from the sensor 9.

FIG. 2 is a diagram showing a configuration example of the holding devices 3 and 4 in the optical fiber drawing device 1. Hereinafter, only the upper holding device 3 will be described, and the lower holding device 4 will not be described because it has the same structure.

In FIG. 2, reference numeral 40 denotes an opening / closing chuck for suspending and holding an optical fiber preform.
A pair of arms 42, 42 are provided on the upper side. The arms 42, 42 are reciprocally movable by a rail 41a, and extend in a direction orthogonal to the rail 41a. On the inside of the extending ends of the arms 42, 42, claw portions 44, 44 capable of engaging with the surface of the optical fiber preform from both sides.
Is provided. V-grooves 44 are provided on the opposing surfaces of the claw portions 44
a, 44a are formed to position and hold the optical fiber preform. On the other hand, an opening / closing mechanism 45 is provided at the base end of the arms 42, 42. The opening / closing mechanism 45 includes a ball screw 45a extending along the rail 41a, and a motor 45b that drives the ball screw 45a to rotate.
The arms 42 can be opened and closed in conjunction with each other.

An XY stage 20 for suspending the optical fiber preform is provided directly below the heating device 8 (FIG. 1) below the opening / closing chuck 40 described above. X
The Y stage 20 is provided on a base 21 so as to be displaceable in one axis direction (X axis direction in the figure). The X stage 22 is provided on the X stage 22 so as to be displaceable in a direction orthogonal to this (Y axis direction). Drive mechanisms 24 and 25 provided between the Y stage 23, the base 21 and the X stage 22, and between the XY stages 22 and 23, respectively.
By the drive control of 5, the opening / closing chuck 40 can be moved to an arbitrary position in the horizontal direction.

In the holding device 3 of this embodiment, in order to stably hold the optical fiber preform without bending or undulation, the opening / closing chuck 40 is horizontally moved between the XY stage 20 and the opening / closing chuck 40. XY free table 30 for moving in the direction is provided.
At the tip of the opening / closing chuck 40, support mechanisms 43, 43 for swinging the claws 44, 44 are provided.

FIG. 3 is a diagram showing an example of the configuration of the XY free table 30, in which an X table 32 and a Y table 33 are sequentially stacked on a base 31. Direct-acting ball bearings 34 are provided between the base 31 and the X table 32 and between the X table 32 and the Y table 33, respectively, so that the opening / closing chuck 40 can be moved smoothly and lightly in the horizontal direction. ing. XY table 3
On the lower surfaces of the X and Y tables 32 and 33, respectively.
Movement prevention means 35, 3 for restraining the movement of the moving object 33
5 are provided. As shown in FIG. 4, the movement preventing means 35 includes a pair of disk pads 36, 36 provided on both sides of a guide rail 34a forming a linear motion ball bearing 34, and an electromagnetic type air for opening and closing both disk pads 36, 36. It is composed of a drive mechanism (not shown) such as a
a is sandwiched from both sides to restrict the movement of the XY tables 32 and 33.

FIG. 5 is an enlarged view of a configuration example of the support mechanism 43. A first holder 48 rotatably provided inside the extending end of the arm 42, and a first holder 48
And a second holder 49 provided in front of the second holder. A swing shaft 46 protrudes behind the first holder 48, and is rotatably supported by the arm 42 by the swing shaft 46. In addition, the front surface of the second holder 49 is provided with a flange 4 at a predetermined interval.
9b, 49b are formed so as to protrude, and both flanges 49b, 49b are formed.
b and the swing shaft 4
7 rotatably supported. Here, the swing shafts 46 and 47 extend perpendicularly to each other, so that the claw portion 44 can swing in the vertical direction (pitching direction) B and the horizontal direction (yaw direction) A, respectively. . On the other hand, behind the second holder 49, four slide shafts 49a are protruded as shown in an exploded view in FIG. 6, and these slide shafts 49a are supported by the first holder 48 so as to be able to move forward and backward. ing. A compression coil spring 50 is previously provided on the outer circumference of the slide shaft 49a.
(Elastic member) is interposed, and the second holder 4
9 (that is, the claw portion 44) is urged forward.

The claw 4 is attached to the arm 42 and the holder 49 similarly to the XY free table 30.
A swing preventing means for preventing the swing movement of No. 4 is provided.

FIGS. 7 to 9 show various embodiments of the swing prevention means.

The oscillating prevention means 51 shown in FIG. 7 forms the surfaces of the oscillating shafts 46 and 47 into flat surfaces at predetermined angles, and presses the tips of the screws 52 and 52 against these flat portions to form the shafts 46 and 47. 47 is controlled.

The swinging prevention means 51 shown in FIG.
Flanges 53 are formed at the ends of the swing shafts 46 and 47, and a friction plate 54 is pressed against the flanges 53 to prevent rotation. The friction plate 54 is normally separated from the flange 53 by a return spring 55,
When the electromagnet (not shown) is energized, it moves forward against the urging force of the spring 55 and is pressed against the flange 53. In addition, as a drive source of the friction plate 54, an air cylinder or the like may be used instead of the electromagnet.

Further, the swing prevention means 51 shown in FIG.
By rotating a sleeve 57 provided around the ends of the swing shafts 46, 47, the claws 58, 5
8 are reduced in diameter to grip the shafts 46, 47.

Next, the operation of the optical fiber drawing apparatus 1 will be described.

As shown in FIGS. 10 (1) and 10 (2), when the optical fiber preform 11 is gripped by the lower holding device 4, the control device 19 (FIG. 1) first
(FIG. 4) to release the opening / closing chuck 40 so that it is free to move in the horizontal direction.
Is released so that the claw portions 44, 44 can swing freely.
Thereafter, the opening / closing mechanism 45 is driven to close the arms 42, 42, and the optical fiber preform 11 is gripped by the claws 44, 44. After the optical fiber preform 11 is gripped, the movement preventing means 35 and the swing preventing means 51 are operated again to restrain the claw portions 44, 44 from being moved. In this way, when the optical fiber preform 11 is gripped by the holding device 4 on the lower side, if the opening / closing chuck 40 is free to move in the horizontal direction, the optical fiber preform 1
Even if the position 1 is deviated from the original position due to bending or undulation, the claw portions 44 always move to the optimum position and come into contact with the surface of the optical fiber preform 11. It can be held as it is without shifting its position. In addition, since the impact at the moment when the claw portion 44 comes into contact with the optical fiber preform 11 is reduced, the preform 11 does not vibrate. Further, by setting the claws 44, 44 to be freely swingable, the optical fiber preform 11 can be gripped even if its surface shape and verticality are slightly deviated. 11
The vibration and misalignment occurring in the above are reduced as much as possible.

As shown in FIGS. 10 (2) and 10 (3), the upper holding device 3 is released from the state where the optical fiber preform 11 is gripped by both the upper and lower holding devices 3 and 4. When the optical fiber preform 11 is detached from the optical fiber preform 11 in the same manner as described above,
1 is released, and the opening / closing mechanism 45 is driven to move the arm 4.
Open 2,42. As a result, at the moment when the claw portion 44 separates from the optical fiber preform 11, the optical fiber preform 11 is smoothly separated without causing axial deviation or vibration.

As shown in FIGS. 10 (4) to 10 (6),
When welding a new optical fiber preform 12 onto the optical fiber preform 11 and separating the lower holding device 4 from the integrated optical fiber preform 13,
In the same manner as described above, the claws 44, 44 are smoothly separated from the optical fiber preform 13, so that the optical fiber preform 13 does not vibrate or shift.

During the operations (1) to (6) described above, the control device 19 controls the holding device 3 based on the signal from the sensor 9.
By moving the XY stage 20 of No. 4, the optical fiber preform 11 is always positioned at the center of the upper seal cup 8a of the heating device 8.

As described above, according to the present embodiment, even if the optical fiber preform 11 is bent or undulated, the optical fiber preform 11 can always be gripped and released by the claw portions 44 at the optimum position and posture. The fluctuation of the position and vibration of the preform 11 can be eliminated, and the preform 11 can be supplied to the heating device 8 smoothly. Therefore, the optical fiber preform 1
Collisions of the heating devices 8 with the upper seal cup 8a and displacement of the optical fiber 14 during drawing can be reliably prevented. In addition, since the optical fiber preform 11 can always be gripped at the center of the claw portions 44, 44, the optical fiber preform 11 can be gripped with a sufficient gripping force. Can be prevented.

According to the present embodiment, the first and second
The claw portion 44 is held via the two holders 48, 49, and the compression coil spring 5 is interposed between the holders 48, 49.
0 is provided to urge the claw portion 44 forward, so that the impact when the claw portion 44 comes into contact with the outer periphery of the optical fiber preform can be absorbed by the compression coil spring 50, and the shock at the time of gripping / opening can be absorbed. Can be further softened.

The XY stage 20 is moved based on the detection signal from the sensor 9 and the optical fiber preform is always positioned at the center of the heating device 8, so that the optical fiber preform 13 after welding is placed on the heating device 8. When the optical fiber 14 collides with the seal cup 8a or the lower seal cup 8
Contact with b can also be reliably prevented.

[0041]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) Since the position fluctuation of the optical fiber preform when holding and releasing the optical fiber preform can be suppressed as much as possible, a plurality of optical fiber preforms can be smoothly supplied into the heating device. Become.

(2) The optical fiber preform can be gripped with a sufficient gripping force.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an optical fiber drawing apparatus.

FIG. 2 is a schematic perspective view showing a configuration example of a holding device applied to the optical fiber drawing device of the present invention.

FIG. 3 shows XY applied to the optical fiber drawing apparatus of the present invention.
FIG. 3 is an exploded perspective view showing a configuration example of a free table.

FIG. 4 is a diagram showing a configuration example of a movement preventing means provided in an XY free table.

FIG. 5 is an enlarged view showing a configuration example of a support mechanism applied to the optical fiber drawing apparatus of the present invention.

FIG. 6 is an exploded perspective view of a support mechanism.

FIG. 7 is a view showing one embodiment of a swing prevention means provided in a support mechanism.

FIG. 8 is a view showing another embodiment of the swing prevention means provided in the support mechanism.

FIG. 9 is a view showing still another embodiment of the swing prevention means provided in the support mechanism.

FIG. 10 is a diagram showing a series of operations of the optical fiber drawing apparatus shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 optical fiber drawing device 2 guide bar 3 upper holding device 4 lower holding device 7 welding device 8 heating device 9 sensor 20 XY stage 30 XY free table 35 movement prevention means 40 opening / closing chuck 42 arm 43 support mechanism 44 claw portion 46, 47 swing shaft 50 compression coil spring 51 swing prevention means

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shigenori Nemoto 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture Inside the Hidaka Factory, Hitachi Cable Co., Ltd. (72) Inventor Hideo Matsuo Hidaka-cho, Hitachi City, Ibaraki Prefecture 5-1-1, Hidaka Electric Wire Co., Ltd. (72) Inventor Tetsuro Nakagawa 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Pref. JP-A-5-97453 (JP, A) JP-A-5-279067 (JP, A) JP-A-6-329433 (JP, A) JP-A-4-130030 (JP, A) (58) Int.Cl. ⁷ , DB name) C03B 37/012-37/029

Claims (2)

(57) [Claims] 1. A fiber optic preform which is gripped by the upper holding device melted wire drawing by feeding to the heating device by the lowering of the upper holding device, an optical fiber preform of the fusion line引中 of the upper holding device It is gripped by the lower holding device provided on the lower side , and then newly held by the upper holding device.
The other optical fiber preform is gripped, the lower end of the other optical fiber preform is welded to the upper end of the optical fiber preform being drawn , and then the lower holding device is
When the gripping of the optical fiber preform by the
The optical fiber welded up and down by the upper holding device
Holds the preform and continuously supplies it to the heating device
In the method of drawing an optical fiber for melting and drawing ,
Side holding device and the lower retaining device includes a pair of arms smooth to be movable in the horizontal direction together with the opening and closing around a predetermined position, provided in each of the inner side of the arms up and down
A pair of claw portions capable of swinging in the horizontal and horizontal directions;
Movement preventing means for restraining movement of the arm,
Means for restraining the head from swinging.
The grip of the fiber preform can swing the claw.
The arm in such a state that the
After sandwiching the fiber preform,
And the movement of the arm and the
This is performed by restraining the swing of the claws,
Release of the grip of the bapreform is performed by the movement preventing means and
Movement of the arm by the swing prevention means and the claw
After releasing the head restraint, move the arm
To separate the claws from the optical fiber preform.
An optical fiber drawing method characterized by performing the following . 2. An optical fiber held by an upper holding device.
The bapreform is heated by lowering the upper holding device.
Into the device and draw the melt, and the optical fiber
A lower side where a bapreform is provided below the upper holding device.
Grasp with the holding device, and then newly with the upper holding device
Hold another optical fiber preform and hold the other optical fiber.
Optical fiber in which the lower end of iva preform is being melt-drawn
Welded to the upper end of the preform and then the lower holding device
When the gripping of the optical fiber preform by the
The optical fiber welded up and down by the upper holding device
Holds the preform and continuously supplies it to the heating device
In the optical fiber wire drawing apparatus to pull fusion line with, the upper
The side holding device and the lower holding device are arranged around a predetermined position.
A pair of doors that can be opened and closed and move smoothly in the horizontal direction
Arm and the upper and lower
A pair of claw portions capable of swinging in the horizontal and horizontal directions;
Movement preventing means for restraining movement of the arm,
Means for restraining the head from swinging.
The arm is moved so that the swing of the
After sandwiching the optical fiber preform by the part, the
The arm is moved by the movement preventing means and the swing preventing means.
By restraining the movement of the
The optical fiber preform is gripped to prevent the movement.
Means and the movement of the arm by the means for preventing swinging.
And after releasing the restraint of the swing of the claw,
Move the claw from the optical fiber preform
By separating the optical fiber preform,
An optical fiber drawing device wherein the holding is released .