JP2002326835A - Device and method for holding glass rod to produce optical fiber preform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple glass rod holder which is used for manufacturing a porous glass preform by depositing glass fine powder on a core glass rod and holds the rod firmly and does not cause swinging or shaking notion of the rod. SOLUTION: A glass rod holding device 1 holds both end parts of the glass rod 3 to produce the porous glass preform 2 by scrolling chucks 11 and is rotated by power. At least one end part of both of the end parts is held by the two-stage scrolling chucks 11 in series.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for holding a glass rod, which is used for producing a porous glass preform as a raw material of an optical fiber by depositing glass particles on a glass rod. Things.

[0002]

2. Description of the Related Art After a porous glass preform is sintered and reduced in diameter, it is drawn into an optical fiber.

[0003] The porous glass preform is manufactured by, for example, an external vapor deposition method (OVD method) in which fine glass particles blown from a burner are sprayed and deposited on the surface of a rotating glass rod. Heretofore, a porous glass preform has been manufactured by rotating both ends of the rod while holding it with one scroll chuck at a time.

[0004] In order to improve the productivity of optical fibers, porous glass preforms are manufactured to be heavy, long and large in diameter. When manufacturing the glass rod, it is difficult to grasp the glass rod by gripping both ends of the glass rod one by one because of the looseness of the chuck and the bending of the rod due to its own weight. A break will occur. As a result, there is a problem that the glass fine particles are deposited unevenly, and the porous glass base material is easily eccentric and the yield is deteriorated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is used when a glass fine particle is deposited on a core glass rod to produce a porous glass base material. It is an object of the present invention to provide a simple apparatus for holding a glass rod which does not cause whirling or blurring, and a method for manufacturing a porous glass base material using the same.

[0006]

A glass rod gripping device 1 according to the present invention, which has been made to achieve the above object, will be described with reference to FIG. A gripping device for gripping both ends of the glass rod 3 with the scroll chuck 11 and rotating the glass rod 3 by power so that at least one of the two ends has two stages of scroll chucks 11 in series. Is gripped by

It is preferable that the power-side end of the two ends is gripped in series by a two-stage scroll chuck. Both ends may be gripped in series by two-stage scroll chucks and connected to power.

When the apparatus 1 is used, the rod 3 is easily and securely gripped by the two-stage scroll chuck 11. Therefore, even when a large-sized porous glass base material is manufactured, the rod 3 can be rotated stably without causing whirling and wobbling.

A method for producing a porous glass base material 2 according to the present invention is carried out using this apparatus 1. In this manufacturing method, both ends of the glass rod 3 are rotated by power while being gripped by the scroll chuck 11, and the burner 5 is rotated.
(See FIG. 3) is a method for producing a porous glass preform 2 by depositing glass fine particles from the surface of the glass rod 3, wherein at least one of the two ends is
That is, it is gripped by the two-stage scroll chuck 11 in series.

The rod 3 rotates without whirling or wobbling. Therefore, a high-quality porous glass base material 2 in which glass fine particles are uniformly deposited can be manufactured.

The gripping device 1 may be used not only when manufacturing a porous glass base material but also when performing flame polishing on the sintered surface of the base material, and may be used when subsequently extending. You may.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a glass rod holding device 1 to which the present invention is applied will be described below in detail with reference to the drawings. FIG. 1 is a partial cross-sectional view of the front of a glass rod gripping device 1.

In this apparatus 1, both ends of a glass rod 3 are gripped by a scroll chuck 11 and rotated by power.

As the glass rod 3, a gas phase shafting method (V
A core glass rod having a core layer and a clad layer prepared by the AD method) is used.

As shown in FIG. 1 showing the vicinity of one end of both ends of the glass rod 3, the glass rod 3 is gripped in series by a two-stage scroll chuck 11.

As shown in FIG. 2, six scroll chucks 11 closer to the base material 2 of the two stages are arranged evenly in the radial direction. Six notches 22 are provided in a thick circular plate 12 having a hole through which the glass rod 3 penetrates at the center, and the scroll chuck 11 is fitted into each of the cuts 22.

Guide projections 21 are provided on both sides of the scroll chuck 11 facing the surface of the cut 22.

As shown in FIG. 1, the guide projection 21 is formed in the guide groove 13 formed on the inner wall surface of the notch 22 of the disc 12.
It is stuck in.

Glass rod 3 of scroll chuck 11
On the end side surface, female screw circular arcs 18 are provided side by side along the direction b that moves radially.

Glass rod 3 of scroll chuck 11
Near the end, a disk 20 that is located at the center of the hole through which the glass rod 3 passes is disposed. On one side of the disk 20,
A groove 19 swirling toward the rotation axis of the glass rod 3 is provided. This groove 19 meshes with the female screw arcs 18 of all six scroll chucks 11. The other surface of the disk 20 is provided with a tooth profile to be screwed with the bevel gear 15. The bevel gear 15 has an axis 16 that is parallel to the direction b in which the scroll chuck 11 moves forward and backward. The shaft core 16 is fitted in a through hole 14 which is opened at six places in a cylinder 17 surrounding the disk 12 and has a diameter slightly smaller than the diameter of the cap base of the bevel gear 15.

The outer scroll chuck 11 of the two stages has the same configuration.

The two-stage scroll chucks 11 are connected via a connecting plate 32 and, together with the motor connecting tool 33, are tightened and integrated with bolts 31 and nuts 34.
The motor connection tool 33 is connected to the rotation motor 4 (see FIG. 3).

The other end of the glass rod 3 is also held by a similar scroll chuck 11.

Hereinafter, an example in which the gripping device 1 is used will be described. As shown in FIG. 3, the apparatus 1 converts the glass fine particles blown from the burner 5 into a rotating core glass rod 3.
It is used when the porous glass base material 2 is manufactured by an external deposition method of depositing on the surface of the glass substrate.

First, as shown in FIG. 1, one end of the core glass rod 3 is inserted into a first-stage space and a second-stage space surrounded by six scroll chucks 11.

One of two stages of the scroll chuck 1
It is turned in the direction a by a hexagon wrench 30 inserted into a hexagonal hole of the shaft core 16 of the bevel gear 15 connected to 1. Then, the bevel gear 15 rotates and the disk 20 screwed with the bevel gear 15
Rotates. The six scroll chucks 11 interlock and protrude by the female screw circular arc 18 meshing with the spiral groove provided on the surface of the disk 20. Since the scroll chuck 11 moves along the guide groove 13 in which the guide protrusion 21 is fitted, the scroll chuck 11 protrudes toward the glass rod 3 in the direction b.

The other one of the two stages, the scroll chuck 11, is operated in the same manner. By tightening the two-stage scroll chuck 11 in this manner, the rod 3 is securely held.

The other end of the rod 3 is similarly gripped by the scroll chuck 11.

Next, as shown in FIG. 3, while rotating the glass rod 3 by the rotating motor 4 which is a power, the burner reciprocating motor 6 is simultaneously driven. The burner 5 that is screwed to the screw rod and blows out the glass fine particles starts reciprocating motion parallel to the glass rod 3. The glass fine particles are sequentially and uniformly deposited on the surface of the glass rod 3, and the porous glass base material 2 is obtained.

One end of a core glass rod having a diameter of 50 mm and a length of 3 m is fastened with a two-stage scroll chuck,
The whirling was only 0.2 mm when the rod was rotated while being gripped by a gripping device that clamps the other end of the rod with a one-stage scroll chuck. Further, the porous glass base material sprayed with the glass fine particles and the optical fiber obtained by sintering and drawing the same had an eccentricity of only 0.1% with respect to the diameter.

For comparison, when using a gripping device in which both ends of a similar core glass rod are tightened with a single-stage scroll chuck, the whirling is as large as 0.4 mm, and the eccentricity of the porous glass base material and the optical fiber is increased. Was as high as 0.2%.

[0032]

As described above in detail, the use of the glass rod holding device of the present invention makes it possible to easily reduce whirling and blurring when rotating the glass rod. When this apparatus is used, a homogeneous high-quality porous glass base material having no eccentricity can be easily obtained, and an optical fiber derived therefrom has high quality without eccentricity.

[Brief description of the drawings]

FIG. 1 is a front partial cross-sectional view of an embodiment of a glass rod gripping device to which the present invention is applied.

FIG. 2 is a side view of an embodiment of a glass rod holding device to which the present invention is applied.

FIG. 3 is a schematic view of an embodiment of a method for manufacturing a porous glass base material using a glass rod holding device to which the present invention is applied.

[Explanation of symbols]

1 is a holding device for a glass rod, 2 is a porous glass base material,
3 is a glass rod, 4 is a rotation motor, 5 is a burner, 6
Is a burner reciprocating motor, 11 is a scroll chuck,
12 is a thick disk, 13 is a guide groove, 14 is a through hole, 15 is a bevel gear, 16 is a shaft core, 17 is a cylinder, 18 is a female screw arc,
19 is a spiral groove, 20 is a disk, 21 is a guide projection,
22 is a cut, 30 is a hexagon wrench, 31 is a bolt, 32
Is a connection plate, 33 is a motor connection tool, 34 is a nut, a is a rotation direction, and b is a forward and backward direction.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kiyoshi Yokokawa 2-13-1 Isobe, Annaka-shi, Gunma F-term in Shin-Etsu Kagaku Kogyo Co., Ltd. Precision Functional Materials Laboratory 4G021 EA00 EA03

Claims (3)

[Claims] 1. A gripping device for gripping both ends of a glass rod with a scroll chuck and rotating the glass rod by power to produce a porous glass base material, wherein at least one end of the both ends is A glass rod holding device, which is held in series by a two-stage scroll chuck. 2. The glass rod gripping device according to claim 1, wherein the power-side end of the two ends is gripped in series by a two-stage scroll chuck. 3. A method for producing a porous glass base material by rotating both ends of a glass rod by a power while gripping the both ends with a scroll chuck and depositing glass particles blown out from a burner on the surface of the glass rod. A method of manufacturing a porous glass base material, wherein at least one end of the both ends is gripped by a two-stage scroll chuck in series.