JPH09249428A - Production of parent material for optical fiber - Google Patents

Production of parent material for optical fiber

Info

Publication number
JPH09249428A
JPH09249428A JP5895996A JP5895996A JPH09249428A JP H09249428 A JPH09249428 A JP H09249428A JP 5895996 A JP5895996 A JP 5895996A JP 5895996 A JP5895996 A JP 5895996A JP H09249428 A JPH09249428 A JP H09249428A
Authority
JP
Japan
Prior art keywords
base material
ingot
tension
rod
optical fiber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP5895996A
Other languages
Japanese (ja)
Inventor
Kazuhiro Hamaguchi
一宏 濱口
Hideo Hirasawa
秀夫 平沢
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shin Etsu Chemical Co Ltd
Original Assignee
Shin Etsu Chemical Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shin Etsu Chemical Co Ltd filed Critical Shin Etsu Chemical Co Ltd
Priority to JP5895996A priority Critical patent/JPH09249428A/en
Publication of JPH09249428A publication Critical patent/JPH09249428A/en
Pending legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03BMANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01Manufacture of glass fibres or filaments
    • C03B37/012Manufacture of preforms for drawing fibres or filaments
    • C03B37/01205Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
    • C03B37/01225Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing
    • C03B37/0124Means for reducing the diameter of rods or tubes by drawing, e.g. for preform draw-down

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacture, Treatment Of Glass Fibers (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a production process for a parent material of optical fiber which can decrease the distortion of the rod of the parent material of the optical fiber after drawing in the step that an ingot of the optical fiber parent material is drawn into a rod of a smaller diameter than that of the ingot (before drawing). SOLUTION: In this production of a parent material for optical fiber, an ingot of the parent material for optical fiber is drawn to a rod of the parent material with a smaller diameter than that of the original parent material. In this drawing, the direction of the tension on the ingot-taking up side is measured, when the ingot is drawn, and the ingot of the parent material is moved its position so that the tension becomes downward in the vertical direction according to the direction of the tension.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【発明の属する技術分野】本発明は光ファイバ母材の製
造方法、特には光ファイバ母材インゴットをこれより小
径の母材ロッドに延伸する工程において、延伸後の光フ
ァイバ母材ロッドの曲がりを低減化する光ファイバ母材
の製造方法に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical fiber preform, and more particularly, in a process of drawing an optical fiber preform ingot into a preform rod having a smaller diameter than the ingot, the bending of the optical fiber preform rod after being drawn The present invention relates to a method for manufacturing a reduced optical fiber preform.

【0002】[0002]

【従来の技術】母材インゴットをこれより小径の母材ロ
ッドに延伸して光ファイバ母材を製造する方法について
は、光ファイバ母材を酸水素火炎や電気炉にて加熱し軟
化させながら加熱溶融部の外径を外径測定器などを用い
て測定し、その測定値に基づいて引取り速度を制御する
という方法がとられている。この場合、母材インゴット
の把持用として母材インゴットの両端に把持用ダミー棒
をガラス旋盤等を用いて溶着し、把持用ダミー棒を把持
することによって母材インゴットを延伸装置にセットし
ているが、把持用ダミー棒の溶着作業は、作業者がガラ
ス旋盤等を用いて母材インゴットとダミー棒の軸中心を
目視にて調整しながら行っているため、溶着時のダミー
棒の芯出し精度は作業者個人の技能によることになり、
芯出し精度にばらつきが生じやすい。
2. Description of the Related Art A method for producing an optical fiber preform by stretching a preform ingot on a preform rod having a smaller diameter than this is to heat the optical fiber preform with an oxyhydrogen flame or an electric furnace to soften it. A method has been adopted in which the outer diameter of the melted portion is measured by using an outer diameter measuring device or the like, and the take-up speed is controlled based on the measured value. In this case, for gripping the base material ingot, dummy gripping rods are welded to both ends of the base metal ingot using a glass lathe or the like, and the base metal ingot is set in the stretching device by gripping the gripping dummy rods. However, the welding work of the gripping dummy rod is performed while the operator visually adjusts the axial center of the base material ingot and the dummy rod using a glass lathe, etc., so the centering accuracy of the dummy rod during welding is Depends on the skill of the individual worker,
The centering accuracy tends to vary.

【0003】また、母材インゴットは多孔質体から透明
ガラス化する際に収縮するため、収縮の度合に円周方向
でばらつきが生じると、透明ガラス化時に母材インゴッ
トが曲がってしまうことがある。曲がった母材インゴッ
トは、ダミー棒を溶着する際に作業者によって曲がりが
修正されるが、曲がりの修正は全くの手作業であり、作
業者個人の技量によって仕上り精度が大きく左右される
ため、曲がりの生じた母材インゴットの曲がりを完全に
は取り除くことができない。それゆえ、透明ガラス化時
に曲がりの生じた母材インゴットは、溶着されたダミー
棒とは中心からずれてしまい、いわゆる芯ずれが生じる
場合がある。
Further, since the base material ingot shrinks from the porous body when it is made into transparent glass, if the degree of shrinkage varies in the circumferential direction, the base material ingot may be bent at the time of transparent glass formation. . The bending of the bent base material ingot is corrected by the worker when welding the dummy rod, but the correction of the bending is completely manual work, and the finishing accuracy greatly depends on the individual skill of the worker. The bending of the bent base metal ingot cannot be completely removed. Therefore, the base material ingot, which is bent during the transparent vitrification, may be offset from the center of the welded dummy rod, resulting in so-called misalignment.

【0004】上記のような場合には、延伸時に母材イン
ゴット溶融部にかかる張力は、縦型延伸装置の中心軸方
向すなわち鉛直方向からずれてしまう。このような理由
で発生した母材インゴットの溶融部に働く斜め方向の力
は、母材インゴットより製作される母材ロッドの曲がり
の原因となる。また、母材ロッドの曲がりが一旦発生す
ると、延伸装置の吊り下げおよび引取り機構の中心軸が
精度よく一致している場合にも、延伸中にその曲がりが
解消されることは少なく、延伸の最後まで一旦生じた曲
がりの影響が及んでしまいがちである。言い換えれば、
母材ロッドの引取り開始側の部分に曲がりが生じてしま
うと、その曲がりが次の曲がりを誘発させ易く、母材ロ
ッド全長に渡って曲がりが生じてしまうことになる。
In the above case, the tension applied to the base material ingot fusion portion during the drawing is deviated from the central axis direction of the vertical drawing apparatus, that is, the vertical direction. The oblique force acting on the molten portion of the base material ingot generated for this reason causes bending of the base material rod manufactured from the base material ingot. Further, once the bending of the base material rod occurs, even if the central axes of the suspending and retracting mechanisms of the stretching device are accurately aligned, the bending is rarely eliminated during stretching, and It tends to be affected by the bend that has occurred until the end. In other words,
If a bend occurs in the part of the base material rod on the take-off start side, that bend easily induces the next bend, and the bend occurs over the entire length of the base material rod.

【0005】[0005]

【発明が解決しようとする課題】すなわち、母材インゴ
ットをこれより小径の母材ロッドに延伸するときに上記
の理由で曲がりが発生する場合、この母材ロッドの曲が
りは線引き時における作業性ならびにファイバ特性の安
定性を大きく損なう要因となるので、曲がりの生じた母
材ロッドは曲がりを修正する必要があるが、修正作業は
工程が増えるので作業効率を大きく低下させる。したが
って、生産性向上のためには、母材インゴット把持用の
ダミー棒が偏心していたり、母材インゴット自身が曲が
っている場合でも、母材インゴットを延伸して製作する
母材ロッドに曲がりを生じさせないことが欠かせない条
件とされるために、母材インゴットに曲がりが生じる原
因がある場合でも曲がりの少ない母材ロッドを提供でき
る方法が求められている。
That is, when the base material ingot is bent to a base material rod having a smaller diameter than the base material, bending occurs due to the above-mentioned reasons. Since it becomes a factor that greatly deteriorates the stability of the fiber characteristics, it is necessary to correct the bending of the base material rod in which the bending has occurred. However, since the correction work requires more steps, the work efficiency is greatly reduced. Therefore, in order to improve productivity, even if the dummy rod for holding the base material ingot is eccentric or the base material ingot itself is bent, the base material rod produced by stretching the base material ingot will bend. Since it is an indispensable condition not to do so, there is a demand for a method capable of providing a base material rod with little bending even when there is a cause of bending of the base material ingot.

【0006】[0006]

【課題を解決するための手段】本発明はこのような問題
点を解決した光ファイバ母材の製造方法に関するもので
あり、これは光ファイバ母材インゴットをこれより小径
の母材ロッドに延伸する光ファイバ母材の製造方法にお
いて、母材インゴットを延伸する際の母材インゴット引
取り側の張力方向を測定し、その張力方向に応じて張力
が鉛直下向きになるように母材インゴットの位置を移動
させることを特徴とするものである。
SUMMARY OF THE INVENTION The present invention relates to a method for manufacturing an optical fiber preform which solves the above problems, in which an optical fiber preform ingot is drawn into a preform rod having a smaller diameter than the ingot. In the manufacturing method of the optical fiber preform, the tension direction of the base material ingot take-up side when stretching the preform material ingot is measured, and the position of the preform material ingot is adjusted so that the tension becomes vertically downward depending on the tension direction. It is characterized by being moved.

【0007】[0007]

【発明の実施の形態】母材インゴットの延伸は通常、縦
型の延伸装置で行なわれるが、この装置では母材インゴ
ットの中心軸と延伸装置の中心軸のずれは水平方向のず
れとして現れることになるので、母材インゴットの軸中
心と延伸装置の軸中心がなんらかの理由でずれた場合
は、母材インゴットの溶融部が延伸時に引き取られる方
向は、水平方向成分のために鉛直方向からずれてしま
う。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Stretching of a base material ingot is usually carried out by a vertical stretching apparatus. In this apparatus, the deviation between the center axis of the base material ingot and the center axis of the drawing apparatus appears as a horizontal deviation. Therefore, if the axial center of the base material ingot and the axial center of the stretching device are displaced for some reason, the direction in which the molten portion of the base material ingot is taken during stretching is deviated from the vertical direction due to the horizontal component. I will end up.

【0008】それ故に引取り張力の方向がずれている場
合には、母材インゴットの溶融部が傾いていること、つ
まりは母材インゴットの軸中心が延伸装置の中心軸から
ずれているので、延伸時の引取り側の張力を測定してそ
の張力の方向を求めれば、母材インゴットの延伸装置中
心軸からのずれを間接的に求めることができる。この場
合、延伸時の引取り側の張力は、縦型延伸装置では鉛直
下向きであるべきであり、引取り側の張力が鉛直方向か
らずれていることは母材インゴットを曲げる力が水平方
向に働いていることになる。
Therefore, when the direction of the take-up tension is deviated, the molten portion of the base material ingot is inclined, that is, the axial center of the base material ingot is deviated from the central axis of the stretching device. If the tension on the take-up side during stretching is measured and the direction of the tension is determined, the deviation of the base material ingot from the central axis of the stretching apparatus can be indirectly determined. In this case, the tension on the take-up side during stretching should be vertically downward in the vertical stretching device, and the fact that the tension on the take-up side deviates from the vertical direction means that the force for bending the base material ingot is in the horizontal direction. I'm working.

【0009】したがって、母材インゴットを曲げようと
する水平方向に働く力を低減化させるように母材インゴ
ットの位置調整を行なえば、母材インゴットを延伸して
作成される母材ロッドの曲がりを低減化させることがで
きる。本発明では、母材インゴットの全長に亘り引取り
側の張力を鉛直方向と水平方向の2方向から測定し、張
力が鉛直方向のみで、水平方向に生じなくなるように、
母材インゴットの位置を調整して母材インゴットを常に
延伸装置の中心に位置して延伸するのであり、これによ
り母材ロッドの延伸中の曲がりの発生を最小に抑えるこ
とができる。
Therefore, if the position of the base metal ingot is adjusted so as to reduce the force acting in the horizontal direction to bend the base metal ingot, the bending of the base metal rod formed by stretching the base metal ingot will be suppressed. It can be reduced. In the present invention, the tension on the take-up side is measured from the two directions of the vertical direction and the horizontal direction over the entire length of the base material ingot, so that the tension is only in the vertical direction and does not occur in the horizontal direction.
The position of the base material ingot is adjusted so that the base material ingot is always positioned in the center of the stretching device and stretched, and thereby, the occurrence of bending during the stretching of the base material rod can be minimized.

【0010】本発明による光ファイバ母材の製造装置を
添付の図面に基づいて説明する。図1は本発明で使用さ
れる延伸装置の縦断面概要図を例示したもので、図にお
いて母材インゴット1は把持用ダミー棒3を介して吊り
下げ用チャック5に吊り下げられている。この吊り下げ
用チャック5はXYステージ6を備えており移動用モー
ター8、ネジ送り機構7と連なっている。母材インゴッ
ト1は加熱ヒーター4で加熱溶融され、把持用ダミー棒
3を介した延伸引き取り用チャック9で延伸されて母材
インゴット1より小径の母材ロッド2に延伸される。こ
の場合、母材ロッド2の外径は外径測定器10で測定さ
れ、その結果が演算処理CPU12に記録され、このとき
の引取り側の張力は引取り張力測定器11で測定され、こ
の結果も演算処理CPU12に記録される。
An apparatus for manufacturing an optical fiber preform according to the present invention will be described with reference to the accompanying drawings. FIG. 1 exemplifies a vertical cross-sectional schematic view of a stretching device used in the present invention. In the figure, a base material ingot 1 is suspended by a suspending chuck 5 via a holding dummy rod 3. The hanging chuck 5 includes an XY stage 6, and is connected to a moving motor 8 and a screw feeding mechanism 7. The base material ingot 1 is heated and melted by the heater 4, drawn by the draw-and-take chuck 9 via the holding dummy rod 3, and drawn to the base material rod 2 having a smaller diameter than the base material ingot 1. In this case, the outer diameter of the base material rod 2 is measured by the outer diameter measuring device 10, the result is recorded in the arithmetic processing CPU 12, and the tension on the take-up side at this time is measured by the take-up tension measuring device 11. The result is also recorded in the arithmetic processing CPU 12.

【0011】母材インゴット1の把持用ダミー棒3の位
置に芯ずれがある場合や母材インゴット1に曲りがある
場合、母材インゴット1を延伸装置にそのままセットし
たのでは母材インゴットの軸中心と延伸装置の軸中心は
一致しない。縦型の延伸炉の場合にはこの軸ずれは水平
方向に母材インゴットがずれた状態でセットされたこと
を意味する。この状態で引取りを始めると加熱用ヒータ
ー近傍の母材ロッド溶融部には水平方向の力が作用する
ことになり、引取り側の張力は鉛直方向からはずれるこ
とになる。そこで引取り側の張力を鉛直方向と水平方向
の2方向から測定し、この張力が鉛直方向のみに働き水
平方向に生じなくなるようにXYステージ6において母
材インゴット1の位置を調整する。さらに延伸中におい
ても、引取り側の張力を鉛直方向と水平方向から測定
し、張力の方向により母材インゴットの位置調整を行
い、これを繰返し実施することにより、母材インゴット
全長に亘って母材インゴットの溶融部における引取り側
の張力を鉛直下向きとし、水平方向に生じないようにし
て延伸を行う。
If there is a misalignment in the position of the holding dummy bar 3 of the base material ingot 1 or if the base material ingot 1 is bent, the base material ingot 1 may be set as it is in the stretching device. The center and the axial center of the stretching device do not coincide. In the case of a vertical drawing furnace, this axis shift means that the base material ingot was set in a horizontal direction with a shift. When the take-up operation is started in this state, a horizontal force acts on the molten portion of the base material rod near the heating heater, and the take-up side tension deviates from the vertical direction. Therefore, the tension on the take-up side is measured from two directions, the vertical direction and the horizontal direction, and the position of the base material ingot 1 is adjusted on the XY stage 6 so that this tension acts only in the vertical direction and does not occur in the horizontal direction. Even during stretching, the tension on the take-up side is measured from the vertical direction and the horizontal direction, the position of the base metal ingot is adjusted according to the direction of the tension, and by repeating this, the base metal ingot is stretched over the entire length of the base metal ingot. Stretching is performed with the tension on the take-up side in the molten portion of the material ingot facing vertically downward so that it does not occur in the horizontal direction.

【0012】[0012]

【実施例】つぎに本発明の実施例、比較例をあげる。曲
がり量の測定方法は、図2に示すように、900mm の間隔
に配置した2個の架台13に母材インゴット1又は母材ロ
ッド2を置き、その上にダイヤルゲージ14をセットし、
母材インゴット1又は母材ロッド2をその軸を中心に1
回転したときのダイヤルゲージ14の最大値と最小値の目
盛差d(mm)を測定し、これを場所を変えて行って求
め、その最大値を曲がり量(mm)とした。 実施例1 図1に示した延伸位置を用いて透明ガラス化時に曲りの
発生した、外径 120mm、有効部長さ 800mm、全長1300mm
の母材インゴット1を延伸したが、延伸に先立って母材
インゴット1の曲がり量を測定したところ、インゴット
下部の 1,000mmの部分に 2.4mmの曲がりのあることが確
認された。
Next, examples of the present invention and comparative examples will be described. As shown in FIG. 2, the bending amount is measured by placing the base material ingot 1 or the base material rod 2 on two mounts 13 arranged at intervals of 900 mm, and setting the dial gauge 14 on it.
Base material ingot 1 or base material rod 2 with its axis as the center 1
The scale difference d (mm) between the maximum value and the minimum value of the dial gauge 14 when it was rotated was measured and found by changing the place, and the maximum value was taken as the bending amount (mm). Example 1 Bending occurred during transparent vitrification using the drawing position shown in FIG. 1, outer diameter 120 mm, effective part length 800 mm, total length 1300 mm
The base material ingot 1 was stretched, and the amount of bending of the base material ingot 1 was measured prior to the stretching. As a result, it was confirmed that the 1,000 mm portion below the ingot had a bending of 2.4 mm.

【0013】ついで、この母材インゴット1の両端に把
持用ダミー棒3をガラス旋盤を用いて溶着させたが、こ
の状態では母材インゴット1と把持用ダミー棒3の中心
軸は一致しておらず、把持用ダミー棒3の両端を結ぶ直
線上から母材インゴット1の一部がずれた状態となって
いたので、この母材インゴット1を縦型延伸装置にセッ
トした場合も、図3に示したように母材インゴット1は
延伸装置の軸中心からずれて配置された。
Next, the holding dummy bars 3 were welded to both ends of the base material ingot 1 by using a glass lathe. In this state, the central axes of the base material ingot 1 and the holding dummy bars 3 are not aligned. However, since a part of the base material ingot 1 was displaced from the straight line connecting both ends of the holding dummy bar 3, the base material ingot 1 was set in the vertical stretching device as shown in FIG. As shown, the base material ingot 1 was arranged offset from the axial center of the stretching device.

【0014】つぎに、母材インゴット1を図1に示す延
伸炉内にセットして加熱ヒーター4で加熱溶融させ、引
取りを開始したが、引取りを開始した時から引取り張力
検出器11で引取り側の張力の測定を行なって水平方向成
分を求め、この水平成分が生じなくなるようにXYステ
ージ6により母材インゴットを移動させ、母材インゴッ
ト溶融部に働く張力が鉛直下向きになるように調整し
た。このときの引取り側の張力の水平成分と、母材イン
ゴットの軸中心と延伸装置の軸中心とのずれ量(図3中
のδd)は、測定の結果から図5のような関係が得られ
ているので、図3により引取り側の張力の水平方向成分
に対応したずれ量を求め、母材インゴット1の位置調整
をおこなった。
Next, the base material ingot 1 was set in the drawing furnace shown in FIG. 1 and was heated and melted by the heating heater 4 to start taking-up. The tension on the take-up side is measured to find the horizontal component, and the base material ingot is moved by the XY stage 6 so that this horizontal component does not occur, so that the tension acting on the base material ingot melting portion is vertically downward. Adjusted to. At this time, the horizontal component of the tension on the take-up side and the deviation amount (δd in FIG. 3) between the axial center of the base material ingot and the axial center of the stretching device have the relationship shown in FIG. 5 from the measurement results. Therefore, the shift amount corresponding to the horizontal component of the tension on the take-up side was obtained from FIG. 3 and the position of the base material ingot 1 was adjusted.

【0015】この場合、延伸を開始してからは母材イン
ゴット1の延伸張力を30秒に1回ずつ測定し、その都度
上記の方法で母材インゴット1に働く延伸張力が鉛直方
向のみになるように母材位置を調整しながら延伸を行な
い、引取り張力の水平方向成分のうち左右方式について
の測定結果を記録したところ、図6の□印に示すとおり
の結果が得られた。
In this case, the stretching tension of the base material ingot 1 is measured once every 30 seconds after the stretching is started, and the stretching tension acting on the base material ingot 1 by the above method becomes only in the vertical direction each time. Stretching was performed while adjusting the position of the base material as described above, and the measurement results of the horizontal method of the horizontal component of the take-up tension were recorded. As a result, the results shown by □ in FIG. 6 were obtained.

【0016】また、延伸中における外径制御は従来通り
に延伸中のテーパー部の外径を外径測定器10を用いて測
定し、その外径が一定となるように引取り速度を制御し
たが、本実施例では母材ロッド2の最終外径が40mmにな
るように引取り速度を制御した。なお、この方法で延伸
を行なって作成した母材ロッド2を1mずつ切り分けて
図2に示した装置で母材ロッド2の曲がり量を測定した
ところ、母材ロッド2の各分割における曲がり量は表1
に示したように 0.6mm未満と十分に小さくなっていた。
Further, the outer diameter control during stretching is carried out by measuring the outer diameter of the taper portion during stretching using an outer diameter measuring device 10 as usual, and the take-up speed is controlled so that the outer diameter becomes constant. However, in this example, the take-up speed was controlled so that the final outer diameter of the base material rod 2 was 40 mm. It should be noted that when the preform rod 2 produced by stretching by this method is cut into 1 m pieces and the bending amount of the preform rod 2 is measured by the device shown in FIG. 2, the bending amount in each division of the preform rod 2 is Table 1
As shown in, it was sufficiently smaller than 0.6 mm.

【0017】[0017]

【表1】 [Table 1]

【0018】実施例2 外径 120mm、有効部長さ 800mm、全長1300mmの母材イン
ゴット1に下側保持用ダミー棒3を母材インゴットの軸
中心から5mmずらして溶着したものを図1の延伸装置に
セットしたところ、母材インゴットは延伸装置の中心軸
上にはセットされなかった。しかし、このままで昇温後
延伸を開始し、延伸開始と共に引取り張力検出器11で引
取り側の張力の測定を行い水平成分を求め、実施例1と
同様に張力の水平成分が生じなくなるように吊り下げ側
の把持部を移動させ母材インゴット溶融部に働く張力が
鉛直下向きになるように母材インゴットの位置を調整し
た。
Example 2 A stretching device shown in FIG. 1 is obtained by welding a lower holding dummy rod 3 to a base material ingot 1 having an outer diameter of 120 mm, an effective portion length of 800 mm, and a total length of 1300 mm with a lower holding dummy rod 3 displaced from the center of the base material ingot by 5 mm. However, the base material ingot was not set on the central axis of the stretching device. However, the stretching is started after the temperature is raised as it is, and the tension on the take-up side is measured by the take-up tension detector 11 at the same time as the stretching is started to obtain the horizontal component, so that the horizontal component of the tension is not generated as in Example 1. The position of the base metal ingot was adjusted so that the holding part on the suspension side was moved to the vertical direction so that the tension acting on the base metal ingot melting part was vertically downward.

【0019】この場合、延伸中における外径制御は従来
通りとし、実施例1と同じように母材ロッド2の最終外
径が40mmになるように引取り速度を制御し、引取りを開
始してからは母材インゴットの引取り側の張力を30秒毎
に1回ずつ測定し、上記の方法でその都度母材インゴッ
トに働く張力が鉛直下向きになるように母材位置を調整
しながら延伸を行なった。つぎに、この方法で延伸を行
なった母材ロッド2を1mずつ切り分けて、母材ロッド
2の曲がり量を測定したところ、母材ロッド2の各分割
における曲がり量は表2に示したように 0.6mm未満と十
分に小さくなっていた。
In this case, the outer diameter control during stretching is the same as the conventional one, and as in Example 1, the take-up speed is controlled so that the final outer diameter of the base material rod 2 becomes 40 mm, and the take-up is started. After that, the tension on the take-up side of the base metal ingot is measured once every 30 seconds, and the base metal position is adjusted so that the tension acting on the base metal ingot is vertically downward by the above method. Was done. Next, the base material rod 2 stretched by this method was cut into pieces of 1 m each, and the bending amount of the base material rod 2 was measured. The bending amount in each division of the base material rod 2 is as shown in Table 2. It was sufficiently small, less than 0.6 mm.

【0020】[0020]

【表2】 [Table 2]

【0021】比較例1 実施例1と同様の外径 120mm、有効部長さ 800mmで、全
長1300mmの透明ガラス化時に実施例1のものと同じ量の
曲がりが発生している母材インゴットに把持用ダミー棒
を溶着接続し、これを延伸装置にセットしたところ、こ
の母材インゴットと延伸装置はその軸中心が一致してい
なかった。これについて延伸を開始し、引取り張力の水
平方向成分の測定は行なったけれども、測定張力の水平
成分に基づく母材インゴットの位置調整は行なわなかっ
た。
Comparative Example 1 The same as in Example 1, with an outer diameter of 120 mm, an effective portion length of 800 mm, and a total length of 1300 mm, which was bent into transparent glass, the same amount of bending as in Example 1 was used for gripping. When the dummy rods were welded and set and set in a stretching device, the axes of the base material ingot and the stretching device did not coincide. Although stretching was started for this and the horizontal component of the take-up tension was measured, the position adjustment of the base material ingot based on the horizontal component of the measured tension was not performed.

【0022】また、この場合における延伸中における外
径制御は従来通りとし、実施例1と同じように母材ロッ
ド2の最終外径が40mmになるように引取り速度を制御
し、この方法で延伸して得た母材ロッドを1mずつ切り
分けて、母材ロッドの曲がり量を測定したところ、表1
に示したように母材ロッドの各分割における曲がり量は
1.2〜1.6mm で実施例1に比べて大きな曲がりが生じて
いた。
In this case, the outer diameter control during stretching is the same as the conventional one, and as in Example 1, the take-up speed is controlled so that the final outer diameter of the base material rod 2 is 40 mm. The base material rod obtained by stretching was cut into pieces each having a length of 1 m, and the bending amount of the base material rod was measured.
As shown in, the bending amount in each division of the base material rod is
At 1.2 to 1.6 mm, a larger bend than in Example 1 was generated.

【0023】すなわち、これには母材インゴットの曲が
りにより影響が認められ、また延伸開始側に生じた曲が
りのために延伸の終了まで曲がりが引続いて発生してい
ることが判ったが、延伸時の引取り張力の水平方向成分
について実施例1と比較してみると、実施例1では母材
インゴットの位置調整により水平方向成分は図6の□印
に示すように 50g以下に制御されているが、比較例1で
は図6の〇印に示すように500g付近までの水平方向張力
が発生しており、この引取り側の張力の水平方向成分量
の差が延伸して作成される母材ロッド2の曲がり量に影
響している。
That is, it was found that this was influenced by the bending of the base material ingot, and that the bending continued to the end of the drawing due to the bending generated on the drawing start side. Comparing the horizontal component of the take-up tension with that in Example 1, in Example 1, the horizontal component was controlled to be 50 g or less by the position adjustment of the base material ingot as shown by □ in FIG. However, in Comparative Example 1, horizontal tension up to around 500 g is generated as indicated by the circle in FIG. 6, and the difference between the horizontal component amounts of the tension on the take-up side is stretched to create the mother. The bending amount of the material rod 2 is affected.

【0024】比較例2 実施例2と同じように、外径 120mm、有効部長さ 800m
m、全長1300mmの母材インゴットに下側把持用ダミー棒
を母材インゴットの軸中心から5mmずらして溶着したも
のを延伸装置にセットしたところ、母材インゴットと延
伸装置の中心軸は一致しなかったが、このままの状態で
延伸を開始した。この場合も比較例1と同じように、引
取り張力の水平方向成分についての測定は行なったが、
実施例2のように張力の水平方向成分により母材インゴ
ットを位置調整することは行なわなかった。
Comparative Example 2 As in Example 2, the outer diameter was 120 mm and the effective length was 800 m.
The base material ingot and the center axis of the drawing machine did not match when the lower gripping dummy rod was welded to the base material ingot with a total length of 1300 mm, offset by 5 mm from the axis of the base material ingot. However, the stretching was started in this state. Also in this case, as in Comparative Example 1, the measurement of the horizontal component of the take-up tension was performed,
The position adjustment of the base material ingot by the horizontal component of the tension as in Example 2 was not performed.

【0025】一方、延伸中における外径制御は実施例1
と同じ従来通りとし、母材ロッド2の最終外径が40mmに
なるように引取り速度を制御し、この方法で得られた母
材を1mずつ切り分けて母材ロッド2の曲がり量を測定
したところ、母材ロッド2の各分割における曲がり量は
表2に示したように1.19〜1.71mmで実施例2に比べて大
きな曲がりが生じていた。これは下側把持用ダミー棒が
ずれて溶着されたために大きな曲がりが生じ、延伸の進
行と共に曲がりが緩和されたためと考えられるが、この
比較例2でも延伸途中で発生した曲がりはそれ以降の延
伸部分にかなりの影響を及ぼしていることが判った。
On the other hand, the outer diameter control during stretching was carried out in Example 1.
Same as the conventional method, the take-up speed was controlled so that the final outer diameter of the base material rod 2 was 40 mm, and the amount of bending of the base material rod 2 was measured by cutting the base material obtained by this method by 1 m. However, the amount of bending in each division of the base material rod 2 was 1.19 to 1.71 mm as shown in Table 2, and a large amount of bending occurred compared to Example 2. It is considered that this is because the lower gripping dummy rod was displaced and welded to cause a large bend, and the bend was alleviated as the stretching proceeded. It turned out that it had a considerable influence on the part.

【0026】[0026]

【発明の効果】本発明によれば、母材インゴットに曲が
りや把持用ダミー棒が母材インゴットに対して偏心して
いる場合に、母材インゴットの溶融部にかかる引取り側
の張力を鉛直下向きにすることで、母材インゴットを延
伸して製作される母材ロッドの曲がりを小さく抑えるこ
とが出来る。
According to the present invention, when the base material ingot is bent or the holding dummy rod is eccentric with respect to the base material ingot, the tension on the take-up side applied to the molten portion of the base material ingot is vertically downward. By doing so, the bending of the base material rod produced by stretching the base material ingot can be suppressed to be small.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明による母材インゴットの延伸装置の縦断
面概要図を示したものである。
FIG. 1 is a schematic vertical sectional view of a drawing apparatus for a base material ingot according to the present invention.

【図2】母材ロッドの曲がり測定装置の縦断面概要図を
示したものである。
FIG. 2 is a schematic vertical sectional view of a bending measurement device for a base material rod.

【図3】曲がりの生じた母材インゴットを延伸装置にセ
ットしたものの縦断面概要図を示したものである。
FIG. 3 is a schematic vertical sectional view of a bent base material ingot set in a stretching device.

【図4】母材インゴットに下側把持用ダミー棒をずれて
溶着したものの縦断面概要図を示したものである。
FIG. 4 is a schematic vertical cross-sectional view of a base material ingot in which a lower holding dummy bar is displaced and welded.

【図5】引取り張力の水平成分と母材インゴットのずれ
量との関係グラフを示したものである。
FIG. 5 is a graph showing the relationship between the horizontal component of the take-up tension and the amount of displacement of the base material ingot.

【図6】本発明の実施例1と比較例1の引取り張力の水
平方向成分と時間との関係グラフを示したものである。
FIG. 6 is a graph showing the relationship between the horizontal component of the take-up tension and time in Example 1 of the present invention and Comparative Example 1.

【符号の説明】[Explanation of symbols]

1…母材インゴット 2…延伸後の母材ロッド 3…把持用ダミー棒 4…加熱用ヒーター 5…吊り下げ用チャック 6…XYステージ 7…ねじ送り機構 8…移動用モーター 9…延伸引取り用チャック 10…外径測定器 11…引取り張力検出器 12…演算処理CPU 13…架台 14…ダイヤルゲージ 1 ... Base material ingot 2 ... Base material rod after drawing 3 ... Dummy rod for gripping 4 ... Heating heater 5 ... Suspending chuck 6 ... XY stage 7 ... Screw feeding mechanism 8 ... Moving motor 9 ... For drawing / drawing Chuck 10 ... Outer diameter measuring device 11 ... Pulling tension detector 12 ... Calculation processing CPU 13 ... Stand 14 ... Dial gauge

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 光ファイバ母材インゴットをこれより小
径の母材ロッドに延伸する光ファイバ母材の製造方法に
おいて、母材インゴットを延伸する際の母材インゴット
引取り側の張力方向を測定し、その張力方向に応じて張
力が鉛直下向きになるように母材インゴットの位置を移
動させることを特徴とする光ファイバ母材の製造方法。
1. A method of manufacturing an optical fiber preform in which an optical fiber preform ingot is drawn to a preform rod having a diameter smaller than that of the preform, and the tension direction of the preform ingot taking side when the preform ingot is drawn is measured. A method for manufacturing an optical fiber preform, wherein the position of the preform ingot is moved so that the tension is directed vertically downward according to the tension direction.
【請求項2】 光ファイバ母材インゴットをこれより小
径の母材ロッドに延伸する光ファイバ母材の製造方法に
おいて、母材インゴットを延伸する際の母材インゴット
引取り側の張力方向を少なくとも鉛直方向と水平方向の
2方向から測定する請求項1に記載した光ファイバ母材
の製造方法。
2. A method of manufacturing an optical fiber preform in which an optical fiber preform ingot is extended to a preform rod having a diameter smaller than that of the preform, and at least the vertical direction of tension on the preform ingot taking side when the preform ingot is extended. The method for producing an optical fiber preform according to claim 1, wherein the measurement is performed from two directions, i.e., the horizontal direction and the horizontal direction.
JP5895996A 1996-03-15 1996-03-15 Production of parent material for optical fiber Pending JPH09249428A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5895996A JPH09249428A (en) 1996-03-15 1996-03-15 Production of parent material for optical fiber

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5895996A JPH09249428A (en) 1996-03-15 1996-03-15 Production of parent material for optical fiber

Publications (1)

Publication Number Publication Date
JPH09249428A true JPH09249428A (en) 1997-09-22

Family

ID=13099385

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5895996A Pending JPH09249428A (en) 1996-03-15 1996-03-15 Production of parent material for optical fiber

Country Status (1)

Country Link
JP (1) JPH09249428A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005090246A1 (en) * 2004-03-18 2005-09-29 Shin-Etsu Chemical Co., Ltd. Method for drawing base material of optical fiber
JP2013230960A (en) * 2012-05-02 2013-11-14 Shin-Etsu Chemical Co Ltd Method and apparatus for elongating glass base material

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005090246A1 (en) * 2004-03-18 2005-09-29 Shin-Etsu Chemical Co., Ltd. Method for drawing base material of optical fiber
US7458234B2 (en) 2004-03-18 2008-12-02 Shin- Etsu Chemical Co., Ltd. Elongating method of optical fiber base material
JP2013230960A (en) * 2012-05-02 2013-11-14 Shin-Etsu Chemical Co Ltd Method and apparatus for elongating glass base material

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