JPH08208260A - Production of optical fiber preform - Google Patents
Production of optical fiber preformInfo
- Publication number
- JPH08208260A JPH08208260A JP1890595A JP1890595A JPH08208260A JP H08208260 A JPH08208260 A JP H08208260A JP 1890595 A JP1890595 A JP 1890595A JP 1890595 A JP1890595 A JP 1890595A JP H08208260 A JPH08208260 A JP H08208260A
- Authority
- JP
- Japan
- Prior art keywords
- ingot
- preform
- base material
- 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.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/012—Manufacture of preforms for drawing fibres or filaments
- C03B37/01205—Manufacture of preforms for drawing fibres or filaments starting from tubes, rods, fibres or filaments
- C03B37/01225—Means for changing or stabilising the shape, e.g. diameter, of tubes or rods in general, e.g. collapsing
- C03B37/0124—Means 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
Description
【０００１】[0001]
【産業上の利用分野】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 extending an optical fiber preform ingot into a preform rod having a diameter smaller than that of the ingot, the bending of the optical fiber preform rod after the extension is prevented. 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、母材インゴットを酸水素火炎や電気炉で加熱して軟
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
という方法が採られている。そして、この引取り機構に
は、母材ロッドの外径を一定に制御できるように、外径
測定器で測定された測定外径と連動するように引取り速
度を制御する機構が備えられており、これにはまた延伸
時における引取り張力を測定できる張力測定器も設けら
れていて、この張力測定器で測定された張力に基づい
て、母材インゴットの延伸時の各時点における酸水素火
炎の火力や電気炉のヒーターパワーを制御して一定張力
で延伸が行なわれるように設計されている。2. Description of the Related Art A method for manufacturing an optical fiber preform by drawing a preform ingot into a preform rod having a smaller diameter than that, and heating and melting the preform ingot with an oxyhydrogen flame or an electric furnace to soften it. A method is used in which the outer diameter of is measured using an outer diameter measuring device and the pulling speed is controlled based on the measured value. Further, this take-up mechanism is provided with a mechanism for controlling the take-up speed so as to be interlocked with the measured outer diameter measured by the outer diameter measuring instrument so that the outer diameter of the base material rod can be constantly controlled. This is also provided with a tension measuring device that can measure the take-up tension during stretching, and based on the tension measured by this tension measuring device, the oxyhydrogen flame at each point during stretching of the base metal ingot It is designed to draw at a constant tension by controlling the heating power of the heater and the heater power of the electric furnace.
【０００３】[0003]
【発明が解決しようとする課題】しかし、この延伸時に
おける張力の一定化は引取りを開始してから後の外径制
御性の向上ならびにロッドの曲がりの抑制には効果があ
るが、昇温開始から引取り開始までの時間は一定にして
延伸を行なっているとしても延伸開始時の引取り張力は
必ずしも一定になるとは限らない。However, the constant tension during the stretching is effective for improving the outer diameter controllability and suppressing the bending of the rod after the start of the pulling, but the temperature rise is increased. Even if stretching is performed with a constant time from the start to the start of take-up, the take-up tension at the start of stretching does not always become constant.
【０００４】その理由の一つは母材インゴットの末端部
のテーパー形状のばらつきが挙げられる。すなわち、酸
水素火炎の火力や電気炉のヒーターのパワーは母材イン
ゴットの外径に応じて調整されているが、これは母材イ
ンゴットの直胴部に関してのみのことであり、末端部の
テーパー部においては外径に応じた火力やヒーターパワ
ーの調整は行なわれていないので、延伸開始時に最初に
加熱される母材インゴットの末端のテーパー部において
は、その時々において粘度が変化し、その結果、引取り
の張力が変動してしまうことがあり、したがって延伸の
初期においては母材ロッドの粘度が小さくなって引張り
張力が小さくなり、母材ロッドに曲がりが生じ易くな
る。このように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、その曲がりがつぎの曲がりを誘発
させ易く、つぎつぎに曲がりが生ずることになり、母材
ロッド全長にわたって曲がりが生じてしまうことがあ
る。One of the reasons is that the taper shape of the end portion of the base material ingot varies. That is, the heating power of the oxyhydrogen flame and the power of the heater of the electric furnace are adjusted according to the outer diameter of the base material ingot, but this is only for the straight body part of the base material ingot and the taper of the end part Since the heating power and heater power according to the outer diameter are not adjusted in the part, the viscosity changes at each time in the taper part at the end of the base material ingot that is first heated at the start of stretching, and as a result, However, the tension of the take-up may fluctuate, and therefore, the viscosity of the base material rod becomes small at the initial stage of stretching, the tensile tension becomes small, and the base material rod is likely to bend. When a bend occurs in the part of the base material rod on the take-up start side in this way, the bend easily induces the next bend, which in turn causes the bend to occur over the entire length of the base material rod. It may end up.
【０００５】また、この延伸開始時に引張り張力が変動
する別の理由としては延伸炉内の温度分布の変化が挙げ
られる。すなわち、前回の延伸終了から今回の延伸開始
までの時間に極端な差がある場合には、その時間によっ
て延伸炉内の温度分布が変ることがあり、例えば延伸終
了後で母材ロッドの冷却が済んだ直後に次の母材インゴ
ットをセットして延伸を開始した場合と、延伸終了後１
日経過後に次の延伸を行なった場合とでは、延伸炉内の
断熱材などの温度に差が生ずることがあり、その結果と
して延伸炉内の温度分布に差が生じるため、母材インゴ
ットの温度、つまりその粘度が各ロッド毎にばらつきが
生じ、したがって延伸の初期においても母材ロッドに曲
がりが生じ易くなる。Further, another reason why the tensile tension fluctuates at the start of stretching is a change in temperature distribution in the stretching furnace. That is, if there is an extreme difference in the time from the end of the previous stretching to the start of the current stretching, the temperature distribution in the stretching furnace may change depending on the time, and for example, cooling of the base material rod after the stretching is completed. Immediately after the completion, the next base material ingot is set and the stretching is started,
When the next drawing is performed after a lapse of days, the temperature of the heat insulating material in the drawing furnace may differ, resulting in a difference in the temperature distribution in the drawing furnace. That is, the viscosity varies among the rods, and therefore the base material rod is likely to bend even in the initial stage of stretching.
【０００６】そのため、前記したように昇温後引取り開
始までの待ち時間を一定にしても、上記したような理由
から延伸初期に母材ロッドに曲がりが生じ、この初期の
曲がりが母材ロッド全長にわたって影響を与えることに
なるので、延伸初期における曲がりの発生は極力低減化
させる必要があり、それ故に引取り開始時における母材
ロッドの粘度およびその結果としての引取り張力はこれ
を一定に保つ必要がある。For this reason, even if the waiting time after the temperature rise until the start of take-up is constant as described above, the base material rod is bent at the initial stage of the drawing for the reason described above, and this initial bending is caused by the base material rod. Since it affects the entire length, it is necessary to reduce the occurrence of bending in the initial stage of stretching as much as possible.Therefore, the viscosity of the base material rod at the start of drawing and the resulting take-up tension keep it constant. Need to keep.
【０００７】[0007]
【課題を解決するための手段】本発明はこのような課題
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おいて、母
材インゴットの引取りを開始するまでに、引取り側にお
いてロッドに張力を与えたときの応力または伸びを測定
することにより、母材インゴットの引取り開始時期を決
定す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 a preform ingot is extended to a preform rod having a smaller diameter than that of the optical fiber. In the method of manufacturing the base material, by measuring the stress or elongation when tension is applied to the rod on the take-up side before starting the take-up of the base material ingot, the start time of the take-up of the base material ingot can be determined. It is characterized by making a decision.
【０００８】すなわち、本発明者ら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
化する方法について種々検討したところ、これについて
は母材インゴットを加熱して母材ロッドに延伸するため
の引取りを開始するまでの間に、延伸引取り用チャック
から張力を与えたところ、この引取り張力とロッドの曲
がり量に特定の関係があり、引取り張力がある値以上と
なるとロッドの曲がり量が急に小さくなるという事実が
判明し、したがってこの時点を母材インゴットの引取り
開始時期とすれば曲がりの低減された母材ロッドを得る
ことができることを確認して本発明を完成させた。以下
にこれをさらに詳述する。That is, the present inventors have made various studies on a method of reducing the bending of the optical fiber base material rod after the drawing in the step of drawing the optical fiber base material ingot into the base material rod having a diameter smaller than that. Regarding this, when tension was applied from the draw-and-take chuck before heating the base material ingot and starting the draw for drawing the base material rod, the draw tension and the amount of bending of the rod were It was found that there was a specific relationship, and the bending amount of the rod suddenly decreased when the pulling tension exceeded a certain value. Therefore, if this point was set as the start time of pulling the base metal ingot, the bending was reduced. The present invention has been completed by confirming that a base material rod can be obtained. This will be described in more detail below.
【０００９】本発明は光ファイバ母材の製造方法に関す
るものであり、これは前記したように母材インゴットを
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
製造する方法において、母材インゴットの引取りを開始
するまでに、引取り側からロッドに張力を与えてそのと
きの応力を測定して母材インゴットの引取り開始時期を
決定するというものであり、これによれば曲がりの少な
い母材ロッドが得られるという有利性が与えられる。The present invention relates to a method for producing an optical fiber preform, which is a method for producing an optical fiber preform by extending a preform ingot into a preform rod having a diameter smaller than that of the ingot as described above. Before starting the take-up of the material ingot, tension is applied to the rod from the take-up side and the stress at that time is measured to determine the time to start taking the base material ingot. The advantage is given that a base material rod with a reduced amount of material is obtained.
【００１０】本発明による光ファイバ母材の製造は図１
に示した装置で行なわれる。図１は本発明による光ファ
イバ母材製造装置の縦断面図を示したものであるが、母
材インゴット１と延伸された母材ロッド２は加熱ヒータ
ー３を有する延伸炉４の中に入れられている。母材イン
ゴット１は把持用ダミー５を把持した吊り下げ用チャッ
ク６によって延伸炉４の中に吊下げられており、これは
送り込み速度Ｖ1 で延伸炉４の中に送り込まれ、母材ロ
ッド２は把持用ダミー５を把持した延伸引取り用チャッ
ク７で延伸され、この延伸された母材ロッドの外径は外
径測定器８により測定され、この測定結果が演算処理器
ＣＰＵ９により計算されて引取り速度Ｖ2 が決定され
る。The manufacture of the optical fiber preform according to the present invention is illustrated in FIG.
It is performed by the device shown in. FIG. 1 is a vertical sectional view of an optical fiber preform manufacturing apparatus according to the present invention, in which a preform ingot 1 and a stretched preform rod 2 are placed in a drawing furnace 4 having a heater 3. ing. The base material ingot 1 is suspended in a stretching furnace 4 by a suspending chuck 6 which holds a gripping dummy 5, which is fed into the stretching furnace 4 at a feeding speed V 1 and the base material rod 2 Is stretched by the stretching and pulling chuck 7 that grips the gripping dummy 5, the outer diameter of the stretched base material rod is measured by the outer diameter measuring device 8, and the measurement result is calculated by the arithmetic processing unit CPU 9. The take-off speed V 2 is determined.
【００１１】本発明の光ファイバ母材の製造では、母材
インゴット１の引取りを開始するまでの間に、まず加熱
ヒーター３によって母材インゴット１が加熱され軟化さ
れてから延伸引取り用チャック７から張力がかけられ、
この張力によって母材インゴットに与えられる応力が張
力測定器10によって測定される。この応力は母材インゴ
ット１の温度が次第に上昇していくと時間と共に低下し
ていくので、この応力がある一定値に達したら吊り下げ
用チャック６を用いて母材インゴット１を延伸炉内に一
定速度Ｖ1 で送り込みつつ、引取り用チャック７で速度
Ｖ2 で母材ロッド２の引取りを開始すればよい。In the production of the optical fiber preform of the present invention, the preform ingot 1 is first heated and softened by the heater 3 until the preform ingot 1 is started to be drawn, and then the draw pulling chuck is performed. Tension is applied from 7,
The stress applied to the base material ingot by this tension is measured by the tension measuring device 10. This stress decreases with time as the temperature of the base material ingot 1 gradually rises. Therefore, when the stress reaches a certain value, the suspending chuck 6 is used to move the base material ingot 1 into the drawing furnace. It is sufficient to start the pulling of the base material rod 2 at the velocity V 2 by the pulling chuck 7 while feeding at the constant velocity V 1 .
【００１２】この引取り開始時期については、例えば外
径 110mmφの母材インゴット４本を、昇温後一定時間経
過後に引取りを開始したときの引取り張力を調べたとこ
ろ、これは 13kgfから 35kgfまでばらついていた。この
引取り開始時の引張り張力と母材ロッドの延伸開始時の
１ｍ部分の曲がりをしらべたところ、図３に示したよう
に母材インゴットの温度が高く、したがって引取り張力
が 20kgf以下のときは曲がり量が 1.1mm〜0.5mm と比較
的大きいが、母材インゴットの温度が低くなりこの引取
り張力が 20kgfを越えるとこの曲がり量が 0.4〜0.36mm
まで低下することが確認された。Regarding the take-off start timing, for example, the take-up tension was examined when four take-up ingots having an outer diameter of 110 mmφ were started after a certain period of time after the temperature was raised. It was scattered up to. When the pulling tension at the start of pulling and the bending of the 1m portion at the start of stretching the base material rod were examined, the temperature of the base material ingot was high as shown in Fig. 3, and therefore when the pulling tension was 20kgf or less. Has a relatively large bending amount of 1.1 mm to 0.5 mm, but when the pulling tension exceeds 20 kgf due to the low temperature of the base metal ingot, the bending amount is 0.4 to 0.36 mm.
It was confirmed that
【００１３】また、これについては外径が 130mmφ中の
母材インゴット４本を、昇温後一定時間経過後に引取り
を開始してその引取り張力をしらべたところ、これは 1
9kgfから 44kgfまでばらついていた。この引取り開始時
の引張り張力と母材ロッドの延伸開始時の１ｍ部分の曲
がり量をしらべたところ、図４に示したように母材イン
ゴットの温度が高く、したがって引取り張力が 27kgf以
下のときには曲がり量が 1.1mm〜0.6mm と比較的大きい
が、母材インゴットの温度が低くなり、この引取り張力
が 27kgfを越えるとこの曲がり量が 0.5〜0.36mmまで低
下することが確認された。Regarding this, when four base metal ingots having an outer diameter of 130 mmφ were taken out after a lapse of a certain time after the temperature was raised and the take-up tension was examined, it was found that
It varied from 9kgf to 44kgf. When the pulling tension at the start of pulling and the bending amount of the 1 m portion at the start of stretching the base material rod were examined, the temperature of the base material ingot was high as shown in Fig. 4, and therefore the pulling tension was 27 kgf or less. It was confirmed that the bending amount was 1.1 mm to 0.6 mm, which was relatively large, but the temperature of the base metal ingot became low, and when the pulling tension exceeded 27 kgf, the bending amount dropped to 0.5 to 0.36 mm.
【００１４】したがって、母材インゴットの引取り開始
時の引取り張力、すなわち母材インゴットに生じた応力
を母材インゴット径に応じたある一定の範囲以内となる
ようにすること、換言すれば母材インゴットの引取り開
始時期をこの時点とすれば母材ロッドの曲がりを低く抑
えることができるということが確認された。また、この
母材インゴットの応力の測定の代りに引取り側において
ロッドに張力を与えたときの伸びを測定してもよいこと
が判った。Therefore, the take-up tension at the time of starting the take-up of the base metal ingot, that is, the stress generated in the base metal ingot is set within a certain range according to the diameter of the base metal ingot, in other words, the base metal ingot. It was confirmed that the bending of the base metal rod can be suppressed to a low level by setting the start time of the material ingot collection to this time. It has also been found that instead of measuring the stress of the base material ingot, the elongation when tension is applied to the rod on the take-up side may be measured.
【００１５】なお、この方法では母材インゴットを昇温
したのち、これに一定の引張り張力を与えて、そのとき
の母材インゴットに生ずる応力または伸びを測定し、こ
れが一定の範囲以内となったときを母材インゴットの引
取り開始時期とするものであるが、この応力または伸び
からは母材インゴットの粘度を算出することができるの
で、これについては母材インゴットの粘度が常に同一の
粘度となった時点で引取り開始をしてもよい。この方法
によれば母材インゴットの粘度が低すぎるために延伸初
期に母材ロッドに曲がりが発生する可能性を大幅に低減
することができ、また延伸初期における母材ロッドの曲
がりを低減化することにより母材ロッド全体の曲がりを
低減化することができるという有利性が与えられる。In this method, after the base material ingot was heated, a constant tensile tension was applied to the base material ingot and the stress or elongation generated in the base material ingot at that time was measured, and this was within a predetermined range. The time is the time to start taking the base metal ingot, but since the viscosity of the base metal ingot can be calculated from this stress or elongation, the viscosity of the base metal ingot is always the same. You may start taking over when it becomes. According to this method, since the viscosity of the base material ingot is too low, it is possible to significantly reduce the possibility that the base material rod will be bent at the initial stage of drawing, and the bending of the base material rod at the initial stage of drawing will be reduced. This provides the advantage that the bending of the entire preform rod can be reduced.
【００１６】[0016]
【作用】本発明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、延伸初期の
光ファイバ母材ロッドの曲がりを低減する光ファイバ母
材製造方法の提供を目的とするものであり、その光ファ
イバ母材の製造方法は、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
において、母材インゴットの引取りを開始するまでに、
引取り側において母材インゴットに張力を与えてこのと
きに母材インゴットに発生する応力またはその伸びを測
定し、この応力、伸びから算出される母材インゴットの
粘度が一定値になったときに母材インゴットの引取りを
開始させることを特徴とするものである。本発明によれ
ば母材インゴットの形状のばらつきなどによる延伸開始
時の引取り張力のばらつきをなくすことができ、常に母
材インゴットの粘度が一定の状態で延伸を開始すること
ができるので、延伸初期の母材インゴットの粘度の低下
による引張張力の低下に起因する曲がりを減少し、母材
ロッド全体の曲がりも小さく抑えることができるという
有利性が与えられる。SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical fiber preform manufacturing method for reducing bending of the optical fiber preform rod in the initial stage of drawing in the step of drawing the optical fiber preform ingot into a rod having a smaller diameter. The method of manufacturing the optical fiber preform is a method of manufacturing the optical fiber preform by extending the preform ingot to a preform rod having a smaller diameter than this, by the time the start of the preform ingot ,
When tension is applied to the base metal ingot on the take-up side and the stress generated in the base metal ingot at this time or its elongation is measured, and when the viscosity of the base metal ingot calculated from this stress and elongation reaches a constant value The present invention is characterized by starting the taking of the base material ingot. According to the present invention, it is possible to eliminate variations in the take-up tension at the start of stretching due to variations in the shape of the base material ingot, and it is possible to always start the stretching in a state where the viscosity of the base material ingot is constant, There is an advantage that the bending due to the decrease in tensile tension due to the decrease in the viscosity of the initial base material ingot is reduced, and the bending of the entire base material rod can be suppressed to a small value.
【００１７】[0017]
【実施例】つぎに本発明の実施例、比較例をあげる。な
お、母材ロッドの曲がりの測定は図２に示した支持台11
の中間にダイヤルゲージ12を配置した曲がり測定器を用
い、長さ１ｍに切断した母材ロッド２を図２のように支
持台11に置き、その上にダイヤルゲージ12を配置し、次
いで母材ロッド２を長手軸を中心に１回転してダイヤル
ゲージ値を求めこれを母材ロッド２の位置を変えて２回
行い、その最大値を曲り量（mm）とした。 実施例１ 図１に示した装置を使用し、外径 120mm、長さ１ｍの母
材インゴット１を延伸炉４内にセットし、加熱ヒーター
３で昇温させたのち、引取り用チャック７で母材インゴ
ット１に一定の張力を与え、このときに母材インゴット
に生じた応力を張力測定器10で測定し、母材インゴット
１の昇温に伴なって応力が20〜22kgf の範囲の一定値に
達したときに、母材インゴット１を10mm／分の速度（Ｖ
1 ）で延伸炉に送り込み、延伸引取り用チャック７でＣ
ＰＵ９で算出された90mm／分の引取り速度（Ｖ2 ）で外
径が40mmの母材ロッド２を引取って母材ロッド２の引取
りを開始して母材インゴット１から長さ１ｍの母材ロッ
ド２を９本製造した。EXAMPLES Next, examples and comparative examples of the present invention will be described. The bending of the base material rod is measured by the support base 11 shown in FIG.
Using a bend measuring instrument with a dial gauge 12 placed in the middle of, the base material rod 2 cut to a length of 1 m is placed on a support 11 as shown in FIG. 2, the dial gauge 12 is placed on it, and then the base material is placed. The rod 2 was rotated once around the longitudinal axis to obtain a dial gauge value, which was repeated twice with the position of the base material rod 2 changed, and the maximum value was defined as the bending amount (mm). Example 1 Using the apparatus shown in FIG. 1, a base material ingot 1 having an outer diameter of 120 mm and a length of 1 m was set in a drawing furnace 4 and heated by a heater 3, and then a chuck 7 for take-up was used. A constant tension is applied to the base material ingot 1, and the stress generated in the base material ingot at this time is measured by the tension measuring device 10. The stress is constant within the range of 20 to 22 kgf as the temperature of the base material ingot 1 rises. When the value is reached, the base material ingot 1 is moved at a speed of 10 mm / min (V
In 1 ), it is sent to the drawing furnace and C is drawn by the drawing and pulling chuck 7.
At the pulling speed (V 2 ) calculated by PU9 of 90 mm / min, the base metal rod 2 with an outer diameter of 40 mm was pulled, the pulling of the base metal rod 2 was started, and the length of 1 m from the base metal ingot 1 Nine base material rods 2 were manufactured.
【００１８】この工程を５回繰り返し、昇温後引取り開
始までの待ち時間をしらべたところ、これには８分〜10
分という若干のばらつきがあったけれども、引張り開始
時の引取り張力は表１に示したように20〜22kgf の範囲
に収まり、母材ロッドの引取り開始１本目の曲がり量、
全母材ロッドの曲がり量の平均については表１に示した
とおりの結果が得られ、これは引取り開始１本目の曲が
り量と全母材ロッドの曲がり量の平均値とも0.55mmを下
回っており、曲がり量が十分小さくなっていることが確
認された。This process was repeated 5 times, and the waiting time until the start of the take-up after the temperature was raised was examined.
Although there was some variation such as a minute, the pulling tension at the start of pulling was within the range of 20 to 22 kgf as shown in Table 1, and the bending amount of the first starting rod of the base metal rod was
Regarding the average bending amount of all base material rods, the results shown in Table 1 were obtained, and the average bending amount of the first starting wire and the bending amount of all base material rods were both below 0.55 mm. It was confirmed that the bending amount was sufficiently small.
【００１９】[0019]
【表１】 [Table 1]
【００２０】実施例２ 実施例１と同じ実験を行なったが、母材インゴット１に
一定張力を与えたときに母材インゴット１に生ずる応力
を測定する代わりに、母材インゴット１の伸びを引取り
機構中に設けた位置検出器（図示せず）を用いて測定
し、この伸び量が一定量に達したときに母材インゴット
１の引取りを開始することとし、これを５回繰返したと
ころ、表２に示したとおりの結果が得られ、この場合に
は表２に示したように引取り開始１本目の曲がり量も、
全母材ロッドの曲がり量の平均値も0.6mmを下回ってお
り、曲がり量は十分少なくなっていることが確認され
た。Example 2 The same experiment as in Example 1 was conducted, except that the elongation of the base material ingot 1 was measured instead of measuring the stress generated in the base material ingot 1 when a constant tension was applied to the base material ingot 1. Measurement was performed using a position detector (not shown) provided in the take-up mechanism, and when the amount of elongation reached a certain amount, the take-up of the base material ingot 1 was started, and this was repeated 5 times. However, the results shown in Table 2 were obtained, and in this case, as shown in Table 2, the bending amount of the first take-up start was also
The average amount of bending of all base metal rods was less than 0.6 mm, and it was confirmed that the amount of bending was sufficiently small.
【００２１】[0021]
【表２】 [Table 2]
【００２２】比較例 実施例１と同じように母材インゴット１を延伸炉４内に
セットしたのち、加熱ヒーター３で加熱して昇温させ、
９分間の待ち時間ののち、延伸を開始したところ、この
ときの引取り開始時の張力は前記したような母材インゴ
ットの形状ならびに延伸からつぎの延伸までの間隔の差
などにより 14kgf〜34kgf とばらついたが、そのときの
延伸後の母材ロッドの曲がり量を測定したところ、表３
に示したように引取り開始１本目の引取り張力の低い母
材ロッドに比較的大きな曲がりが発生し、この結果から
も本発明のものが有効であることが確認された。Comparative Example As in Example 1, the base material ingot 1 was set in the drawing furnace 4 and then heated by the heater 3 to raise the temperature.
When the stretching was started after the waiting time of 9 minutes, the tension at the start of pulling at this time was 14 kgf to 34 kgf depending on the shape of the base material ingot as described above and the difference in the interval from one stretching to the next stretching. Although there were variations, the bending amount of the base material rod after stretching at that time was measured, and Table 3
As shown in (4), a relatively large bend was generated in the first base metal rod having a low pulling tension at the start of pulling, and from this result, it was confirmed that the present invention is effective.
【００２３】[0023]
【表３】 [Table 3]
【００２４】[0024]
【発明の効果】本発明は光ファイバ母材の製造方法に関
するものであり、これによれば母材インゴットの形状の
ばらつきなどによる引取り開始時の引取り張力のばらつ
きをなくすことができ、常に母材インゴットの粘度が一
定の状態で延伸を開始することができるので、延伸初期
の母材インゴットの粘度の低さに起因する曲がりを減少
し、母材ロッド全体の曲がりも小さく抑えることができ
るという有利性が与えられる。Industrial Applicability The present invention relates to a method for manufacturing an optical fiber preform, and according to the present invention, it is possible to eliminate variations in the take-up tension at the start of take-up due to variations in the shape of the preform ingot, etc. Since stretching can be started in a state where the viscosity of the base material ingot is constant, the bending due to the low viscosity of the base material ingot in the initial stage of stretching can be reduced, and the bending of the entire base material rod can be suppressed to be small. The advantage is given.
【図１】本発明による母材インゴット延伸装置の一例の
縦断面図を示したものである。FIG. 1 is a longitudinal sectional view of an example of a base material ingot drawing device according to the present invention.
【図２】母材ロッドの曲がり測定装置の縦断面図を示し
たものである。FIG. 2 is a vertical sectional view of a bending measurement device for a base material rod.
【図３】外径 110mmφ中の母材インゴットの引取り開始
時の引取り張力と母材ロッド曲がり量との関係図を示し
たものである。FIG. 3 is a diagram showing a relationship between a pulling tension at the start of pulling a base metal ingot having an outer diameter of 110 mmφ and a bending amount of a base metal rod.
【図４】外径 130mmφ中の母材インゴットの引取り開始
時の引取り張力と母材ロッド曲がり量との関係図を示し
たものである。FIG. 4 is a diagram showing a relationship between a pulling tension at the start of pulling a base metal ingot having an outer diameter of 130 mmφ and a bending amount of a base metal rod.
１…母材インゴット ２…母材ロッド ３…加熱用ヒーター ４…延伸炉 ５…把持用ダミー ６…吊り下げ用チャック ７…延伸引取り用チャック ８…外径測定器 ９…ＣＰＵ 10…張力測定器 11…保持部、 12…ダイヤルゲージ 1 ... Base material ingot 2 ... Base material rod 3 ... Heating heater 4 ... Stretching furnace 5 ... Gripping dummy 6 ... Suspension chuck 7 ... Stretching and taking chuck 8 ... Outer diameter measuring instrument 9 ... CPU 10 ... Tension measurement Container 11… Holding part, 12… Dial gauge
Claims (3)
ッドに延伸して光ファイバ母材を製造する方法におい
て、母材インゴットの引取りを開始するまでに、引取り
側においてロッドに張力を与えたときの応力を測定する
ことにより、母材インゴットの引取り開始時期を決定す
ることを特徴とする光ファイバ母材の製造方法。1. A method for producing an optical fiber preform by stretching a preform ingot onto a preform rod having a smaller diameter than the preform ingot, wherein a tension is applied to the rod on the take-up side before starting the take-up of the preform ingot. A method for manufacturing an optical fiber preform, characterized in that a start time for taking out the preform ingot is determined by measuring a stress when applied.
ッドに延伸して光ファイバ母材を製造する方法におい
て、母材インゴットの引取りを開始するまでに、引取り
側においてロッドに張力を与えたときの伸びを測定する
ことにより、母材インゴットの引取り開始時期を決定す
ることを特徴とする光ファイバ母材の製造方法。2. A method for producing an optical fiber preform by stretching a preform ingot onto a preform rod having a smaller diameter than this, wherein tension is applied to the rod on the take-up side before the take-up of the preform ingot is started. A method for producing an optical fiber preform, characterized in that the start time for taking up the preform ingot is determined by measuring the elongation when applied.
ッドに延伸して光ファイバ母材を製造する方法におい
て、母材インゴットの引取りを開始するまでに、引取り
側においてロッドに張力を与えたときの単位時間あたり
の伸びを測定することにより、母材インゴットの引取り
開始時間を決定することを特徴とする光ファイバ母材の
製造方法。3. A method for producing an optical fiber preform by stretching a preform ingot on a preform rod having a smaller diameter than the preform ingot, wherein tension is applied to the rod on the take-up side before starting the take-up of the preform ingot. A method for producing an optical fiber preform, wherein the start time for taking the preform ingot is determined by measuring the elongation per unit time when given.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1890595A JP3151367B2 (en) | 1995-02-07 | 1995-02-07 | Manufacturing method of optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1890595A JP3151367B2 (en) | 1995-02-07 | 1995-02-07 | Manufacturing method of optical fiber preform |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08208260A true JPH08208260A (en) | 1996-08-13 |
| JP3151367B2 JP3151367B2 (en) | 2001-04-03 |
Family
ID=11984620
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1890595A Expired - Fee Related JP3151367B2 (en) | 1995-02-07 | 1995-02-07 | Manufacturing method of optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3151367B2 (en) |
Cited By (1)
| 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 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4417837A1 (en) | 1994-05-20 | 1995-11-23 | Basf Ag | Substituted 3-phenylpyrazoles |
-
1995
- 1995-02-07 JP JP1890595A patent/JP3151367B2/en not_active Expired - Fee Related
Cited By (2)
| 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3151367B2 (en) | 2001-04-03 |
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