JPH0859274A - Manufacture of optical fiber preform - Google Patents
Manufacture of optical fiber preformInfo
- Publication number
- JPH0859274A JPH0859274A JP19241694A JP19241694A JPH0859274A JP H0859274 A JPH0859274 A JP H0859274A JP 19241694 A JP19241694 A JP 19241694A JP 19241694 A JP19241694 A JP 19241694A JP H0859274 A JPH0859274 A JP H0859274A
- Authority
- JP
- Japan
- Prior art keywords
- speed
- outer diameter
- optical fiber
- stretching
- average
- 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
- C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
- C03B37/01466—Means for changing or stabilising the diameter or form of tubes or rods
-
- 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
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (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
バ母材の全長に渡って光ファイバ母材ロッドの最終外径
の変動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 producing an optical fiber preform, and more particularly to a process of extending an optical fiber preform ingot into a preform rod having a smaller diameter than the ingot. The present invention relates to a method for manufacturing an optical fiber preform that reduces fluctuations in the final outer diameter of the optical fiber preform rod.
【０００２】[0002]
【従来の技術】光ファイバの製造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、ついでこれをファイ
バとするという方法で行なわれているが、この母材イン
ゴットからの小径の母材の製造は、例えば図５に示され
ているように、光ファイバ母材をヒーターで加熱して軟
化させ、この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ローラーによる
引取り速度を制御するという方法で行なわれているが、
この場合には加熱溶融部の外径を一定に制御することに
よって延伸後の母材ロッドの最終外径を一定値に保つよ
うにされている。2. Description of the Related Art An optical fiber is manufactured by a method in which a base material ingot is drawn into a base material rod having a smaller diameter than that, and then this is used as a fiber. For example, as shown in FIG. 5, the optical fiber preform is heated by a heater to soften it, and the outer diameter of the heated and melted portion is measured using an outer diameter measuring device or the like. Based on the method of controlling the take-up speed by the take-off roller,
In this case, the final outer diameter of the base material rod after stretching is maintained at a constant value by controlling the outer diameter of the heating and melting portion to be constant.
【０００３】[0003]
【発明が解決しようとする課題】この場合、加熱溶融部
の外径を一定に保つためには、延伸中におけるネックダ
ウン部の最も伸び易い部分の外径を制御するので、これ
は外径制御の応答性のすぐれたものとなり、さらに母材
インゴットの外径が一定であればネックダウン部の形状
も母材インゴットの位置によらずにほぼ一定となり、加
熱溶融部の外径を一定に保てば最終外径も一定に保たれ
る。しかし、この母材インゴットは図６に示したよう
に、その両端において母材外径がテーパー状に変化して
おり、ネックダウン部の形状もそれに伴なって変化する
ために、この母材インゴットの直胴部の両末端では前記
のような方法では最終外径を一定に制御するのが困難に
なる。In this case, in order to keep the outer diameter of the heating and melting portion constant, the outer diameter of the most stretchable portion of the neck-down portion during stretching is controlled. If the outer diameter of the base metal ingot is constant, the shape of the neck-down part will be almost constant regardless of the position of the base metal ingot, and the outer diameter of the heating and melting part will be kept constant. The final outer diameter is also kept constant. However, as shown in FIG. 6, the base material ingot has a taper-shaped base material outer diameter at both ends thereof, and the shape of the neck-down portion also changes accordingly. At both ends of the straight body part, it becomes difficult to control the final outer diameter to be constant by the above method.
【０００４】さらに、この母材インゴットについては図
６に示したように、一部が完全にガラス化されておら
ず、末端にガラス化されていない多孔質シリカ母材があ
る場合にはこの多孔質シリカ母材とガラス化されている
ガラス母材との物性の違いによって母材インゴットの伸
び方が刻一刻変化するために外径制御性が著しく困難に
なり、したがって上記したような複雑な外径変動や物性
値の不連続的な変化のある母材インゴットを加熱溶融部
の外径のみに基づいて制御性良く、一定径に延伸するこ
とは極めて困難なものとなっている。Further, as shown in FIG. 6, in the base material ingot, when a part of the base material ingot is not completely vitrified and there is a non-vitrified porous silica base material, the porosity is increased. Due to the difference in physical properties between the vitreous silica base material and the vitrified glass base material, the elongation of the base material ingot changes every moment, which makes it extremely difficult to control the outer diameter. It has been extremely difficult to control a base material ingot having a diameter variation and a discontinuous change in physical property values to a constant diameter based on only the outer diameter of the heating and melting portion.
【０００５】なお、実際にこの図５に示した方法で加熱
溶融部の外径を制御してこれを一定に保つ方法におい
て、延伸初期の母材インゴットの直胴部末端および延伸
終了後の母材インゴットの直胴部末端の延伸を行なう
と、図７に示したように最終外径に大きな外径変動が生
じてしまうという問題点がある。これは母材インゴット
の直胴部とテーパー部の外径差および多孔質シリカ母材
部分とガラス部分の物性の違いにより、直胴部末端では
加熱溶融部のネックダウン形状が時々刻々に変化するた
めである。In the method shown in FIG. 5, in which the outer diameter of the heating and melting portion is controlled to keep it constant, the straight body end of the base material ingot in the initial stage of stretching and the mother body after the stretching are finished. When the straight body end of the material ingot is stretched, there is a problem that a large outer diameter variation occurs in the final outer diameter as shown in FIG. This is due to the difference in the outer diameter between the straight body and taper of the base metal ingot and the difference in the physical properties of the porous silica base material and glass. This is because.
【０００６】なお、例えば延伸終了部側末端にガラス化
されていない多孔質シリカ母材が存在する場合にこの直
胴部を延伸すると、終了側直胴部末端の部分の粘度の違
いによってネックダウン形状の変化が刻一刻生じ、溶融
部の外径を一定に保っていても結果的には母材ロッドの
最終外径に変動が生じてしまうという欠点があり、この
外径制御性の困難さは母材インゴット径が増大するほど
増加するため、大型インゴットほど外径変動も増大す
る。If, for example, a non-vitrified porous silica base material is present at the end of the end of the stretched portion, if this straight body is stretched, neck down will occur due to the difference in viscosity at the end of the straight body at the end side. There is a drawback that the final outer diameter of the base metal rod will fluctuate as a result, even if the outer diameter of the fusion zone is kept constant as the shape changes every moment. As the diameter of the base metal ingot increases, the larger the ingot, the larger the fluctuation of the outer diameter.
【０００７】[0007]
【課題を解決するための手段】本願発明はこのような不
利、欠点、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、母材インゴットの末端周辺部を延伸する
際の延伸条件を、直胴部での平均引取り速度よりも速い
速度で引き伸ばす区間と直胴部での平均引取り速度より
も遅い速度で引き伸ばす区間とを有するものとしてなる
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 disadvantages, drawbacks, and problems, in which a preform ingot is formed into a preform rod having a smaller diameter. In the method for producing an optical fiber preform by stretching, the stretching conditions when stretching the peripheral end portion of the preform ingot, in the straight body section and the stretch section at a speed faster than the average take-up speed in the straight body section. And an interval for stretching at a speed slower than the average take-up speed of.
【０００８】すなわち、本発明者らは光ファイバ母材を
より小径の母材ロッドに延伸して径の均一な光ファイバ
母材を製造する方法について種々検討した結果、直胴部
末端では母材外径の変化や物性の差によりネックダウン
形状が変化するため、このネックダウン形状の変化に応
じてこの引取り速度を平均引取り速度より速い区間と平
均引取り速度より遅い区間に区分して、これらをネック
ダウン形状に応じて選択すれば目的とする母材ロッドの
最終直径を一定にすることができることを見出して本発
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 conducted various studies on a method of producing an optical fiber preform having a uniform diameter by stretching the optical fiber preform on a preform rod having a smaller diameter. Since the neck-down shape changes due to changes in outer diameter and differences in physical properties, the take-up speed is divided into a section faster than the average take-up speed and a section slower than the average take-up speed according to the change in the neck-down shape. The present invention has been completed by finding that the final diameter of the target base material rod can be made constant by selecting these according to the neck-down shape. This will be described in more detail below.
【０００９】[0009]
【作用】本発明による光ファイバ母材の製造方法は母材
インゴットの末端周辺部を延伸する際の延伸条件を、直
胴部での平均速度よりも速い速度で引き伸ばす区間と直
胴部での平均速度よりも遅い速度で引き伸ばす区間とを
有するものとするものである。すなわち、光ファイバ母
材を延伸してこれより小径の光ファイバ母材を製造する
方法において、直胴部末端を延伸するときに一定の平均
速度で延伸すると、母材外径の変化や物性の差によりネ
ックダウン形状が変化するため溶融部外径と最終外径に
変化が生じる。In the method for producing an optical fiber preform according to the present invention, the stretching conditions for stretching the peripheral portion of the end of the preform ingot are the stretched section and the straight barrel section at a speed higher than the average speed in the straight barrel section. And a section that stretches at a speed slower than the average speed. That is, in the method of producing an optical fiber preform having a smaller diameter by stretching the optical fiber preform, when the straight body end is stretched at a constant average speed, the change in the outer diameter of the preform and the physical properties Since the neck-down shape changes due to the difference, the outer diameter of the fusion zone and the final outer diameter change.
【００１０】したがって、例えば 120mmφの光ファイバ
母材を45mmφの母材ロッドに延伸を行なった場合、これ
を図１に示したように直胴部末端の距離に応じてＬ1 、
Ｌ2、Ｌ3 と区分し、溶融部外径を一定に制御するため
に平均引取り速度で延伸を行なったところ、このネック
ダウン形状の変化によって中央直胴部、Ｌ1 、Ｌ2 、Ｌ
3 ではその溶融部外径と最終径について表１に示したよ
うな変動が生じ、中央直胴部では溶融部外径を一定に保
つことができて最終径は45mmに保つことができたが、区
間Ｌ1 では母材の長手方向にわたって外径および物性の
差により溶融部と最終外径の差が大きくなり、最終外径
は41mmと中央定常部の約91％の外径となり、同様に区間
Ｌ3 では最終外径が51mmで中央定常部の約 113％の外径
となった。Accordingly, for example, when the optical fiber preform 120mmφ was performed stretched preform rod 45 mm, L 1 according to the distance of the straight body section end as shown in figure 1,
When it was divided into L 2 and L 3 and stretched at an average take-up speed in order to control the outer diameter of the fusion zone at a constant value, the change in the neck-down shape caused the central straight body portion, L 1 , L 2 , L
In No. 3 , the outer diameter of the fusion zone and the final diameter fluctuated as shown in Table 1, and the outer diameter of the fusion zone could be kept constant and the final diameter could be kept at 45 mm in the central body section. In the section L 1 , the difference between the melted portion and the final outer diameter becomes large due to the difference in the outer diameter and the physical properties in the longitudinal direction of the base material, and the final outer diameter is 41 mm, which is approximately 91% of the outer diameter of the central steady portion. In the section L 3 , the final outer diameter was 51 mm, which was 113% of the outer diameter of the central stationary portion.
【００１１】[0011]
【表１】 [Table 1]
【００１２】そのため、本発明者らはこの最終径を一定
にするための延伸条件について検討した結果、中央直胴
部における延伸速度を平均引取り速度（1.00Ｖm ）とし
て溶融部の設定径を54mmとすることとし、表２に示した
ように区間Ｌ1 については最終径が41mmで中央直胴部の
91％であることから溶融部の設定径を58mmとして、この
径になるように引取り速度を平均引取り速度よりも遅い
速度である0.83Ｖm とし、区間Ｌ3 については最終外径
が51mmで中央直胴部の 113％であることから溶融部の設
定径を48mmとすることにして、この引取り速度を平均引
取り速度より速い速度である1.28Ｖm としたところ、各
区間での母材ロッドの最終外径を45mmと略々一定にでき
ることを見出した。Therefore, as a result of studying the stretching conditions for making the final diameter constant, the present inventors set the stretching speed in the central straight body part as the average take-up speed (1.00 V m ) and set the set diameter of the fusion zone. As shown in Table 2, the final diameter of the section L 1 is 41 mm and the center straight body part
Since it is 91%, the set diameter of the fusion zone is set to 58 mm, and the take-up speed is set to 0.83 V m , which is slower than the average take-up speed, so that the final outer diameter of the section L 3 is 51 mm. Since it is 113% of the center straight body part, the set diameter of the fusion part was set to 48 mm, and this take-up speed was set to 1.28 V m , which is faster than the average take-up speed. It was found that the final outer diameter of the base material rod can be made almost constant at 45 mm.
【００１３】[0013]
【表２】 [Table 2]
【００１４】また、この場合における引取り速度Ｖm は
母材インゴットの径Ｄ0 と延伸後の母材ロッドの径Ｄ1
および母材インゴットの送り込み速度Ｖ0 とから、次式 Ｖm ＝Ｖ0 × (Ｄ0 ／Ｄ1)2 で算出できるので、この引取り速度についてはこの式か
ら算出される速度で延伸すれば目的とする母材ロッドの
外径はこれを一定なものとすることができる。The take-up speed V m in this case is the diameter D 0 of the base material ingot and the diameter D 1 of the base material rod after drawing.
And the feed rate V 0 of the base material ingot, the following equation V m = V 0 × (D 0 / D 1 ) 2 can be calculated. Therefore, if the take-up speed is drawn at the speed calculated from this equation, The outer diameter of the target base material rod can be constant.
【００１５】なお、本発明による光ファイバ母材の延伸
は上記したように平均引取り速度よりも速い速度で延伸
する区間と平均引取り速度よりも遅い速度で延伸する区
間を設けるものであるが、これについては上記した実験
例に示されているように平均引取り速度よりも速い速度
で延伸する区間と平均引取り速度よりも遅い速度で延伸
する区間との間に平均引取り速度で延伸する区間を設け
てもよい。また、この平均引取り速度よりも速い速度で
引き伸ばすときの速度についてはこれがあまり速いと得
られる母材の最終外径が細くなってしまうので、これは
平均引取り速度の 110〜 150％、特には 125〜 135％の
範囲とすることがよく、平均引取り速度よりも遅い速度
で引き伸ばすときの速度もこれが遅すぎると目的とする
母材の最終外径が太くなってしまうので、これは平均引
取り速度の70〜90％、特には80〜90％の範囲とすること
がよい。In the drawing of the optical fiber preform according to the present invention, as described above, there are provided a section which is drawn at a speed higher than the average drawing speed and a section which is drawn at a speed lower than the average drawing speed. For this, as shown in the above-mentioned experimental example, stretching was performed at an average take-up speed between a section stretched at a speed higher than the average take-up speed and a section stretched at a speed slower than the average take-up speed. You may provide the section to do. Also, regarding the speed when stretching at a speed faster than this average take-up speed, if this is too fast, the final outer diameter of the base material obtained will become thin, so this is 110-150% of the average take-up speed, especially Is preferably in the range of 125 to 135%, and the speed when stretching at a speed slower than the average take-up speed is too slow. The take-up speed is preferably 70 to 90%, particularly 80 to 90%.
【００１６】[0016]
【実施例】つぎに本発明の実施例、比較例をあげる。 実施例１ 直径が 120mmφの光ファイバ母材から直径45mmφの光フ
ァイバ母材を製作すべく、光ファイバ母材の中央部を溶
融して延伸したが、延伸開始部から母材中央部までは溶
融部外径を測定してそれを一定に制御するという公知の
延伸方法で延伸したが、それ以降は図１に示したように
母材インゴットの延伸終了側において直胴部末端部を３
つの区間Ｌ1 、Ｌ2 、Ｌ3 に分け、中央よりの区間Ｌ1
では溶融部外径と最終外径の差が大きくなるため、直胴
部における引取り速度を平均引取り速度Ｖm の107mm/分
よりも遅い引取り速度Ｖ1 ＝ 88.8mm/分（Ｖ1 ＝0.83Ｖ
m）で引取り、区間Ｌ2 では平均引取り速度Ｖm ＝107mm
/分で引取り、さらに末端よりのＬ3 では溶融部外径と
最終外径との差が小さくなるため、直胴部における引取
り速度を平均引取り速度Ｖm よりも速い引取り速度Ｖ3
＝137mm/分（Ｖ3 ＝1.28Ｖm ）で引取るようにした。EXAMPLES Next, examples and comparative examples of the present invention will be described. Example 1 The central portion of the optical fiber preform was melted and stretched in order to manufacture an optical fiber preform having a diameter of 45 mmφ from the optical fiber preform having a diameter of 120 mm. Stretching was carried out by a known stretching method in which the outside diameter of the part was measured and controlled to be constant. After that, as shown in FIG.
It is divided into two sections L 1 , L 2 and L 3 , and the section L 1 from the center
Since the difference between the outer diameter of the fusion zone and the final outer diameter becomes large, the take-up speed in the straight body is slower than the average take-up speed V m of 107 mm / min. The take-up speed V 1 = 88.8 mm / min (V 1 = 0.83V
m ), the average take-up speed V m = 107 mm in section L 2.
Since the difference between the outer diameter of the melted portion and the final outer diameter becomes small at L 3 from the end, the take-up speed in the straight body portion is faster than the average take-up speed V m. 3
= 137 mm / min (V 3 = 1.28 V m ).
【００１７】なお、この場合における直胴部における平
均引取り速度Ｖm は母材インゴット径Ｄ0 と延伸後の母
材ロッドの径Ｄ1 および母材インゴットの送り込み速度
Ｖ0より、次式 Ｖm ＝Ｖ0 × (Ｄ0 ／Ｄ1)2 で求められるが、上記したような引取り条件で延伸を行
なったところ、直胴部末端における溶融部外径は一定値
ではなくなったが、目的とする母材ロッドの最終外径の
変動は図２に示したように 0.3mmに抑えることができ
た。The average take-up speed V m in the straight body portion in this case is calculated from the following formula V from the diameter D 0 of the base metal ingot, the diameter D 1 of the base metal rod after drawing and the feeding speed V 0 of the base metal ingot. m = V 0 × (D 0 / D 1 ) 2, which was obtained. When the drawing was carried out under the above-mentioned pulling conditions, the outer diameter of the melted portion at the end of the straight body portion was not a constant value, but the purpose was As shown in Fig. 2, the fluctuation of the final outer diameter of the base metal rod can be suppressed to 0.3 mm.
【００１８】実施例２ 母材インゴットを延伸開始部、延伸中央部、延伸終了部
の３つに大きく分け、延伸中央部と延伸終了部について
は実施例１と同一条件で延伸した。しかし、この延伸開
始部については図３に示したように直胴部末端部を２つ
の区間Ｌ4 、Ｌ5 に分け、末端よりの区間Ｌ4 では溶融
部外径と最終外径の差が小さくなるため、この引取り速
度を直胴部における平均引取り速度Ｖm の107mm/分より
も速い引取り速度Ｖ4 ＝127.3mm/分（Ｖ4 ＝1.19Ｖm ）
で引取り、中央よりの区間Ｌ5 では溶融部外径と最終外
径の差が大きくなるため、この引取り速度を直胴部にお
ける平均引取り速度Ｖm よりも遅い引取り速度Ｖ5 ＝ 9
3.1mm/分（Ｖ5 ＝0.87Ｖm ）で引取るようにした。 こ
のような引取り条件で延伸を行なったところ、図４に示
したように延伸開始側の直胴部末端における最終外径の
変動は0.2mmに抑えることができた。Example 2 A base material ingot was roughly divided into three parts, a drawing start part, a drawing center part and a drawing end part, and the drawing center part and the drawing end part were drawn under the same conditions as in Example 1. However, as shown in FIG. 3, the end portion of the straight body portion of this stretching start portion is divided into two sections L 4 and L 5 , and in the section L 4 from the end, the difference between the outer diameter of the fusion zone and the final outer diameter is Since this becomes smaller, the take-up speed is faster than the average take-up speed V m of 107 mm / min in the straight body part V 4 = 127.3 mm / min (V 4 = 1.19 V m ).
In the section L 5 from the center, the difference between the outer diameter of the molten portion and the final outer diameter is large, so this take-up speed is slower than the average take-up speed V m in the straight body portion V 5 = 9
It was settled at 3.1 mm / min (V 5 = 0.87 V m ). When the drawing was carried out under such a take-up condition, as shown in FIG. 4, the fluctuation of the final outer diameter at the end of the straight body portion on the drawing start side could be suppressed to 0.2 mm.
【００１９】比較例 図５に示したように、電気炉で加熱を行ないながら加熱
溶融部の外径を測定し、この加熱溶融部の外径を一定に
制御する方法で実施例１と同一外径の母材インゴットを
延伸したところ、図７に示したように母材インゴット直
胴部の両末端部において溶融部外径は一定値に保つこと
ができたけれども、目的とする母材ロッドの最終外径に
ついては延伸開始側で３mm、延伸終了側で５mmの外径変
動が生じた。この変動量は実施例の外径変動の10倍以上
であり、このままでは母材ロッドを線引きしたときに、
完全な外径制御が行えず、ファイバ径に変動が生じてし
まうので、この母材ロッドについては線引き前にガラス
旋盤などにより外径修正が必要となった。Comparative Example As shown in FIG. 5, the outer diameter of the heating / melting portion was measured while heating in an electric furnace, and the outer diameter of the heating / melting portion was controlled to be the same as in Example 1. When the base metal ingot with the same diameter was stretched, as shown in FIG. 7, the outer diameter of the fusion zone could be kept at a constant value at both ends of the straight body of the base metal ingot. Regarding the final outer diameter, the outer diameter varied by 3 mm on the stretching start side and 5 mm on the stretching end side. This fluctuation amount is 10 times or more the outer diameter fluctuation of the embodiment, and as it is, when the base material rod is drawn,
Since the outer diameter cannot be controlled completely and the fiber diameter fluctuates, the outer diameter of this preform rod needs to be corrected by a glass lathe before drawing.
【００２０】[0020]
【発明の効果】本発明による光ファイバ母材の製造方法
によれば、母材インゴットの外径の変化や物性の違いに
より溶融部を一定に制御するだけでは最終外径に変動が
生じてしまう場合でも、最終外径をほぼ一定に制御する
ことができる。According to the method of manufacturing an optical fiber preform according to the present invention, the final outer diameter varies when the melted portion is controlled to be constant due to a change in the outer diameter of the preform ingot and a difference in physical properties. Even in this case, the final outer diameter can be controlled to be substantially constant.
【図１】本発明による終了側直胴部末端延伸方法の縦断
面図を示したものである。FIG. 1 is a vertical cross-sectional view of a method for stretching a terminal end of a straight body portion according to the present invention.
【図２】本発明の実施例１における延伸ロッドの溶融部
外径と最終外径に関する母材長さと外径との関係グラフ
を示したものである。FIG. 2 is a graph showing a relationship between a base material length and an outer diameter with respect to a melted portion outer diameter and a final outer diameter of a stretched rod in Example 1 of the present invention.
【図３】本発明の実施例２における開始側直胴部末端延
伸方法の縦断面図を示したものである。FIG. 3 is a vertical cross-sectional view of a starting side straight trunk end stretching method in Example 2 of the present invention.
【図４】本発明の実施例２における延伸ロッドの溶融部
外径と最終外径に関する母材長さと外径との関係グラフ
を示したものである。FIG. 4 is a graph showing a relationship between a base material length and an outer diameter with respect to a melted portion outer diameter and a final outer diameter of a drawn rod in Example 2 of the present invention.
【図５】従来法における母材インゴット延伸方法の縦断
面図を示したものである。FIG. 5 is a longitudinal sectional view showing a base material ingot drawing method in a conventional method.
【図６】従来法における母材インゴットの概形縦断面図
を示したものである。FIG. 6 is a schematic vertical sectional view of a base material ingot in the conventional method.
【図７】従来法の溶融部一定制御によって延伸した延伸
ロッドの溶融部外径、最終外径に関する母材長さと外径
との関係グラフを示したものである。FIG. 7 is a graph showing a relationship between a base material length and an outer diameter with respect to an outer diameter of a molten portion and a final outer diameter of a stretched rod stretched by a constant control of a molten portion of a conventional method.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 平沢 秀夫 群馬県安中市磯部２丁目13番１号 信越化 学工業株式会社精密機能材料研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Hirasawa 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. Precision Materials Research Laboratory
Claims (6)
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、母材インゴットの末端周辺部を延伸する際の延伸条
件を、直胴部での平均引取り速度よりも速い速度で引き
伸ばす区間と直胴部での平均引取り速度よりも遅い速度
で引き伸ばす区間を有するものとしてなることを特徴と
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 the stretching condition for stretching the peripheral end portion of the preform ingot is a straight body part. The method for producing an optical fiber preform, characterized in that it has a section that is stretched at a speed higher than the average pulling speed of the above and a section that is stretched at a speed slower than the average pulling speed at the straight body part.
ばす区間と、平均引取り速度よりも遅い速度で引き伸ば
す区間との間に、平均引取り速度で引き伸ばす区間を設
けてなる請求項１に記載した光ファイバ母材の製造方
法。2. A section for stretching at an average take-up speed is provided between a section for stretching at a speed faster than the average take-up speed and a section for stretching at a speed slower than the average take-up speed. Of manufacturing a preformed optical fiber preform.
ばす速度が平均引取り速度の 110〜 150％の範囲である
請求項１または２に記載した光ファイバ母材の製造方
法。3. The method for producing an optical fiber preform according to claim 1 or 2, wherein the rate of stretching at a rate higher than the average pulling rate is in the range of 110 to 150% of the average pulling rate.
ばす速度が平均引取り速度の 125〜 135％の範囲である
請求項１または２に記載した光ファイバ母材の製造方
法。4. The method for producing an optical fiber preform according to claim 1, wherein the drawing speed at a speed higher than the average drawing speed is in the range of 125 to 135% of the average drawing speed.
ばす速度が平均引取り速度の70〜90％の範囲である請求
項１または２に記載した光ファイバ母材の製造方法。5. The method for producing an optical fiber preform according to claim 1 or 2, wherein the rate of stretching at a rate slower than the average pulling rate is in the range of 70 to 90% of the average pulling rate.
ばす速度が平均引取り速度の80〜90％の範囲である請求
項１または２に記載した光ファイバ母材の製造方法。6. The method for producing an optical fiber preform according to claim 1 or 2, wherein the rate of stretching at a rate slower than the average pulling rate is in the range of 80 to 90% of the average pulling rate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19241694A JP3151358B2 (en) | 1994-08-16 | 1994-08-16 | Manufacturing method of optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19241694A JP3151358B2 (en) | 1994-08-16 | 1994-08-16 | Manufacturing method of optical fiber preform |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0859274A true JPH0859274A (en) | 1996-03-05 |
| JP3151358B2 JP3151358B2 (en) | 2001-04-03 |
Family
ID=16290963
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19241694A Expired - Lifetime JP3151358B2 (en) | 1994-08-16 | 1994-08-16 | Manufacturing method of optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3151358B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0881196A1 (en) * | 1997-05-30 | 1998-12-02 | Shin-Etsu Chemical Company, Ltd. | Method for drawing a glass ingot to a rod |
| US6279353B1 (en) | 1997-03-25 | 2001-08-28 | The Furukawa Electric Co., Ltd. | Electric furnace extension method and extension apparatus for optical fiber glass preform |
| KR20190089437A (en) * | 2018-01-22 | 2019-07-31 | 포항공과대학교 산학협력단 | Manufacturing method of ultralong, uniform, and subwavelength-diameter optical fiber |
-
1994
- 1994-08-16 JP JP19241694A patent/JP3151358B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6279353B1 (en) | 1997-03-25 | 2001-08-28 | The Furukawa Electric Co., Ltd. | Electric furnace extension method and extension apparatus for optical fiber glass preform |
| US6729162B2 (en) | 1997-03-25 | 2004-05-04 | The Furukawa Electric Co., Ltd. | Electric furnace extension method and extension apparatus for optical fiber glass preform |
| EP0881196A1 (en) * | 1997-05-30 | 1998-12-02 | Shin-Etsu Chemical Company, Ltd. | Method for drawing a glass ingot to a rod |
| US6220057B1 (en) | 1997-05-30 | 2001-04-24 | Shin-Etsu Chemical Co., Ltd. | Apparatus and method for drawing a glass ingot |
| KR20190089437A (en) * | 2018-01-22 | 2019-07-31 | 포항공과대학교 산학협력단 | Manufacturing method of ultralong, uniform, and subwavelength-diameter optical fiber |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3151358B2 (en) | 2001-04-03 |
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