JP2000247672A - Method for processing optical fiber preform and processing apparatus therefor - Google Patents
Method for processing optical fiber preform and processing apparatus thereforInfo
- Publication number
- JP2000247672A JP2000247672A JP11047856A JP4785699A JP2000247672A JP 2000247672 A JP2000247672 A JP 2000247672A JP 11047856 A JP11047856 A JP 11047856A JP 4785699 A JP4785699 A JP 4785699A JP 2000247672 A JP2000247672 A JP 2000247672A
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- fiber preform
- preform
- processing
- bending
- 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
-
- 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
- C03B37/0126—Means for supporting, rotating, translating the rod, tube or preform
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
- Y02P40/57—Improving the yield, e-g- reduction of reject rates
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えば光ファイバ
母材の曲りを修正し、高温下の加工中にＳｉＯの蒸発に
起因するクラッドの厚み痩せを防止するための加工技術
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing technique for correcting, for example, the bending of an optical fiber preform and preventing the cladding from becoming thinner due to the evaporation of SiO during processing at a high temperature.
【０００２】[0002]
【従来の技術】従来、光ファイバを製造するにあたり、
いきなり極細のファイバを作ると屈折率分布を最適に制
御するのが困難である等の理由から、まず第１段階とし
て、同じ屈折率分布を有する棒状の光ファイバ母材（プ
リフォーム）が製造される。このような光ファイバ母材
の製造方法のひとつにいわゆる外付けＣＶＤ法（ＯＶＤ
法）があり、コア母材の表面に光ファイバ原料の四塩化
ケイ素等を酸素、水素ガスとともに吹付け、酸水素バー
ナにより火炎加水分解反応を起こさせてスートを堆積し
て多孔質母材を形成し、これを脱水、焼結ガラス化を行
って光ファイバ母材を製造した後、次工程の線引機の設
備に対応した外径、長さに修正したり、曲りを矯正する
ため、ガラス旋盤等で加工を行っている。2. Description of the Related Art Conventionally, in manufacturing an optical fiber,
First, a rod-shaped optical fiber preform (preform) having the same refractive index distribution is manufactured as the first step because it is difficult to optimally control the refractive index distribution when a very fine fiber is suddenly produced. You. One of the manufacturing methods of such an optical fiber preform is a so-called external CVD method (OVD).
The optical fiber material silicon tetrachloride is sprayed on the surface of the core preform together with oxygen and hydrogen gas, and a flame hydrolysis reaction is caused by an oxyhydrogen burner to deposit soot to form a porous preform. After forming, dehydrating, sintering and vitrifying to produce an optical fiber preform, to correct the outer diameter and length corresponding to the equipment of the drawing machine in the next process, or to correct the bend, Processing is done with a glass lathe.
【０００３】そして、中心部がコアで外周がクラッドか
らなる光ファイバ母材（以下、母材ロッドということが
ある）の加工精度は、均一で高精度な光ファイバ品質を
得るため、例えば曲りが５００μｍ／１０００ｍｍ以下
で、かつ、コア部とクラッド部の比率が極めて高精度に
加工される必要がある。The processing accuracy of an optical fiber preform (hereinafter, sometimes referred to as a preform rod) having a core at the center and a clad at the outer periphery is, for example, bent in order to obtain uniform and high-precision optical fiber quality. It is necessary to process the core and clad at an extremely high precision of 500 μm / 1000 mm or less.
【０００４】従来、この母材ロッドの曲りの修正は、人
手によってガラス旋盤の一端のチャックに母材ロッドを
把持して２０〜４０ｒｐｍで回転させながらチャックの
方側から順に要曲り修正部をガスバーナで加熱し、次の
要曲り修正部に修正用のこてを当てることにより行われ
る。この加熱により母材ロッドの要曲り修正部は徐々に
軟化してくる。この時、こて先を手で固定してこての中
間で母材ロッドを支持し、回転する母材ロッドの曲りに
よりこてを押し下げようとする脈動を感じなくなるまで
加熱軟化して、曲りによる脈動を感じなくなったらガス
バーナの火力を絞って徐冷し、固化させて曲り修正を終
了する。この操作を母材ロッドの元の方から例えば数箇
所ある要曲り修正部について、順次全長にわたって行う
ことによって、母材ロッドの曲り修正を完了する。しか
し、上記精度を出すには相当の熟練を要し人手がかかり
かつ個人差が生ずる欠点があった。Conventionally, the correction of the bending of the base material rod is performed by manually holding the base material rod in the chuck at one end of the glass lathe and rotating the required bending correction portion sequentially from the chuck side while rotating it at 20 to 40 rpm. Is performed, and a trowel for correction is applied to the next required bending correction section. Due to this heating, the required bending correction portion of the base material rod gradually softens. At this time, fix the iron tip by hand, support the base metal rod in the middle of the iron, heat soften until you do not feel the pulsation to push down the iron due to the bending of the rotating base material rod, When the pulsation is no longer felt, the heat of the gas burner is squeezed to gradually cool and solidify to complete the bending correction. This operation is sequentially performed over the entire length of, for example, several required bending correction portions from the original side of the base material rod to complete the bending correction of the base material rod. However, there are drawbacks in that the above-described accuracy requires considerable skill, requires labor, and causes individual differences.
【０００５】そこでこのような母材ロッドの曲り修正を
自動化する方法が提案された（特開平６−１４４８６１
号参照）。この方法では、母材ロッドの曲り量を重量計
で検出しているが、重量検出では曲り修正の要、不要の
判定が現実的に困難である。これは、母材ロッドに要求
されている曲り精度が５００μｍ／１０００ｍｍ以下で
あるのに対して母材ロッドの非円率が０〜４００μｍの
バラツキがあり、その他支持治具等の摩耗等で検出精度
が十分でないからである。また、１個のこてでは曲りの
大きな母材ロッドに対して十分な修正力を印加すること
が難しく、しかも設備的には高価な重量センサーを必要
とする等の欠点がある。Therefore, a method for automating the correction of the bending of the base material rod has been proposed (Japanese Patent Laid-Open No. 6-148661).
No.). In this method, the amount of bending of the base material rod is detected by a weighing scale. However, it is practically difficult to determine whether correction of bending is necessary or not in weight detection. This is because, while the bending accuracy required for the base material rod is 500 μm / 1000 mm or less, the non-circularity of the base material rod varies from 0 to 400 μm, and is detected by wear of a support jig or the like. This is because the accuracy is not sufficient. In addition, it is difficult to apply a sufficient correcting force to a base material rod having a large bend by using a single iron, and there is a drawback that an expensive weight sensor is required in terms of equipment.
【０００６】一方、光ファイバ母材の品質として、コア
部とクラッド部の比率が光信号伝送特性上極めて重要で
あることが知られている。そして、母材ロッドの曲りを
修正する場合は、母材ロッドの芯まで完全に軟化するよ
うにガスバーナで加熱しなければならないが、強力な火
力で急激に加熱すると母材ロッドの熱伝導率が小さいた
め、軟化が芯に至るまでに母材ロッドの表面温度が極め
て高くなり、図４に示したように２０００℃以上になる
と石英ガラス（ＳｉＯ2 ）がＳｉＯガスとなって揮発し
始め、２２００℃辺りから急激に揮発するようになる。
従ってクラッド部が痩せてしまい、コア／クラッド比が
崩れて光ファイバ特性が不良となってしまう。On the other hand, it is known that the ratio of the core portion to the clad portion is extremely important in terms of the optical signal transmission characteristics as the quality of the optical fiber preform. When correcting the bending of the base material rod, it is necessary to heat it with a gas burner so that it completely softens up to the core of the base material rod. small Therefore, softening the surface temperature of the preform rod becomes very high to reach the core, becomes more than 2000 ° C. as shown in FIG quartz glass (SiO 2) begins to volatilize a SiO gas, 2200 It rapidly evaporates around ℃.
Therefore, the clad portion becomes thin, the core / clad ratio collapses, and the optical fiber characteristics become poor.
【０００７】近年、光ファイバの生産性の向上を図るた
め、従来３０〜４０ｍｍ口径の母材ロッドであったもの
が６０〜９０ｍｍ口径と大口径のものが要求されるよう
になってきている。このような大口径母材ロッドの曲り
修正における母材ロッドの表面と芯の温度差は、特に直
径が５０ｍｍ以上の大口径になるほど大きくなり易い。
例えば母材ロッドの直径が５０ｍｍの場合、水素ガス２
００Ｌ／分、酸素ガス８０Ｌ／分にて、加熱した場合、
約３分で表面温度が２０００℃に達するが、芯はせいぜ
い８００℃程度であり、芯の温度を曲げ加工が可能な石
英ガラスの軟化点である１６５０℃以上になるまで加熱
すれば、内部が軟化するまでに表面の温度が上り過ぎ、
ＳｉＯが蒸発してクラッド部が痩せて母材ロッドの品質
低下を招き易くなる。よって、それを防止するために弱
火にて加熱すると、石英ガラス内部まで軟化するのに長
時間を要し、軟化が不十分であると修正精度に個人差が
出るため、またはクラッド部のやせ過ぎによる品質不良
のために、歩留りが低下するという欠点がある。In recent years, in order to improve the productivity of optical fibers, a base material rod having a diameter of 30 to 40 mm has been required to have a diameter as large as 60 to 90 mm, which has been conventionally used. The temperature difference between the surface of the base material rod and the core in the correction of the bending of the large-diameter base material rod tends to increase particularly as the diameter increases to 50 mm or more.
For example, when the diameter of the base material rod is 50 mm, hydrogen gas 2
When heated at 00 L / min and oxygen gas 80 L / min,
Although the surface temperature reaches 2000 ° C. in about 3 minutes, the core is at most about 800 ° C. If the temperature of the core is heated to 1650 ° C. or more, which is the softening point of quartz glass that can be bent, the inside becomes The surface temperature rises too much before softening,
SiO evaporates and the cladding becomes thinner, which tends to lower the quality of the base material rod. Therefore, when heating with low heat to prevent this, it takes a long time to soften to the inside of the quartz glass, and if the softening is insufficient, there is an individual difference in correction accuracy, or the cladding is too thin There is a disadvantage that the yield is reduced due to poor quality due to the above.
【０００８】[0008]
【発明が解決しようとする課題】そこで、本発明は、光
ファイバ母材の曲りを修正する加工技術において、特に
曲り位置における加熱に制御を加えてクラッド部の厚み
痩せを防止して品質劣化を防ぎ、曲り修正操作を機械
化、自動化して加工時間を短縮し、生産性と歩留の向上
を図ることのできる光ファイバ母材の加工方法および加
工装置を提供することを主たる目的とする。SUMMARY OF THE INVENTION Accordingly, the present invention relates to a processing technique for correcting the bending of an optical fiber preform, in particular, by controlling the heating at the bending position to prevent the thickness of the cladding from becoming thinner and to reduce the quality deterioration. It is a main object of the present invention to provide a method and an apparatus for processing an optical fiber preform capable of preventing, bending and mechanizing and automating a bending operation to shorten a processing time and improve productivity and yield.
【０００９】[0009]
【課題を解決するための手段】上記課題を解決するため
本発明の請求項１に記載した発明は、光ファイバ母材を
軸周りに回転させつつガスバーナで表面に火炎を吹き付
けながら該母材の曲りを修正する方法であって、外径測
定器により軸方向のブレ量と曲り位置を検出し、該曲り
位置にガスバーナを対面させて該母材を加熱軟化させる
と共に、エアシリンダで駆動される少なくとも２本のロ
ーラで該母材を支持しつつブレ量を減衰させる応力付与
機構により曲りを修正し、その後ガスバーナのガス量を
絞って徐冷、固化し、曲り修正を完了することを特徴と
する光ファイバ母材の加工方法である。In order to solve the above-mentioned problems, the invention described in claim 1 of the present invention is to rotate an optical fiber preform around an axis while blowing a flame on the surface with a gas burner. A method of correcting a bend, in which an outside diameter measuring device detects an axial blurring amount and a bend position, heats and softens the base material by facing a gas burner at the bend position, and is driven by an air cylinder. The bending is corrected by a stress applying mechanism that attenuates the amount of shake while supporting the base material with at least two rollers, and then the gas amount of the gas burner is reduced to gradually cool and solidify to complete the bending correction. This is a method for processing an optical fiber preform.
【００１０】このように、光ファイバ母材の全長にわた
って外径測定器により軸方向のブレ量と曲り位置を検出
した後、先ず最初の曲り位置をガスバーナで加熱軟化さ
せ、その先でエアシリンダで駆動される少なくとも２本
のローラで該母材を支持しつつブレ量を減衰させる応力
付与機構により曲りを修正し、その後ガスバーナのガス
量を絞って徐冷、固化し、曲り修正を完了させ、この操
作を数箇所の要曲り修正部について反覆実施すれば、全
長にわたって曲りが殆どない高品質の光ファイバ母材を
得ることができると共に、加工期間中を通じて個人差を
なくして操業の安定化が図れ、歩留りや生産性が向上
し、コストダウンを図ることができる。As described above, after detecting the amount of deflection and the bending position in the axial direction by the outer diameter measuring device over the entire length of the optical fiber preform, the first bending position is first softened by heating with a gas burner, and then the air cylinder is used. The bending is corrected by a stress applying mechanism that attenuates the amount of blur while supporting the base material with at least two rollers to be driven, then gradually cooling and solidifying by reducing the gas amount of the gas burner, and completing the bending correction, If this operation is repeated for several required bending correction sections, a high-quality optical fiber preform having almost no bending over the entire length can be obtained, and the operation can be stabilized by eliminating individual differences throughout the processing period. As a result, the yield and productivity are improved, and the cost can be reduced.
【００１１】この場合、請求項２に記載したように、応
力付与機構で光ファイバ母材を支持する位置を、現在修
正中の曲り位置の次の曲り位置とすることができる。こ
のようにすると、現在修正中の曲り位置におけるブレ量
の経時変化が直接応力付与機構の２本ローラに伝達され
るので、応力付与機構の修正力が時間差なく追随するこ
とができ、容易に素早く曲りを修正することができる。In this case, the position where the optical fiber preform is supported by the stress applying mechanism can be the next bending position after the bending position currently being corrected. With this configuration, the temporal change in the amount of blur at the curving position currently being corrected is directly transmitted to the two rollers of the stress applying mechanism, so that the correcting force of the stress applying mechanism can follow without a time difference, and can be easily and quickly performed. The bend can be corrected.
【００１２】さらに、請求項３に記載したように、光フ
ァイバ母材の加工方法において、該母材のクラッド部の
ＳｉＯの蒸発を抑制するために、ガスバーナの加熱用ガ
ス量を光ファイバ母材の直径に応じて調整し、また、請
求項４に記載したように、ガスバーナの加熱時間を光フ
ァイバ母材の直径に応じて調整することができる。この
ように加工の対象となる光ファイバ母材の直径に応じ
て、ガスバーナのガス量と加熱時間を適宜調整して、母
材ロッドの表面温度の過熱を防ぐと共に、芯の軟化温度
に到達する時間をできるだけ短縮するようにすれば、母
材ロッド表面からのＳｉＯの蒸発は抑制され、クラッド
部の厚み痩せはなくなり、コア／クラッド比の精度が確
保されると共に、母材ロッドの曲り修正加工も短時間で
安定して高い精度を得ることができる。According to a third aspect of the present invention, in the method of processing an optical fiber preform, the amount of gas for heating the gas burner is reduced in order to suppress evaporation of SiO in a clad portion of the optical fiber preform. The heating time of the gas burner can be adjusted according to the diameter of the optical fiber preform. In this way, according to the diameter of the optical fiber preform to be processed, the gas amount and the heating time of the gas burner are appropriately adjusted to prevent overheating of the surface temperature of the preform rod and to reach the softening temperature of the core. If the time is shortened as much as possible, the evaporation of SiO from the surface of the base material rod is suppressed, the thickness of the clad portion is not reduced, the accuracy of the core / clad ratio is secured, and the bending of the base material rod is corrected. Also, high accuracy can be obtained stably in a short time.
【００１３】そして、本発明の請求項５に記載した発明
は、光ファイバ母材の加工方法において、該母材のクラ
ッド部のＳｉＯの蒸発を抑制するためにガスバーナの加
熱用ガス量を、曲りが修正可能な温度に到達した後、時
間の経過に従って順次減少させ、クラッド表層温度を２
３００℃以下とするものである。このようにすると、母
材ロッド表面からのＳｉＯの蒸発は殆どなく、クラッド
部の厚み痩せはなくなり、コア／クラッド比の精度が確
保されると共に、母材ロッドの曲り修正加工も短時間で
安定した操作が可能となり、高い精度を得ることができ
る。According to a fifth aspect of the present invention, in the method for processing an optical fiber preform, the amount of the gas for heating the gas burner is bent to suppress the evaporation of SiO in the clad portion of the preform. After the temperature reaches the correctable temperature, the temperature is gradually decreased over time, and the cladding surface layer temperature is decreased by 2 times.
The temperature is set to 300 ° C. or less. By doing so, SiO is hardly evaporated from the surface of the base material rod, the thickness of the clad portion is not reduced, the accuracy of the core / clad ratio is secured, and the bending correction process of the base material rod is stable in a short time. Operation can be performed, and high accuracy can be obtained.
【００１４】そして、請求項６に記載したように、光フ
ァイバ母材の加工方法において、該母材の曲りが修正さ
れた時点でこれを固化する徐冷時間を該母材の直径に応
じて調整するようにすることができる。このように母材
ロッドの要曲り修正部は加熱、軟化された状態で曲りが
修正されるが、修正完了状態を固定するには軟化温度以
下に冷却して固化する必要があり、母材ロッドの直径に
応じて徐冷時間を調整すれば、曲り修正を完了した光フ
ァイバ母材に歪みやひび割れが発生するのを防止するこ
とができる。According to a sixth aspect of the present invention, in the method for processing an optical fiber preform, when the bend of the preform is corrected, the slow cooling time for solidifying the bend is set according to the diameter of the preform. Can be adjusted. As described above, the bending correction portion of the base rod is heated and softened, and the bending is corrected. However, in order to fix the correction completed state, it is necessary to cool to a temperature lower than the softening temperature and solidify. By adjusting the slow cooling time according to the diameter of the optical fiber, it is possible to prevent the optical fiber preform after the bending correction from being deformed or cracked.
【００１５】次に、本発明の請求項７に記載した発明
は、応力付与機構の光ファイバ母材支持ローラに一定の
圧力を印加後、エアシリンダの出入口弁を閉じてエアク
ッションを形成し、該母材をエアクッションで保持しな
がら加熱軟化させ、ブレが減衰して曲り修正が終わった
時点をローラの変位量あるいはエアシリンダの圧力変動
量から検出した後、徐冷に入るようにした。このよう
に、応力付与機構の光ファイバ母材支持ローラに一定の
圧力を印加して所定の高さで母材ロッドを支持した後、
エアシリンダの出入口弁を閉じてエアクッションを形成
し、該母材をエアクッションで保持しながら加熱軟化さ
せ、ブレが減衰して曲り修正が終わった時点、すなわち
ローラの上下振動の振幅がなくなった時点、あるいはエ
アシリンダの圧力変動がなくなった時点を検出した後、
ガスバーナの火力を絞って徐冷に入るようにすれば、曲
り修正精度を確実に許容限度内に確保することができ
る。Next, according to a seventh aspect of the present invention, after applying a certain pressure to the optical fiber preform supporting roller of the stress applying mechanism, the inlet / outlet valve of the air cylinder is closed to form an air cushion, The base material was heated and softened while being held by an air cushion, and the point at which the blur was attenuated and the bending was corrected was detected from the displacement amount of the roller or the pressure fluctuation amount of the air cylinder, and then the cooling was started. Thus, after applying a certain pressure to the optical fiber preform supporting roller of the stress applying mechanism and supporting the preform rod at a predetermined height,
The inlet / outlet valve of the air cylinder was closed to form an air cushion, and the base material was heated and softened while being held by the air cushion, and the vibration was attenuated and the bending was corrected, that is, the amplitude of the vertical vibration of the roller was lost. After detecting the time point or the time point when the air cylinder pressure fluctuation disappears,
If the heat of the gas burner is reduced to start slow cooling, the bending correction accuracy can be reliably ensured within an allowable limit.
【００１６】この場合、請求項８に記載したように、応
力付与機構のエアシリンダに印加する圧力は、光ファイ
バ母材の曲り修正箇所のブレ量と母材の直径に対応して
調整される。このように応力付与機構の２本ローラが受
ける力は母材ロッドの重量とブレ量に比例した遠心力で
あるから、これに対抗する応力をエアシリンダで保持す
れば曲りを修正することができる。In this case, as described in claim 8, the pressure applied to the air cylinder of the stress applying mechanism is adjusted in accordance with the amount of deflection at the bending correction portion of the optical fiber preform and the diameter of the preform. . As described above, the force applied to the two rollers of the stress applying mechanism is a centrifugal force proportional to the weight of the base material rod and the amount of shake, and therefore, if the opposing stress is held by the air cylinder, the bending can be corrected. .
【００１７】さらに、請求項９に記載したように、応力
付与機構の光ファイバ母材支持ローラに一定の圧力を印
加後、エアシリンダの出入口弁を閉じてエアクッション
を形成し、該母材をエアクッションで保持しながら加熱
軟化させるに際し、ローラの変位量あるいはエアシリン
ダの圧力変動量に応じてガスバーナの加熱用ガス量を調
整することができる。このように母材ロッドの要曲り修
正部の軟化程度をローラの変位量あるいはエアシリンダ
の圧力変動量として検出し、これらに対応してガスバー
ナの火力を調整すれば、過熱により一気に軟化したり、
急冷により固化したりして曲り修正が不可能になった
り、不十分な修正になることを回避することができる。Furthermore, after applying a certain pressure to the optical fiber preform supporting roller of the stress applying mechanism, the inlet / outlet valve of the air cylinder is closed to form an air cushion, and the preform is formed. When heating and softening while holding with an air cushion, the heating gas amount of the gas burner can be adjusted according to the amount of displacement of the roller or the amount of pressure fluctuation of the air cylinder. As described above, the degree of softening of the required bending correction portion of the base material rod is detected as the amount of displacement of the roller or the amount of pressure fluctuation of the air cylinder, and if the heat of the gas burner is adjusted in accordance with these, the softening can be suddenly caused by overheating,
It is possible to prevent the bending correction from being impossible due to the solidification due to rapid cooling or the insufficient correction.
【００１８】次に、本発明の請求項１０に記載した発明
は、光ファイバ母材の軸方向の少なくとも一端を把持
し、把持された光ファイバ母材の軸方向に沿って移動可
能となり、かつ光ファイバ母材の曲り位置とブレ量を測
定する外径測定手段を備え、この外径測定手段の測定結
果に基づいて移動可能となりかつ光ファイバ母材の表面
に向けて火炎を吹き付けることのできるガスバーナと、
エアシリンダで駆動される少なくとも２本のローラで該
母材を支持しつつブレ量を減衰させることのできる応力
付与機構を備えた光ファイバ母材の加工装置である。Next, according to a tenth aspect of the present invention, at least one end of the optical fiber preform in the axial direction is gripped, the optical fiber preform can be moved in the axial direction of the optical fiber preform, and An outer diameter measuring means for measuring the bending position and the amount of blur of the optical fiber preform is provided, which can be moved based on the measurement result of the outer diameter measuring means, and which can blow a flame toward the surface of the optical fiber preform. Gas burners,
An optical fiber preform processing apparatus provided with a stress applying mechanism capable of attenuating the amount of blur while supporting the preform with at least two rollers driven by an air cylinder.
【００１９】このように構成された光ファイバ母材の加
工装置を使用して、母材ロッドに存在する曲りを修正す
る加工を行えば、例えば数箇所に存在する曲りを母材ロ
ッドの一端から順次自動的に修正することができると共
に母材ロッドの表面を曲り修正に要する軟化温度以上に
過熱することがないのでＳｉＯの蒸発によるクラッド部
の厚み痩せがなく、コア／クラッド比を高精度に保持し
た高品質の光ファイバ母材を得ることができる光ファイ
バ母材の加工装置となる。By using the optical fiber preform processing apparatus configured as described above to perform a process of correcting a bend existing in the preform rod, for example, a bend existing in several places can be corrected from one end of the preform rod. Since the surface can be automatically corrected sequentially and the surface of the base material rod does not overheat beyond the softening temperature required for the correction, the thickness of the clad portion does not become thin due to evaporation of SiO, and the core / clad ratio can be adjusted with high precision. An optical fiber preform processing apparatus capable of obtaining a held high quality optical fiber preform.
【００２０】この場合、請求項１１に記載したように、
応力付与機構のエアシリンダの背圧変動またはローラの
変位量を測定してガスバーナのガス量を制御する制御手
段を備えたものとすることができる。このように母材ロ
ッドの要曲り修正部の軟化程度をローラの変位量あるい
はエアシリンダの圧力変動量として検出し、これらに対
応してガスバーナの火力を調整すれば、過熱により一気
に軟化したり、急冷により固化したりして曲り修正が不
可能になったり、不十分な修正になることを回避するこ
とができると共に高精度の加工ができる光ファイバ母材
の加工装置となる。In this case, as described in claim 11,
A control means for controlling the gas amount of the gas burner by measuring the back pressure fluctuation of the air cylinder or the displacement amount of the roller of the stress applying mechanism can be provided. As described above, the degree of softening of the required bending correction portion of the base material rod is detected as the amount of displacement of the roller or the amount of pressure fluctuation of the air cylinder, and if the heat of the gas burner is adjusted in accordance with these, the softening can be suddenly caused by overheating, An optical fiber preform processing apparatus capable of preventing bending correction due to solidification due to quenching, making it impossible to perform bending correction, and insufficient correction, and capable of performing high-precision processing.
【００２１】[0021]
【発明の実施の形態】以下、本発明の実施の形態につい
て添付した図面に基づいて説明するが、本発明はこれら
に限定されるものではない。ここで、図１（ａ）は本発
明の光ファイバ母材の加工装置の一例を正面から見た概
略構成図、図１（ｂ）は応力付与機構の母材ロッド支持
ローラを側面から見た略図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited thereto. Here, FIG. 1A is a schematic configuration diagram of an example of an optical fiber preform processing apparatus of the present invention as viewed from the front, and FIG. 1B is a side view of a preform rod support roller of a stress applying mechanism. It is a schematic diagram.
【００２２】本発明に係る光ファイバ母材の加工方法
は、例えば外付けＣＶＤ法（ＯＶＤ法）により、出発コ
アの表面に四塩化ケイ素（ＳｉＣｌ4 ）等のファイバ原
料を、酸素（Ｏ2 ）、水素（Ｈ2 ）ガス等とともに吹き
付けて、加水分解反応を起こさせ、すす状の堆積物を堆
積させてクラッド部を形成した後、脱水、焼結等の工程
を経て製造された光ファイバ母材の内、曲り箇所が多
く、曲り度合いの大きい母材ロッドを、所定の精度を有
する直線状ロッドに加工するような加工方法に適用さ
れ、母材ロッドの一端を軸周りに回転可能に把持した
後、曲り位置とブレ量を検出し、曲り位置の表面に酸水
素火炎を吹き付けて加熱しながら曲り修正加工を自動的
に行ない、特に加熱条件を適切に制御してクラッド部の
厚み痩せを防止し、加工効率の向上を図るとともに、製
品ロスの低減を図るようにしている。In the method for processing an optical fiber preform according to the present invention, a fiber material such as silicon tetrachloride (SiCl 4 ) is coated on the surface of a starting core by oxygen (O 2 ) by, for example, an external CVD method (OVD method). , A hydrogen (H 2 ) gas, etc., to cause a hydrolysis reaction, deposit soot-like deposits to form a clad portion, and then perform an optical fiber mother manufactured through processes such as dehydration and sintering. Applied to a processing method in which a base material rod with many bends and a large degree of bending in the material is processed into a linear rod with predetermined accuracy, one end of the base material rod is rotatably held around an axis. After that, the bending position and the amount of blur are detected, and the surface of the bending position is blown with an oxyhydrogen flame to automatically perform the bending correction processing while heating.In particular, the heating conditions are appropriately controlled to reduce the thickness of the clad part. Prevent and processing effect With improved, so that it reduces product loss.
【００２３】本加工装置１は、従来のガラス旋盤を基本
とした構成にしており、例えば図１（ａ）に示すよう
に、機台２上の一端にコラム３とその前面側に取付けら
れるチャック５と、機台２の長手方向に沿って移動自在
な移動台６と、装置１の作動を制御する制御コンピュー
タ７を備えており、前記移動台６には、チャック５で保
持される光ファイバ母材Ｗの表面に向けて火炎を吹き付
けることの出来るガスバーナ８と、光ファイバ母材Ｗの
外径を測定する外径測定器１０が取付けられるととも
に、外径測定器の近傍には応力付与機構１１が設けら
れ、この応力付与機構１１は、前記移動台６と同期して
同じ方向に移動し得るようにされている。The processing apparatus 1 has a configuration based on a conventional glass lathe. For example, as shown in FIG. 1A, a column 3 is provided at one end of a machine base 2 and a chuck attached to the front side thereof. 5, a movable table 6 movable along the longitudinal direction of the machine base 2, and a control computer 7 for controlling the operation of the apparatus 1. The movable table 6 includes an optical fiber held by a chuck 5. A gas burner 8 capable of spraying a flame toward the surface of the preform W and an outer diameter measuring device 10 for measuring the outer diameter of the optical fiber preform W are attached, and a stress applying mechanism is provided near the outer diameter measuring device. The stress applying mechanism 11 can be moved in the same direction in synchronization with the moving table 6.
【００２４】また、チャック５で保持された母材ロッド
Ｗは、不図示の駆動モータによって軸周りに回転自在に
されている。以上説明した片端支持型とは別に、機台２
の長手方向に沿って対向配置され且つ相対移動機構によ
って相互間隔が調整自在な左右一対のコラムと、各コラ
ムの前面側に取付けられるチャックから成る母材ロッド
の両端支持型の加工装置にも本発明の加工技術を適用す
ることが出来る。The base material rod W held by the chuck 5 is rotatable around its axis by a drive motor (not shown). In addition to the one-end support type described above,
The present invention is also applied to a processing device for supporting both ends of a base material rod comprising a pair of left and right columns which are arranged to face each other along the longitudinal direction and whose mutual distance is adjustable by a relative moving mechanism, and a chuck attached to the front side of each column. The processing technology of the invention can be applied.
【００２５】前記ガスバーナ８は、水素ガスを酸素ガス
で燃焼させ、母材ロッドＷの表面に酸水素火炎を吹き付
けて、要曲り修正部を加熱して軟化させ、曲り修正を行
うようにしている。そして、母材ロッドＷの直径や要曲
り修正部の大きさに対応してガスバーナ８の火炎噴射口
と母材ロッドとの間隔、火炎噴射口の幅、母材ロッドに
対する噴射角度等はある範囲内で設定自在になってい
る。The gas burner 8 burns hydrogen gas with oxygen gas, blows an oxyhydrogen flame on the surface of the base material rod W, heats the required bending correction portion to soften it, and performs bending correction. . The distance between the flame injection port of the gas burner 8 and the base material rod, the width of the flame injection port, the injection angle with respect to the base material rod, and the like are in a certain range in accordance with the diameter of the base material rod W and the size of the bending correction portion. It can be set freely within.
【００２６】前記外径測定器１０としては、例えば一対
の発光器と受光器から成り、これらの間に通された母材
ロッドＷの存在による透過光量の大小から外径を測定す
るものが挙げられる。計測用の光線は波長安定化レーザ
を使用するのが、精度、能率、操作性の面で有利とされ
ている。移動台６の上に備えた外径測定器１０で母材ロ
ッドＷのチャック５の把持部側から他端側（遊端側）ま
で走査すれば、母材ロッドＷの全長にわたって全ての曲
り位置とブレ量（曲り量）を検出することができる。そ
こで要修正部を確定するためには、ブレ量に許容限度を
設定してこの限度を越えたブレ量と位置を制御コンピュ
ータ７に記憶させておくようにしている。The outer diameter measuring device 10 includes, for example, a pair of a light emitting device and a light receiving device, and measures the outer diameter based on the amount of transmitted light due to the presence of the base rod W passed therebetween. Can be It is said that using a wavelength-stabilized laser for measurement light is advantageous in terms of accuracy, efficiency, and operability. When the outer diameter measuring device 10 provided on the moving table 6 scans from the gripping side of the chuck 5 of the base material rod W to the other end (the free end side), all the bending positions over the entire length of the base material rod W are obtained. And the amount of shake (the amount of bending) can be detected. Therefore, in order to determine the portion requiring correction, an allowable limit is set for the shake amount, and the shake amount and the position exceeding the limit are stored in the control computer 7.
【００２７】前記応力付与機構１１は、例えば図１
（ａ）、（ｂ）に示したように、エアシリンダ１３とピ
ストンロッドの先端に取りつけた母材ロッドＷを支持す
る二本のグラファイト製ローラ１２から成り、曲り修正
操作中は修正中の曲り位置の次の曲り位置の母材ロッド
Ｗを所定のエア圧力で支持し、母材ロッドのブレをエア
クッションで吸収して減衰させ曲りを修正するようにし
ている。圧縮空気は不図示のエアコンプレッサーから送
られ、高圧エアタンク１４、電磁弁（出入り口弁）１５
を経てエアシリンダ１３を駆動している。The stress applying mechanism 11 is, for example, shown in FIG.
As shown in (a) and (b), it is composed of an air cylinder 13 and two graphite rollers 12 supporting a base material rod W attached to the tip of a piston rod. The base material rod W at the next bending position is supported by a predetermined air pressure, and the deflection of the base material rod is corrected by absorbing and attenuating the vibration of the base material rod with an air cushion. The compressed air is sent from an air compressor (not shown), and a high-pressure air tank 14, a solenoid valve (inlet / outlet valve) 15
, The air cylinder 13 is driven.
【００２８】尚、前記移動台６の軸方向の位置は、不図
示のリニヤスケールによって測定可能とされ、また、こ
の移動台６と同期して移動する応力付与機構１１の位置
情報も測定可能にされるとともに、このリニヤスケール
によって測定された応力付与機構１１の位置情報は、制
御コンピュータ７に送られて記憶されるようにしてい
る。The position of the moving table 6 in the axial direction can be measured by a linear scale (not shown), and the position information of the stress applying mechanism 11 that moves in synchronization with the moving table 6 can also be measured. At the same time, the position information of the stress applying mechanism 11 measured by the linear scale is sent to the control computer 7 and stored.
【００２９】次に、以上のような加工装置１による本発
明の加工方法について説明する。先ず、光ファイバ母材
Ｗの一端をチャック５で把持して、２０〜４０ｒｐｍの
回転速度で回転させながら、外径測定器１０で曲り位置
とブレ量を検出し、これらを制御コンピュータ７に記憶
させておく。この曲り検出操作はガスバーナによる曲り
修正操作を行う前に予め全長にわたって実施しておいて
もよいし、チャック５の把持部側から曲り検出操作、曲
り修正操作、次の曲り検出操作、……と順次反覆して行
うこともできる。Next, a processing method of the present invention using the above-described processing apparatus 1 will be described. First, while grasping one end of the optical fiber preform W with the chuck 5 and rotating the optical fiber preform W at a rotation speed of 20 to 40 rpm, the outer diameter measuring device 10 detects the bending position and the amount of shake, and stores these in the control computer 7. Let it be. This bending detection operation may be performed over the entire length before performing the bending correction operation by the gas burner, or may be performed from the grip portion side of the chuck 5, such as a bending detection operation, a bending correction operation, and a next bending detection operation. It can also be performed repeatedly.
【００３０】次に母材ロッドＷを２０〜４０ｒｐｍで回
転させながらチャック５に把持されている母材ロッドＷ
の元の方から順次曲りを修正するが、該母材のクラッド
部のＳｉＯの蒸発を抑制しつつ曲りを修正するために、
母材ロッドの直径に応じた加熱ガス量あるいは加熱時間
を調整する。例えば、図２に示したような要曲り修正部
を母材ロッドＷの直径に応じた火力（ガス量）および図
３に示したような加熱時間（加熱スケジュール）でガス
バーナ８を用いて加熱し、直径に応じた軟化開始時間を
見計らって（図３の第１段加熱減少時間）次の要曲り修
正部の位置にある応力付与機構１１のエアシリンダ１３
で駆動される２本の母材ロッド支持ローラ１２で母材ロ
ッドＷを支持して曲りの修正が行われる。Next, the base material rod W held by the chuck 5 is rotated while rotating the base material rod W at 20 to 40 rpm.
The bend is corrected sequentially from the original side, but in order to correct the bend while suppressing the evaporation of SiO in the clad portion of the base material,
The heating gas amount or heating time is adjusted according to the diameter of the base material rod. For example, the bend correcting portion as shown in FIG. 2 is heated using the gas burner 8 with a heating power (gas amount) corresponding to the diameter of the base material rod W and a heating time (heating schedule) as shown in FIG. The softening start time according to the diameter is estimated (the first stage heating reduction time in FIG. 3), and the air cylinder 13 of the stress applying mechanism 11 at the position of the next required bending correction portion
The base material rod W is supported by the two base material rod support rollers 12 driven by and the bending is corrected.
【００３１】この時ガスバーナ８のガス量を上記母材ロ
ッドの直径に応じた標準ガス量（図２）の８０％位まで
順次低減して（図３の第１段加熱減少、第２段加熱減
少）、光ファイバ母材Ｗの表面温度が２０００℃以上に
上り過ぎてクラッド部の石英ガラス（ＳｉＯ2 ）がＳｉ
Ｏとなって逃散するのを防ぐ事が重要である。例えば図
４は、光ファイバ母材（直径６７ｍｍ）の表面温度とＳ
ｉＯの揮発速度の関係を表した図であって、２０００℃
辺りから揮発が始まり２２００℃辺りから加速度的に揮
発することが判る。また、図５は、光ファイバ母材（直
径６７ｍｍ）の加熱時間と表面温度との関係を、ガス量
不制御の場合と本発明のようにガス量を制御して絞った
場合について表した図であり、例えばガス量制御を加熱
開始から５００秒経過した時点で第１段の加熱減少に入
り、６００秒で第２段の加熱減少を行って表面温度を１
９００℃に保持している。At this time, the gas amount of the gas burner 8 is sequentially reduced to about 80% of the standard gas amount (FIG. 2) corresponding to the diameter of the base material rod (first stage heating reduction, second stage heating in FIG. 3). Decrease), the surface temperature of the optical fiber preform W is too high to exceed 2000 ° C., and the quartz glass (SiO 2 )
It is important to prevent O from escaping. For example, FIG. 4 shows the surface temperature and S of the optical fiber preform (diameter 67 mm).
FIG. 3 is a diagram showing the relationship between the volatilization rate of iO and 2000 ° C.
It can be seen that volatilization starts around 2200 ° C. and accelerates. FIG. 5 is a diagram showing the relationship between the heating time and the surface temperature of the optical fiber preform (diameter 67 mm) in the case where the gas amount is not controlled and in the case where the gas amount is controlled and reduced as in the present invention. For example, when the gas amount control is started for 500 seconds after the start of heating, the first stage heating reduction is started, and the second stage heating reduction is performed in 600 seconds to reduce the surface temperature to 1
It is kept at 900 ° C.
【００３２】このように、応力付与機構１１の光ファイ
バ母材支持ローラ１２に一定の圧力を印加して所定の高
さで母材ロッドＷを支持した後、エアシリンダ１３の出
入口弁１５を閉じてエアクッションを形成し、該母材を
エアクッションで保持しながら加熱軟化させ、ブレが減
衰して曲り修正が終わった時点、すなわちローラの上下
振動の振幅がなくなった時点、あるいはエアシリンダの
圧力変動がなくなった時点を検出した後、ガスバーナの
火力を絞って徐冷に入るようにすれば、曲り修正精度を
確実に許容限度内に確保することができる。この冷却時
間も歪みが残らないよう母材ロッドの直径に応じて徐冷
することが必要である。After applying a predetermined pressure to the optical fiber preform supporting roller 12 of the stress applying mechanism 11 to support the preform rod W at a predetermined height, the inlet / outlet valve 15 of the air cylinder 13 is closed. When the air cushion is formed and the base material is heated and softened while being held by the air cushion, the deflection is reduced and the correction is completed, that is, when the amplitude of the vertical vibration of the roller is eliminated, or the pressure of the air cylinder is reduced. After detecting the point in time when the fluctuation has ceased, if the gas burner is throttled down to start slow cooling, the bending correction accuracy can be reliably ensured within an allowable limit. This cooling time also requires slow cooling according to the diameter of the base material rod so that no distortion remains.
【００３３】以上の曲り修正操作を光ファイバ母材の全
長にわたって要曲り修正部の箇所について実施すること
により、クラッド部の厚み痩せを防止しながら、曲り修
正を完了することができる。By performing the above-described bending correction operation over the entire length of the optical fiber preform at the required bending correction portion, the bending correction can be completed while preventing the clad portion from becoming thinner.
【００３４】[0034]
【実施例】次に、本発明の実施例を挙げて具体的に説明
するが、本発明は、これらに限定されるものではない。 （実施例）図１に示す加工装置を用いて光ファイバ母材
の曲り修正加工を行った。母材ロッドは直径６７ｍｍ、
長さ９５０ｍｍのものを用いた。応力付与機構は、直径
１６ｍｍ×ストローク１００ｍｍのエアシリンダのピス
トンロッドの先端に直径５５ｍｍのカーボンローラを２
本、４５度のＹ字型に取り付けたものである。このエア
シリンダの作動を上下動および中間停止ができるように
５ポートの電磁弁を用いた。Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. (Example) The optical fiber preform was corrected for bending using the processing apparatus shown in FIG. The base material rod is 67mm in diameter,
The one having a length of 950 mm was used. The stress applying mechanism includes a 55 mm diameter carbon roller at the tip of a piston rod of an air cylinder having a diameter of 16 mm and a stroke of 100 mm.
The book is attached in a 45-degree Y-shape. A 5-port solenoid valve was used so that the operation of the air cylinder could be moved up and down and stopped intermediately.
【００３５】先ず、光ファイバ母材の一端をチャックで
把持して、２５ｒｐｍの回転速度で回転させながら、レ
ーザ外径測定器で一定間隔毎にブレ量を測定し、曲り位
置を検出し、その位置を確定する。これらのデータは制
御コンピュータ７に記憶させた。要曲り修正部はチャッ
ク把持部を起点０として、２０５ｍｍ、３８０ｍｍ、５
２０ｍｍの３箇所にあり、ブレはそれぞれ５４０μｍ、
８２０μｍ、１０３０μｍであった。First, while holding one end of the optical fiber preform with a chuck and rotating it at a rotation speed of 25 rpm, the amount of blur is measured at regular intervals by a laser outer diameter measuring device, and the bending position is detected. Confirm the position. These data were stored in the control computer 7. The required bending correction part is 205 mm, 380 mm, 5
There are three places of 20mm, each shake is 540μm,
It was 820 μm and 1030 μm.
【００３６】次に母材ロッドを２５ｒｐｍで回転させな
がらチャックに把持されている母材ロッドの元の方から
順次、該母材のクラッド部のＳｉＯの蒸発を抑制しつつ
曲りを修正するために、母材ロッドの直径６７ｍｍに応
じた火力（水素ガス：１４２Ｌ／ｍｉｎ、酸素ガス：６
３Ｌ／ｍｉｎ）および加熱スケジュール（加熱開始後１
０００秒で曲り修正完了）でガスバーナを用いて加熱
し、直径に応じた軟化開始時間を見計らって次の曲り位
置に配置された応力付与機構のエアシリンダで駆動され
る２本のロッド支持ローラで母材ロッドを支持して曲り
の修正を行った。Next, while rotating the preform rod at 25 rpm, in order to correct the bending while suppressing the evaporation of SiO in the clad portion of the preform in order from the original side of the preform rod held by the chuck. Thermal power (hydrogen gas: 142 L / min, oxygen gas: 6) according to the base material rod diameter of 67 mm
3 L / min) and heating schedule (1 after starting heating)
(The bending correction is completed in 2,000 seconds.) The heating is performed using a gas burner, and the two rod supporting rollers driven by the air cylinder of the stress applying mechanism arranged at the next bending position after estimating the softening start time according to the diameter. The bending was corrected by supporting the base metal rod.
【００３７】この時ガスバーナのガス量を上記標準ガス
量の８０％位まで２段階で順次低減して（６００秒後の
第１段の加熱減少に続いて７００秒で第２段加熱減少に
入る）、光ファイバ母材Ｗの表面温度が２０００℃以上
に上り過ぎてクラッド部の石英ガラス（ＳｉＯ2 ）がＳ
ｉＯとなって逃散するのを防止した。At this time, the gas amount of the gas burner is sequentially reduced in two stages to about 80% of the standard gas amount (after the first stage heating reduction after 600 seconds, the second stage heating reduction is started in 700 seconds). ), The surface temperature of the optical fiber preform W has risen to 2000 ° C. or more, and the quartz glass (SiO 2 )
I escaped as iO.
【００３８】このように母材ロッドＷの表面から軟化温
度に到達して軟化が開始され、母材ロッドＷの芯まで軟
化温度に到達するまでの間は、所定圧力のエアシリンダ
で支持され、回転しながらブレ量は徐々に減衰して行
き、芯が軟化温度に到達した時点でエアシリンダの出入
り口弁を閉じて曲がり修正が完了するまでの間、その位
置で停止した。また、曲りが完全に修正される温度に到
達した９００秒経過した時点でガスバーナの火力を落し
て徐冷に入り、加熱開始から１０００秒で曲り修正を完
了した。As described above, softening is started when the softening temperature is reached from the surface of the base material rod W, and it is supported by the air cylinder of a predetermined pressure until the softening temperature is reached up to the core of the base material rod W. While rotating, the amount of blur gradually attenuated, and when the core reached the softening temperature, the inlet / outlet valve of the air cylinder was closed and stopped at that position until the correction of the bending was completed. Further, when 900 seconds had elapsed after the temperature reached the temperature at which the bending was completely corrected, the gas burner was cooled down and slow cooling was started, and the bending correction was completed 1000 seconds after the start of heating.
【００３９】以上の曲り修正操作を前記３箇所について
実施した結果、ブレはそれぞれ９０μｍ、４５μｍ、７
０μｍまで修正され、規格の許容限度内（５００μｍ／
１０００ｍｍ）に収まっていた。また、母材ロッドの外
径は、各曲り位置で６７．３０±０．０６ｍｍ、６７．
２５±０．０６ｍｍ、６７．２０±０．０７ｍｍであっ
たものが曲り修正後は、それぞれ６７．２８±０．０６
ｍｍ、６７．２３±０．０６ｍ、６７．１８±０．０７
ｍｍとなり、コア／クラッド比に影響はなかった。As a result of performing the above-mentioned bending correction operation on the above three points, the blurring was 90 μm, 45 μm, 7
0 μm, within the allowable limit of the standard (500 μm /
1000 mm). The outer diameter of the base material rod is 67.30 ± 0.06 mm at each bending position, and 67.30 ± 0.06 mm.
What was 25 ± 0.06 mm and 67.20 ± 0.07 mm was 67.28 ± 0.06 mm after bending correction.
mm, 67.23 ± 0.06 m, 67.18 ± 0.07
mm, and there was no effect on the core / cladding ratio.
【００４０】以上のことから、本発明のように、光ファ
イバ母材の曲り修正加工に際し、ガスバーナの火力を母
材ロッドの直径に応じた加熱スケジュールに従って制御
し、応力付与機構を具備した加工装置を使用して曲り修
正加工を行えば、自動的に高精度で曲りの修正が可能で
ある。また、母材ロッド表面からのＳｉＯの蒸発は抑制
されてクラッド部の厚み痩せはなくなり、コア／クラッ
ド比の精度が確保されると共に、全長にわたって曲りが
殆どない高品質光ファイバ母材を短時間で安定して高い
精度で得ることができ、歩留りや生産性が向上し、コス
トダウンを図ることができる。From the above, as in the present invention, in the bending correction processing of the optical fiber preform, the working power of the gas burner is controlled according to the heating schedule according to the diameter of the preform rod, and the processing apparatus provided with the stress applying mechanism. If the bend correction processing is performed by using, the bend can be automatically corrected with high accuracy. Further, the evaporation of SiO from the surface of the preform rod is suppressed, the thickness of the clad portion is not reduced, the accuracy of the core / clad ratio is ensured, and a high-quality optical fiber preform having almost no bending over the entire length is produced in a short time. Thus, it is possible to obtain a stable and high accuracy, improve the yield and productivity, and reduce the cost.
【００４１】尚、本発明は、上記実施形態に限定される
ものではない。上記実施形態は、例示であり、本発明の
特許請求の範囲に記載された技術的思想と実質的に同一
な構成を有し、同様な作用効果を奏するものは、いかな
るものであっても本発明の技術的範囲に包含される。The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.
【００４２】上記実施例においては、直径６７ｍｍの母
材ロッドの曲りを修正する場合の加熱パターンについて
説明したが、本発明は原則として母材ロッドの直径に関
わらず適用できるものであり、例えば直径３０〜８０ｍ
ｍ、あるいはそれ以上のものについても図２〜図５に示
した加熱パターンを適用することができる。In the above embodiment, the heating pattern for correcting the curvature of the base material rod having a diameter of 67 mm has been described. However, the present invention is applicable in principle regardless of the diameter of the base material rod. 30-80m
The heating pattern shown in FIGS. 2 to 5 can be applied to m or more.
【００４３】[0043]
【発明の効果】以上詳述したように、本発明のように、
光ファイバ母材の曲り修正加工に際し、ガスバーナの火
力を母材ロッドの直径に応じた加熱スケジュールに従っ
て制御し、応力付与機構を具備した加工装置を使用して
曲り修正加工を行えば、全長にわたって曲りが殆どない
光ファイバ母材を短時間で安定して高い精度で得ること
ができると共に、母材ロッド表面からのＳｉＯの蒸発は
抑制されてクラッド部の厚み痩せはなくなり、コア／ク
ラッド比の精度が確保された高品質の光ファイバ母材の
歩留りや生産性が向上し、コストダウンを図ることがで
きる。As described in detail above, as in the present invention,
At the time of bending correction processing of the optical fiber preform, controlling the thermal power of the gas burner according to a heating schedule according to the diameter of the preform rod and performing bending correction processing using a processing device equipped with a stress applying mechanism, the bending over the entire length. An optical fiber preform having almost no cracks can be stably obtained with high accuracy in a short time, the evaporation of SiO from the preform rod surface is suppressed, the thickness of the clad portion is not reduced, and the accuracy of the core / cladding ratio is reduced. The yield and productivity of a high-quality optical fiber preform that has been improved can be improved, and costs can be reduced.
【図１】本発明の光ファイバ母材加工装置の構成例を示
す概要図である。 （ａ）本加工装置の正面概要図、（ｂ）応力付与機構の
母材ロッド支持ローラを側面から見た略図。FIG. 1 is a schematic view showing a configuration example of an optical fiber preform processing apparatus of the present invention. (A) Schematic front view of the present processing apparatus, (b) Schematic view of a base material rod support roller of a stress applying mechanism viewed from a side.
【図２】光ファイバ母材直径と曲り修正加工に要する酸
水素ガス量の関係を表した図である。FIG. 2 is a diagram illustrating a relationship between an optical fiber preform diameter and an oxyhydrogen gas amount required for bending correction processing.
【図３】光ファイバ母材直径と曲り修正加工に要する加
熱時間（加熱スケジュール）の関係を表した図である。FIG. 3 is a diagram showing a relationship between an optical fiber preform diameter and a heating time (heating schedule) required for bending correction processing.
【図４】光ファイバ母材（直径６７ｍｍ）の表面温度と
ＳｉＯの揮発速度の関係を表した図である。FIG. 4 is a diagram showing the relationship between the surface temperature of an optical fiber preform (diameter: 67 mm) and the evaporation rate of SiO.
【図５】光ファイバ母材（直径６７ｍｍ）の加熱時間と
表面温度との関係を、ガス量不制御の場合と本発明のよ
うにガス量を制御して絞った場合について表した図であ
る。FIG. 5 is a diagram illustrating a relationship between a heating time and a surface temperature of an optical fiber preform (diameter: 67 mm) in a case where the gas amount is not controlled and a case where the gas amount is controlled and reduced as in the present invention. .
１…加工装置、２…機台、３…コラム、５…チャック、
６…移動台、７…制御コンピュータ、８…ガスバーナ、
１０…外径測定器、１１…応力付与機構、１２…母材ロ
ッド支持ローラ、１３…エアシリンダ、１４…高圧エア
タンク、１５…電磁弁（出入り口弁）。Ｗ…光ファイバ
母材（母材ロッド）。1 ... processing equipment, 2 ... machine stand, 3 ... column, 5 ... chuck,
6: moving table, 7: control computer, 8: gas burner,
10: outer diameter measuring device, 11: stress applying mechanism, 12: base material rod supporting roller, 13: air cylinder, 14: high pressure air tank, 15: solenoid valve (inlet / outlet valve). W: Optical fiber preform (base material rod).
───────────────────────────────────────────────────── フロントページの続き (72)発明者 星野 昇次 群馬県安中市磯部２丁目13番１号 信越化 学工業株式会社群馬事業所内 (72)発明者 山村 和市 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 (72)発明者 島田 忠克 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 (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 Ｆターム(参考） 4G021 BA00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoji Hoshino 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Kagaku Kogyo Co., Ltd. Gunma Office (72) Inventor Kazuichi Yamamura Isobe, Annaka-shi, Gunma 2-13-1 Shin-Etsu Kagaku Kogyo Co., Ltd.Precision Functional Materials Research Laboratories (72) Inventor Tadakatsu Shimada 2-13-1 Isobe Annaka-shi, Gunma Pref. Inventor Hideo Hirasawa 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Kagaku Kogyo Co., Ltd. Precision Functional Materials Laboratory F-term (reference) 4G021 BA00
Claims (11)
ガスバーナで表面に火炎を吹き付けながら該母材の曲り
を修正する方法であって、外径測定器により軸方向のブ
レ量と曲り位置を検出し、該曲り位置にガスバーナを対
面させて該母材を加熱軟化させると共に、エアシリンダ
で駆動される少なくとも２本のローラで該母材を支持し
つつブレ量を減衰させる応力付与機構により曲りを修正
し、その後ガスバーナのガス量を絞って徐冷、固化し、
曲り修正を完了することを特徴とする光ファイバ母材の
加工方法。1. A method for correcting the curvature of an optical fiber preform while rotating the optical fiber preform about an axis while blowing a flame on the surface with a gas burner. A gas burner is opposed to the bending position to heat-soften the base material, and a stress applying mechanism that attenuates the amount of blur while supporting the base material with at least two rollers driven by an air cylinder. Correct the bend, then gradually reduce the gas volume of the gas burner, solidify,
A method for processing an optical fiber preform, wherein bending correction is completed.
持する位置を、現在修正中の曲り位置の次の曲り位置と
することを特徴とする請求項１に記載の光ファイバ母材
の加工方法。2. The processing of an optical fiber preform according to claim 1, wherein the position at which the optical fiber preform is supported by the stress applying mechanism is a bending position next to the bending position currently being corrected. Method.
て、該母材のクラッド部のＳｉＯの蒸発を抑制するため
に、ガスバーナの加熱用ガス量を光ファイバ母材の直径
に応じて調整することを特徴とする請求項１または請求
項２に記載の光ファイバ母材の加工方法。3. The optical fiber preform processing method according to claim 1, wherein the amount of gas for heating the gas burner is adjusted according to the diameter of the optical fiber preform in order to suppress evaporation of SiO in the clad portion of the preform. The method for processing an optical fiber preform according to claim 1 or 2, wherein:
て、該母材のクラッド部のＳｉＯの蒸発を抑制するため
にガスバーナの加熱時間を光ファイバ母材の直径に応じ
て調整することを特徴とする請求項１ないし請求項３の
いずれか１項に記載の光ファイバ母材の加工方法。4. A method for processing an optical fiber preform, wherein a heating time of a gas burner is adjusted according to a diameter of the optical fiber preform in order to suppress evaporation of SiO in a clad portion of the preform. The method for processing an optical fiber preform according to any one of claims 1 to 3.
て、該母材のクラッド部のＳｉＯの蒸発を抑制するため
にガスバーナの加熱用ガス量を、曲りが修正可能な温度
に到達した後、時間の経過に従って順次減少させ、クラ
ッド表層温度を２３００℃以下とすることを特徴とする
請求項１ないし請求項４のいずれか１項に記載した光フ
ァイバ母材の加工方法。5. The method for processing an optical fiber preform according to claim 1, wherein the amount of heating gas of the gas burner is reduced after reaching a temperature at which a bend can be corrected in order to suppress evaporation of SiO in a clad portion of the preform. The method for processing an optical fiber preform according to any one of claims 1 to 4, wherein the surface temperature of the cladding is gradually reduced to 2300 ° C or less as time elapses.
て、該母材の曲りが修正された時点でこれを固化する徐
冷時間を該母材の直径に応じて調整することを特徴とす
る請求項１ないし請求項５のいずれか１項に記載した光
ファイバ母材の加工方法。6. The method of processing an optical fiber preform according to claim 1, wherein when the bending of the preform is corrected, a slow cooling time for solidifying the bend is adjusted according to a diameter of the preform. The method for processing an optical fiber preform according to any one of claims 1 to 5.
ローラに一定の圧力を印加後、エアシリンダの出入口弁
を閉じてエアクッションを形成し、該母材をエアクッシ
ョンで保持しながら加熱軟化させ、ブレが減衰して曲り
修正が終わった時点をローラの変位量あるいはエアシリ
ンダの圧力変動量から検出した後、徐冷に入ることを特
徴とする請求項１ないし請求項６のいずれか１項に記載
した光ファイバ母材の加工方法。7. After applying a predetermined pressure to the optical fiber preform supporting roller of the stress applying mechanism, an inlet / outlet valve of the air cylinder is closed to form an air cushion, and the base material is heated and softened while being held by the air cushion. 7. The method according to claim 1, wherein the cooling is started after detecting the time when the blur is attenuated and the correction of the bending is completed based on the displacement of the roller or the pressure fluctuation of the air cylinder. The method for processing an optical fiber preform described in the paragraph.
する圧力は、光ファイバ母材の曲り修正箇所のブレ量と
母材の直径に対応して調整されることを特徴とする請求
項１ないし請求項７のいずれか１項に記載した光ファイ
バ母材の加工方法。8. The optical fiber preform according to claim 1, wherein the pressure applied to the air cylinder of the stress applying mechanism is adjusted in accordance with the amount of shake of the bent portion of the optical fiber preform and the diameter of the preform. A method for processing an optical fiber preform according to claim 7.
ローラに一定の圧力を印加後、エアシリンダの出入口弁
を閉じてエアクッションを形成し、該母材をエアクッシ
ョンで保持しながら加熱軟化させるに際し、ローラの変
位量あるいはエアシリンダの圧力変動量に応じてガスバ
ーナの加熱用ガス量を調整することを特徴とする請求項
１ないし請求項７のいずれか１項に記載した光ファイバ
母材の加工方法。9. After applying a constant pressure to the optical fiber preform supporting roller of the stress applying mechanism, the inlet / outlet valve of the air cylinder is closed to form an air cushion, and the base material is heated and softened while being held by the air cushion. The optical fiber preform according to any one of claims 1 to 7, wherein the amount of heating gas of the gas burner is adjusted in accordance with the amount of displacement of the roller or the amount of pressure fluctuation of the air cylinder. Processing method.
一端を把持し、把持された光ファイバ母材の軸方向に沿
って移動可能となり、かつ光ファイバ母材の曲り位置と
ブレ量を測定する外径測定手段を備え、この外径測定手
段の測定結果に基づいて移動可能となりかつ光ファイバ
母材の表面に向けて火炎を吹き付けることのできるガス
バーナと、エアシリンダで駆動される少なくとも２本の
ローラで該母材を支持しつつブレ量を減衰させることの
できる応力付与機構を備えたことを特徴とする光ファイ
バ母材の加工装置。10. An optical fiber preform is gripped at least at one end in the axial direction, is movable along the axial direction of the gripped optical fiber preform, and measures a bending position and a blur amount of the optical fiber preform. A gas burner which is provided with an outer diameter measuring means, is movable based on the measurement result of the outer diameter measuring means and can blow a flame toward the surface of the optical fiber preform, and at least two gas burners driven by an air cylinder An apparatus for processing an optical fiber preform, comprising a stress applying mechanism capable of attenuating the amount of blur while supporting the preform with a roller.
圧変動またはローラの変位量を測定してガスバーナのガ
ス量を制御する制御手段を備えたことを特徴とする請求
項１０に記載の光ファイバ母材の加工装置。11. The optical fiber according to claim 10, further comprising control means for controlling a gas amount of a gas burner by measuring a back pressure fluctuation of an air cylinder or a displacement amount of a roller of the stress applying mechanism. Base metal processing equipment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04785699A JP3198291B2 (en) | 1999-02-25 | 1999-02-25 | Processing method and processing apparatus for optical fiber preform |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04785699A JP3198291B2 (en) | 1999-02-25 | 1999-02-25 | Processing method and processing apparatus for optical fiber preform |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000247672A true JP2000247672A (en) | 2000-09-12 |
| JP3198291B2 JP3198291B2 (en) | 2001-08-13 |
Family
ID=12787023
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04785699A Expired - Fee Related JP3198291B2 (en) | 1999-02-25 | 1999-02-25 | Processing method and processing apparatus for optical fiber preform |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3198291B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005092807A1 (en) * | 2004-03-25 | 2005-10-06 | Shin-Etsu Chemical Co., Ltd. | Method and apparatus for processing glass matrix for optical fiber |
| JP2006193369A (en) * | 2005-01-13 | 2006-07-27 | Shin Etsu Chem Co Ltd | Method and apparatus for processing quartz glass bar and carbon tool used for the same |
| JP2006265000A (en) * | 2005-03-22 | 2006-10-05 | Sumitomo Metal Ind Ltd | Method and device for producing quartz glass material |
| CN110746108A (en) * | 2019-11-28 | 2020-02-04 | 杭州富通通信技术股份有限公司 | Manufacturing method of precast rod core rod |
| CN110746107A (en) * | 2019-11-28 | 2020-02-04 | 杭州富通通信技术股份有限公司 | Method for manufacturing preform loose body |
| KR102151801B1 (en) * | 2020-06-16 | 2020-09-03 | 김성춘 | Glass forming machine |
| CN114105468A (en) * | 2021-12-17 | 2022-03-01 | 江苏亨通光纤科技有限公司 | Device and method for straightening quartz tube rod |
-
1999
- 1999-02-25 JP JP04785699A patent/JP3198291B2/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005092807A1 (en) * | 2004-03-25 | 2005-10-06 | Shin-Etsu Chemical Co., Ltd. | Method and apparatus for processing glass matrix for optical fiber |
| JP2006193369A (en) * | 2005-01-13 | 2006-07-27 | Shin Etsu Chem Co Ltd | Method and apparatus for processing quartz glass bar and carbon tool used for the same |
| JP4583938B2 (en) * | 2005-01-13 | 2010-11-17 | 信越化学工業株式会社 | Method and apparatus for processing quartz glass rod |
| JP2006265000A (en) * | 2005-03-22 | 2006-10-05 | Sumitomo Metal Ind Ltd | Method and device for producing quartz glass material |
| JP4546300B2 (en) * | 2005-03-22 | 2010-09-15 | 株式会社オハラ | Method and apparatus for producing quartz glass material |
| CN110746108A (en) * | 2019-11-28 | 2020-02-04 | 杭州富通通信技术股份有限公司 | Manufacturing method of precast rod core rod |
| CN110746107A (en) * | 2019-11-28 | 2020-02-04 | 杭州富通通信技术股份有限公司 | Method for manufacturing preform loose body |
| CN110746107B (en) * | 2019-11-28 | 2022-04-05 | 杭州富通通信技术股份有限公司 | Method for manufacturing preform loose body |
| KR102151801B1 (en) * | 2020-06-16 | 2020-09-03 | 김성춘 | Glass forming machine |
| CN114105468A (en) * | 2021-12-17 | 2022-03-01 | 江苏亨通光纤科技有限公司 | Device and method for straightening quartz tube rod |
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|---|---|
| JP3198291B2 (en) | 2001-08-13 |
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