JP4040127B2

JP4040127B2 - Method and apparatus for manufacturing quartz glass tube

Info

Publication number: JP4040127B2
Application number: JP27748496A
Authority: JP
Inventors: 明彦須釜
Original assignee: Shin Etsu Quartz Products Co Ltd
Current assignee: Shin Etsu Quartz Products Co Ltd
Priority date: 1996-09-27
Filing date: 1996-09-27
Publication date: 2008-01-30
Anticipated expiration: 2016-09-27
Also published as: JPH10101352A

Description

【０００１】
【発明の属する技術分野】
本発明は、石英ガラス製中空管を使用して半導体製造装置の炉心管等の半導体治具部材や光ファイバー用石英ガラス管等に使用される中空石英ガラス管の製造方法とその装置に関する。
【０００２】
【従来の技術】
従来より、中空石英ガラス管の製造方法は、石英ガラス製厚肉シリンダを使用して、その一端を封止した状態で内部に内圧用の窒素等の圧縮ガスを導入した状態で所定引抜き径を持つダイスに導入し、前記内圧を加圧して、ダイス内で前記シリンダを膨らませながら前記ダイス径により外径を規制しつつ引き出し、所定外径を持つ薄肉筒状部材である石英ガラス管を得るようにしている。
【０００３】
かかる装置を図８に基づいて例示的に説明するに、図において、炉体１０２に石英ガラス製シリンダ１００を加熱軟化させる筒状発熱体１０３を配置するとともにその出口側にダイス支持部１０４を設け、該ダイス支持部１０４内周に回転自在に嵌挿され、所定内径を持つダイス本体１０５を取り付ける。
そして上記ダイス本体１０５内径より小さい外径を持つ前記石英ガラス製シリンダ１００を先端を封止した状態でダイス本体に挿入しつつ矢印１０６方向に回転させながら窒素または空気等を矢印Ｐ方向にシリンダ１００内に導入して内圧を発生させ、前記ダイス本体１０５内でシリンダ内径を膨らませながら矢印１０７方向に回転引き出すことにより、ダイス本体１０５により外径規制された所定外径Ｄ１を持つ石英ガラス管を形成することが出来る。（実用新案登録第２５０２８６８号）
【０００４】
【発明が解決しようとする課題】
かかる装置においては、下記問題点を内蔵している。
即ち、
１）ダイス本体１０５内で、加熱軟化した石英ガラス製シリンダ１００を内圧Ｐにより膨らませ、ダイス径により外径規制をするため、内圧の選択により外径精度はある程度確保できるが、前記短幅のダイス本体内で膨出させて外径規制する為に、図７（Ｂ）に示すように規制時点の肉厚の変動が大きく、幅方向に肉厚に波を打つ場合がある。
２）上記問題に対しダイス幅を長くすることも考えられるが、ダイスとシリンダ外周との摺動抵抗が増大し引抜きがうまく行かないのみならず、加熱炉も必然的に長くなる問題があり、コスト高の原因を形成する。
３）又、加熱炉の温度は２０００℃以上である為に、ダイス幅を長くするグラファイト製のダイス本体は脆く破損され易く、又ダイス本体を支持するダイス支持部１０４もこれに対応して必然的に長くなり、特にダイス支持部は金属（Ｃｕ）で形成され内部に冷却媒体が還流可能な冷却手段が付加されているために、これを加熱炉内部まで延在させる事は中々困難であるのみならず構造も複雑化する。
４）前記ダイス本体は、上記製作する石英ガラス管の外径のそれぞれに対応して準備するとともに、その都度交換する必要があり、取り換えに伴う冷却時間等による休転時間の増大延いては稼動率低下の問題がある。
【０００５】
本発明は、上記問題点に鑑みなされたもので、即ち、
外径精度並びに肉厚バラツキを最小に押さえることができ、また、製造する石英ガラス管の外径の変更の都度交換する必要のない外径設定治具を備えた石英ガラス管の製造装置を提供するようにしたものである。
【０００６】
また、請求項２記載の発明は、前記発明の目的に加え、外径規制につき、製造する石英ガラス管の外径変更に随意対応できるようにした、外径制御による均一肉厚を持つ石英ガラス管の製造装置の提供を目的としたものである。
【０００７】
また、本発明は、現場作業員による手動操作を改めて外径規制とともに、内圧制御の自動化を図った石英ガラス管の製造装置の提供を目的としたものである。
【０００８】
また、請求項３及び請求項４記載の発明は、更に精度のよい石英ガラス管の外径と肉厚制御を可能とする石英ガラス管御の製造装置の提供を目的としたものである。
【０００９】
また、請求項５及び６記載の発明は、更に精度のよい石英ガラス管の外径と均一肉厚を有する石英ガラス管の製造方法の提供を目的としたものである。
【００１０】
【課題を解決するための手段】
かかる課題を解決するために、請求項１記載の発明は、先端を封止してチューブ状に形成させた石英ガラス製中空管を加熱軟化させる加熱手段と、
前記中空管内部に内圧用ガスを導入するとともに加熱軟化させた中空管を膨出させる内圧生成手段と、
前記膨出させた加熱軟化状態にある中空管（以下石英ガラス管という）外周面に接触させ外径規制させる外径設定治具とを備え、
前記石英ガラス管を加熱手段内で軸方向に移動させつつ所定外径の石英ガラス管を製造する装置において、
前記外径設定治具との接触手前位置で、外径設定治具通過後の石英ガラス管外径Ｄ１を僅か上回る石英ガラス管外径Ｄ２を持つ膨張部を形成するように外径規制及び内圧制御可能に構成し、
前記外径規制は、非加熱領域からの遠隔測定で得られた石英ガラス管膨張部外径と外径設定治具通過後の石英ガラス管外径との差△Ｄを演算して、該△Ｄ（前記膨張量△Ｄ＝［（Ｄ２−Ｄ１）／２］）が、０＜△Ｄ≦１ｍｍの範囲に維持するように内圧制御を行うことを特徴とするものである。
【００１１】
上記内圧操作は炉内部での膨張部の膨らみ状況の目視観測結果に基づき、手動バルブ操作により行ってもよく、又レーザ外径測定器よりの測定結果に基づいて電磁弁等によるバルブ操作により行ってもよい。
【００１２】
この場合請求項２記載のように、前記外径設定治具の規制幅を変位可能に構成するとともに、外径規制後の石英ガラス管外径を計測する手段を設け、該計測手段による計測値に基づいて外径設定治具の規制幅若しくは内圧を制御しながら所定外径の石英ガラス管を得るようにするのがよい。
【００１３】
請求項５記載の発明は、先端を封止してチューブ状に形成させた石英ガラス製中空管を加熱炉で加熱軟化させ、該中空管内部に内圧用ガスを導入するとともに、外径設定治具を前記加熱軟化状態にある石英ガラス管外周面に接触させ、外径規制させた状態で、前記石英ガラス管を軸方向に移動させつつ所定外径の石英ガラス管を製造する方法において、
上記石英ガラス管の加熱軟化領域を内圧操作により、外径設定治具接触手前位置で、外径設定治具通過後の石英ガラス管外径Ｄ１を僅か上回る石英ガラス管外径Ｄ２を持つ膨張部を形成させ、該膨張部を外径設定治具に侵入させながら前記石英ガラス管の外径規制を行うとともに、前記外径規制は、非加熱領域からの遠隔測定で得られた石英ガラス管膨張部外径と外径設定治具通過後の石英ガラス管外径との差△Ｄを演算して、該△Ｄ（前記膨張量△Ｄ＝［（Ｄ２−Ｄ１）／２］）が、０＜△Ｄ≦１ｍｍの範囲に維持するように内圧制御を行うことを特徴とする石英ガラス管の製造方法にある。
この場合、具体的な数値としては、前記膨張量△Ｄ＝［（Ｄ２−Ｄ１）／２］の適正設定範囲が、０＜△Ｄ≦１ｍｍ、好ましくは０＜△Ｄ≦０．５ｍｍであるのがよい。
【００１４】
かかる発明によれば、外径規制手前で石英ガラス製シリンダの外径を内圧操作と加熱軟化とにより均一な薄肉状筒体に薄肉膨張させ、爾後外径設定治具を介して外径規制をすることにより、外径精度並びに肉厚精度の向上を図ることが出来る。
【００１５】
なお、前記外径設定治具は加熱炉出口側の加熱温度分布立ち下がり部に位置し、該外径設定治具による外径規制後石英ガラス管を加熱させないようにするのがよい。
そして更に具体的には請求項５記載のように、前記外径設定治具は、中空管状母材を挟んで母材半径方向に変位可能な一対の平行規制板により構成され、
前記外径設定治具により外径規制後の母材外径が所定外径Ｄ１に近付くように前記一対の平行規制板の規制幅を制御可能に構成するのがよい。
【００１６】
かかる構成によれば、従来のリング状ダイスによる外径規制では、被外径規制石英ガラス管を回転状態で挟持する板状部材による回転狭窄機能を使用したため、石英ガラス管の外径寸法の変更に対しても板状部材の間隔を制御するだけで問題なく処理できる。
また、高温石英ガラス管に接するグラファイト製板状部材の冷却も簡単にできる効果を持つ。
【００１７】
【発明の実施の形態】
以下、本発明の実施例の形態を、図示例と共に説明する。ただし、この実施例に記載されている構成部品の寸法、形状、その相対的位置等は特に特定的な記載がないかぎりは、この発明の範囲をそれに限定する趣旨ではなく、単なる説明例にすぎない。
図１は本発明の基本構成に係る石英ガラス管の製造装置で、１０は厚肉の石英ガラス製シリンダで、先端を丸封させるとともに、他端の開口部を窒素導入治具１６で封止し、内圧調整バルブ１８を介して石英ガラス製シリンダ１０内に内圧が導入可能に構成されている。
又、丸封された石英ガラス製シリンダ１０の軸側には、中心軸に沿ってダミーロッド２３が延設されており、該ダミーロッド２３の自由端側と石英ガラス製シリンダ１０の基端側にはそれぞれ移動回転治具２２Ａ及び２２Ｂが回転自在に支持されており、該移動回転治具２２Ａ、２２Ｂにより石英ガラス製シリンダ１０を回転させながら加熱炉内に沿って中心軸上を移動可能に構成されている。
【００１８】
前記基端側に設けた内圧導入部（窒素導入治具１６及び内圧調整バルブ１８）を介しての内圧操作Ｐと並行する前記石英ガラス製シリンダを加熱軟化膨張させる加熱炉１３は、周囲に断熱材１３ａが巻き回された円筒状の電気炉で構成されているとともに、該加熱炉１３の外側に基部を持ちダミーロッド２３側よりシリンダ１０の軸線と平行に一対のホルダ１４ａが加熱炉１３内側末端付近に向け延設され、その延設端である自由端側にグラファイト製平行規制板１４ｂが石英ガラス管に対面する位置に配設されている。
即ち、外径設定治具１４は一対のホルダ１４ａと一対の平行規制板１４ｂとからなる。前記ホルダ１４ａは銅部材で内部に冷媒が還流可能に構成され、平行規制板１４ｂを裏面側より冷却させるとともに、石英ガラス管１２のラジアル方向の矢印Ａに沿い手動操作にて互いに反対方向に変位可能に構成する。
平行規制板１４ｂは、加熱軟化により膨張した石英ガラス管１２を狭持するようにして石英ガラス管１２の回転と相俟ってその挟圧力により外径規制を可能にし、且つ石英ガラス管１２の長軸方向に平行に配設された一対のグラファイト製平行規制板１４ｂにより構成されている。
【００１９】
かかる構成によれば、加熱炉１３内に設けた外径規制用の平行規制板１４ｂの間隔を所定外径Ｄ１に設定した後、石英ガラス製シリンダ１０を回転させながら加熱炉１３に挿入させて加熱軟化させ、窒素導入治具１６及びバルブ１８を介してシリンダ１０内に内圧Ｐを加圧する。
そして略２３００℃の加熱温度で加熱軟化させた石英ガラス製シリンダ１０が平行規制板１４ｂに接触する手前で、所定外径Ｄ１を僅かに上回る石英ガラス管１２の外径Ｄ２を持つ膨張部１１を形成させ、該膨張部１１を前記平行規制板１４ｂにより押圧させながら外径規制をして、図７（Ａ）に示すように所定外径Ｄ１の均一肉厚を持つ石英ガラス管１２を得ることが出来る。
【００２０】
上記内圧操作は、本実施例では内圧を内圧調整バルブ１８により手動操作して所定外径Ｄ１より微小膨張した膨張部１１の外径Ｄ２を前記外径設定治具１４により押圧させるようにしてある。
そして前記膨張部位１１における微小膨張分である△Ｄ（＝［Ｄ２−Ｄ１］／２）が大きくなった場合は平行規制板１４ｂはホルダ１４ａの自由端側に配設されているために、該平行規制板１４ｂはその際広がり現象を起こし高精度の外径規制ができない。
従って上記△Ｄの適切な値の適正設定範囲は、０＜△Ｄ≦０．５〜１ｍｍ程度であり、好ましくは０＜△Ｄ≦０．５ｍｍがよく、この範囲内においては外径、肉厚が安定した石英ガラス管１２の製造が可能である。
つまり、△Ｄが上記設定範囲内にあるよう、内圧制御することが本発明の必須条件となる。又、外径設定治具１４の設定位置は、図２に示すように、加熱炉１３内の加熱温度分布が立ち下がり位置に外径設定治具１４の平行規制板１４ｂを配置して外径規制を行うのが良い。
【００２１】
さて前記実施例においては、製造された石英ガラス管１２の外径をオペレータがノギスで測定し、所定外径から外れた場合にホルダ１４ａの間隔調整を手動で行うために、外径測定作業と前記治具による設定作業を頻繁に行う必要があり、また、得られた石英ガラス管１２の外径変動も大きく歩留まり低下の原因を形成する。
【００２２】
そこで、上記問題を解決する為に、図３に示すように、石英ガラス管１２の外径測定をレーザ外径測定器等による遠隔測定を行い、得られた石英ガラス管１２の外径と所定外径との差をコンピュータで演算して外径規制の精度向上を図るのがよい。
図３は、前記外径規制を自動的に行う本発明の他の実施例を示す石英ガラス管の製造装置で、１９は加熱炉１３の外部出口側に配設されたレーザ外径測定器、２１はホルダ１４ａを介して一対の平行規制板１４ｂを矢印Ａの幅方向に変位させるホルダ自動調整用モータ、２０は外径自動調整用制御機器で、レーザ外径測定器により測定した検出信号により正しい規制外径Ｄ１との偏差量△ｄに基づくホルダ自動調整用モータ２１を駆動制御する。
【００２３】
次にかかる構成の動作を図４に基づいて説明する。
１）先ず予め、正しい規制外径Ｄ１を外径自動調整用制御機器２０に入力して置く。
２）次に外径自動調整用制御機器２０を介してホルダ自動調整用モータ２１を駆動制御させ、ホルダ１４ａを介して一対の平行規制板１４ｂの間隔を所定外径Ｄ１に設定する。
３）次に前記実施形態に基づく石英ガラス管１２の製造を開始し、該ガラス管を前記間隔設定をした一対の平行規制板１４ｂに接触安定させる。
４）外径自動調整用制御機器２０を自動運転モードに切り換える。
５）レーザ外径測定器１９（走査形外径測定器による遮断パルス数のカウント出力）で石英ガラス管１２の外径Ｄ１を測定する。
６）測定された外径データを外径自動調整用制御機器２０のコンピュータに取込み設定されている所定外径Ｄ１との偏差量（△ｄ）の値を求める。
７）求めた前記偏差量（△ｄ）の分だけ、グラファイト製の平行規制板１４ｂをホルダ１４ａを介して移動させるために、ホルダ自動調整用モータ２１に信号を送る。
８）ホルダ自動調整用モータ２１が作動し、平行規制板１４ｂはホルダ１４ａを介して移動する。
９）オペレータは、炉内を監視しながら、石英ガラス管１２を前記グラファイト製の平行規制板１４ｂに接触させる。
１０）上記５）〜８）までの操作を繰り返し行うことによって、偏差量（△ｄ）の値を極力小さくすることが可能となる。これにより、製造された石英ガラス管１２の外径は、非常に安定したものになる。
【００２４】
図５は前記内圧操作をも自動化した他の実施例である。該実施例による内圧自動操作は、手動による内圧調整バルブ１８の代りに設けたガス導入用内圧自動調整電磁バルブ１８ａとリリース用電磁バルブ１８ｂと、該バルブ群を開閉制御するガス内圧自動調整装置３０と、該内圧自動調整装置３０に連携する画像処理装置３２と、該画像処理装置３２に映像信号を入力する膨張部１１の外径Ｄ２を測定する画像処理装置用ＣＣＤカメラ３１、３１と、同じく前記画像処理装置３２にカウンタ信号を入力する石英ガラス管１２の外径Ｄ１を測定するレーザ外径測定器１９（走査形外径測定器による遮断パルス数のカウント数により検出）とよりなる。
そして外径規制後の加熱炉１３の出口側の石英ガラス管外径（所定外径Ｄ１）に対するレーザ測定器１９よりのカウンタ計測信号と、膨張部１１の外径Ｄ２の前記ＣＣＤカメラ３１による映像信号とを入力して、前記［Ｄ２とＤ１との差△Ｄを画像処理装置３２で演算し、演算した△Ｄと前記適正設定範囲（０＜△Ｄ≦０．５ｍｍ）とを内圧自動調整装置３０で比較し、その比較結果に基づきガス導入用内圧自動調整電磁バルブ１８ａとリリース用電磁バルブ１８ｂとを制御し、内圧操作の自動制御を行うもので、前記△Ｄが常に前記適正設定範囲で変動するようにして、より安定した肉厚を持つ石英ガラス管１２が得られるようにしてある。
【００２５】
次にかかる実施例の動作手順を図６に示すブロック図に基づいて説明する。
１）石英ガラス管１２の引き始めの部分は、オペレータによる手動操作で行う。
２）石英ガラス管１２の外径が所定の外径Ｄ１になり安定したところで、自動運転に入る。
３）まず、レーザ外径測定器１９で石英ガラス管１２の外径Ｄ１を測定し、Ｄ１データを形成するカウンタ出力を画像処理装置３２に入力させる。
４）画像処理用ＣＣＤカメラ３１、３１により膨張部外径を測定し、Ｄ２データを形成する映像信号を画像処理装置３２に入力させる。
５）画像処理装置３２のコンピュータで、前記入力したＤ１データとＤ２データとの演算処理により△Ｄを求める。
６）求めた△Ｄを内圧自動調整装置３０のコンピュータにおくる。
７）内圧自動調整装置３０のコンピュータには、予め前記△Ｄの範囲を設定しておく。
設定範囲は、更に０．１ｍｍ＜△Ｄ≦０．４ｍｍに設定してある。
８）内圧自動調整装置３０のコンピュータは、前記△Ｄが前記△Ｄの設定範囲に入るように、内圧→ガス導入用内圧自動調整電磁バルブ１８ａとリリース用電磁バルブ１８ｂとを作動させる。
９）電磁バルブの制御方法は、△Ｄが△Ｄの設定範囲の下限値に近付いた場合、内圧自動調整電磁バルブ１８ａを開け、リリース用電磁バルブ１８ｂを閉じ、石英ガラス製シリンダ１０に内圧をかける。
一方△Ｄの上限に近付いた場合、内圧自動調整電磁バルブ１８ａを閉じ、リリース用電磁バルブ１８ｂを開け、石英ガラス製シリンダ１０より内圧を抜く。
なお、上記３）〜９）までのフィードバックスピードを速くすることによって、△Ｄの設定範囲を狭めることが可能となる。結果として、製造された石英ガラス管１２の肉厚は非常に安定したものになる。
【００２６】
従って本実施例によれば、△Ｄに基づいて内圧が自動制御されるため、製造された石英ガラス管１２の寸法精度は顕著に向上し、特に外径規制の手前で内圧操作及び加熱炉１３における温度操作により膨張部を形成するようにしたため、外径精度ばかりでなく肉厚のバラツキも最小に押さえることができる。また、フィードバック数値制御による内圧制御により、外径、肉厚ともに精度の高い石英ガラス管１２を得ることが可能である。
【００２７】
【発明の効果】
以上記載のごとく本発明によれば、外径精度並びに肉厚バラツキを最小に押さえることができ、また、製造する石英ガラス管の外径変更の都度交換する必要がなく、生産性の極めて高い石英ガラス管の製造方法とその装置を得ることが出来る。
【図面の簡単な説明】
【図１】本発明の第１実施例に係わる石英ガラス管の製造装置の概略構成図である。
【図２】加熱炉内の温度分布と外径設定治具（平行規制板）の配置図を示す。
【図３】本発明の第２実施例で、外径規制の自動化を図った石英ガラス管の製造装置の概略構成図である。
【図４】図３の外径規制の制御機構を示すブロック図である。
【図５】本発明の第３実施例で、内圧制御と外径規制の自動化を図った石英ガラス管の製造装置の概略構成図である。
【図６】図５の内圧制御の制御機構の概略の構成を示すブロック図である。
【図７】本発明により製造した石英ガラス管の肉厚バラツキを従来装置に比較して示す断面図で、（Ａ）は本発明による製造法による場合を示し、（Ｂ）は従来装置による場合を示す。
【図８】従来の石英ガラス管の製造装置の概略構成図である。
【符号の説明】
１０石英ガラス製シリンダ
１１膨張部
１２石英ガラス管
１３加熱炉
１４外径設定治具
１４ａホルダ
１４ｂ平行規制板
１８内圧調整バルブ
１８ａ内圧自動調整電磁バルブ
１８ｂリリース用電磁バルブ
１９レーザ外径測定器
２０外径自動調整用制御機器
２１ホルダ自動調整用モータ
３０内圧自動調整装置
３１画像処理装置用ＣＣＤカメラ
３２画像処理装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for manufacturing a hollow quartz glass tube used for a semiconductor jig member such as a core tube of a semiconductor manufacturing apparatus or a quartz glass tube for an optical fiber using a quartz glass hollow tube.
[0002]
[Prior art]
Conventionally, a method for manufacturing a hollow quartz glass tube has used a quartz glass thick-walled cylinder, with a predetermined drawing diameter in a state in which a compressed gas such as nitrogen for internal pressure is introduced inside with one end sealed. The quartz glass tube, which is a thin-walled cylindrical member having a predetermined outer diameter, is introduced into a die having the inner pressure, pulled out while regulating the outer diameter by the die diameter while inflating the cylinder in the die. I have to.
[0003]
Such an apparatus will be exemplarily described with reference to FIG. 8. In the figure, a cylindrical heating element 103 for heating and softening a quartz glass cylinder 100 is disposed in a furnace body 102, and a die support 104 is provided on the outlet side thereof. A die body 105 having a predetermined inner diameter is attached to the inner periphery of the die support portion 104 so as to be freely rotatable.
The quartz glass cylinder 100 having an outer diameter smaller than the inner diameter of the die body 105 is inserted into the die body with the tip sealed, and nitrogen or air is rotated in the direction of the arrow 106 while rotating the cylinder 100 in the direction of the arrow P. A quartz glass tube having a predetermined outer diameter D1 whose outer diameter is regulated by the die body 105 is formed by generating the internal pressure by introducing it into the die body 105 and rotating it in the direction of the arrow 107 while expanding the cylinder inner diameter in the die body 105. I can do it. (Utility model registration No. 2502868)
[0004]
[Problems to be solved by the invention]
Such an apparatus incorporates the following problems.
That is,
1) In the die body 105, the heat-softened quartz glass cylinder 100 is inflated by the internal pressure P, and the outside diameter is regulated by the die diameter. In order to restrict the outer diameter by bulging in the body, as shown in FIG. 7 (B), the fluctuation of the wall thickness at the time of regulation is large, and there is a case where the wave is waved in the width direction.
2) Although it is conceivable to increase the die width for the above problem, not only does the sliding resistance between the die and the cylinder outer periphery increase and the drawing does not work well, but also the heating furnace inevitably becomes longer, Form the cause of high costs.
3) Since the temperature of the heating furnace is 2000 ° C. or higher, the die body made of graphite that makes the die width longer is brittle and easily damaged, and the die support portion 104 that supports the die body is inevitably corresponding to this. In particular, since the die support portion is formed of metal (Cu) and a cooling means capable of circulating the cooling medium is added to the inside, it is difficult to extend the inside of the heating furnace. Not only is the structure complicated.
4) The die body must be prepared corresponding to each of the outer diameters of the quartz glass tube to be manufactured, and needs to be replaced each time. There is a problem of rate drop.
[0005]
The present invention has been made in view of the above problems, that is,
Quartz glass tube manufacturing equipment with an outer diameter setting jig that can minimize outer diameter accuracy and wall thickness variation and does not need to be replaced whenever the outer diameter of the manufactured quartz glass tube changes. It is what you do.
[0006]
In addition to the object of the present invention, the invention according to claim 2 is a quartz glass having a uniform wall thickness by controlling the outer diameter so as to be able to cope with a change in the outer diameter of the quartz glass tube to be manufactured with respect to the outer diameter restriction. The purpose is to provide a pipe manufacturing apparatus.
[0007]
Another object of the present invention is to provide an apparatus for manufacturing a quartz glass tube in which manual operation by a field worker is re-executed and the inner diameter control is automated along with the outer diameter regulation.
[0008]
Further, the inventions according to claim 3 and claim 4 are intended to provide a quartz glass tube manufacturing apparatus capable of controlling the outer diameter and thickness of the quartz glass tube with higher accuracy.
[0009]
The inventions of claims 5 and 6 are intended to provide a method for producing a quartz glass tube having a more accurate outer diameter and uniform wall thickness.
[0010]
[Means for Solving the Problems]
In order to solve such a problem, the invention according to claim 1 includes heating means for heating and softening a quartz glass hollow tube having a sealed tip and formed into a tube shape,
An internal pressure generating means for introducing an internal pressure gas into the hollow tube and expanding the heated and softened hollow tube;
An outer diameter setting jig for contacting the outer surface of the hollow tube (hereinafter referred to as a quartz glass tube) that is in the heat-softened state that has been swelled to regulate the outer diameter;
In the apparatus for producing a quartz glass tube having a predetermined outer diameter while moving the quartz glass tube in the axial direction in the heating means,
Outer diameter regulation and inner pressure so as to form an expanded portion having a quartz glass tube outer diameter D2 slightly larger than the quartz glass tube outer diameter D1 after passing through the outer diameter setting jig at a position just before the contact with the outer diameter setting jig. Configured to be controllable ,
The outer diameter restriction is calculated by calculating a difference ΔD between the outer diameter of the expanded portion of the quartz glass tube obtained by remote measurement from the non-heated region and the outer diameter of the quartz glass tube after passing through the outer diameter setting jig. The internal pressure control is performed so that D (the expansion amount ΔD = [(D2−D1) / 2]) is maintained in a range of 0 <ΔD ≦ 1 mm .
[0011]
The internal pressure operation may be performed by manual valve operation based on the result of visual observation of the expansion state of the expansion part inside the furnace, or by valve operation using a solenoid valve or the like based on the measurement result from the laser outer diameter measuring instrument. May be.
[0012]
In this case, as defined in claim 2, the restriction width of the outer diameter setting jig is configured to be displaceable, and a means for measuring the outer diameter of the quartz glass tube after the outer diameter restriction is provided. It is preferable to obtain a quartz glass tube having a predetermined outer diameter while controlling the regulation width or the inner pressure of the outer diameter setting jig based on the above.
[0013]
The invention according to claim 5 is to heat and soften a quartz glass hollow tube sealed in a tube shape in a heating furnace, introduce an internal pressure gas into the hollow tube, and In a method of manufacturing a quartz glass tube having a predetermined outer diameter while moving the quartz glass tube in the axial direction in a state in which the setting jig is brought into contact with the outer peripheral surface of the quartz glass tube in the heat softened state and the outer diameter is regulated. ,
An expansion portion having a quartz glass tube outer diameter D2 slightly larger than the outer diameter D1 of the quartz glass tube after passing through the outer diameter setting jig at a position before the outer diameter setting jig is contacted by an internal pressure operation in the heat softening region of the quartz glass tube. The outer diameter of the quartz glass tube is regulated while allowing the expansion portion to enter the outer diameter setting jig, and the outer diameter regulation is performed by expanding the quartz glass tube obtained by remote measurement from a non-heated region. The difference ΔD between the outer diameter of the portion and the outer diameter of the quartz glass tube after passing through the outer diameter setting jig is calculated, and ΔD (the expansion amount ΔD = [(D2−D1) / 2]) is 0. In the method for producing a quartz glass tube, the internal pressure is controlled so as to be maintained in the range of <ΔD ≦ 1 mm .
In this case, as a specific numerical value, an appropriate setting range of the expansion amount ΔD = [(D2−D1) / 2] is 0 <ΔD ≦ 1 mm, preferably 0 <ΔD ≦ 0.5 mm. It is good.
[0014]
According to this invention, the outer diameter of the quartz glass cylinder is thinly expanded into a uniform thin cylindrical body by internal pressure operation and heat softening before the outer diameter restriction, and the outer diameter restriction is performed via the outer diameter setting jig. By doing so, it is possible to improve the outer diameter accuracy and the wall thickness accuracy.
[0015]
The outer diameter setting jig is preferably located at the falling portion of the heating temperature distribution on the outlet side of the heating furnace so that the quartz glass tube is not heated after the outer diameter is regulated by the outer diameter setting jig.
And more specifically, as described in claim 5, the outer diameter setting jig is constituted by a pair of parallel restricting plates that can be displaced in the base metal radial direction with a hollow tubular base material interposed therebetween,
It is preferable that the restriction widths of the pair of parallel restriction plates be controllable so that the outer diameter of the base material after the outer diameter restriction approaches the predetermined outer diameter D1 by the outer diameter setting jig.
[0016]
According to such a configuration, in the outer diameter restriction by the conventional ring-shaped die, the outer diameter dimension of the quartz glass tube is changed because the rotation constriction function by the plate-like member that sandwiches the outer diameter restricted quartz glass tube in a rotating state is used. However, it can be processed without problems only by controlling the interval between the plate-like members.
In addition, the graphite plate-like member in contact with the high-temperature quartz glass tube can be easily cooled.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the form of the Example of this invention is demonstrated with the example of illustration. However, unless otherwise specified, the dimensions, shapes, relative positions, and the like of the components described in this embodiment are merely illustrative examples, and are not intended to limit the scope of the present invention. Absent.
FIG. 1 shows a quartz glass tube manufacturing apparatus according to the basic configuration of the present invention. Reference numeral 10 denotes a thick quartz glass cylinder, which has a circular end sealed with a nitrogen introduction jig 16 at the other end. The internal pressure can be introduced into the quartz glass cylinder 10 through the internal pressure adjusting valve 18.
A dummy rod 23 extends along the central axis on the axis side of the cylinder 10 made of quartz glass that is sealed, and the free end side of the dummy rod 23 and the base end side of the cylinder 10 made of quartz glass. Each of the rotary rotation jigs 22A and 22B is rotatably supported, and can move on the central axis along the heating furnace while rotating the quartz glass cylinder 10 by the rotary rotation jigs 22A and 22B. It is configured.
[0018]
A heating furnace 13 that heats and softens and expands the quartz glass cylinder in parallel with the internal pressure operation P through the internal pressure introducing portion (the nitrogen introducing jig 16 and the internal pressure adjusting valve 18) provided on the base end side is thermally insulated. It is composed of a cylindrical electric furnace around which a material 13a is wound, and has a base on the outside of the heating furnace 13 and a pair of holders 14a parallel to the axis of the cylinder 10 from the dummy rod 23 side. A graphite parallel restricting plate 14b is disposed at a position facing the quartz glass tube on the free end side which is an extended end of the graphite parallel restricting plate 14b.
That is, the outer diameter setting jig 14 includes a pair of holders 14a and a pair of parallel restriction plates 14b. The holder 14a is made of a copper member so that the refrigerant can be recirculated therein, the parallel regulating plate 14b is cooled from the back side, and is displaced in the opposite direction by manual operation along the arrow A in the radial direction of the quartz glass tube 12. Configure as possible.
The parallel regulating plate 14b allows the outer diameter to be regulated by the clamping pressure in combination with the rotation of the quartz glass tube 12 so as to sandwich the quartz glass tube 12 expanded by heat softening. It is comprised by a pair of graphite parallel control boards 14b arrange | positioned in parallel with the major axis direction.
[0019]
According to this configuration, after setting the interval between the outer diameter regulating parallel regulating plates 14b provided in the heating furnace 13 to the predetermined outer diameter D1, the quartz glass cylinder 10 is inserted into the heating furnace 13 while rotating. The internal pressure P is increased in the cylinder 10 through heating and softening and the nitrogen introduction jig 16 and the valve 18.
The expansion portion 11 having the outer diameter D2 of the quartz glass tube 12 slightly exceeding the predetermined outer diameter D1 is just before the quartz glass cylinder 10 heated and softened at a heating temperature of about 2300 ° C. contacts the parallel regulating plate 14b. The quartz glass tube 12 having a uniform thickness with a predetermined outer diameter D1 as shown in FIG. 7A is formed by regulating the outer diameter while pressing the expanding portion 11 with the parallel restriction plate 14b. I can do it.
[0020]
In the present embodiment, the internal pressure operation is performed by manually operating the internal pressure with the internal pressure adjusting valve 18 and pressing the external diameter D2 of the inflating portion 11 slightly expanded from the predetermined external diameter D1 with the external diameter setting jig 14. .
When ΔD (= [D2−D1] / 2), which is a minute expansion in the expansion portion 11, increases, the parallel restriction plate 14b is disposed on the free end side of the holder 14a. At that time, the parallel restricting plate 14b causes a spreading phenomenon, and the outer diameter cannot be regulated with high accuracy.
Therefore proper setting range of appropriate values of the △ D is 0 <△ D ≦ 0.5~1mm about, the good Mashiku 0 <△ D ≦ 0.5mm C., the outer diameter is within this range The quartz glass tube 12 with a stable wall thickness can be manufactured.
That, △ D to be within the above Ki設 constant range, that pressure control is a prerequisite of the present invention. Further, as shown in FIG. 2, the setting position of the outer diameter setting jig 14 is such that the parallel restriction plate 14b of the outer diameter setting jig 14 is arranged at the position where the heating temperature distribution in the heating furnace 13 falls. It is good to regulate.
[0021]
In the above embodiment, the operator measures the outer diameter of the manufactured quartz glass tube 12 with a caliper and manually adjusts the distance between the holders 14a when the operator deviates from the predetermined outer diameter. It is necessary to frequently perform setting work using the jig, and fluctuations in the outer diameter of the obtained quartz glass tube 12 are large, which causes a decrease in yield.
[0022]
Therefore, in order to solve the above problem, as shown in FIG. 3, the outer diameter of the quartz glass tube 12 is measured remotely by a laser outer diameter measuring device or the like. It is preferable to improve the accuracy of the outer diameter regulation by calculating the difference from the outer diameter with a computer.
FIG. 3 is a quartz glass tube manufacturing apparatus showing another embodiment of the present invention that automatically performs the outer diameter regulation, wherein 19 is a laser outer diameter measuring device disposed on the external outlet side of the heating furnace 13, Reference numeral 21 denotes a holder automatic adjustment motor for displacing the pair of parallel regulating plates 14b in the width direction of the arrow A via the holder 14a. Reference numeral 20 denotes an outer diameter automatic adjustment control device, which is based on a detection signal measured by a laser outer diameter measuring instrument. The holder automatic adjustment motor 21 is driven and controlled based on the deviation amount Δd from the correct regulated outer diameter D1.
[0023]
Next, the operation of this configuration will be described with reference to FIG.
1) First, the correct regulated outer diameter D1 is first input to the outer diameter automatic adjustment control device 20 in advance.
2) Next, the holder automatic adjustment motor 21 is driven and controlled via the outer diameter automatic adjustment control device 20, and the interval between the pair of parallel restriction plates 14b is set to a predetermined outer diameter D1 via the holder 14a.
3) Next, manufacture of the quartz glass tube 12 based on the above-described embodiment is started, and the glass tube is brought into contact with and stabilized by the pair of parallel regulating plates 14b having the above-mentioned interval.
4) The outer diameter automatic adjustment control device 20 is switched to the automatic operation mode.
5) The outer diameter D1 of the quartz glass tube 12 is measured by the laser outer diameter measuring device 19 (counting output of the number of cutoff pulses by the scanning outer diameter measuring device).
6) The measured outside diameter data is taken into the computer of the outside diameter automatic adjustment control device 20 and a deviation amount (Δd) from the predetermined outside diameter D1 set is obtained.
7) A signal is sent to the motor 21 for automatic adjustment of the holder in order to move the parallel restriction plate 14b made of graphite through the holder 14a by the calculated deviation (Δd).
8) The holder automatic adjustment motor 21 is operated, and the parallel restricting plate 14b moves through the holder 14a.
9) The operator brings the quartz glass tube 12 into contact with the graphite parallel regulating plate 14b while monitoring the inside of the furnace.
10) By repeatedly performing the above operations 5) to 8), the value of the deviation amount (Δd) can be made as small as possible. Thereby, the outer diameter of the manufactured quartz glass tube 12 becomes very stable.
[0024]
FIG. 5 shows another embodiment in which the internal pressure operation is also automated. The internal pressure automatic operation according to this embodiment includes a gas introduction internal pressure automatic adjustment electromagnetic valve 18a and a release electromagnetic valve 18b provided in place of the manual internal pressure adjustment valve 18, and a gas internal pressure automatic adjustment device 30 that controls opening and closing of the valve group. And an image processing device 32 that cooperates with the internal pressure automatic adjustment device 30, and CCD cameras 31 and 31 for the image processing device that measure the outer diameter D2 of the expansion portion 11 that inputs a video signal to the image processing device 32, A counter signal is input to the image processing device 32, and a laser outer diameter measuring device 19 (detected by a count number of cutoff pulses by a scanning type outer diameter measuring device) for measuring the outer diameter D1 of the quartz glass tube 12 is provided.
Then, a counter measurement signal from the laser measuring device 19 for the quartz glass tube outer diameter (predetermined outer diameter D1) on the outlet side of the heating furnace 13 after the outer diameter regulation, and an image by the CCD camera 31 of the outer diameter D2 of the expansion portion 11. enter the signal, the [D2 and the difference △ D between D1 calculated by the image processing device 32, the proper setting range and the calculated △ D (0 <△ D ≦ 0.5mm) and the internal pressure automatically adjusted compared with 30 controls the gas inlet pressure automatically adjusting solenoid valve 18a and the release solenoid valve 18b on the basis of the comparison result, which performs automatic control of the internal pressure operation, the △ D is always the appropriate setting range Thus, the quartz glass tube 12 having a more stable thickness is obtained.
[0025]
Next, the operation procedure of this embodiment will be described based on the block diagram shown in FIG.
1) The pulling start portion of the quartz glass tube 12 is manually operated by an operator.
2) When the outer diameter of the quartz glass tube 12 reaches a predetermined outer diameter D1 and is stabilized, automatic operation is started.
3) First, the outer diameter D1 of the quartz glass tube 12 is measured by the laser outer diameter measuring device 19, and a counter output for forming D1 data is input to the image processing device 32.
4) The outer diameter of the expanded portion is measured by the image processing CCD cameras 31 and 31, and a video signal forming D2 data is input to the image processing device 32.
5) In the image processing apparatus 32 of the computer determines the △ D by calculation of the D1 data and the D2 data the input.
6) send the obtained △ D to the internal pressure automatic adjuster 30 computer.
7) The internal pressure automatic adjusting device 30 of the computer, setting the range of advance the △ D.
The setting range is further set to 0.1 mm <ΔD ≦ 0.4 mm.
8) of the internal pressure automatic adjusting device 30 computer, the △ D to enter the set range of the △ D, actuates the pressure → gas inlet pressure automatically adjusting solenoid valve 18a and the release solenoid valve 18b.
9) The method of the electromagnetic valve, when approaching the lower limit of the setting range of △ D is △ D, open the internal pressure automatically adjusting electromagnetic valve 18a, close the release solenoid valve 18b, the pressure in the quartz glass cylinder 10 Call.
On the other hand, when the upper limit of ΔD is approached, the internal pressure automatic adjustment electromagnetic valve 18 a is closed, the release electromagnetic valve 18 b is opened, and the internal pressure is released from the quartz glass cylinder 10.
In addition, it becomes possible to narrow the setting range of (DELTA) D by making the feedback speed to said 3) -9) faster. As a result, the thickness of the manufactured quartz glass tube 12 becomes very stable.
[0026]
Therefore, according to this embodiment, since the internal pressure is automatically controlled based on ΔD, the dimensional accuracy of the manufactured quartz glass tube 12 is remarkably improved. In particular, the internal pressure operation and the heating furnace 13 are performed before the outer diameter regulation. Since the expansion portion is formed by the temperature operation at, not only the outer diameter accuracy but also the thickness variation can be minimized. Moreover, it is possible to obtain the quartz glass tube 12 with high accuracy in both the outer diameter and the wall thickness by the internal pressure control by the feedback numerical control.
[0027]
【The invention's effect】
As described above, according to the present invention, it is possible to minimize the outer diameter accuracy and the wall thickness variation, and it is not necessary to replace the quartz glass tube to be manufactured every time the outer diameter is changed. A glass tube manufacturing method and apparatus can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an apparatus for producing a quartz glass tube according to a first embodiment of the present invention.
FIG. 2 shows a layout of temperature distribution in the heating furnace and an outer diameter setting jig (parallel restriction plate).
FIG. 3 is a schematic configuration diagram of an apparatus for producing a quartz glass tube in which the outer diameter regulation is automated in the second embodiment of the present invention.
4 is a block diagram showing an outer diameter regulation control mechanism of FIG. 3; FIG.
FIG. 5 is a schematic configuration diagram of an apparatus for manufacturing a quartz glass tube in which internal pressure control and external diameter regulation are automated in a third embodiment of the present invention.
6 is a block diagram showing a schematic configuration of a control mechanism for internal pressure control in FIG. 5; FIG.
FIG. 7 is a cross-sectional view showing a variation in the thickness of a quartz glass tube manufactured according to the present invention in comparison with a conventional apparatus. FIG. 7 (A) shows the case of the manufacturing method according to the present invention, and FIG. Indicates.
FIG. 8 is a schematic configuration diagram of a conventional quartz glass tube manufacturing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Quartz glass cylinder 11 Expansion part 12 Quartz glass tube 13 Heating furnace 14 Outer diameter setting jig 14a Holder 14b Parallel restriction plate 18 Internal pressure adjustment valve 18a Internal pressure automatic adjustment electromagnetic valve 18b Release electromagnetic valve 19 Laser outer diameter measuring device 20 Outer Diameter automatic adjustment control device 21 Holder automatic adjustment motor 30 Internal pressure automatic adjustment device 31 CCD camera for image processing device 32 Image processing device

Claims

先端を封止してチューブ状に形成させた石英ガラス製中空管を加熱軟化させる加熱手段と、
前記中空管内部に内圧用ガスを導入するとともに加熱軟化させた中空管を膨出させる内圧生成手段と、
前記膨出させた加熱軟化状態にある中空管（以下石英ガラス管という）外周面に接触させ外径規制させる外径設定治具とを備え、
前記石英ガラス管を加熱手段内で軸方向に移動させつつ所定外径の石英ガラス管を製造する装置において、
前記外径設定治具との接触手前位置で、外径設定治具通過後の石英ガラス管外径Ｄ１を僅か上回る石英ガラス管外径Ｄ２を持つ膨張部を形成するように外径規制及び内圧制御可能に構成し、
前記外径規制は、非加熱領域からの遠隔測定で得られた石英ガラス管膨張部外径と外径設定治具通過後の石英ガラス管外径との差△Ｄを演算して、該△Ｄ（前記膨張量△Ｄ＝［（Ｄ２−Ｄ１）／２］）が、０＜△Ｄ≦１ｍｍの範囲に維持するように内圧制御を行うことを特徴とする石英ガラス管の製造装置。A heating means for heating and softening a quartz glass hollow tube whose end is sealed and formed into a tube shape;
An internal pressure generating means for introducing an internal pressure gas into the hollow tube and expanding the heated and softened hollow tube;
An outer diameter setting jig for contacting the outer surface of the hollow tube (hereinafter referred to as a quartz glass tube) that is in the heat-softened state that has been swelled to regulate the outer diameter;
In the apparatus for producing a quartz glass tube having a predetermined outer diameter while moving the quartz glass tube in the axial direction in the heating means,
Outer diameter regulation and inner pressure so as to form an expanded portion having a quartz glass tube outer diameter D2 slightly larger than the quartz glass tube outer diameter D1 after passing through the outer diameter setting jig at a position just before the contact with the outer diameter setting jig. Configured to be controllable ,
The outer diameter restriction is calculated by calculating a difference ΔD between the outer diameter of the expanded portion of the quartz glass tube obtained by remote measurement from the non-heated region and the outer diameter of the quartz glass tube after passing through the outer diameter setting jig. An apparatus for producing a quartz glass tube , wherein internal pressure control is performed such that D (the expansion amount ΔD = [(D2−D1) / 2]) is maintained in a range of 0 <ΔD ≦ 1 mm .

前記外径設定治具の規制幅を変位可能に構成するとともに、外径規制後の石英ガラス管外径を計測する手段を設け、該計測手段による計測値に基づいて外径データを外径自動調整用制御機器のコンピュータに取込み設定されている所定外径Ｄ１との偏差量（△ｄ）の値を求め、該求めた前記偏差量（△ｄ）の分だけ、外径設定治具を移動制御可能に構成したことを特徴とする請求項１記載の石英ガラス管の製造装置。 The control width of the outer diameter setting jig is configured to be displaceable, and a means for measuring the outer diameter of the quartz glass tube after the outer diameter control is provided, and the outer diameter data is automatically calculated based on the measurement value by the measuring means. The deviation amount (Δd) with respect to the predetermined outer diameter D1 taken in and set in the computer of the control device for adjustment is obtained, and the outer diameter setting jig is moved by the obtained deviation amount (Δd). 2. The quartz glass tube manufacturing apparatus according to claim 1, wherein the apparatus is configured to be controllable .

前記外径設定治具が加熱炉出口側の加熱温度分布立ち下がり部に位置し、該外径設定治具による外径規制後石英ガラス管を加熱させないようにした請求項１記載の石英ガラス管の製造装置。 The quartz glass tube according to claim 1, wherein the outer diameter setting jig is located at a falling portion of the heating temperature distribution on the outlet side of the heating furnace, and the quartz glass tube is not heated after the outer diameter is regulated by the outer diameter setting jig. Manufacturing equipment.

前記外径設定治具は、中空管状母材を挟んで母材半径方向に変位可能な一対の平行規制板より構成され、
前記外径設定治具により外径規制後の母材外径が所定外径Ｄ１に近づくように前記一対の平行規制板の規制幅を制御可能に構成したことを特徴とする請求項１記載の石英ガラス管の製造装置。The outer diameter setting jig is composed of a pair of parallel restriction plates that can be displaced in the radial direction of the base metal with a hollow tubular base material interposed therebetween,
The control width of the pair of parallel restricting plates is configured to be controllable so that the outer diameter of the base material after the outer diameter restriction approaches the predetermined outer diameter D1 by the outer diameter setting jig. Quartz glass tube manufacturing equipment.

先端を封止してチューブ状に形成させた石英ガラス製中空管を加熱炉で加熱軟化させ、該中空管内部に内圧用ガスを導入するとともに、外径設定治具を前記加熱軟化状態にある石英ガラス管外周面に接触させ、外径規制させた状態で、前記石英ガラス管を軸方向に移動させつつ所定外径の石英ガラス管を製造する方法において、
上記石英ガラス管の加熱軟化領域を内圧操作により、外径設定治具接触手前位置で、外径設定治具通過後の石英ガラス管外径Ｄ１を僅か上回る石英ガラス管外径Ｄ２を持つ膨張部を形成させ、該膨張部を外径設定治具に侵入させながら前記石英ガラス管の外径規制を行うとともに、前記外径規制は、非加熱領域からの遠隔測定で得られた石英ガラス管膨張部外径と外径設定治具通過後の石英ガラス管外径との差△Ｄを演算して、該△Ｄ（前記膨張量△Ｄ＝［（Ｄ２−Ｄ１）／２］）が、０＜△Ｄ≦１ｍｍの範囲に維持するように内圧制御を行うことを特徴とする石英ガラス管の製造方法。A quartz glass hollow tube whose end is sealed and formed into a tube shape is heated and softened in a heating furnace, an internal pressure gas is introduced into the hollow tube, and an outer diameter setting jig is heated and softened. In a method of manufacturing a quartz glass tube having a predetermined outer diameter while moving the quartz glass tube in the axial direction in a state where the outer diameter of the quartz glass tube is in contact with the outer peripheral surface of the quartz glass tube,
An expansion portion having a quartz glass tube outer diameter D2 slightly larger than the outer diameter D1 of the quartz glass tube after passing through the outer diameter setting jig at a position before the outer diameter setting jig is contacted by an internal pressure operation in the heat softening region of the quartz glass tube. The outer diameter of the quartz glass tube is regulated while allowing the expansion portion to enter the outer diameter setting jig, and the outer diameter regulation is performed by expanding the quartz glass tube obtained by remote measurement from a non-heated region. The difference ΔD between the outer diameter of the portion and the outer diameter of the quartz glass tube after passing through the outer diameter setting jig is calculated, and ΔD (the expansion amount ΔD = [(D2−D1) / 2]) is 0. <ΔD ≦ 1 mm A method for producing a quartz glass tube, wherein the internal pressure is controlled so as to be maintained in a range of 1 mm .

前記外径設定治具の規制幅を変位可能に構成するとともに、外径規制後の石英ガラス管外径を計測する手段による計測値に基づいて外径データを外径自動調整用制御機器のコンピュータに取込み設定されている所定外径Ｄ１との偏差量（△ｄ）の値を求め、該求めた前記偏差量（△ｄ）の分だけ、外径設定治具を移動制御した後に、前記石英ガラス管の外径規制を行うことを特徴とする請求項５記載の石英ガラス管の製造方法。 The control width of the outside diameter setting jig is configured to be displaceable, and the outside diameter data is controlled based on the measured value by the means for measuring the outside diameter of the quartz glass tube after the outside diameter is regulated. The deviation amount (Δd) with respect to the predetermined outer diameter D1 taken in and set is obtained, and the outer diameter setting jig is moved and controlled by the obtained deviation amount (Δd), and then the quartz is obtained. 6. The method for producing a quartz glass tube according to claim 5, wherein the outer diameter of the glass tube is regulated .