JP4282196B2

JP4282196B2 - Superconducting coil and manufacturing method thereof

Info

Publication number: JP4282196B2
Application number: JP2000009759A
Authority: JP
Inventors: 努来栖; 孝治伊藤; 泰造戸坂; 司和田; 茂雄中山; 伴之服部
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1999-04-27
Filing date: 2000-01-19
Publication date: 2009-06-17
Anticipated expiration: 2020-01-19
Also published as: JP2001015324A

Description

【０００１】
【発明の属する技術分野】
本発明は、金属間化合物超電導線にガラスやセラミックス絶縁を施した絶縁被覆超電導線を巻枠に巻回し、その後に超電導生成熱処理を施して形成される超電導コイルおよびその製造方法に関する。
【０００２】
【従来の技術】
一般に、極低温下で使用する超電導線としては、ＮｂＴｉ等の金属超電導線とＮｂ₃ＳｎやＮｂＡｌ等の金属間化合物超電導線が用いられる。この内Ｎｂ₃ＳｎやＮｂＡｌ等の金属間化合物超電導線を巻枠に巻回して形成する超電導コイルは高磁界中でも超電導特性に優れている。その反面長手方向の引っ張り力や曲げ歪に非常に弱く、臨界電流が急激に小さくなる欠点がある。
【０００３】
したがって、事前に熱処理を施した超電導線を巻枠に巻回して超電導コイルを形成することは曲げ歪が０．２％以下になるような大径コイルで一部実用化されているものの、一般的には未熱処理の超電導線を巻枠に巻回後に超電導生成熱処理を施して超電導コイルを製造する。超電導生成熱処理はアルゴンガス等の不活性ガスや真空炉中で６００℃から７００℃の高温で数十時間処理されるために、超電導線の電気絶縁にはその温度でも熱劣化の起きにくいセラミックス繊維やガラス繊維が使用される。
【０００４】
【発明が解決しようとする課題】
しかしながら、超電導線に被覆するガラス繊維には製紐作業等を容易にするために、一般に、澱粉等の有機材料が数％混入されている。このような絶縁被覆超電導線で形成された超電導コイルを前記したように、アルゴンガスや真空雰囲気中の無酸素状態で６００℃から７００℃の超電導生成熱処理をすると、これら有機物は所謂蒸し焼き状態になって、導電性の炭素となってガラス繊維からなる絶縁被覆に残留する。したがって、超電導線間や沿面方向に導電性の電流パスができて絶縁破壊電圧が低下し、絶縁不良や絶縁破壊が起き易くなる。
【０００５】
これを避けるために、超電導生成熱処理の前に、超電導コイルを一度約３００℃大気中で熱処理し、有機物を一酸化炭素や二酸化炭素等にガス化して放出する所謂一次熱処理工程が施される。しかし、この一次熱処理工程を実施しても、絶縁被覆超電導線が幾重にも多層に巻回された超電導コイルでは、巻き芯近傍の内層まで大気が十分拡散浸透せず、この部分の有機物は酸素欠乏によって未反応でそのまま残留したり、一部は蒸し焼き状態での炭化物として残留する。この未反応で残留した有機物は超電導生成熱処理（以下、二次熱処理工程と称す）で当然炭化してしまい、結果として絶縁不良や絶縁破壊が起き易くなる。
【０００６】
一方、内層と外気が自然対流や分圧で相互拡散するために、一次熱処理工程を長時間行うと、超電導線を構成する銅等の酸化膜が厚くなって正味の銅が減少し、超電導特性が不安定な超電導線になる。
【０００７】
また、一次熱処理工程で有機物が完全にガス化して放出したかの確認方法がなく、これまでは経験に基づいて処理時間が決定されていた。そのために、超電導コイルの形状や寸法によっては、有機物が炭化物として残留して絶縁不良箇所が生じ、それが原因で絶縁破壊による放電やジュール発熱で超電導線が溶断する虞があった。
【０００８】
さらに、超電導線を巻枠に巻回する際には一定の張力を加えながら行うが、ガラス被覆絶縁は非常に弱くて巻回時に巻線機や隣接する超電導線同士がこすれて破損しやすく、加える張力に限界がある。したがって、例えば、レーストラック状の超電導コイルを製造する場合など直線部の膨らみが大きく、寸法精度の悪い超電導コイルになる。
【０００９】
そこで、本発明は、超電導線の絶縁被覆に混入している有機物を超電導線が損傷劣化しない比較的短時間の加熱によりガス化して放出し、絶縁上有害な炭化物が残留しない信頼性の高い超電導コイルおよびその製造方法を提供することを目的とする。
【００１０】
さらに、本発明は、巻回時に超電導線に過度な張力を加えることなく、寸法精度の高い超電導コイルの製造方法を提供することを目的とする。
【００１１】
【課題を解決するための手段】
請求項１の発明に係わる超電導コイルは、巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルにおいて、前記巻枠に流体が流通する複数個の貫通孔を設け、前記巻枠の側面の貫通孔と多数回巻回された絶縁被覆超電導線との間、または絶縁被覆超電導線間に、銀からなるシート状の板を設けたことを特徴とする。
【００１２】
本発明では、酸素含有気体が巻枠に設けられた複数個の貫通孔から超電導コイルの内部まで容易に拡散して、絶縁被覆に混入する有機物を一次熱処理工程でガス化して放出できるので、絶縁不良等を回避できる。
さらに、酸素含有気体の透過通路は最外層から各層の絶縁被覆を通り最内層の絶縁被覆から銀シート板を通り貫通孔から外へ出る。また超電導線間に銀シート板を設けている場合には最外層から最内層への酸素含有気体の透過をスムーズにする。
【００１３】
請求項２の発明に係わる超電導コイルは、請求項１の発明において、貫通孔は、巻き芯の内周と外周を連通する穴、または巻きつばのコイル側と反コイル側とを連通する穴の少なくともいずれか一方であることを特徴とする。
【００１４】
本発明では、請求項１記載の発明の作用効果に加えて、酸素含有気体が巻き芯の内周と外周を連通する穴、または巻きつばのコイル側と反コイル側とを連通する穴から超電導コイルの内部まで容易に拡散して絶縁被覆に混入する有機物を一次熱処理工程でガス化して放出できるので、絶縁不良等を回避できる。
【００１５】
特に、酸素が欠乏し易い巻き芯側の内層側でも、酸素含有気体との反応面積が増加するとともに、超電導コイルの内部まで容易に酸素含有気体が浸透する。
【００２０】
請求項３の発明に係わる超電導コイルは、請求項１の発明において、巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルにおいて、巻枠はその材質として銀を用いたことを特徴とする。
【００２１】
本発明では、請求項１の発明の作用効果に加え、酸素含有気体が酸素透過性の優れた銀材質の巻枠から超電導コイルの内部まで容易に拡散して絶縁被覆に混入する有機物を一次熱処理工程でガス化して放出できるので、絶縁不良等を回避できる。
【００２２】
請求項４の発明に係わる超電導コイルの製造方法は、巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルの製造方法において、巻枠に流体が流通する複数個の貫通孔を設ける工程と、巻枠へのコイル巻回に先立って巻枠に絶縁材を被着する工程と、この絶縁材の上に絶縁被覆超電導線を巻回する巻回工程と、絶縁材および絶縁被覆に含まれる有機物をガス化して放出させる一次熱処理工程と、一次熱処理工程が終了したことを判定する一次熱処理完了判定工程と、超電導線を超電導体化するための二次熱処理工程とを具備したことを特徴とする。
【００２３】
本発明では、一次熱処理工程中に絶縁被覆に含まれる有機物がほぼガス化して放出されたことを判定する工程を具備したので、残留有機物が二次熱処理工程で炭化し、絶縁不良等を起こすのを回避できる。
【００２４】
請求項５の発明に係わる超電導コイルの製造方法は、巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルの製造方法において、前記巻枠に流体が流通する複数個の貫通孔を設ける工程と、前記巻枠へのコイル巻回に先立って離型剤を介して前記巻枠に設けられた貫通孔の位置に貫通孔が設けられた金属箔を装着する工程と、この金属箔の上に絶縁材を被着する工程と、この絶縁材の上に絶縁被覆超電導線を巻回する巻回工程と、絶縁材および絶縁被覆に含まれる有機物をガス化して放出させる一次熱処理工程と、前記一次熱処理工程が終了したことを判定する一次熱処理完了判定工程と、前記超電導線を超電導体化するための二次熱処理工程と、絶縁材および絶縁被覆超電導線を絶縁物で含浸一体化する工程と、その後巻枠をコイルから分解する工程とを具備したことを特徴とする。
【００２５】
本発明では、請求項４の発明の作用効果に加え、巻枠をコイルから分解して使用する超電導コイルでも、コイル巻回に先立って巻枠に離型剤を介して金属箔を装着したので、絶縁物で含浸一体化した後でも容易に巻枠を分解できる。
【００２６】
すなわち、分解の際に、まず最初に巻き枠を金属箔から分離し、次に金属箔を絶縁物で含浸された超電導コイルから剥離する。この場合、薄い金属箔は可撓性に富むので、僻開力で含浸絶縁物から容易に引き剥がすことができる。したがって、二次熱処理終了後の脆くなっている超電導線に過度の力が加わることもなく、超電導性能の劣化を回避できる。
【００２７】
請求項６の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、巻枠に流体が流通する複数個の貫通孔を設ける工程に代えて、巻枠を銀で形成する工程としたことを特徴とする。
【００２８】
本発明では、請求項４または請求項５の発明の作用効果に加え、一次熱処理工程において、絶縁材および絶縁被覆に含まれる有機物を適切にガス化して放出させることができる。
【００２９】
請求項７の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、巻枠に流体が流通する複数個の貫通孔を設ける工程と、巻枠の側面の貫通孔と多数回巻回された絶縁被覆超電導線との間、または絶縁被覆超電導線間に、銀からなるシート状の板を設ける工程と追加して設けたことを特徴とする。
【００３０】
本発明では、請求項４または請求項５の発明の作用効果に加え、一次熱処理工程において、絶縁材および絶縁被覆に含まれる有機物を適切にガス化して放出させることができる。
【００３１】
請求項８の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、一次熱処理工程は、酸素を含有する気体中で炉中加熱する工程であり、一次熱処理完了判定工程は、炉内の一酸化炭素あるいは二酸化炭素濃度が規定値以下であること確認する工程であることを特徴とする。
【００３２】
本発明では、請求項４または請求項５の発明の作用効果に加え、一次熱処理完了判定を炉内の一酸化炭素あるいは二酸化炭素濃度を測定し、その値が例えば炉内に供給する酸素含有気体のレベルとほぼ同等である規定値以下であることを確認し、一次熱処理を完了する。仮に酸素含有気体が大気の場合は、通常の二酸化濃度は約４００ｐｐｍであり、これを規定値にする。
【００３３】
このように、有機物の残留がないことを確認するので、超電導コイルの形状や寸法に影響しない方法で判定できる。したがって、残留炭化物による絶縁不良等を回避できる。
【００３４】
請求項９の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、一次熱処理工程は、酸素を含有する気体中で炉中加熱する工程であり、一次熱処理完了判定工程は、炉内の酸素濃度が規定値以上であることを確認する工程であることを特徴とする。
【００３５】
本発明では、請求項４または請求項５の発明の作用効果に加え、一次熱処理完了判定を炉内の酸素濃度を測定し、その値が例えば炉内に供給する酸素含有気体のレベルとほぼ同等である規定値以上であることを確認し、一次熱処理を完了する。仮に酸素含有気体が大気の場合は、通常、酸素濃度は約２１％であることから、これを規定値にする。
【００３６】
このように、有機物の残留がないことを、超電導コイルの形状や寸法に影響しない絶対法で判定できる。したがって、残留炭化物による絶縁不良等を回避できる。
【００３７】
請求項１０の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、一次熱処理完了判定工程後に、さらに、炉内を減圧脱気して再び炉内を酸素含有気体に置換して加熱する追加の熱処理工程を具備したことを特徴とする。
【００３８】
本発明では、請求項４または請求項５の発明の作用効果に加え、一次熱処理完了判定をさらに信頼性を高めるために、例えば、二酸化炭素濃度が規定値以下になった後に、炉内を減圧脱気して再び炉内を酸素含有気体に置換して加熱する。減圧脱気することによりコイル内部の気体が排出され、酸素含有気体に容易に置換される。この状態で加熱を続行すると、もし未反応の有機物が残留している場合には、置換された酸素含有気体と酸化反応して、炉内の二酸化濃度が再び上昇する。二酸化濃度が規定値以下になるまでこの工程を繰り返して実施する。一方、残留有機物が完全に放出されている場合には、置換した後も二酸化濃度が規定値以下になる。本方法によれば、一次熱処理完了判定の信頼性が格段に向上し、絶縁不良のない超電導コイルを製造できる。
【００３９】
請求項１１の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、一次熱処理工程は、真空中に微量の水素を含有する炉中加熱する工程であることを特徴とする。
【００４０】
本発明では、炉内を真空にして不要な成分を除去した雰囲気中で、水素を供給して加熱するので、絶縁被覆に混入した有機物が効率よく水素と反応し、ガス化して放出できる。
【００４１】
請求項１２の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、一次熱処理工程は、水素プラズマ雰囲気を保持している炉中加熱する工程であることを特徴とする。
【００４２】
本発明では、水素プラズマを使用することにより水素を使用する場合よりも、さらに効率よく、絶縁被覆に混入する有機物が水素と反応し、ガス化して放出できる。
【００４３】
請求項１３の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、請求項１または請求項２記載の超電導コイルを製造するための超電導コイルの製造方法において、一次熱処理工程は、巻き鍔に設けられた貫通孔をジャケットで覆い、このジャケットに接続された給気管で外部から酸素含有気体を強制給気しながら加熱する工程であることを特徴とする。
【００４４】
本発明では、請求項４または請求項５の発明の作用効果に加え、外部から酸素含有気体を強制給気しながら加熱するので、コイル内部に常に酸素が供給され、絶縁被覆に混入する有機物を効率よくガス化して放出できる。また、強制給気することによって、酸化反応で生成した二酸化炭素等のガスもコイル内部に滞留することなく、外部に排出される。したがって、残留炭化物による絶縁不良等を回避できる。
【００４５】
請求項１４の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、請求項１または請求項２記載の超電導コイルを製造するための超電導コイルの製造方法において、一次熱処理工程は、巻き芯の両端部を蓋で覆い、この蓋に接続された給気管で外部から酸素を含有した気体を強制給気しながら加熱する工程であることを特徴とする。
【００４６】
本発明では、請求項４または請求項５の発明の作用効果に加え、外部から強制給気された酸素含有気体は、巻き芯内側からコイル最内層に流れ、コイルの絶縁被覆内を貫流して巻き鍔に設けられた穴やコイルの外周から排出される。したがって、コイル内部に常に酸素が供給され、絶縁被覆に混入する有機物を効率よくガス化して放出できる。また、強制給気することによって、酸化反応で生成した二酸化炭素等のガスもコイル内部に滞留することなく、外部に排出される。その結果、残留炭化物による絶縁不良等を回避できる。
【００４７】
請求項１５の発明に係わる超電導コイルの製造方法は、請求項４または請求項５の発明において、巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルの製造方法において、巻回工程は絶縁被覆超電導線が巻枠に巻回される手前で絶縁被覆超電導線を加熱する工程と、巻枠に巻回された後、速やかに絶縁被覆超電導線を冷却する工程とを具備したことを特徴とする。
【００４８】
本発明では、巻回前と巻回後の超電導線の熱膨張差を利用して超電導線に一定の張力を加えることができる。したがって、絶縁被覆の破損による絶縁不良を回避できる。さらに、レーストラック状の超電導コイルで起こりがちの直線部の膨らみも抑止できる。
【００５７】
請求項１６の発明に係わる超電導コイルの製造方法は、請求項１または請求項２記載の超電導コイルを製造するための超電導コイルの製造方法において、超電導線に絶縁被覆を編付ける製紐工程と、絶縁被覆超電導線を巻枠に巻回する巻回工程と、巻回された絶縁被覆超電導線の絶縁被覆内に残存する有機物質を除去する工程とを具備したことを特徴とする。
【００５８】
本発明では、超電導線の絶縁被覆には有機物が含まれていないので、絶縁不良が抑制できると共に、一次熱処理工程が省略できる。さらに、一次熱処理が省略できることから、超電導線を構成する銅等の酸化膜が厚くなって正味の銅が減少し、超電導特性が不安定となることも避けることができる。
【００５９】
請求項１７の発明に係わる超電導コイルの製造方法は、請求項１６の発明において、有機物質除去工程は、水を用いて有機物質を洗浄する工程であることを特徴とする。
【００６０】
本発明では、澱粉などの有機物質が水に溶けやすい性質を利用しているので、室温付近の比較的低温で有機物質を除去することができる。
【００６１】
請求項１８の発明に係わる超電導コイルの製造方法は、請求項１７の発明において、有機物質除去工程は、超音波またはバブルを併用することを特徴とする。
【００６２】
本発明では、水洗いのときに超音波またはバブルを併用するので、有機物を効果的に除去することができ、超電導コイルとしての絶縁性能が高く、電気的に安定となり、高性能な超電導コイルを製造できる。
【００６３】
【発明の実施の形態】
以下、本発明の実施の形態を説明する。図１は本発明の第１の実施の形態に係わる超電導コイルの説明図であり、図１（ａ）は超電導コイルの断面図、図１（ｂ）は絶縁被覆超電導線の斜視図である。
【００６４】
図１（ａ）に示すように、超電導コイル１は超電導コイル本体１ａと巻枠７とら構成される。超電導コイル本体１ａは絶縁被覆超電導線４と絶縁材８とから構成され、巻枠７は中空の巻き芯５とその端部に形成された巻き鍔６とから構成されている。すなわち、巻枠７の巻き芯５には貫通孔９ｂが設けられ、また巻枠７の巻き鍔６には貫通孔９ａが設けられている。
【００６５】
絶縁被覆超電導線４は、図１（ｂ）に示すように、超電導線２に絶縁被覆３が施されたものであり、超電導線２の素線材料としてＮｂ_３ＳｎやＮｂＡｌ等の金属間化合物超電導線が用いられ、その超電導線２に素線絶縁としてガラス繊維やセラミックス繊維等の絶縁被覆３が施される。
【００６６】
このように構成された絶縁被覆超電導線４を、図１（ａ）に示すように、巻き芯５の両側に巻き鍔６を有する巻枠７に対して、絶縁材８を介して幾重にも多層に巻回して超電導コイル本体１ａは形成されている。そして、巻枠７には前述したように、流体が流通する複数個の貫通孔９が設けられている。
【００６７】
このように形成された超電導コイル１は、絶縁材８や絶縁被覆３に含まれる澱粉等の有機物を酸素含有気体と酸化反応させ、ガス化して放出するために一次熱処理工程が実施される。
【００６８】
図２は、その一次熱処理工程の説明図である。この一次熱処理工程は、超電導コイル１を酸素含有気体雰囲気の加熱炉１０中に置き、酸素含有気体を補給しながら、約３００℃で約十時間加熱する。その後、ガス濃度計１１で二酸化炭素や一酸化炭素濃度を測定し、その濃度が規定値以下であることを判定して一次熱処理工程を完了する。
【００６９】
ここで、酸素含有気体が大気の場合、通常の大気中の二酸化濃度は約４００ｐｐｍであり、これを規定値にする。大気以外の酸素含有気体の場合の規定値も同様に、その気体に元々含まれる二酸化炭素濃度でよい。
【００７０】
そして、一次熱処理完了判定後に降温し、加熱炉１０内の気体を排気装置１２で排気してアルゴンガス等の不活性ガス１３や真空に置換した後、超電導生成処理として、加熱炉１０中で６００℃から７００℃の高温で数十時間二次熱処理を行う。
【００７１】
次に、このような貫通孔９を有する超電導コイル１の熱処理の際の作用を説明する。一次熱処理工程の際には、酸素含有気体が巻枠７に設けられた複数個の貫通孔９から超電導コイル本体１ａの内部まで容易に拡散していく。すなわち、巻き鍔６に設けられた貫通孔９ａおよび巻き芯５に設けられた貫通孔９ｂから、酸素含有気体は超電導コイル本体１ａの内部まで拡散し、絶縁材８や絶縁被覆３に含有する有機物をガス化して放出する。
【００７２】
これにより、特に、酸素が欠乏し易い巻き芯５側に近接する超電導コイル本体１ａの内層１a側でも、酸素含有気体との反応面積が増加するとともに、超電導コイル本体１ａの内部まで容易に酸素含有気体が浸透する。したがって、残存有機物を適正に除去できるので、残存有機物が前記した二次熱処理で炭化することによって起こる絶縁不良等を回避できる。
【００７３】
以上の説明では、中空の巻き芯５に貫通孔９ｂを設けたものを示したが、図３に示すように、巻き芯５が中実である場合には、貫通孔９ｂに代えて溝５ａを設ける。すなわち、中実の巻き芯５の外周に軸方向に沿う複数本の溝５aを形成し、巻き鍔６には、その溝５aに対峙する位置にコイル側と反コイル側とを連通する穴９aが設けられている。
【００７４】
このように構成された超電導コイル１の場合にも、一次熱処理工程の際には、酸素含有気体は巻き鍔６に設けられた穴９ａから巻き芯５に形成された溝５aに流入し、この溝５aから超電導コイル１の内部まで容易に拡散し、絶縁材８や絶縁被覆３に含有する有機物をガス化して放出する。特に、酸素が欠乏し易い巻き芯５側に近接する超電導コイル本体１ａの内層側でも、酸素含有気体との反応面積が増加するとともに、超電導コイル本体１ａの内部まで容易に酸素含有気体が浸透する。したがって、残存有機物が前記した二次熱処理で炭化することによって起こる絶縁不良等を回避できる。
【００７５】
さらに、ガス濃度計１１を二酸化炭素や一酸化炭素濃度計に代えて酸素濃度計にしてもよい。この場合は、一次熱処理完了判定を炉内の酸素濃度を測定し、その値が例えば炉内に供給する酸素含有気体のレベルとほぼ同等である規定値以上であることを確認し、一次熱処理を完了することになる。仮に酸素含有気体が大気の場合は、通常、酸素濃度は約２１％であることから、これを規定値にする。
【００７６】
このように、超電導コイル１を構成する巻枠７に複数個の貫通孔９を設けておくので、一次熱処理の際の酸素含有気体の透過性が格段に向上する。酸素含有気体の透過通路は最外層から各層の絶縁被覆３を通り、最内層の絶縁被覆３から貫通孔９へ至る。また、その逆の経路も可能である。
【００７７】
したがって、超電導コイル本体１ａを形成する絶縁被覆超電導線４の各層中の絶縁被覆３に含まれる有機物に酸素が十分に行き渡り、ガス化して放出される。このため、絶縁不良や絶縁破壊の原因となる炭素材の存在は皆無となる。なお、貫通孔９の大きさは穴開け作業上１〜３ｍｍぐらいが妥当である。
【００７８】
また、絶縁被覆超電導線４の各層が多い場合には、中間層に酸素透過性の高い銀シートを挿入して最内層への酸素含有気体の透過をスムーズに起こるようにしてもよい。
【００７９】
また、巻枠７の材料を酸素透過性の優れた銀材料にすることも可能である。この場合の酸素含有気体の透過通路は最外層から各層の絶縁被覆３を通り最内層の絶縁被覆３から銀材料の巻枠７を通り外へ出る。この場合においても、超電導が多い場合、中間層に銀シートを挿入し、最内層への酸素含有気体の透過をスムーズに起こるようにしてもよい。
【００８０】
ここで、巻枠７に複数個の貫通孔９を設けてから有機物を炭化する一次熱処理と超電導生成のための二次熱処理とを行った後、このコイルを超電導状態にして磁場を発生すると、フープ力が発生する。このフープ力による超電導線２の材料の劣化を防ぐためにエポキシ樹脂を超電導コイル１の巻枠７全体に含浸する。
【００８１】
この場合、巻枠７に複数個の貫通孔９を明けたままでいると、エポキシ樹脂が貫通孔９から漏れ出て含浸できなくなるので、巻枠７の貫通孔９を設けた箇所に酸素透過性の優れたシート状の銀材料を介在させる。その後に、絶縁被覆超電導線４を多層にソレノイド状に巻く作業を行う。これにより、一連の熱処理後にエポキシ樹脂を含浸してもエポキシ樹脂は銀シートに阻まれて漏れ出ることはなく、正常な含浸作業が完了できる利点がある。
【００８２】
一次熱処理する温度は２５０℃から５００℃位がよい。２５０℃の場合は４０〜１００時間程度、５００℃では５時間程度の熱処理でよいが、超電導コイル１の大きさ、つまり絶縁被覆超電導線４の絶縁被覆３に含まれる有機物の絶対量によって熱処理温度と時間を決めることになる。
【００８３】
次に、本発明の第１の実施の形態における実施例１乃至実施例３および比較例をについて説明する。
【００８４】
（実施例１）
図４に示すように、巻き鍔６の外径３００ｍｍ、巻き芯５の外径５０ｍｍ、巻き芯５の内径４０ｍｍ、巻き芯５の長さ２５０ｍｍのステンレス製からなる巻枠７を用意し、巻き芯５および巻き鍔６に直径２ｍｍの複数個の貫通穴９を約１０ｍｍ間隔で設けた。そして、この巻枠７の巻き芯５および巻き鍔６に板厚さ２ｍｍの銀シートを設け、直径１ｍｍの絶縁被覆超電導線４を２５層巻き付けた。
【００８５】
これを３００℃で２０時間、酸素含有気体中（大気中）で一次熱処理を行い、各層の絶縁被覆（ガラス繊維）中の有機物を大気中の酸素と反応させ、炭酸ガス化してガラス繊維から除いた。次に巻かれた絶縁被覆超電導線４中の超電導相の生成のために７００℃で５０時間真空中（１×１０^-6ｔｏｒｒ）で熱処理を行った。
【００８６】
そして、各層の絶縁被覆超電導線４における絶縁被覆（ガラス繊維）の絶縁性を確認するために巻きほぐし、各層の絶縁被覆超電導線４をサンプリングした。これらの絶縁被覆超電導線４を絶縁抵抗計で測り、絶縁被覆（ガラス繊維）の絶縁性を調べた。各層の絶縁抵抗は５００Ｖの印加に対し無限大を示し、極めて良好な絶縁性があることが判った。
【００８７】
（実施例２）
巻き鍔６の外径３００ｍｍ、巻き芯５の外径５０ｍｍ、巻き芯５の内径４０ｍｍ、巻き芯５の長さ２５０ｍｍのステンレス製からなる巻枠７を用意し、巻き芯５および巻き鍔６の絶縁被覆超電導線４が配置される部分に板厚さ１ｍｍの銀シートを設け、直径１ｍｍの絶縁被覆超電導線４を２５層巻き付けた。
【００８８】
これを３００℃で２０時間、酸素含有気体中（大気中）で一次熱処理を行い、各層の絶縁被覆（ガラス繊維）中の有機物を大気中の酸素と反応させ、炭酸ガス化してガラス繊維から除いた。次に巻かれた絶縁被覆超電導線４中の超電導相の生成のために７００℃で５０時間真空中（１×１０^-6ｔｏｒｒ）で二次熱処理を行った。
【００８９】
そして、各層の絶縁被覆超電導線４におけるガラス繊維の絶縁性を確認するために巻きほぐし、各層の絶縁被覆超電導線４をサンプリングした。これらの絶縁被覆超電導線４を絶縁抵抗計で測り、ガラス繊維の絶縁性を調べた。各層の絶縁抵抗は無限大を示し、極めて良好な絶縁性があることが判った。
【００９０】
（実施例３）
巻き鍔６の外径３００ｍｍ、巻き芯５の外径５０ｍｍ、巻き芯５の内径４０ｍｍ、巻き芯５の長さ２５０ｍｍの銀製からなる巻枠７を用意し、直径１ｍｍの絶縁被覆超電導線４を２５層巻き付けた。
【００９１】
これを３００℃で２０時間、酸素含有気体中（大気中）で一次熱処理を行い、各層の絶縁被覆（ガラス繊維）中の有機物を大気中の酸素と反応させ、炭酸ガス化してガラス繊維から除いた。次に巻かれた絶縁被覆超電導線４中の超電導相の生成のために７００℃で５０時間真空中（１×１０^-6ｔｏｒｒ）で二次熱処理を行った。
【００９２】
そして、各層の絶縁被覆超電導線４におけるガラス繊維の絶縁性を確認するために巻きほぐし、各層の絶縁被覆超電導線４をサンプリングした。これらの絶縁被覆超電導線４を絶縁抵抗計で測り、ガラス繊維の絶縁性を調べた。各層の絶縁抵抗は無限大を示し、極めて良好な絶縁性があることが判った。
【００９３】
また、本発明のこれらの実施例１乃至実施例３との比較のため、実施例１乃至実施例３で採用した巻枠７と同等寸法の貫通孔９のないステンレス製の巻枠７を作り、銀シートを使用しない巻枠７に直径１ｍｍの絶縁被覆超電導線４を２５層巻き付けた。
【００９４】
これに、実施例１乃至実施例３で述べた同等の一次熱処理および二次熱処理を行った後、各層の絶縁被覆超電導線４におけるガラス繊維の絶縁性を確認するために巻きほぐし、各層の絶縁被覆超電導線４をサンプリングした。これらの絶縁被覆超電導線４を絶縁抵抗計で測り、ガラス繊維の絶縁性を調べた。
【００９５】
図５は本発明の実施例での各層のガラス繊維の電気絶縁抵抗、および比較例での各層のガラス繊維の電気絶縁抵抗を示している。本発明の実施例では、各層のガラス繊維の絶縁抵抗は無限大を示し、極めて良好な絶縁性示しているのに対し、比較例では、大気（酸素）と一番接する最外層は無限大の絶縁抵抗を示したが、各層のガラス繊維の絶縁抵抗は最内層へいくほど抵抗値が低下し、層全体的に不均一な絶縁性であることが判った。
【００９６】
第１の実施の形態によれば、超電導コイル１を構成する巻枠７に複数個の貫通孔９を設けたり、絶縁被覆超電導線４と接する部分に銀材料を設けることにより、巻枠７に多層に巻かれた絶縁被覆超電導線４の最外層から最内層まで酸素透過性のよい構造体になる。このため、酸素含有気体中で熱処理を行うことにより、絶縁被覆超電導線４の絶縁被覆（セラミックスやガラス繊維）に含まれている有機物をガス化して蒸発させることが可能になる。したがって、絶縁被覆３中に導電性の炭素が残留することがなく、絶縁被覆超電導線４間の絶縁性の優れた超電導コイルを提供することが可能となる。
【００９７】
次に、本発明の第２の実施の形態について説明する。第２の実施の形態は、第１の実施の形態における超電導コイルの製造方法の工程に対し、一次熱処理完了判定工程後に、さらに、加熱炉１０内を減圧脱気して再び加熱炉１０内を酸素含有気体に置換して加熱する熱処理工程を追加して設けたものである。
【００９８】
一次熱処理完了判定工程で、二酸化炭素や一酸化炭素あるいは酸素の濃度が規定値に達してほぼ一定になると、絶縁材８や絶縁被覆３に含有する有機物と酸素との酸化反応がほぼ終了したことを示す。この状態になったとしても、超電導コイル１の内部等酸素が十分供給されない部分では、未反応のまま有機物が残留している虞がある。
【００９９】
そこで、例えば、二酸化炭素濃度が規定値以下になった後に、加熱炉１０の炉内を排気装置１２で減圧脱気して再び加熱炉１０の炉内雰囲気を酸素含有気体に置換して加熱する。減圧脱気することにより超電導コイル本体１ａの内部の絶縁材８や絶縁被覆３に存在する二酸化炭素の豊富な気体が排出され、酸素含有気体に容易に置換される。
【０１００】
この状態で加熱を続行すると、もし未反応の有機物が残留している場合には、置換された酸素含有気体と酸化反応して加熱炉１０内の二酸化濃度が再び上昇する。この二酸化濃度をガス濃度系１１でモニターし、二酸化濃度が規定値以下になるまでこの工程を繰り返して実施する。一方、残留有機物が完全に放出されている場合には、置換した後も二酸化濃度が規定値以下になる。
【０１０１】
この第２の実施の形態によれば、一次熱処理完了判定の信頼性が格段に向上し、絶縁不良のない超電導コイルを製造できる。
【０１０２】
次に、本発明の第３の実施の形態について説明する。第３の実施の形態は、第１の実施の形態における超電導コイルの製造方法の工程に対し、巻枠７に絶縁材８を被着する前工程として、巻枠７と絶縁材８との間に巻枠７に設けられた貫通孔の位置に貫通孔が設けられた金属箔を被着する工程を追加している。超電導コイル１の完成姿としては巻枠７を装着したままのものと、絶縁物を含浸後に巻枠７を分解するものとがある。この第３の実施の形態は巻枠７を分解する超電導コイル１の製造方法に適用させるものである。
【０１０３】
図６は、第３の実施の形態に係わる超電導コイルの製造方法を適用する超電導コイル１の断面図である。図６において、超電導コイル１は、コイル巻回に先立って巻枠７に離型剤１４を介在して巻枠７に設けられた貫通孔の位置に貫通孔が設けられた金属箔１５を装着し、さらに、この金属箔１５の上に絶縁材８を被着して絶縁被覆超電導線４を幾重にも多層に巻回される。以後、第１の実施の形態と同様に一次熱処理工程と、一次熱処理完了判定工程と、二次熱処理工程を経て、絶縁材８および絶縁被覆超電導線４を絶縁物で含浸一体化する。その後巻枠７を超電導コイル１から分解する製造方法である。
【０１０４】
この第３の実施の形態によれば、第１の実施の形態の作用効果に加えて、巻枠７を超電導コイル１から分解して使用する超電導コイルでも、絶縁被覆超電導線４の巻回に先立って巻枠７に離型剤１４を介在して金属箔１５を装着したので、超電導コイル１を絶縁物で含浸一体化した後でも容易に巻枠７を分解できる。
【０１０５】
すなわち、分解の際に、まず最初に巻枠７を金属箔１５から分離し、次に金属箔１５を絶縁物で含浸された超電導コイル１から剥離する。この場合、薄い金属箔１５は可撓性に富むので、僻開力で含浸絶縁物から容易に引き剥がすことができる。したがって、二次熱処理終了後の脆くなっている絶縁被覆超電導線４に過度の力が加わることもなく、超電導性能の劣化を回避できる。
【０１０６】
ここで、離型剤１４としては、二次熱処理温度である６００℃から７００℃に耐え、かつ、含浸絶縁物と離型し易いボロンナイトライド粉末や窒化クロムコーティングが適している。また、金属箔１５としては、耐食性に優れ、かつ強度の高いステンレス鋼やインコネル等のニッケル合金が適している。
【０１０７】
次に本発明の第４の実施の形態について説明する。図７は、本発明の第４の実施の形態における、一次熱処理工程時の超電導コイル１を示す断面図である。第４の実施の形態は、第１の実施の形態における超電導コイルの製造方法の工程に対し、一次熱処理工程は、巻き鍔６に設けられた貫通孔９aをジャケット16で覆い、このジャケット16に接続された給気管17で外部から酸素含有気体を強制給気しながら加熱する工程としたものである。
【０１０８】
図７において、一次熱処理工程は、巻き鍔６に設けられた貫通孔９aをジャケット16で覆い、このジャケット16に接続された給気管17で図示しない加熱炉の外部から酸素含有気体を強制給気しながら加熱する。
【０１０９】
一次熱処理工程の際、加熱炉の外部から給気管１７でジャケット１６内に強制給気された酸素含有気体は、巻枠７に設けられた複数個の貫通孔９ａ、９ｂから超電導コイル１の内部に流入し、超電導コイル１内を貫流して外周から加熱炉内に排出される。この過程で、超電導コイル１の内部まで酸素含有気体が容易に拡散して絶縁材８や絶縁被覆３に含有する有機物と酸化反応し、有機物を一酸化炭素や二酸化炭素にガス化して放出する。特に、酸素が欠乏し易い巻き芯５側に近接する超電導コイル１の内層側でも、酸化反応が活発に行われる。さらに、酸化反応で生成した二酸化炭素等の反応ガスも超電導コイル１の内部に滞留することなく外部に排出される。
【０１１０】
このように、第４の実施の形態によれば、絶縁材８絶縁被覆３に含有する有機物を一次熱処理でほぼ完全に除去できるので、残存有機物が二次熱処理で炭化することによって起こる絶縁不良等を回避できる。
【０１１１】
以上の説明では、ジャケット１６を用いたものを示したが、図８に示すように、ジャケット１６に代えて、蓋１８を使用するようにしてもよい。
【０１１２】
図８において、一次熱処理工程において巻き芯５の両端部を蓋１８で覆い、この蓋１８に接続された給気管１７で図示しない加熱炉の外部から酸素含有気体を強制給気しながら加熱する。一次熱処理工程の際、加熱炉の外部から蓋１８に接続された給気管１７で巻き芯５内に強制給気された酸素含有気体は、巻き芯５に設けられた複数個の孔９bから超電導コイル１の最内層に流れ、超電導コイル１の絶縁材８や絶縁被覆３内を貫流して巻き鍔６に設けられた穴９aや超電導コイル１の外周から加熱炉内に排出される。
【０１１３】
この過程で、超電導コイル１の内部まで酸素含有気体が容易に拡散して絶縁材８や絶縁被覆３に含有する有機物と酸化反応し、有機物を一酸化炭素や二酸化炭素にガス化して放出する。特に、酸素が欠乏し易い巻き芯５側に近接する超電導コイル１の内層側でも、酸化反応が活発に行われる。さらに、酸化反応で生成した二酸化炭素等の反応ガスも超電導コイル１の内部に滞留することなく、外部に排出される。
【０１１４】
したがって、絶縁材８や絶縁被覆３に含有する有機物を一次熱処理でほぼ完全に除去できるので、残存有機物が二次熱処理で炭化することによって起こる絶縁不良等を回避できる。
【０１１５】
次に、本発明の第５の実施の形態を説明する。図９は、第５の実施の形態に係る超電導コイルの製造方法の工程のうち、絶縁被覆超電導線の巻回工程を示す構成図である。
【０１１６】
図９において、絶縁被覆超電導線４はボビン１９に巻かれており、ボビン１９から所定の張力で巻枠７に巻き取られる。ボビン１９には張力付加装置２３が取り付けられており、この張力付加装置２３で一定の張力がかけられ、巻枠７に取り付けられた巻線機２０でボビン１９に巻かれた絶縁被覆超電導線４を巻枠７に巻回して超電導コイル１を製造する。
【０１１７】
第５の実施の形態では、絶縁被覆超電導線４が巻枠７に巻回される手前に、絶縁被覆超電導線４を加熱する加熱手段２１が設けられており、さらに、巻枠７に巻回された後、速やかに絶縁被覆超電導線４を冷却するための冷却手段２２が設けられている。
【０１１８】
加熱手段２１で加熱された絶縁被覆超電導線４は、巻線する場所（巻枠７）の雰囲気温度より数℃高く、巻枠７に巻回されると同時に速やかに冷却手段２２で冷却される。したがって、熱膨張差により巻枠７に巻回される絶縁被覆超電導線４は緩みなく適切に巻回される。
【０１１９】
この際の熱膨張差に起因して超電導線２に働く張力Ｆは、以下の（１）式のように示される。
Ｆ＝Ｅ・α・Ｔ・Ａ …（１）
ここで、Ｅは超電導線２のヤング率、αは超電導線２の線膨張係数、Ｔは雰囲気と加熱された超電導線２との温度差、Ａは超電導線２の断面積である。
【０１２０】
また、張力Ｆは、Ｆ＝σ・Ａでも表わすことができる。ここで、σは超電導線２に生じる応力で、σ＝Ｅ・α・Ｔとなる。一般に、ガラス絶縁被覆の超電導線２に負荷できる張力は、絶縁被覆の健全性の点から５ｋgに抑えられる。しかし、寸法精度を上げるには、１０ｋg以上の張力が望ましい。そこで、超電導線２にＴ＝５０℃の温度差を与えた場合の応力は、σ＝８．５ｋg/mm²にもなる。したがって、張力付加装置２３との併用で１０ｋｇ以上の張力を付加できる。
【０１２１】
さらに、超電導コイル１の形状が円形でなく、直線部を有するレーストラック状の場合は、レーストラック状の超電導コイルで起こりがちの直線部の膨らみ防止に対しても効果大である。一例として、直線部の長さが１５０ｍｍのレーストラック状超電導コイルの場合について説明する。直線部の膨らみが１ｍｍとすると、約３℃の温度差で膨らみをほぼゼロにできる。
【０１２２】
以上の説明では、加熱手段２１はボビン１９と巻線機２０との間に配設し、絶縁被覆超電導線４を加熱するようにしているが、ボビン１９自体を加熱するようにしてもよい。また、冷却手段２２としては、巻枠７に冷却流体を流すか、あるいは、外部から冷却流体を吹き付けて強制冷却してもよい。
【０１２３】
このように、第５の実施の形態によれば、巻回前と巻回後の超電導線の熱膨張差を利用して超電導線に一定の張力を加えることができる。したがって、絶縁被覆の破損による絶縁不良を回避できる。さらに、レーストラック状の超電導コイルで起こりがちの直線部の膨らみも抑止でき、寸法精度が高くなる。
【０１２４】
次に、本発明の第６の実施の形態を説明する。図１０は、第６の実施の形態に係る超電導コイルの製造方法の工程のうち、水素使用による一次熱処理工程を示す構成図である。一次熱処理工程において、一旦、加熱炉１０内を１Pa程度まで、真空排気装置１１で排気し、その後、水素ボンベ２４から加熱炉１０内へ水素ガスを少量供給する。このとき、絶縁材８や絶縁被覆３に含有する有機物は、
Ｃ＋２Ｈ₂ → ＣＨ₄
のように反応し、有機物中の炭素がガス化する。加熱炉１０内は水素の圧力分だけの低い圧力になっているので、生成されたガスは、そのほとんどが超電導コイル１から加熱炉１０内へ放出される。超電導コイル１内の残留ガスも排出するためには反応が完了した後に、再び、真空排気装置１１により発生ガスを排気する。
【０１２５】
反応の完了は、前述した酸素濃度や一酸化炭素濃度の検出により行うことができる。また、加熱炉１０にマイクロ波発生器２５を取り付けることにより水素ガスをプラズマ化することが可能になる。水素プラズマは、
Ｃ＋４Ｈ⁺ → ＣＨ₄
のように反応し、水素よりも激しく反応するために短時間でより確実に炭素がガス化する。
【０１２６】
さらに、この方法においては、二次熱処理である真空雰囲気中の無酸素状態で６００℃から７００℃で行う超電導生成と同時に処理することができ、一次熱処理工程について省略できる利点がある。一次熱処理工程を長時間行うと、超電導線を構成する銅等の酸化膜が厚くなって正味の銅が減少し、超電導特性が不安定となることがあるが、一次熱処理工程を省略できるので、信頼性の高い安価な超電導コイルの製造が可能となる。
【０１２７】
次に本発明の第７の実施の形態について説明する。図１１は、本発明の第７の実施の形態における絶縁被覆内に残存する有機物質除去作業を含む製紐作業を示す説明図である。超電導線に製紐機を用いて絶縁被覆を編付けた後、ボビンに絶縁被覆超電導線を巻き付ける前に、水洗い工程および乾燥工程を行う。
【０１２８】
図１１において、超電導線２に製紐機２６で絶縁被覆を編付けた後、ボビン１９に絶縁被覆超電導線４を巻き付ける前に、水洗い工程および乾燥工程を行う。
【０１２９】
水洗い工程では、微細化した水２７を吹き付けて製紐作業用に混入した澱粉等の有機物質を洗い落とす。次いで乾燥工程において乾燥機（図示せず）で温度を高めた空気２８を送り、絶縁被覆内あるいは超電導線の表面に残っている水分を除去する。水洗いの方法は、シャワー式によらないときは浴槽に水を張り、浸漬してもよい。また、水に代えて、水蒸気を使用してもよい。
【０１３０】
この方法においては一次熱処理工程を省略できるので、長時間にわたる一次熱処理工程のために超電導線を構成する銅等の酸化膜が厚くなって正味の銅が減少し、超電導特性が不安定となるのを抑制することができ、信頼性の高い安価な超電導コイルの製造が可能となる。
【０１３１】
このように、第７の実施の形態によれば、二次熱処理後に炭化物として残留し、絶縁不良の原因となる有機物を含まない超電導線をコイルに巻回すことができるので、絶縁不良が確実に抑えられると共に、一次熱処理工程が省略できるので、信頼性の高い安価な超電導コイルの製造が可能になる。
【０１３２】
次に本発明の第８の実施の形態について説明する。図１２は、本発明の第８の実施の形態における絶縁被覆内に残存する有機物質除去作業を含むコイル巻回作業を示す説明図である。絶縁被覆超電導線を巻き付けてあるボビンから巻線機を用いて巻枠に巻回する間に、水洗い工程および乾燥工程を行う。
【０１３３】
図１２において、絶縁被覆超電導線４を巻き取っているボビン１９から巻線機（図示せず）で巻枠７に巻回する間に、水洗い工程および乾燥工程を行う。水洗い工程では、微細化した水２７を吹き付けて製紐作業用に混入した澱粉等の有機物質を洗い落とす。次いで乾燥工程において乾燥機（図示せず）で温度を高めた空気２８を送り、絶縁被覆内あるいは超電導線の表面に残っている水分を除去する。水洗いの方法は、シャワー式によらないときは容器に水を張り、浸漬してもよい。また、水に代えて、水蒸気を使用してもよい。
【０１３４】
この方法においては一次熱処理工程を省略できるので、長時間にわたる一次熱処理工程のために超電導線を構成する銅等の酸化膜が厚くなって正味の銅が減少し、超電導特性が不安定となるのを抑制することができ、信頼性の高い安価な超電導コイルの製造が可能となる。
【０１３５】
このように、第８の実施の形態によれば、二次熱処理後に炭化物として残留し、絶縁不良の原因となる有機物を含まない超電導線をコイルに巻回すことができるので、絶縁不良が確実に抑えられると共に、一次熱処理工程が省略できるので、信頼性の高い安価な超電導コイルの製造が可能となる。
【０１３６】
次に本発明の第９の実施の形態について説明する。図１３は、本発明の第９の実施の形態における絶縁被覆内に残存する有機物質除去作業を含むコイル巻回作業を示す構成図である。超電導コイルを巻回した後、二次熱処理を行う前に、超電導コイルを水槽に入れ、超音波発生器を用いて超音波洗浄する。
【０１３７】
図１３において、通常の手順で超電導コイル１を巻回した後、二次熱処理を行う前に、超電導コイル１を水を張った水槽２９に入れる。超電導コイル１を水中に置くだけでは超電導コイル１の内層側の絶縁材や絶縁被覆に含有する有機物が十分に水に溶ける可能性がない。そこで、超音波発生器３０から超電導コイル１に超音波を発射して超音波洗浄する。
【０１３８】
このような超音波を利用することにより超電導コイル１の内層側の絶縁材や絶縁被覆に含有する有機物が十分に水に溶け出し、有機物を除去することができる。使用する水は、温度の高い温水を使用することで、より効果を高めることができる。なお、本実施の形態は超音波発生器３０に代えて、バブル発生器によりバブルを発生させる方法を用いてもよい。
【０１３９】
本実施の形態によれば、超音波またはバブルを併用するので、有機物を効果的に除去することができる。したがって、超電導コイルとしての絶縁性が高く、電気的に安定となり、高性能な超電導コイルを製造できる。
【０１４０】
【発明の効果】
以上説明したように、本発明によれば、絶縁被覆超電導線を巻回して形成した超電導コイルにおいて、絶縁被覆などに含有している有機物を超電導線が損傷劣化しない比較的短時間の加熱によりガス化して確実に放出でき、あるいは、特別な加熱処理を施さずに、電気絶縁上有害な炭化物が残留しない信頼性の高い超電導コイルおよびその製造方法を提供することができる。
【０１４１】
また、本発明によれば、絶縁被覆超電導線の巻回時に過度な張力を加えなくとも高い寸法精度を実現でき、絶縁被覆の損傷がない高性能、高精度の超電導コイルの製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態に係る超電導コイルを示すもので、（ａ）は超電導コイルの断面図、（ｂ）は絶縁被覆超電導線の斜視図。
【図２】本発明の第１の実施の形態に係る超電導コイルを形成する際の一次熱処理工程を示す説明図。
【図３】本発明の第１の実施の形態に係る超電導コイルの他の一例を示す断面図。
【図４】本発明の第１の実施の形態における実施例１で使用した巻枠を示す斜視図。
【図５】本発明の第１の実施の形態にける実施例での各層のガラス繊維の電気絶縁特性を従来例との比較で示した特性図。
【図６】本発明の第３の実施の形態に係る超電導コイルの製造方法を適用した超電導コイルを示す断面図。
【図７】本発明の第４の実施の形態に係る超電導コイルの製造方法を適用した場合の一次熱処理工程時の超電導コイルを示す断面図。
【図８】本発明の第４の実施の形態に係る超電導コイルの製造方法を適用した場合の一次熱処理工程時の超電導コイルの他の例を示す断面図。
【図９】本発明の第５の実施の形態に係る超電導コイルの製造方法の工程のうち、絶縁被覆超電導線の巻回工程を示す構成図。
【図１０】本発明の第６の実施の形態に係る超電導コイルの製造方法の工程のうち、水素使用による一次熱処理工程を示す構成図。
【図１１】本発明の第７の実施の形態に係る超電導コイルの製造方法の工程のうち、有機物質除去工程を示す説明図。
【図１２】本発明の第８の実施の形態に係る超電導コイルの製造方法の工程のうち、有機物質除去工程を示す説明図。
【図１３】本発明の第９の実施の形態に係る超電導コイルの製造方法の工程のうち、有機物質除去工程を示す構成図。
【符号の説明】
１超電導コイル
１ａ超電導コイル本体
２超電導線
３絶縁被覆
４絶縁被覆超電導線
５巻き芯
６巻き鍔
７巻枠
８絶縁材
９貫通孔
１５金属箔
１６ジャケット
１８蓋[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a superconducting coil formed by winding an insulating coated superconducting wire obtained by applying glass or ceramic insulation to an intermetallic compound superconducting wire around a winding frame, and then performing a superconducting heat treatment.
[0002]
[Prior art]
In general, superconducting wires used at extremely low temperatures include metal superconducting wires such as NbTi and Nb_ThreeAn intermetallic compound superconducting wire such as Sn or NbAl is used. Of these, Nb_ThreeA superconducting coil formed by winding an intermetallic compound superconducting wire such as Sn or NbAl around a winding frame has excellent superconducting characteristics even in a high magnetic field. On the other hand, it is very weak against the tensile force and bending strain in the longitudinal direction, and has the disadvantages that the critical current rapidly decreases.
[0003]
Therefore, forming a superconducting coil by winding a preheated superconducting wire around a winding frame has been put into practical use with a large-diameter coil with a bending strain of 0.2% or less. Specifically, a superconducting coil is manufactured by winding an unheated superconducting wire around a winding frame and then performing a superconducting heat treatment. Since the superconducting heat treatment is performed in an inert gas such as argon gas or in a vacuum furnace at a high temperature of 600 ° C. to 700 ° C. for several tens of hours, ceramic fibers that are less susceptible to thermal degradation at that temperature are used for electrical insulation of superconducting wires. Glass fiber is used.
[0004]
[Problems to be solved by the invention]
However, in order to facilitate the stringing operation and the like, the glass fiber covering the superconducting wire generally contains several percent of organic material such as starch. As described above, when a superconducting coil formed of such an insulation-coated superconducting wire is subjected to a superconducting heat treatment at 600 ° C. to 700 ° C. in an oxygen-free state in argon gas or a vacuum atmosphere, these organic substances are in a so-called steamed state. Thus, it becomes conductive carbon and remains on the insulating coating made of glass fiber. Therefore, a conductive current path can be formed between the superconducting wires and in the creeping direction, the dielectric breakdown voltage is lowered, and insulation failure and dielectric breakdown are likely to occur.
[0005]
In order to avoid this, a so-called primary heat treatment step in which the superconducting coil is heat-treated once in the atmosphere at about 300 ° C. and gasified into carbon monoxide, carbon dioxide or the like and released is performed before the superconducting heat treatment. However, even if this primary heat treatment step is performed, in the superconducting coil in which the insulation superconducting wire is wound in multiple layers, the atmosphere does not sufficiently diffuse and penetrate to the inner layer near the winding core, and the organic matter in this part is oxygen Due to the deficiency, it remains unreacted or partly remains as a carbide in the steamed state. This unreacted remaining organic matter is naturally carbonized in a superconducting heat treatment (hereinafter referred to as a secondary heat treatment step), and as a result, insulation failure and dielectric breakdown are likely to occur.
[0006]
On the other hand, since the inner layer and the outside air are mutually diffused by natural convection and partial pressure, if the primary heat treatment process is performed for a long time, the oxide film such as copper constituting the superconducting wire becomes thicker and the net copper is reduced. Becomes an unstable superconducting wire.
[0007]
In addition, there is no method for confirming whether organic substances are completely gasified and released in the primary heat treatment step, and the treatment time has been determined based on experience so far. For this reason, depending on the shape and dimensions of the superconducting coil, the organic matter remains as carbides, resulting in defective insulation, which may cause the superconducting wire to melt due to discharge due to dielectric breakdown or Joule heating.
[0008]
Furthermore, when winding the superconducting wire around the winding frame, it is performed while applying a certain tension, but the glass-coated insulation is very weak and the winding machine and adjacent superconducting wires are easily rubbed and damaged during winding. There is a limit to the tension applied. Therefore, for example, in the case of manufacturing a racetrack-shaped superconducting coil, the bulge of the straight portion is large and the superconducting coil has poor dimensional accuracy.
[0009]
Therefore, the present invention provides a highly reliable superconducting material in which organic matter mixed in the insulation coating of the superconducting wire is gasified and released by heating in a relatively short time that the superconducting wire is not damaged and deteriorated, and no harmful carbides remain on insulation. An object of the present invention is to provide a coil and a manufacturing method thereof.
[0010]
Furthermore, an object of the present invention is to provide a method of manufacturing a superconducting coil with high dimensional accuracy without applying excessive tension to the superconducting wire during winding.
[0011]
[Means for Solving the Problems]
  The superconducting coil according to the invention of claim 1 is a superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of a winding core.AboveFluid flows through the reelMultipleThrough holesA sheet-like plate made of silver is provided between the through-hole on the side surface of the winding frame and the insulation-coated superconducting wire wound many times, or between the insulation-coated superconducting wires.It is characterized by that.
[0012]
  In the present invention, the oxygen-containing gas easily diffuses from the plurality of through holes provided in the winding frame to the inside of the superconducting coil, and the organic matter mixed in the insulating coating can be gasified and released in the primary heat treatment process. Defects can be avoided.
Further, the oxygen-containing gas permeation path passes from the outermost layer through the insulating coating of each layer and out of the through hole from the innermost insulating coating through the silver sheet plate. Further, when a silver sheet plate is provided between the superconducting wires, the permeation of the oxygen-containing gas from the outermost layer to the innermost layer is made smooth.
[0013]
According to a second aspect of the present invention, there is provided a superconducting coil according to the first aspect of the present invention, wherein the through hole is a hole communicating the inner periphery and the outer periphery of the winding core, or a hole communicating the coil side and the non-coil side of the winding collar. It is characterized by being at least one of them.
[0014]
In the present invention, in addition to the function and effect of the first aspect of the invention, superconductivity is achieved from a hole through which the oxygen-containing gas communicates between the inner circumference and the outer circumference of the winding core, or a hole that communicates the coil side and the non-coil side of the winding collar. Since the organic matter that diffuses easily into the coil and enters the insulating coating can be gasified and discharged in the primary heat treatment step, insulation failure or the like can be avoided.
[0015]
In particular, the reaction area with the oxygen-containing gas also increases and the oxygen-containing gas easily penetrates into the superconducting coil even on the inner layer side on the winding core side where oxygen is easily deficient.
[0020]
  Claim3The superconducting coil according to the invention isIn the invention of claim 1,In a superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of the winding core, the winding frame is characterized by using silver as its material.
[0021]
  In the present invention,In addition to the effects of the invention of claim 1,Oxygen-containing gas can be easily diffused from the silver frame with excellent oxygen permeability to the inside of the superconducting coil, and organic substances mixed in the insulation coating can be gasified and released in the primary heat treatment process, thus avoiding insulation failure etc. .
[0022]
  Claim4The method of manufacturing a superconducting coil according to the invention is the method of manufacturing a superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of the winding core. A step of providing a plurality of through-holes, a step of attaching an insulating material to the winding frame prior to winding the coil on the winding frame, and a winding step of winding an insulation-coated superconducting wire on the insulating material; A primary heat treatment step for gasifying and releasing organic substances contained in the insulating material and the insulation coating, a primary heat treatment completion judgment step for judging that the primary heat treatment step is completed, and a secondary heat treatment for converting the superconducting wire into a superconductor And a process.
[0023]
In the present invention, since the organic substance contained in the insulating coating is judged to be almost gasified and released during the primary heat treatment process, the residual organic substance is carbonized in the secondary heat treatment process, resulting in insulation failure and the like. Can be avoided.
[0024]
  Claim5The method of manufacturing a superconducting coil according to the invention is a method of manufacturing a superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of the winding core. A step of providing a plurality of through holes, and a coiling agent prior to winding the coil on the winding frameA through hole was provided at a position of the through hole provided in the winding frame.Included in the step of attaching the metal foil, the step of depositing the insulating material on the metal foil, the winding step of winding the insulating coating superconducting wire on the insulating material, and the insulating material and the insulating coating A primary heat treatment step for gasifying and releasing organic matter;AboveA primary heat treatment completion determination step for determining that the primary heat treatment step is completed;AboveIt comprises a secondary heat treatment step for converting the superconducting wire into a superconductor, a step of impregnating and integrating the insulating material and the insulation coated superconducting wire with an insulator, and a step of disassembling the winding frame from the coil. To do.
[0025]
  In the present invention, the claims4In addition to the effects of the invention, even in a superconducting coil that is used by disassembling the winding frame from the coil, since the metal foil is attached to the winding frame via a release agent prior to coil winding, impregnation with an insulator is integrated. The reel can be easily disassembled even after
[0026]
That is, at the time of disassembly, the winding frame is first separated from the metal foil, and then the metal foil is peeled off from the superconducting coil impregnated with the insulator. In this case, since the thin metal foil is rich in flexibility, it can be easily peeled off from the impregnated insulator by the cleavage force. Therefore, excessive force is not applied to the brittle superconducting wire after the end of the secondary heat treatment, and deterioration of the superconducting performance can be avoided.
[0027]
  Claim6A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention, instead of the step of providing a plurality of through holes through which a fluid flows in the winding frame, a step of forming the winding frame with silver is used.
[0028]
  In the present invention, the claims4Or claims5In addition to the effects of the present invention, the organic material contained in the insulating material and the insulating coating can be appropriately gasified and released in the primary heat treatment step.
[0029]
  Claim7A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention of the present invention, the step of providing a plurality of through holes through which the fluid flows in the winding frame and the through hole on the side surface of the winding frame and the insulation coated superconducting wire wound many times, or between the insulating coated superconducting wires The step of providing a sheet-like plate made of silver is additionally provided.
[0030]
  In the present invention, the claims4Or claims5In addition to the effects of the present invention, the organic material contained in the insulating material and the insulating coating can be appropriately gasified and released in the primary heat treatment step.
[0031]
  Claim8A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention, the primary heat treatment step is a step of heating in a furnace in a gas containing oxygen, and the primary heat treatment completion determination step confirms that the concentration of carbon monoxide or carbon dioxide in the furnace is not more than a specified value. It is a process.
[0032]
  In the present invention, the claims4Or claims5In addition to the effects of the invention of the present invention, the determination of completion of the primary heat treatment is performed by measuring the concentration of carbon monoxide or carbon dioxide in the furnace, and the value is, for example, below a specified value that is substantially equivalent to the level of the oxygen-containing gas supplied to the furnace. Confirm that there is, complete the primary heat treatment. If the oxygen-containing gas is the atmosphere, the normal concentration of dioxide is about 400 ppm, which is the specified value.
[0033]
In this way, since it is confirmed that no organic matter remains, it can be determined by a method that does not affect the shape and dimensions of the superconducting coil. Accordingly, it is possible to avoid insulation failure due to residual carbide.
[0034]
  Claim9A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the present invention, the primary heat treatment step is a step of heating in a furnace in a gas containing oxygen, and the primary heat treatment completion determination step is a step of confirming that the oxygen concentration in the furnace is a specified value or more. It is characterized by.
[0035]
  In the present invention, the claims4Or claims5In addition to the operational effects of the invention, the primary heat treatment completion determination is made by measuring the oxygen concentration in the furnace and confirming that the value is equal to or higher than a specified value that is substantially equivalent to the level of the oxygen-containing gas supplied to the furnace, for example. Complete the primary heat treatment. If the oxygen-containing gas is the atmosphere, the oxygen concentration is usually about 21%, so this is set to the specified value.
[0036]
Thus, it can be determined by an absolute method that does not affect the shape and dimensions of the superconducting coil that there is no organic residue. Accordingly, it is possible to avoid insulation failure due to residual carbide.
[0037]
  Claim10A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention, after the primary heat treatment completion determination step, an additional heat treatment step is further provided in which the inside of the furnace is degassed under reduced pressure, and the inside of the furnace is again replaced with an oxygen-containing gas and heated.
[0038]
  In the present invention, the claims4Or claims5In addition to the effects of the invention of the present invention, in order to further improve the reliability of the primary heat treatment completion determination, for example, after the carbon dioxide concentration has fallen below a specified value, the inside of the furnace is degassed under reduced pressure and the inside of the furnace is again filled with oxygen Substitute for heating. By degassing under reduced pressure, the gas inside the coil is discharged and easily replaced with an oxygen-containing gas. When heating is continued in this state, if unreacted organic matter remains, it undergoes an oxidation reaction with the substituted oxygen-containing gas, and the concentration of dioxide in the furnace rises again. This process is repeated until the dioxide concentration is below the specified value. On the other hand, if the residual organic matter is completely released, the dioxide concentration remains below the specified value even after replacement. According to this method, the reliability of the primary heat treatment completion determination is remarkably improved, and a superconducting coil free from defective insulation can be manufactured.
[0039]
  Claim11A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention, the primary heat treatment step is a step of heating in a furnace containing a small amount of hydrogen in a vacuum.
[0040]
In the present invention, hydrogen is supplied and heated in an atmosphere in which the inside of the furnace is evacuated and unnecessary components are removed, so that organic substances mixed in the insulating coating efficiently react with hydrogen and can be gasified and released.
[0041]
  Claim12A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention, the primary heat treatment step is a step of heating in a furnace maintaining a hydrogen plasma atmosphere.
[0042]
In the present invention, by using hydrogen plasma, the organic matter mixed in the insulating coating reacts with hydrogen and can be gasified and released more efficiently than when hydrogen is used.
[0043]
  Claim13A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the invention of claim 1,OrClaim2In the superconducting coil manufacturing method for manufacturing the superconducting coil described, the primary heat treatment step covers the through-hole provided in the curl with a jacket and forces an oxygen-containing gas from the outside with an air supply pipe connected to the jacket. It is a process of heating while supplying air.
[0044]
  In the present invention, the claims4Or claims5In addition to the effects of the present invention, the oxygen-containing gas is heated while being forcedly supplied from the outside, so that oxygen is always supplied to the inside of the coil, and organic substances mixed in the insulating coating can be efficiently gasified and released. In addition, by forced air supply, a gas such as carbon dioxide generated by the oxidation reaction is discharged outside without staying in the coil. Accordingly, it is possible to avoid insulation failure due to residual carbide.
[0045]
  Claim14A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5The superconducting coil manufacturing method for manufacturing the superconducting coil according to claim 1 or 2, wherein the primary heat treatment step covers both ends of the winding core with a lid, and an air supply pipe connected to the lid And a step of heating while forcibly supplying a gas containing oxygen from the outside.
[0046]
  In the present invention, the claims4Or claims5In addition to the effects of the invention, the oxygen-containing gas forcedly supplied from the outside flows from the inner side of the winding core to the innermost layer of the coil, flows through the inside of the insulating coating of the coil, and the outer periphery of the coil Discharged from. Therefore, oxygen is always supplied into the coil, and organic substances mixed in the insulating coating can be efficiently gasified and released. In addition, by forced air supply, a gas such as carbon dioxide generated by the oxidation reaction is discharged outside without staying in the coil. As a result, insulation failure due to residual carbides can be avoided.
[0047]
  Claim15A method of manufacturing a superconducting coil according to the invention is as follows.4Or claims5In the method of manufacturing a superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of the winding core, the winding step is performed by winding the insulation-coated superconducting wire around the winding frame. It is characterized by comprising a step of heating the insulation coated superconducting wire before being performed, and a step of cooling the insulation coated superconducting wire promptly after being wound around the winding frame.
[0048]
In the present invention, a constant tension can be applied to the superconducting wire by utilizing the difference in thermal expansion of the superconducting wire before and after winding. Therefore, it is possible to avoid insulation failure due to breakage of the insulation coating. Furthermore, the bulging of the straight portion that tends to occur in a racetrack-shaped superconducting coil can be suppressed.
[0057]
  Claim16A superconducting coil manufacturing method according to the invention is the superconducting coil manufacturing method for manufacturing a superconducting coil according to claim 1 or claim 2, wherein the superconducting wire is braided with an insulation coating, and the insulation coating superconductivity The method includes a winding step of winding a wire around a winding frame, and a step of removing an organic substance remaining in the insulating coating of the wound insulating coating superconducting wire.
[0058]
In the present invention, since the organic coating is not contained in the insulation coating of the superconducting wire, insulation failure can be suppressed and the primary heat treatment step can be omitted. Furthermore, since the primary heat treatment can be omitted, it is also possible to avoid that the oxide film such as copper constituting the superconducting wire is thick and the net copper is reduced, and the superconducting characteristics are unstable.
[0059]
  Claim17A method of manufacturing a superconducting coil according to the invention is as follows.16In the present invention, the organic substance removing step is a step of washing the organic substance with water.
[0060]
In the present invention, since an organic substance such as starch is easily dissolved in water, the organic substance can be removed at a relatively low temperature around room temperature.
[0061]
  Claim18A method of manufacturing a superconducting coil according to the invention is as follows.17In the invention, the organic substance removing step is characterized by using ultrasonic waves or bubbles in combination.
[0062]
In the present invention, since ultrasonic waves or bubbles are used together when washing with water, organic substances can be effectively removed, and the insulation performance as a superconducting coil is high, which is electrically stable, and produces a high-performance superconducting coil. it can.
[0063]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. FIG. 1 is an explanatory view of a superconducting coil according to a first embodiment of the present invention, FIG. 1 (a) is a sectional view of the superconducting coil, and FIG. 1 (b) is a perspective view of an insulation coated superconducting wire.
[0064]
As shown in FIG. 1A, the superconducting coil 1 is composed of a superconducting coil body 1 a and a winding frame 7. The superconducting coil body 1a is composed of an insulating coated superconducting wire 4 and an insulating material 8, and the winding frame 7 is composed of a hollow core 5 and a winding rod 6 formed at the end thereof. That is, a through hole 9 b is provided in the winding core 5 of the winding frame 7, and a through hole 9 a is provided in the winding rod 6 of the winding frame 7.
[0065]
As shown in FIG. 1 (b), the insulation-coated superconducting wire 4 is obtained by applying an insulation coating 3 to the superconducting wire 2.₃An intermetallic compound superconducting wire such as Sn or NbAl is used, and the superconducting wire 2 is provided with an insulating coating 3 such as glass fiber or ceramic fiber as a strand insulation.
[0066]
As shown in FIG. 1A, the insulation-coated superconducting wire 4 configured in this way is layered over the winding frame 7 having the winding rods 6 on both sides of the winding core 5 through the insulating material 8. The superconducting coil body 1a is formed by winding in multiple layers. The reel 7 is provided with a plurality of through holes 9 through which fluid flows, as described above.
[0067]
Superconducting coil 1 formed in this way undergoes a primary heat treatment step in order to cause an organic substance such as starch contained in insulating material 8 and insulating coating 3 to undergo an oxidation reaction with an oxygen-containing gas, which is gasified and released.
[0068]
FIG. 2 is an explanatory diagram of the primary heat treatment step. In this primary heat treatment step, the superconducting coil 1 is placed in a heating furnace 10 in an oxygen-containing gas atmosphere and heated at about 300 ° C. for about ten hours while replenishing the oxygen-containing gas. Thereafter, the concentration of carbon dioxide and carbon monoxide is measured with the gas concentration meter 11, and it is determined that the concentration is not more than a specified value, and the primary heat treatment step is completed.
[0069]
Here, when the oxygen-containing gas is air, the normal atmospheric dioxide concentration is about 400 ppm, which is set to a specified value. Similarly, the specified value in the case of an oxygen-containing gas other than the atmosphere may be the carbon dioxide concentration originally contained in the gas.
[0070]
Then, the temperature is lowered after the completion of the primary heat treatment, and the gas in the heating furnace 10 is exhausted by the exhaust device 12 and replaced with an inert gas 13 such as argon gas or a vacuum, and then 600 in the heating furnace 10 as a superconducting generation process. Secondary heat treatment is performed for several tens of hours at a high temperature of from 700C to 700C.
[0071]
Next, the effect | action at the time of heat processing of the superconducting coil 1 which has such a through-hole 9 is demonstrated. In the primary heat treatment step, the oxygen-containing gas easily diffuses from the plurality of through holes 9 provided in the winding frame 7 to the inside of the superconducting coil body 1a. That is, the oxygen-containing gas diffuses to the inside of the superconducting coil body 1a from the through-hole 9a provided in the winding rod 6 and the through-hole 9b provided in the winding core 5, and the organic matter contained in the insulating material 8 and the insulating coating 3 Is gasified and released.
[0072]
As a result, especially on the inner layer 1a side of the superconducting coil body 1a close to the core 5 side where oxygen tends to be deficient, the reaction area with the oxygen-containing gas increases, and oxygen can easily be contained in the superconducting coil body 1a. Gas penetrates. Therefore, since the remaining organic matter can be appropriately removed, it is possible to avoid insulation failure caused by carbonization of the remaining organic matter by the secondary heat treatment described above.
[0073]
In the above description, the hollow core 5 provided with the through hole 9b is shown. However, as shown in FIG. 3, when the core 5 is solid, the groove 5a is used instead of the through hole 9b. Is provided. That is, a plurality of grooves 5a along the axial direction are formed on the outer periphery of the solid winding core 5, and the winding rod 6 has a hole 9a that communicates the coil side and the non-coil side at a position facing the groove 5a. Is provided.
[0074]
Also in the case of the superconducting coil 1 configured as described above, in the primary heat treatment step, the oxygen-containing gas flows into the groove 5a formed in the winding core 5 from the hole 9a provided in the winding rod 6, and this It diffuses easily from the groove 5a to the inside of the superconducting coil 1, and gasifies and discharges organic substances contained in the insulating material 8 and the insulating coating 3. In particular, even on the inner layer side of the superconducting coil main body 1a close to the core 5 side where oxygen is easily deficient, the reaction area with the oxygen-containing gas increases and the oxygen-containing gas easily penetrates into the superconducting coil main body 1a. . Therefore, it is possible to avoid insulation failure caused by carbonization of the remaining organic matter by the secondary heat treatment described above.
[0075]
Further, the gas concentration meter 11 may be an oxygen concentration meter instead of carbon dioxide or carbon monoxide concentration meter. In this case, the primary heat treatment completion determination is made by measuring the oxygen concentration in the furnace, and confirming that the value is equal to or higher than a specified value that is substantially equivalent to the level of the oxygen-containing gas supplied into the furnace, for example. Will be completed. If the oxygen-containing gas is the atmosphere, the oxygen concentration is usually about 21%, so this is set to the specified value.
[0076]
As described above, since the plurality of through holes 9 are provided in the winding frame 7 constituting the superconducting coil 1, the permeability of the oxygen-containing gas during the primary heat treatment is remarkably improved. The oxygen-containing gas permeation path passes from the outermost layer through the insulating coating 3 of each layer, and reaches the through hole 9 from the innermost insulating coating 3. The reverse path is also possible.
[0077]
Therefore, oxygen is sufficiently distributed to the organic matter contained in the insulating coating 3 in each layer of the insulating coated superconducting wire 4 forming the superconducting coil body 1a, and is gasified and released. For this reason, there is no carbon material that causes insulation failure or dielectric breakdown. In addition, the size of the through-hole 9 is about 1 to 3 mm for the drilling operation.
[0078]
In addition, when there are many layers of the insulation coating superconducting wire 4, a silver sheet having high oxygen permeability may be inserted into the intermediate layer so that the oxygen-containing gas can be smoothly transmitted to the innermost layer.
[0079]
Further, the material of the reel 7 can be a silver material having excellent oxygen permeability. In this case, the oxygen-containing gas permeation path exits from the outermost layer through the insulating coating 3 of each layer and from the innermost insulating coating 3 through the silver frame 7. Also in this case, when there is much superconductivity, a silver sheet may be inserted into the intermediate layer so that the oxygen-containing gas can be smoothly transmitted to the innermost layer.
[0080]
Here, after providing a plurality of through-holes 9 in the reel 7 and performing a primary heat treatment for carbonizing an organic substance and a secondary heat treatment for superconductivity generation, and then generating a magnetic field with this coil in a superconducting state, Hoop force is generated. In order to prevent deterioration of the material of the superconducting wire 2 due to the hoop force, the entire winding frame 7 of the superconducting coil 1 is impregnated with epoxy resin.
[0081]
In this case, if a plurality of through holes 9 are left open in the reel 7, the epoxy resin leaks out from the through holes 9 and cannot be impregnated. An excellent sheet-shaped silver material is interposed. After that, the work of winding the insulation coating superconducting wire 4 in a multilayered manner in a solenoid shape is performed. Thus, even if the epoxy resin is impregnated after a series of heat treatments, the epoxy resin is not blocked by the silver sheet and does not leak, and there is an advantage that a normal impregnation operation can be completed.
[0082]
The temperature for the primary heat treatment is preferably about 250 ° C to 500 ° C. The heat treatment temperature may be about 40 to 100 hours at 250 ° C. and about 5 hours at 500 ° C., but the heat treatment temperature depends on the size of the superconducting coil 1, that is, the absolute amount of organic matter contained in the insulation coating 3 of the insulation coating superconducting wire 4. And decide the time.
[0083]
Next, examples 1 to 3 and a comparative example according to the first embodiment of the present invention will be described.
[0084]
Example 1
As shown in FIG. 4, a winding frame 7 made of stainless steel having an outer diameter of 300 mm, an outer diameter of the winding core 5 of 50 mm, an inner diameter of 40 mm of the winding core 5 and a length of 250 mm of the winding core 5 is prepared. A plurality of through holes 9 having a diameter of 2 mm were provided in the core 5 and the curl 6 at intervals of about 10 mm. Then, a silver sheet having a plate thickness of 2 mm was provided on the winding core 5 and the winding rod 6 of the winding frame 7, and 25 layers of the insulation coated superconducting wire 4 having a diameter of 1 mm was wound.
[0085]
This is subjected to primary heat treatment at 300 ° C. for 20 hours in an oxygen-containing gas (in the air) to react organic substances in the insulation coating (glass fiber) of each layer with oxygen in the air, and carbon dioxide gas is removed from the glass fiber. It was. Next, in order to generate a superconducting phase in the wound insulation-coated superconducting wire 4, it is vacuumed at 700 ° C. for 50 hours (1 × 10^-6heat treatment at torr).
[0086]
And in order to confirm the insulation of the insulation coating (glass fiber) in the insulation coating superconducting wire 4 of each layer, the insulation coating superconducting wire 4 of each layer was sampled. These insulation coating superconducting wires 4 were measured with an insulation resistance meter, and the insulation of the insulation coating (glass fiber) was examined. The insulation resistance of each layer was infinite when 500 V was applied, and it was found that there was very good insulation.
[0087]
(Example 2)
A winding frame 7 made of stainless steel having an outer diameter of 300 mm, an outer diameter of 50 mm, an inner diameter of 40 mm, and a length of 250 mm of the winding core 5 is prepared. A silver sheet having a plate thickness of 1 mm was provided at a portion where the insulating coating superconducting wire 4 is disposed, and 25 layers of the insulating coating superconducting wire 4 having a diameter of 1 mm were wound.
[0088]
This is subjected to primary heat treatment at 300 ° C. for 20 hours in an oxygen-containing gas (in the air) to react organic substances in the insulation coating (glass fiber) of each layer with oxygen in the air, and carbon dioxide gas is removed from the glass fiber. It was. Next, in order to generate a superconducting phase in the wound insulation-coated superconducting wire 4, it is vacuumed at 700 ° C. for 50 hours (1 × 10^-6Torr) was subjected to secondary heat treatment.
[0089]
And in order to confirm the insulation of the glass fiber in the insulation coating superconducting wire 4 of each layer, it unwinded and sampled the insulation coating superconducting wire 4 of each layer. These insulation coated superconducting wires 4 were measured with an insulation resistance meter, and the insulating properties of the glass fiber were examined. The insulation resistance of each layer was infinite, and it was found that there was very good insulation.
[0090]
(Example 3)
A winding frame 7 made of silver having an outer diameter of 300 mm, an outer diameter of 50 mm, an inner diameter of 40 mm, and a length of 250 mm of the winding core 5 is prepared. 25 layers were wound.
[0091]
This is subjected to primary heat treatment at 300 ° C. for 20 hours in an oxygen-containing gas (in the air) to react organic substances in the insulation coating (glass fiber) of each layer with oxygen in the air, and carbon dioxide gas is removed from the glass fiber. It was. Next, in order to generate a superconducting phase in the wound insulation-coated superconducting wire 4, it is vacuumed at 700 ° C. for 50 hours (1 × 10^-6Torr) was subjected to secondary heat treatment.
[0092]
And in order to confirm the insulation of the glass fiber in the insulation coating superconducting wire 4 of each layer, it unwinded and sampled the insulation coating superconducting wire 4 of each layer. These insulation coated superconducting wires 4 were measured with an insulation resistance meter, and the insulating properties of the glass fiber were examined. The insulation resistance of each layer was infinite, and it was found that there was very good insulation.
[0093]
Further, for comparison with the first to third embodiments of the present invention, a stainless steel reel 7 having no through hole 9 having the same dimensions as the reel 7 employed in the first to third embodiments is made. Then, 25 layers of the insulation coated superconducting wire 4 having a diameter of 1 mm were wound around the winding frame 7 not using the silver sheet.
[0094]
After performing the same primary heat treatment and secondary heat treatment as described in Examples 1 to 3, this was unwound in order to confirm the insulating properties of the glass fibers in the insulation-coated superconducting wire 4 of each layer, and the insulation of each layer The coated superconducting wire 4 was sampled. These insulation coated superconducting wires 4 were measured with an insulation resistance meter, and the insulating properties of the glass fiber were examined.
[0095]
FIG. 5 shows the electrical insulation resistance of the glass fiber of each layer in the example of the present invention and the electrical insulation resistance of the glass fiber of each layer in the comparative example. In the examples of the present invention, the insulation resistance of the glass fiber of each layer shows infinite and very good insulation, whereas in the comparative example, the outermost layer closest to the atmosphere (oxygen) is infinite. Insulation resistance was shown, but it was found that the insulation resistance of the glass fiber of each layer decreased as it went to the innermost layer, and the entire layer was non-uniform insulation.
[0096]
According to the first embodiment, a plurality of through holes 9 are provided in the winding frame 7 constituting the superconducting coil 1, or a silver material is provided in a portion in contact with the insulating coating superconducting wire 4. A structure having good oxygen permeability from the outermost layer to the innermost layer of the insulation-coated superconducting wire 4 wound in multiple layers. For this reason, by performing heat treatment in an oxygen-containing gas, it becomes possible to gasify and evaporate the organic matter contained in the insulating coating (ceramics or glass fiber) of the insulating coating superconducting wire 4. Therefore, no conductive carbon remains in the insulating coating 3, and it is possible to provide a superconducting coil having excellent insulating properties between the insulating coated superconducting wires 4.
[0097]
Next, a second embodiment of the present invention will be described. In the second embodiment, after the primary heat treatment completion determination step, the inside of the heating furnace 10 is further degassed under reduced pressure and again inside the heating furnace 10 with respect to the process of the superconducting coil manufacturing method in the first embodiment. A heat treatment step for heating by substituting with an oxygen-containing gas is additionally provided.
[0098]
In the primary heat treatment completion determination step, when the concentration of carbon dioxide, carbon monoxide or oxygen reaches a specified value and becomes almost constant, the oxidation reaction between the organic substance contained in the insulating material 8 or the insulating coating 3 and oxygen is almost completed. Indicates. Even in this state, there is a possibility that the organic matter remains unreacted in a portion where oxygen is not sufficiently supplied such as inside the superconducting coil 1.
[0099]
Therefore, for example, after the carbon dioxide concentration becomes equal to or less than a specified value, the inside of the furnace 10 is degassed by the exhaust device 12 and the atmosphere inside the furnace 10 is again replaced with an oxygen-containing gas and heated. . By degassing under reduced pressure, the carbon-rich gas present in the insulating material 8 and the insulating coating 3 inside the superconducting coil body 1a is discharged and easily replaced with oxygen-containing gas.
[0100]
If heating is continued in this state, if unreacted organic substances remain, the oxidation reaction with the substituted oxygen-containing gas causes an increase in the concentration of dioxide in the heating furnace 10 again. This dioxide concentration is monitored by the gas concentration system 11, and this process is repeated until the dioxide concentration falls below a specified value. On the other hand, if the residual organic matter is completely released, the dioxide concentration remains below the specified value even after replacement.
[0101]
According to the second embodiment, the reliability of the primary heat treatment completion determination is remarkably improved, and a superconducting coil having no insulation failure can be manufactured.
[0102]
  Next, a third embodiment of the present invention will be described. In the third embodiment, as a pre-process for attaching the insulating material 8 to the winding frame 7 with respect to the process of the method of manufacturing the superconducting coil in the first embodiment, the space between the winding frame 7 and the insulating material 8 is used. InA through hole was provided at the position of the through hole provided in the reel 7.A process for depositing metal foil is added. As a completed form of the superconducting coil 1, there are one in which the winding frame 7 is mounted and another in which the winding frame 7 is disassembled after impregnation with an insulator. This third embodiment is applied to a method of manufacturing a superconducting coil 1 that disassembles the winding frame 7.
[0103]
  FIG. 6 is a cross-sectional view of a superconducting coil 1 to which the superconducting coil manufacturing method according to the third embodiment is applied. In FIG. 6, the superconducting coil 1 has a release agent 14 interposed in the winding frame 7 prior to coil winding.A through hole was provided at the position of the through hole provided in the reel 7.A metal foil 15 is attached, and further, an insulating material 8 is deposited on the metal foil 15 and the insulation-coated superconducting wire 4 is wound in multiple layers. Thereafter, similarly to the first embodiment, the insulating material 8 and the insulation-coated superconducting wire 4 are impregnated and integrated with an insulator through a primary heat treatment step, a primary heat treatment completion determination step, and a secondary heat treatment step. Thereafter, the winding frame 7 is disassembled from the superconducting coil 1.
[0104]
According to the third embodiment, in addition to the function and effect of the first embodiment, the superconducting coil used by disassembling the winding frame 7 from the superconducting coil 1 can be used for winding the insulation-coated superconducting wire 4. Since the metal foil 15 is attached to the winding frame 7 with the release agent 14 interposed in advance, the winding frame 7 can be easily disassembled even after the superconducting coil 1 is impregnated and integrated with an insulator.
[0105]
That is, at the time of disassembly, first, the winding frame 7 is separated from the metal foil 15, and then the metal foil 15 is peeled off from the superconducting coil 1 impregnated with an insulator. In this case, since the thin metal foil 15 is rich in flexibility, it can be easily peeled off from the impregnated insulator by the cleavage force. Therefore, an excessive force is not applied to the insulating coating superconducting wire 4 that has become brittle after the completion of the secondary heat treatment, and deterioration of the superconducting performance can be avoided.
[0106]
Here, as the release agent 14, boron nitride powder or chromium nitride coating that can withstand the secondary heat treatment temperature of 600 ° C. to 700 ° C. and easily release from the impregnated insulator is suitable. As the metal foil 15, a nickel alloy such as stainless steel or inconel having excellent corrosion resistance and high strength is suitable.
[0107]
Next, a fourth embodiment of the present invention will be described. FIG. 7 is a cross-sectional view showing the superconducting coil 1 during the primary heat treatment step in the fourth embodiment of the present invention. In the fourth embodiment, in contrast to the process of the method for manufacturing the superconducting coil in the first embodiment, the primary heat treatment step covers the through-hole 9a provided in the winding rod 6 with a jacket 16, and the jacket 16 This is a process in which the oxygen-containing gas is heated while being forcedly supplied from the outside through the connected supply pipe 17.
[0108]
In FIG. 7, in the primary heat treatment step, a through hole 9 a provided in the curl 6 is covered with a jacket 16, and an oxygen-containing gas is forcibly supplied from the outside of a heating furnace (not shown) through an air supply pipe 17 connected to the jacket 16. Heat while.
[0109]
During the primary heat treatment process, the oxygen-containing gas forcedly supplied into the jacket 16 from the outside of the heating furnace through the air supply pipe 17 passes through the plurality of through holes 9 a and 9 b provided in the winding frame 7 and enters the inside of the superconducting coil 1. , Flows through the superconducting coil 1 and is discharged from the outer periphery into the heating furnace. In this process, the oxygen-containing gas easily diffuses into the superconducting coil 1 and oxidizes with the organic substance contained in the insulating material 8 or the insulating coating 3, and the organic substance is gasified into carbon monoxide or carbon dioxide and released. In particular, the oxidation reaction is actively performed also on the inner layer side of the superconducting coil 1 adjacent to the winding core 5 side where oxygen is easily deficient. Further, the reaction gas such as carbon dioxide generated by the oxidation reaction is also discharged outside without staying in the superconducting coil 1.
[0110]
As described above, according to the fourth embodiment, since the organic matter contained in the insulating material 8 insulating coating 3 can be almost completely removed by the primary heat treatment, insulation failure caused by carbonization of the remaining organic matter by the secondary heat treatment, etc. Can be avoided.
[0111]
In the above description, the jacket 16 is used, but a lid 18 may be used in place of the jacket 16 as shown in FIG.
[0112]
In FIG. 8, both ends of the core 5 are covered with a lid 18 in the primary heat treatment step, and the air containing pipe 17 connected to the lid 18 is heated while forcibly supplying an oxygen-containing gas from the outside of a heating furnace (not shown). During the primary heat treatment step, the oxygen-containing gas forcedly supplied into the winding core 5 by the supply pipe 17 connected to the lid 18 from the outside of the heating furnace is superconducted from a plurality of holes 9b provided in the winding core 5. It flows into the innermost layer of the coil 1, flows through the insulating material 8 and the insulating coating 3 of the superconducting coil 1, and is discharged from the hole 9 a provided in the winding rod 6 and the outer periphery of the superconducting coil 1 into the heating furnace.
[0113]
In this process, the oxygen-containing gas easily diffuses into the superconducting coil 1 and oxidizes with the organic substance contained in the insulating material 8 or the insulating coating 3, and the organic substance is gasified into carbon monoxide or carbon dioxide and released. In particular, the oxidation reaction is actively performed also on the inner layer side of the superconducting coil 1 adjacent to the winding core 5 side where oxygen is easily deficient. Further, the reaction gas such as carbon dioxide generated by the oxidation reaction is discharged outside without staying inside the superconducting coil 1.
[0114]
Therefore, since the organic substance contained in the insulating material 8 and the insulating coating 3 can be almost completely removed by the primary heat treatment, it is possible to avoid an insulation failure caused by carbonization of the remaining organic substance by the secondary heat treatment.
[0115]
Next, a fifth embodiment of the present invention will be described. FIG. 9: is a block diagram which shows the winding process of an insulation coating superconducting wire among the processes of the manufacturing method of the superconducting coil which concerns on 5th Embodiment.
[0116]
In FIG. 9, the insulating coated superconducting wire 4 is wound around a bobbin 19 and is wound around the bobbin 7 with a predetermined tension from the bobbin 19. A tension applying device 23 is attached to the bobbin 19, and a constant tension is applied by the tension applying device 23, and the insulation coated superconducting wire 4 wound around the bobbin 19 by the winding machine 20 attached to the winding frame 7. Is wound around a winding frame 7 to manufacture the superconducting coil 1.
[0117]
In the fifth embodiment, the heating means 21 for heating the insulating coated superconducting wire 4 is provided before the insulating coated superconducting wire 4 is wound around the winding frame 7, and the winding means 7 is further wound around the winding frame 7. Then, a cooling means 22 for quickly cooling the insulating coated superconducting wire 4 is provided.
[0118]
The insulation-coated superconducting wire 4 heated by the heating means 21 is several degrees higher than the ambient temperature of the place to be wound (winding frame 7), and is quickly cooled by the cooling means 22 at the same time as being wound around the winding frame 7. . Therefore, the insulating coating superconducting wire 4 wound around the winding frame 7 due to the difference in thermal expansion is appropriately wound without loosening.
[0119]
The tension F acting on the superconducting wire 2 due to the difference in thermal expansion at this time is represented by the following equation (1).
F = E ・ α ・ T ・ A (1)
Here, E is the Young's modulus of the superconducting wire 2, α is the linear expansion coefficient of the superconducting wire 2, T is the temperature difference between the atmosphere and the heated superconducting wire 2, and A is the cross-sectional area of the superconducting wire 2.
[0120]
The tension F can also be expressed by F = σ · A. Here, σ is a stress generated in the superconducting wire 2 and σ = E · α · T. Generally, the tension that can be applied to the superconducting wire 2 having a glass insulation coating is suppressed to 5 kg from the viewpoint of the soundness of the insulation coating. However, a tension of 10 kg or more is desirable to increase dimensional accuracy. Therefore, the stress when a temperature difference of T = 50 ° C. is applied to the superconducting wire 2 is σ = 8.5 kg / mm.²It also becomes. Therefore, a tension of 10 kg or more can be applied in combination with the tension applying device 23.
[0121]
Furthermore, when the shape of the superconducting coil 1 is not circular but is a race track having a straight portion, it is also effective in preventing the bulging of the straight portion that tends to occur in the race track-shaped superconducting coil. As an example, a case of a racetrack superconducting coil having a straight portion with a length of 150 mm will be described. When the bulge of the straight portion is 1 mm, the bulge can be made almost zero with a temperature difference of about 3 ° C.
[0122]
In the above description, the heating means 21 is disposed between the bobbin 19 and the winding machine 20 and heats the insulation-coated superconducting wire 4. However, the bobbin 19 itself may be heated. The cooling means 22 may be forced cooling by flowing a cooling fluid through the reel 7 or by blowing a cooling fluid from the outside.
[0123]
Thus, according to the fifth embodiment, a constant tension can be applied to the superconducting wire by utilizing the difference in thermal expansion between the superconducting wire before and after winding. Therefore, it is possible to avoid insulation failure due to breakage of the insulation coating. Further, the bulge of the straight portion that tends to occur in the racetrack-shaped superconducting coil can be suppressed, and the dimensional accuracy is increased.
[0124]
Next, a sixth embodiment of the present invention will be described. FIG. 10 is a configuration diagram showing a primary heat treatment process using hydrogen among the processes of the method of manufacturing a superconducting coil according to the sixth embodiment. In the primary heat treatment step, the inside of the heating furnace 10 is once evacuated to about 1 Pa by the vacuum exhaust device 11, and then a small amount of hydrogen gas is supplied from the hydrogen cylinder 24 into the heating furnace 10. At this time, the organic substances contained in the insulating material 8 and the insulating coating 3 are
C + 2H₂  → CH_Four
The carbon in the organic substance is gasified. Since the inside of the heating furnace 10 has a low pressure corresponding to the pressure of hydrogen, most of the generated gas is released from the superconducting coil 1 into the heating furnace 10. In order to discharge the residual gas in the superconducting coil 1, the generated gas is again exhausted by the vacuum exhaust device 11 after the reaction is completed.
[0125]
Completion of the reaction can be performed by detecting the oxygen concentration or carbon monoxide concentration described above. Further, by attaching the microwave generator 25 to the heating furnace 10, it becomes possible to turn hydrogen gas into plasma. Hydrogen plasma
C + 4H⁺  → CH_Four
In this way, carbon reacts more securely in a short time because it reacts more violently than hydrogen.
[0126]
Furthermore, this method has an advantage that the primary heat treatment step can be omitted because the heat treatment can be performed simultaneously with the superconductivity generation performed at 600 ° C. to 700 ° C. in an oxygen-free state in a vacuum atmosphere, which is a secondary heat treatment. If the primary heat treatment step is performed for a long time, the oxide film such as copper constituting the superconducting wire becomes thick and the net copper is decreased, and the superconducting characteristics may become unstable, but the primary heat treatment step can be omitted. A highly reliable and inexpensive superconducting coil can be manufactured.
[0127]
Next, a seventh embodiment of the present invention will be described. FIG. 11 is an explanatory view showing a string making operation including an organic substance removing operation remaining in the insulating coating according to the seventh embodiment of the present invention. After the insulation coating is knitted on the superconducting wire using a string making machine, the washing step and the drying step are performed before the insulation coating superconducting wire is wound around the bobbin.
[0128]
In FIG. 11, after the insulation coating is knitted on the superconducting wire 2 by the string making machine 26, the washing step and the drying step are performed before the insulation coating superconducting wire 4 is wound around the bobbin 19.
[0129]
In the water washing process, fine water 27 is sprayed to wash away organic substances such as starch mixed for stringing work. Next, in the drying process, air 28 whose temperature has been increased by a dryer (not shown) is sent to remove moisture remaining in the insulating coating or on the surface of the superconducting wire. When the method of washing with water is not based on the shower type, water may be applied to the bathtub and immersed. Further, water vapor may be used instead of water.
[0130]
In this method, since the primary heat treatment step can be omitted, the oxide film such as copper constituting the superconducting wire becomes thick due to the long time primary heat treatment step, and the net copper is reduced, and the superconducting characteristics become unstable. Therefore, it is possible to manufacture a highly reliable and inexpensive superconducting coil.
[0131]
As described above, according to the seventh embodiment, the superconducting wire that does not contain organic matter that remains as carbide after the secondary heat treatment and does not cause insulation failure can be wound around the coil. In addition to being suppressed, the primary heat treatment step can be omitted, so that a highly reliable and inexpensive superconducting coil can be manufactured.
[0132]
Next, an eighth embodiment of the present invention will be described. FIG. 12 is an explanatory view showing a coil winding operation including an organic substance removing operation remaining in the insulating coating according to the eighth embodiment of the present invention. A water washing step and a drying step are performed while the bobbin around which the insulating coating superconducting wire is wound is wound around the winding frame using a winding machine.
[0133]
In FIG. 12, a water washing step and a drying step are performed while the bobbin 19 winding the insulation coated superconducting wire 4 is wound around the winding frame 7 by a winding machine (not shown). In the water washing process, fine water 27 is sprayed to wash away organic substances such as starch mixed for stringing work. Next, in the drying process, air 28 whose temperature has been increased by a dryer (not shown) is sent to remove moisture remaining in the insulating coating or on the surface of the superconducting wire. When the method of washing with water is not based on the shower type, the container may be filled with water and immersed. Further, water vapor may be used instead of water.
[0134]
In this method, since the primary heat treatment step can be omitted, the oxide film such as copper constituting the superconducting wire becomes thick due to the long time primary heat treatment step, and the net copper is reduced, and the superconducting characteristics become unstable. Therefore, it is possible to manufacture a highly reliable and inexpensive superconducting coil.
[0135]
Thus, according to the eighth embodiment, the superconducting wire that remains as carbide after the secondary heat treatment and does not contain organic matter that causes insulation failure can be wound around the coil, so that insulation failure is ensured. In addition to being suppressed, the primary heat treatment step can be omitted, so that a highly reliable and inexpensive superconducting coil can be manufactured.
[0136]
Next, a ninth embodiment of the present invention will be described. FIG. 13: is a block diagram which shows the coil winding operation | work including the organic substance removal operation | work which remains in the insulation coating in the 9th Embodiment of this invention. After winding the superconducting coil, before performing the secondary heat treatment, the superconducting coil is put in a water tank and ultrasonically cleaned using an ultrasonic generator.
[0137]
In FIG. 13, after winding the superconducting coil 1 in a normal procedure, the superconducting coil 1 is put into a water tank 29 filled with water before performing the secondary heat treatment. By simply placing the superconducting coil 1 in water, there is no possibility that the organic material contained in the insulating material or the insulating coating on the inner layer side of the superconducting coil 1 is sufficiently dissolved in water. Therefore, ultrasonic cleaning is performed by emitting ultrasonic waves from the ultrasonic generator 30 to the superconducting coil 1.
[0138]
By using such an ultrasonic wave, the organic substance contained in the insulating material and the insulating coating on the inner layer side of the superconducting coil 1 can be sufficiently dissolved in water to remove the organic substance. The water to be used can enhance the effect by using hot water having a high temperature. In the present embodiment, a method of generating bubbles with a bubble generator may be used instead of the ultrasonic generator 30.
[0139]
According to the present embodiment, since ultrasonic waves or bubbles are used in combination, organic substances can be effectively removed. Therefore, the superconducting coil has high insulation, is electrically stable, and can produce a high-performance superconducting coil.
[0140]
【The invention's effect】
As described above, according to the present invention, in a superconducting coil formed by winding an insulation-coated superconducting wire, organic substances contained in the insulation coating or the like are gasified by heating in a relatively short time without damaging and degrading the superconducting wire. Therefore, it is possible to provide a highly reliable superconducting coil that can be reliably released without being subjected to special heat treatment and that does not leave harmful carbides in electrical insulation, and a method for manufacturing the same.
[0141]
Further, according to the present invention, there is provided a method for producing a high-performance, high-precision superconducting coil that can realize high dimensional accuracy without applying excessive tension when winding an insulation-coated superconducting wire and that does not damage the insulation coating. be able to.
[Brief description of the drawings]
1A and 1B show a superconducting coil according to a first embodiment of the present invention, in which FIG. 1A is a cross-sectional view of the superconducting coil, and FIG. 1B is a perspective view of an insulation-coated superconducting wire.
FIG. 2 is an explanatory view showing a primary heat treatment step when forming the superconducting coil according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing another example of the superconducting coil according to the first embodiment of the present invention.
FIG. 4 is a perspective view showing a winding frame used in Example 1 according to the first embodiment of the present invention.
FIG. 5 is a characteristic diagram showing the electrical insulation characteristics of the glass fibers of each layer in the example according to the first embodiment of the present invention in comparison with the conventional example.
FIG. 6 is a sectional view showing a superconducting coil to which a superconducting coil manufacturing method according to a third embodiment of the present invention is applied.
FIG. 7 is a cross-sectional view showing a superconducting coil at the time of a primary heat treatment when a superconducting coil manufacturing method according to a fourth embodiment of the present invention is applied;
FIG. 8 is a cross-sectional view showing another example of the superconducting coil at the time of the primary heat treatment when the superconducting coil manufacturing method according to the fourth embodiment of the present invention is applied.
FIG. 9 is a configuration diagram showing a winding step of an insulation-coated superconducting wire in the steps of a superconducting coil manufacturing method according to a fifth embodiment of the present invention.
FIG. 10 is a configuration diagram showing a primary heat treatment step using hydrogen among the steps of a method of manufacturing a superconducting coil according to a sixth embodiment of the present invention.
FIG. 11 is an explanatory view showing an organic substance removing step among the steps of the superconducting coil manufacturing method according to the seventh embodiment of the present invention.
FIG. 12 is an explanatory view showing an organic substance removing step among the steps of the superconducting coil manufacturing method according to the eighth embodiment of the present invention.
FIG. 13 is a structural diagram showing an organic substance removing step in the steps of the superconducting coil manufacturing method according to the ninth embodiment of the present invention.
[Explanation of symbols]
1 Superconducting coil
1a Superconducting coil body
2 Superconducting wire
3 Insulation coating
4 Insulated superconducting wire
5 rollscore
6 rolls鍔
7 reel
8 Insulation material
9 Through hole
15 Metal foil
16 jacket
18 lid

Claims

巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルにおいて、前記巻枠に流体が流通する複数個の貫通孔を設け、前記巻枠の側面の貫通孔と多数回巻回された絶縁被覆超電導線との間、または絶縁被覆超電導線間に、銀からなるシート状の板を設けたことを特徴とする超電導コイル。In a superconducting coil formed by winding a number of insulation-coated superconducting wires on a winding frame having winding rods on both sides of the winding core, a plurality of through holes through which a fluid flows are provided in the winding frame, and a side surface of the winding frame A superconducting coil, wherein a sheet-like plate made of silver is provided between the through-holes of the wire and the insulation-coated superconducting wire wound many times or between the insulation-coated superconducting wires .

前記貫通孔は、巻き芯の内周と外周を連通する穴、または巻き鍔のコイル側と反コイル側とを連通する穴の少なくともいずれか一方であることを特徴とする請求項１に記載の超電導コイル。 The said through-hole is at least any one of the hole which connects the inner periphery and outer periphery of a winding core, or the hole which connects the coil side and anti-coil side of a winding rod, The Claim 1 characterized by the above-mentioned. Superconducting coil.

巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルにおいて、前記巻枠はその材質として銀を用いたことを特徴とする請求項１に記載の超電導コイル。 The superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of the winding core, wherein the winding frame uses silver as a material thereof. Superconducting coil.

巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルの製造方法において、前記巻枠に流体が流通する複数個の貫通孔を設ける工程と、前記巻枠へのコイル巻回に先立って巻枠に絶縁材を被着する工程と、この絶縁材の上に絶縁被覆超電導線を巻回する巻回工程と、絶縁材および絶縁被覆に含まれる有機物をガス化して放出させる一次熱処理工程と、前記一次熱処理工程が終了したことを判定する一次熱処理完了判定工程と、前記超電導線を超電導体化するための二次熱処理工程とを具備したことを特徴とする超電導コイルの製造方法。 In the manufacturing method of a superconducting coil formed by winding a number of insulation-coated superconducting wires on a winding frame having winding rods on both sides of the winding core, a step of providing a plurality of through holes through which fluid flows in the winding frame; Included in the step of depositing an insulating material on the winding frame prior to winding the coil around the winding frame, the winding step of winding the insulating coating superconducting wire on the insulating material, and the insulating material and the insulating coating It comprises a primary heat treatment step for gasifying and releasing organic matter, a primary heat treatment completion judgment step for judging that the primary heat treatment step is completed, and a secondary heat treatment step for making the superconducting wire a superconductor. A method of manufacturing a superconducting coil, which is characterized .

巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルの製造方法において、前記巻枠に流体が流通する複数個の貫通孔を設ける工程と、前記巻枠へのコイル巻回に先立って離型剤を介して前記巻枠に設けられた貫通孔の位置に貫通孔が設けられた金属箔を装着する工程と、この金属箔の上に絶縁材を被着する工程と、この絶縁材の上に絶縁被覆超電導線を巻回する巻回工程と、絶縁材および絶縁被覆に含まれる有機物をガス化して放出させる一次熱処理工程と、前記一次熱処理工程が終了したことを判定する一次熱処理完了判定工程と、前記超電導線を超電導体化するための二次熱処理工程と、絶縁材および絶縁被覆超電導線を絶縁物で含浸一体化する工程と、その後巻枠をコイルから分解する工程とを具備したことを特徴とする超電導コイルの製造方法。 In the manufacturing method of a superconducting coil formed by winding a number of insulation-coated superconducting wires on a winding frame having winding rods on both sides of the winding core, a step of providing a plurality of through holes through which fluid flows in the winding frame; Prior to winding the coil on the winding frame, a step of attaching a metal foil provided with a through hole at a position of the through hole provided in the winding frame via a release agent, and insulation on the metal foil A step of depositing a material, a winding step of winding an insulating coating superconducting wire on the insulating material, a primary heat treatment step of gasifying and releasing organic substances contained in the insulating material and the insulating coating, and the primary heat treatment A primary heat treatment completion determination step for determining that the process has been completed, a secondary heat treatment step for converting the superconducting wire into a superconductor, a step of impregnating and integrating the insulating material and the insulation-coated superconducting wire with an insulator, and thereafter Work to disassemble the reel from the coil Method of manufacturing a superconducting coil, characterized by comprising and.

前記巻枠に流体が流通する複数個の貫通孔を設ける工程に代えて、前記巻枠を銀で形成する工程としたことを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 The superconducting coil manufacturing method according to claim 4 or 5, characterized in that, instead of the step of providing a plurality of through holes through which fluid flows in the winding frame, the winding frame is formed of silver. Method.

前記巻枠に流体が流通する複数個の貫通孔を設ける工程と、前記巻枠の側面の貫通孔と多数回巻回された絶縁被覆超電導線との間、または絶縁被覆超電導線間に、銀からなるシート状の板を設ける工程と追加して設けたことを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 Between the step of providing a plurality of through-holes through which fluid flows in the winding frame and the through-holes on the side surface of the winding frame and the insulation-coated superconducting wire wound many times, or between the insulating-coated superconducting wires, silver The method for producing a superconducting coil according to claim 4 or 5, wherein the method is provided in addition to the step of providing a sheet-like plate comprising :

前記一次熱処理工程は、酸素を含有する気体中で炉中加熱する工程であり、前記一次熱処理完了判定工程は、炉内の一酸化炭素あるいは二酸化炭素濃度が規定値以下であることを確認する工程であることを特徴とする請求項４または請求項５記載の超電導コイルの製造方法。 The primary heat treatment step is a step of heating in a furnace in a gas containing oxygen, and the primary heat treatment completion determination step is a step of confirming that the concentration of carbon monoxide or carbon dioxide in the furnace is not more than a specified value. The method for manufacturing a superconducting coil according to claim 4 or 5, wherein:

前記一次熱処理工程は、酸素を含有する気体中で炉中加熱する工程であり、前記一次熱処理完了判定工程は、炉内の酸素濃度が規定値以上であることを確認する工程であることを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 The primary heat treatment step is a step of heating in a furnace in a gas containing oxygen, and the primary heat treatment completion determination step is a step of confirming that the oxygen concentration in the furnace is equal to or higher than a specified value. A method for manufacturing a superconducting coil according to claim 4 or 5 .

前記一次熱処理完了判定工程後に、さらに、炉内を減圧脱気して再び炉内を酸素を含有した気体に置換して加熱する追加の熱処理工程を具備したことを特徴とする請求項４または請求項５記載の超電導コイルの製造方法。 5. The method according to claim 4, further comprising an additional heat treatment step after the primary heat treatment completion determination step, wherein the inside of the furnace is degassed under reduced pressure and the inside of the furnace is again replaced with a gas containing oxygen and heated. Item 6. A method for manufacturing a superconducting coil according to Item 5 .

前記一次熱処理工程は、真空中に微量の水素を含有する炉中加熱する工程であることを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 6. The method of manufacturing a superconducting coil according to claim 4, wherein the primary heat treatment step is a step of heating in a furnace containing a small amount of hydrogen in a vacuum .

前記一次熱処理工程は、水素プラズマ雰囲気を保持している炉中加熱する工程であることを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 The method of manufacturing a superconducting coil according to claim 4 or 5 , wherein the primary heat treatment step is a step of heating in a furnace holding a hydrogen plasma atmosphere .

請求項１または請求項２記載の超電導コイルを製造するための超電導コイルの製造方法において、前記一次熱処理工程は、前記巻き鍔に設けられた貫通孔をジャケットで覆い、このジャケットに接続された給気管で外部から酸素を含有した気体を強制給気しながら加熱する工程であることを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 The superconducting coil manufacturing method for manufacturing a superconducting coil according to claim 1 or 2, wherein the primary heat treatment step covers a through-hole provided in the curl with a jacket and supplies the coil connected to the jacket. 6. The method for manufacturing a superconducting coil according to claim 4, wherein the superconducting coil is heated by forcibly supplying a gas containing oxygen from the outside with a trachea .

請求項１または請求項２記載の超電導コイルを製造するための超電導コイルの製造方法において、前記一次熱処理工程は、前記巻き芯の両端部を蓋で覆い、この蓋に接続された給気管で外部から酸素を含有した気体を強制給気しながら加熱する工程であることを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 3. The superconducting coil manufacturing method for manufacturing a superconducting coil according to claim 1 or 2, wherein the primary heat treatment step covers both ends of the winding core with a lid and externally connects with an air supply pipe connected to the lid. 6. The method of manufacturing a superconducting coil according to claim 4, wherein the gas containing oxygen is heated while forcibly supplying air .

巻き芯の両側に巻き鍔を有する巻枠に、絶縁被覆超電導線を多数回巻回して形成した超電導コイルの製造方法において、前記巻回工程は、前記絶縁被覆超電導線が巻枠に巻回される手前で前記絶縁被覆超電導線を加熱する工程と、前記巻枠に巻回された後、速やかに前記絶縁被覆超電導線を冷却する工程とを具備したことを特徴とする請求項４または請求項５に記載の超電導コイルの製造方法。 In the method of manufacturing a superconducting coil formed by winding a number of insulation-coated superconducting wires around a winding frame having winding rods on both sides of the winding core, the winding step includes winding the insulation-coated superconducting wire around the winding frame. 5. The method according to claim 4, further comprising the steps of: heating the insulation-coated superconducting wire before being wound; and cooling the insulation-coated superconducting wire promptly after being wound around the winding frame. 5. A method for producing a superconducting coil according to 5 .

請求項１または請求項２記載の超電導コイルを製造するための超電導コイルの製造方法において、超電導線に絶縁被覆を編付ける製紐工程と、絶縁被覆超電導線を巻枠に巻回する巻回工程と、巻回された前記絶縁被覆超電導線の絶縁被覆内に残存する有機物質を除去する工程とを具備したことを特徴とする超電導コイルの製造方法。3. A superconducting coil manufacturing method for manufacturing a superconducting coil according to claim 1 or 2, wherein a string forming step of knitting an insulating coating on the superconducting wire and a winding step of winding the insulating covering superconducting wire around a winding frame. And a step of removing an organic substance remaining in the insulation coating of the wound insulation coating superconducting wire .

前記有機物質除去工程は、水を用いて有機物質を洗浄する工程であることを特徴とする請求項１６に記載の超電導コイルの製造方法。 The method of manufacturing a superconducting coil according to claim 16 , wherein the organic substance removing step is a step of washing the organic substance with water .

前記有機物質除去工程は、超音波またはバブルを併用することを特徴とする請求項１７に記載の超電導コイルの製造方法。 18. The method of manufacturing a superconducting coil according to claim 17, wherein the organic substance removing step uses ultrasonic waves or bubbles in combination .