JP4189173B2

JP4189173B2 - Insulator

Info

Publication number: JP4189173B2
Application number: JP2002154410A
Authority: JP
Inventors: 英俊岡
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-05-28
Filing date: 2002-05-28
Publication date: 2008-12-03
Anticipated expiration: 2022-05-28
Also published as: JP2003346582A

Description

【０００１】
【発明の属する技術分野】
本発明は、真空装置や加速器の電子銃等に用いられ、電極部材間に絶縁部材を設けた絶縁碍子に関する。
【０００２】
【従来の技術】
従来、真空装置や加速器等の理化学機器においては、電子等の荷電粒子を加速する電極部材間に絶縁をとるための絶縁部材を設けた絶縁碍子が用いられている。この絶縁碍子の基本構成を図３の断面図に、図３の絶縁碍子における絶縁部材１と電極部材12とのろう付部の拡大断面図を図４に示す。これらの図において、１は絶縁部材、３はメタライズ層、４はニッケル（Ｎｉ）メッキ層、５はろう材、12は電極部材であり、主にこれらで絶縁碍子は構成されている。この絶縁碍子は、一般に酸化アルミニウム(Ａｌ₂Ｏ₃)質焼結体からなる円筒状の絶縁部材１と、絶縁部材１の両端部に設けられた、Ｆｅ−Ｎｉ−Ｃｏ合金等の金属から成る略円環状の電極部材12とから成る。２つの電極部材12は、それぞれ円環部12ｂの対向する側の主面に全周にわたって円形の壁部12ａが形成されており、その壁部12ａに絶縁部材1の両端部がそれぞれ嵌入されて両端部の外周面が壁部12ａの内周面にろう付けされている。
【０００３】
電極部材12の絶縁部材１へのろう付による接合は以下のようにして行なわれる。絶縁部材１は、その両端部の外周面に予めモリブデン（Ｍｏ）−マンガン（Ｍｎ）からなるメタライズ層３とＮｉメッキ層４を順次被着しておき、そのメタライズ層３とＮｉメッキ層４が被着された絶縁部材１の両端部の外周面に電極部材12がろう材５を介して接合される。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記従来の絶縁碍子においては、絶縁部材１は酸化アルミニウム質焼結体、電極部材12はＦｅ−Ｎｉ−Ｃｏ合金等の金属からなり、酸化アルミニウム質焼結体の熱膨張係数が約7.9×10^-6／℃(室温〜800℃)、Ｆｅ−Ｎｉ−Ｃｏ合金の熱膨張係数が約10.8×10^-6／℃(室温〜800℃)と相違することから、接合の際に両者の熱膨張係数差に起因して絶縁部材１は径方向に電極部材12の圧縮応力を受けることになる。同時に絶縁部材１は、電極部材12との接合部において、電極部材12の円形の壁部12ａより軸方向に引張応力を受ける。この圧縮応力と引張応力は、絶縁部材１の両端部を径方向で圧縮するとともに軸方向に引っ張るように加わるため上記両端部に荷重が集中することとなり、絶縁部材１に発生する応力は大きいものになる。その結果、その応力が、絶縁部材１の接合部に集中し、絶縁部材１の接合部付近にクラックや割れ等が発生するという問題点を有していた。
【０００５】
従って、本発明は上記従来の問題点に鑑みて完成されたものであり、その目的は、絶縁部材にクラックや割れ等が発生するのを有効に防止し、また絶縁部材に電極部材を強固に固定した高信頼性の絶縁碍子を提供することにある。
【０００６】
【課題を解決するための手段】
本発明の絶縁碍子は、２つの略円環状の金属部材が互いに対向配置され、該金属部材の対向する側の主面のそれぞれに全周にわたる壁部が形成された電極部材と、両端部の外周面が前記壁部のそれぞれの内周面にろう付けされた円筒状の絶縁部材とを具備しており、前記金属部材の前記対向する側の主面と反対側の主面は、前記対向する側の主面と略平行とされ、前記金属部材の前記対向する側の主面には、前記壁部の内周に沿って、前記壁部の内周面と連続した側面を有するとともに前記絶縁部材の厚さよりも幅が小さい溝が全周にわたって形成されており、前記溝は、深さが前記絶縁部材の厚さの４０％以上かつ６０％以下であり、幅が前記絶縁部材の厚さの６０％以上かつ８０％以下であることを特徴とする。
【０００７】
本発明の絶縁碍子は、絶縁部材と電極部材との熱膨張係数差に起因して発生する応力を大幅に緩和することができ、応力によって絶縁部材にクラックや割れ等が発生するのを有効に抑制できる。その結果、絶縁部材に電極部材を強固に固定した信頼性の高い絶縁碍子となる。
【０００８】
本発明の絶縁碍子は、好ましくは、前記溝は、深さが４ｍｍ以上かつ５ｍｍ以下であり、幅が６ｍｍ以上かつ７ｍｍ以下であることを特徴とする。
【０００９】
本発明の絶縁碍子は、絶縁部材と電極部材との熱膨張係数差に起因して絶縁部材の両端部に発生する応力を緩和して、絶縁部材の両端部にクラックや割れ等が生じるのをより有効に抑えることができる。
【００１０】
本発明の絶縁碍子は、好ましくは、前記電極部材は前記壁部の厚さが０．３〜１ｍｍであることを特徴とする。
【００１１】
本発明の絶縁碍子は、絶縁部材と電極部材との接合強度を保持するとともに、絶縁部材と電極部材との熱膨張係数差に起因する応力によって絶縁部材の両端部にクラックや割れ等が生じるのをより有効に抑えることができる。
【００１２】
【発明の実施の形態】
本発明の絶縁碍子を以下に詳細に説明する。本発明の絶縁碍子の基本構成を図１の断面図に、図１の絶縁碍子におけるろう付部の拡大断面図を図２に示す。これらの図において、１は絶縁部材、２はＦｅ−Ｎｉ−Ｃｏ合金，Ｃｕ−Ｗ等の金属からなる電極部材、３はメタライズ層、４はＮｉメッキ層、５はろう材であり、主にこれらで絶縁碍子は構成されている。なお、図１，図２において図３，図４と同じ部位には同じ符号を付している。
【００１３】
そして、本発明の絶縁碍子は、２つの略円環状の金属部材が互いに対向配置され、金属部材の対向する側の主面のそれぞれに全周にわたる壁部２ｂが形成された電極部材２と、両端部の外周面が壁部２ｂのそれぞれの内周面にろう付けされた円筒状の絶縁部材１とを具備し、電極部材２は、壁部２ｂの内周に沿って、壁部２ｂの内周面と連続した側面を有するとともに絶縁部材１の厚さよりも幅が小さい溝２ａが全周にわたって形成されている。
【００１４】
本発明の絶縁部材１は、その両端部に設けられた２つの電極部材２を電気的に絶縁する作用をなし、一般に酸化アルミニウム質焼結体等の電気絶縁材料から成る。この絶縁部材１の両端部の外周面に予めＭｏ−Ｍｎ等のメタライズ層３とＮｉメッキ層４を被着しておき、メタライズ層３とＮｉメッキ層４と電極部材２とをろう材５を介して接合させる。
【００１５】
メタライズ層３の厚さは８〜35μｍがよく、８μｍ未満では、絶縁部材１と電極部材２の接合強度が低下し、また両者を接合する際の応力を緩和することが難しくなる。35μｍを超える場合、メタライズ層３の焼結時にボイド（空隙）が発生し、接合強度が低下し易くなる。
【００１６】
Ｎｉメッキ層４の厚さは１〜10μｍがよく、１μｍ未満では、ろう材５の濡れ性が劣化する。10μｍを超えると、Ｎｉメッキ層４の内部応力が高まるため、メタライズ層３とＮｉメッキ層４のと間で剥がれが生じやすくなる。
【００１７】
ろう材５の厚さは25〜75μｍがよく、25μｍ未満では、絶縁部材１と電極部材２とを接合する際の応力の緩和が難しくなる。75μｍを超えると、ろう材５が均一に流れにくくなり、溜りが生じやすくなる。
【００１８】
また、壁部２ｂの高さ、即ち接合部の軸方向の長さは４ｍｍ程度である。
【００１９】
本発明において、電極部材２と絶縁部材１とを接合する際に、両者の熱膨張係数差に起因して、絶縁部材１は、両端部（接合部）において径方向に電極部材２の圧縮応力を受けるとともに電極部材２の壁部２ｂより軸方向に引張応力を受けるが、これらの圧縮応力と引張応力は溝２ａがない場合には絶縁部材１の両端部を径方向で圧縮するとともに軸方向に引っ張るように加わるため上記両端部に荷重が集中することとなり、絶縁部材１に発生する応力は大きなものになる。その結果、応力に耐えられず、絶縁部材１の接合部付近にクラックや割れ等が発生しやすくなる。本発明の絶縁碍子は、溝２ａを有しているため、溝２ａの空洞により圧縮応力と引張応力は緩和され、絶縁部材１の接合部にかかる径方向の圧縮応力が小さくなり、絶縁部材１の接合部に発生する応力は小さくなる。よって、絶縁部材１の接合部にクラックや割れ等が発生することを有効に抑えられる。
【００２０】
溝２ａの深さＤ（図２）は３〜５ｍｍがよい。３ｍｍ未満では、絶縁部材１と電極部材12との接合部において、熱膨張係数差に起因する応力を十分に緩和させるのが困難になる。その結果、応力に耐えられず、絶縁部材１の接合部付近にクラックや割れ等が発生しやすくなる。５ｍｍを超えると、応力緩和効果が略一定になって向上しにくくなり、また溝２ａを切削等によって機械的に加工する際にバイトの振れが大きくなるため、深さＤを均一にして加工するのが困難になる。
【００２１】
溝２ａの幅Ｗ（図２）は絶縁部材１の径方向の厚さの50〜70％（５〜７ｍｍ程度）がよい。50％未満では、絶縁部材１と電極部材２との接合部において、熱膨張係数差に起因する応力を十分に緩和させるのが困難になる。その結果、応力に耐えられずに絶縁部材１の接合部付近にクラックや割れ等が発生しやすくなる。70％を超えると、絶縁部材１の端面で電極部材２に当接する面積が小さくなり、外力による振動や衝撃等に対する電極部材２の機械的強度が低下し、電極部材２が変形し易くなる。
【００２２】
また、電極部材２は壁部２ｂの厚さ（径方向の厚さ）が0.3〜１ｍｍであることが好ましい。0.3ｍｍ未満では、外力による振動や衝撃等に対する絶縁部材１と電極部材２の接合部の強度が低下し、絶縁部材１と電極部材２とが外れ易くなる。１ｍｍを超えると、絶縁部材１は電極部材２との熱膨張係数差に起因する応力に耐えられずに絶縁部材１の接合部付近にクラックや割れ等が発生しやすくなる。
【００２３】
【実施例】
本発明の絶縁碍子の実施例について以下に説明する。
【００２４】
（実施例１）
実施例１として、図５に示す構成のものを以下のようにして製作した。純度99重量％の酸化アルミニウム質焼結体から成り、内径が20ｍｍ、外径が40ｍｍ、長さが40ｍｍの円筒状の絶縁部材６を用意した。絶縁部材６の両端部の外周面に、Ｍｏ粉末とＭｎ粉末と酸化ケイ素（ＳｉＯ２）粉末とに有機バインダや溶剤を混合してなる金属ペーストを、10〜15μｍの厚さとなるように印刷塗布し、乾燥後加湿したフォーミングガス中で1400℃の温度で焼成した。こうして、絶縁部材６の両端部の外周面に、Ｍｏ−Ｍｎ合金からなるメタライズ層を被着した。その後、メタライズ層上にＮｉメッキ層を電解メッキ法により約２μｍの厚さで被着した。
【００２５】
次に、絶縁部材６の両端部の外周面に、Ｆｅ−Ｎｉ−Ｃｏ合金からなる電極部材７の壁部７ｂの内周面をろう付けした。電極部材７において、円形の壁部７ｂの径方向の厚さは0.7ｍｍ、壁部７ｂの高さは５ｍｍであり、円環部７ｃの外径は60ｍｍ、内径は20ｍｍ、円環部７ｃの厚さは15ｍｍであり、溝７ａの深さＤは４ｍｍ、溝７ａの幅Ｗは６ｍｍである。
【００２６】
このとき、電極部材７の壁部７ｂの端面に、太さの直径が0.7ｍｍの線状のＡｇ−Ｃｕ合金からなるろう材８のプレフォームを設置し、それを820℃に加熱して、絶縁部材６の両端部の外周面と壁部７ｂの内周面との間の隙間にろう材８を毛細管現象により侵入させ、絶縁部材６と電極部材７とを接合した。これにより製作されたものをサンプルＡとした。
【００２７】
比較例１として、溝７ａの深さＤを２ｍｍ、幅Ｗを４ｍｍとした以外は上記実施例１と同様に作製したものをサンプルＢとした。
【００２８】
比較例２として、溝７ａの深さＤを６ｍｍ、幅Ｗを８ｍｍ（絶縁部材６の厚さ10ｍｍの80％）とした以外は上記実施例１と同様に作製したものをサンプルＣとした。
【００２９】
サンプルＡ〜Ｃの接合部を双眼顕微鏡を用いて観察し異常がないか検査した結果を表１に示す。
【００３０】
【表１】

【００３１】
表１より、サンプルＡとサンプルＣには異常が見られなかった。サンプルＢは、絶縁部材６の接合部付近に３分の２周程度にわたりクラックの発生が確認された。
【００３２】
また、上記と同様に製作した別のサンプルＡ〜Ｃそれぞれを用意し、大気雰囲気中、常温で衝撃試験｛ＭＩＬ−ＳＴＤ（Military Standard：アメリカ軍用規格）−202ＦＭＥＴＨＯＤ213Ａ｝を行い、11ｍｓ（ミリ秒）の間に正弦半波の波形で50Ｇ（Ｇ：重力加速度）程度の衝撃を一回加え、各接合部について双眼顕微鏡を用いて観察し異常がないか試験した。その結果を表２に示す。
【００３３】
【表２】

【００３４】
表２より、サンプルＡは異常が見られなかった。サンプルＢは、絶縁部材６と電極部材７をろう付する工程において絶縁部材６の接合部付近に３分の２周程度にわたりクラックが発生したことが確認された。サンプルＣは、電極部材７が変形していることが確認された。また、溝７ａの深さＤが６ｍｍの場合、加工をするうえでバイトの振れが大きくなり深さを均一にして加工するのが困難となり、加工歩留まりが低下し高コストになるといった問題が生じた。
【００３５】
また、上記と同様に製作した別のサンプルＡ〜Ｃそれぞれを用意し、大気雰囲気中、常温で振動試験｛ＭＩＬ−ＳＴＤ−202ＦＭＥＴＨＯＤ201Ａ｝を行い、周波数10〜55Ｈｚ（ヘルツ）、最大振れ幅1.52ｍｍの振動をＸ，Ｙ，Ｚの３方向に順次各２時間づつ加え、各接合部において異常がないかを双眼顕微鏡を用いて観察し検査した。その結果を表３に示す。
【００３６】
【表３】

【００３７】
表３より、サンプルＡは異常が見られなかった。サンプルＢは、絶縁部材６と電極部材７をろう付する工程において絶縁部材６の接合部付近に３分の２周程度にわたりクラックが発生したことが確認された。サンプルＣは、電極部材７が変形していることが確認された。また、溝７ａの深さＤが６ｍｍの場合、加工をするうえでバイトの振れが大きくなり深さＤを均一にして加工するのが困難となり、加工歩留まりが低下し高コストになるといった問題が生じた。
【００３８】
（実施例２）
本実施例２では、実施例１のサンプルＡ、電極部材７の壁部７ｂの厚さが0.2ｍｍのもの（サンプルＤ）、壁部７ｂの厚さが1.2ｍｍのもの（サンプルＥ）をそれぞれ製作し、サンプルＤ，Ｅについて壁部７ｂの厚さ以外の構成は実施例１と同様とした。
【００３９】
サンプルＡ，Ｄ，Ｅのそれぞれについて、大気雰囲気中、常温で衝撃試験{ＭＩＬ−ＳＴＤ（Military Standard：アメリカ軍用規格）−202ＦＭＥＴＨＯＤ213Ａ}を行い、11ｍｓ（ミリ秒）の間に正弦半波の波形で50Ｇ（Ｇ：重力加速度）程度の衝撃を一回加え、各接合部について双眼顕微鏡を用いて観察し異常がないか試験した。その結果を表４に示す。
【００４０】
【表４】

【００４１】
表４より、サンプルＡは接合部に異常は見られなかった。サンプルＤは電極部材７が変形していることが確認された。サンプルＥは、絶縁部材６と電極部材７をろう付する工程において絶縁部材６の接合部付近に３分の２周程度にわたりクラックが発生したことが確認された。
【００４２】
また、上記と同様に製作した別のサンプルＡ〜Ｅそれぞれを用意し、大気雰囲気中、常温で振動試験{ＭＩＬ−ＳＴＤ−202ＦＭＥＴＨＯＤ201Ａ}を行い、周波数10〜55Ｈｚ（ヘルツ）、最大振れ幅1.52mmの振動をＸ，Ｙ，Ｚの３方向に順次各２時間づつ加え、各接合部において異常がないかを双眼顕微鏡を用いて観察し検査した。その結果を表５に示す。
【００４３】
【表５】

【００４４】
表５より、サンプルＡは接合部に異常は見られなかった。サンプルＤは電極部材７が変形していることが確認された。サンプルＥは、絶縁部材６と電極部材７をろう付する工程において絶縁部材６の接合部付近に３分の２周程度にわたりクラックが発生したことが確認された。
【００４５】
以上の結果より、サンプルＡが、絶縁部材６と電極部材７との熱膨張係数差に起因する応力によるクラックや割れ等が発生せず、衝撃および振動等に対して優れていることが判った。
【００４６】
なお、本発明は上記実施の形態および実施例に限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々の変更を施すことは何等差し支えない。
【００４７】
【発明の効果】
本発明の絶縁碍子は、２つの略円環状の金属部材が互いに対向配置され、金属部材の対向する側の主面のそれぞれに全周にわたる壁部が形成された電極部材と、両端部の外周面が壁部のそれぞれの内周面にろう付けされた円筒状の絶縁部材とを具備し、電極部材は、壁部の内周に沿って、壁部の内周面と連続した側面を有するとともに絶縁部材の厚さよりも幅が小さい溝が全周にわたって形成されていることにより、絶縁部材と電極部材との熱膨張係数差に起因して発生する応力を大幅に緩和することができ、応力によって絶縁部材にクラックや割れ等が発生するのを有効に抑制できる。その結果、絶縁部材に電極部材を強固に固定した信頼性の高い絶縁碍子となる。
【００４８】
本発明の絶縁碍子は、好ましくは、溝は深さが３〜５ｍｍであり、幅が絶縁部材の厚さの50〜70％であることにより、絶縁部材と電極部材との熱膨張係数差に起因して絶縁部材の両端部に発生する応力を緩和して、絶縁部材の両端部にクラックや割れ等が生じるのをより有効に抑えることができる。
【００４９】
本発明の絶縁碍子は、好ましくは、電極部材は壁部の厚さが0.3〜１ｍｍであることにより、絶縁部材と電極部材との接合強度を保持するとともに、絶縁部材と電極部材との熱膨張係数差に起因する応力によって絶縁部材の両端部にクラックや割れ等が生じるのをより有効に抑えることができる。
【図面の簡単な説明】
【図１】本発明の絶縁碍子について実施の形態の例を示す断面図である。
【図２】図１の絶縁碍子におけるろう付部の拡大断面図である。
【図３】従来の絶縁碍子の断面図である。
【図４】図３の絶縁碍子におけるろう付部の拡大断面図である。
【図５】本発明の絶縁碍子について実施の形態の他の例を示す断面図である。
【符号の説明】
１：絶縁部材
２：電極部材
２ａ：溝
２ｂ：壁部
２ｃ：円環部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insulator used for an electron gun or the like of a vacuum apparatus or an accelerator and having an insulating member provided between electrode members.
[0002]
[Prior art]
Conventionally, in physics and chemistry equipment such as a vacuum apparatus and an accelerator, an insulator provided with an insulating member for insulating between charged electrode members for accelerating charged particles such as electrons is used. A basic configuration of this insulator is shown in a sectional view of FIG. 3, and an enlarged sectional view of a brazed portion between the insulating member 1 and the electrode member 12 in the insulator of FIG. 3 is shown in FIG. In these drawings, 1 is an insulating member, 3 is a metallized layer, 4 is a nickel (Ni) plating layer, 5 is a brazing material, 12 is an electrode member, and these are mainly composed of an insulator. This insulator is generally made of a cylindrical insulating member 1 made of an aluminum oxide (Al ₂ O ₃ ) -based sintered body, and a metal such as an Fe—Ni—Co alloy provided at both ends of the insulating member 1. And a substantially annular electrode member 12. Each of the two electrode members 12 has a circular wall portion 12a formed over the entire circumference on the opposite main surface of the annular portion 12b, and both end portions of the insulating member 1 are fitted into the wall portion 12a. The outer peripheral surfaces of both end portions are brazed to the inner peripheral surface of the wall portion 12a.
[0003]
The electrode member 12 is joined to the insulating member 1 by brazing as follows. The insulating member 1 has a metallized layer 3 and a Ni plated layer 4 made of molybdenum (Mo) -manganese (Mn) in advance on the outer peripheral surfaces of both ends thereof, and the metallized layer 3 and the Ni plated layer 4 are The electrode member 12 is joined to the outer peripheral surface of the both ends of the deposited insulating member 1 through the brazing material 5.
[0004]
[Problems to be solved by the invention]
However, in the above conventional insulator, the insulating member 1 is made of an aluminum oxide sintered body, the electrode member 12 is made of a metal such as an Fe-Ni-Co alloy, and the thermal expansion coefficient of the aluminum oxide sintered body is about 7.9. × 10 ^-6 / ° C (room temperature to 800 ° C), and the thermal expansion coefficient of Fe-Ni-Co alloy is different from about 10.8 × 10 ^-6 / ° C (room temperature to 800 ° C). Due to the difference in thermal expansion coefficient, the insulating member 1 receives the compressive stress of the electrode member 12 in the radial direction. At the same time, the insulating member 1 receives tensile stress in the axial direction from the circular wall portion 12 a of the electrode member 12 at the joint portion with the electrode member 12. This compressive stress and tensile stress are applied so that both ends of the insulating member 1 are compressed in the radial direction and pulled in the axial direction, so that the load is concentrated on the both ends, and the stress generated in the insulating member 1 is large. become. As a result, the stress is concentrated on the joint portion of the insulating member 1, and there is a problem that cracks, cracks, and the like occur near the joint portion of the insulating member 1.
[0005]
Accordingly, the present invention has been completed in view of the above-described conventional problems, and its purpose is to effectively prevent the insulating member from being cracked or cracked, and to firmly fix the electrode member to the insulating member. The object is to provide a fixed and highly reliable insulator.
[0006]
[Means for Solving the Problems]
The insulator according to the present invention has two substantially annular metal members arranged opposite to each other, and electrode members each having a wall portion extending over the entire circumference on each of the opposing main surfaces of the metal members, and both end portions. A cylindrical insulating member whose outer peripheral surface is brazed to each inner peripheral surface of the wall portion, and the main surface on the opposite side to the main surface on the opposite side of the metal member The main surface on the opposite side of the metal member has a side surface that is continuous with the inner peripheral surface of the wall portion along the inner periphery of the wall portion, and A groove having a width smaller than the thickness of the insulating member is formed over the entire circumference, and the depth of the groove is not less than 40% and not more than 60% of the thickness of the insulating member , and the width is the thickness of the insulating member. It is characterized by being 60% or more and 80% or less .
[0007]
Insulator of the present invention, the stress generated due to a difference in thermal expansion coefficient between the insulation member and the electrode member can be greatly reduced, effectively of cracks or fractures are generated in the insulating member by the stress Can be suppressed. As a result, a highly reliable insulator in which the electrode member is firmly fixed to the insulating member is obtained.
[0008]
The insulator of the present invention is preferably characterized in that the groove has a depth of 4 mm to 5 mm and a width of 6 mm to 7 mm .
[0009]
Insulator of the present invention is to alleviate the stress generated at both ends of the resulting from the insulating member to the difference in thermal expansion coefficient between the insulation member and the electrode member, cracks or fractures may occur on both ends of the insulating member Can be suppressed more effectively.
[0010]
The insulator of the present invention is preferably characterized in that the electrode member has a thickness of the wall portion of 0.3 to 1 mm.
[0011]
Insulator of the present invention holds the bonding strength between the insulation member and the electrode member, cracks or fractures may occur on both ends of the insulating member by a stress caused by the difference in thermal expansion coefficient between the insulating member and the electrode member Can be suppressed more effectively.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The insulator of the present invention will be described in detail below. A basic configuration of the insulator of the present invention is shown in a cross-sectional view of FIG. 1, and an enlarged cross-sectional view of a brazed portion in the insulator of FIG. 1 is shown in FIG. In these figures, 1 is an insulating member, 2 is an electrode member made of a metal such as Fe-Ni-Co alloy, Cu-W, 3 is a metallized layer, 4 is a Ni plating layer, and 5 is a brazing material. These constitute the insulator. 1 and 2, the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals.
[0013]
And the insulator of the present invention has an electrode member 2 in which two substantially annular metal members are arranged to face each other, and wall portions 2b are formed on the respective main surfaces on the opposite sides of the metal members, A cylindrical insulating member 1 whose outer peripheral surfaces at both ends are brazed to the respective inner peripheral surfaces of the wall 2b, and the electrode member 2 extends along the inner periphery of the wall 2b. A groove 2a having a side surface continuous with the inner peripheral surface and having a width smaller than the thickness of the insulating member 1 is formed over the entire periphery.
[0014]
The insulating member 1 of the present invention functions to electrically insulate the two electrode members 2 provided at both ends thereof, and is generally made of an electrically insulating material such as an aluminum oxide sintered body. The metallized layer 3 such as Mo—Mn and the Ni plated layer 4 are previously applied to the outer peripheral surfaces of both ends of the insulating member 1, and the metallized layer 3, the Ni plated layer 4, and the electrode member 2 are bonded to the brazing material 5. To be joined.
[0015]
The thickness of the metallized layer 3 is preferably 8 to 35 μm, and if it is less than 8 μm, the bonding strength between the insulating member 1 and the electrode member 2 is lowered, and it becomes difficult to relieve the stress when bonding the two. If it exceeds 35 μm, voids (voids) are generated during the sintering of the metallized layer 3, and the bonding strength tends to be lowered.
[0016]
The thickness of the Ni plating layer 4 is preferably 1 to 10 μm, and if it is less than 1 μm, the wettability of the brazing material 5 deteriorates. If the thickness exceeds 10 μm, the internal stress of the Ni plating layer 4 increases, so that peeling between the metallized layer 3 and the Ni plating layer 4 is likely to occur.
[0017]
The thickness of the brazing material 5 is preferably 25 to 75 μm, and if it is less than 25 μm, it becomes difficult to relieve stress when the insulating member 1 and the electrode member 2 are joined. When it exceeds 75 μm, the brazing filler metal 5 becomes difficult to flow uniformly, and the accumulation tends to occur.
[0018]
Further, the height of the wall portion 2b, that is, the length of the joint portion in the axial direction is about 4 mm.
[0019]
In the present invention, when the electrode member 2 and the insulating member 1 are joined, the insulating member 1 is compressed in the radial direction at both ends (joined portions) due to the difference in thermal expansion coefficient between the two. In addition to receiving tensile stress in the axial direction from the wall 2b of the electrode member 2, these compressive stress and tensile stress compress both ends of the insulating member 1 in the radial direction and axial direction when there is no groove 2a. Therefore, the load is concentrated on the both end portions, and the stress generated in the insulating member 1 becomes large. As a result, it cannot withstand the stress, and cracks, cracks, and the like are likely to occur near the joint portion of the insulating member 1. Since the insulator of the present invention has the groove 2a, the compressive stress and the tensile stress are relaxed by the cavity of the groove 2a, the radial compressive stress applied to the joint portion of the insulating member 1 is reduced, and the insulating member 1 The stress generated at the joint is reduced. Therefore, it is possible to effectively suppress the occurrence of cracks and cracks in the joint portion of the insulating member 1.
[0020]
The depth D (FIG. 2) of the groove 2a is preferably 3 to 5 mm. If it is less than 3 mm, it becomes difficult to sufficiently relieve the stress caused by the difference in thermal expansion coefficient at the joint between the insulating member 1 and the electrode member 12. As a result, it cannot withstand the stress, and cracks, cracks, and the like are likely to occur near the joint portion of the insulating member 1. If it exceeds 5 mm, the stress relaxation effect becomes substantially constant and is difficult to improve. Further, since the runout of the cutting tool increases when the groove 2a is mechanically processed by cutting or the like, the depth D is made uniform. It becomes difficult.
[0021]
The width W (FIG. 2) of the groove 2a is preferably 50 to 70% (about 5 to 7 mm) of the thickness of the insulating member 1 in the radial direction. If it is less than 50%, it becomes difficult to sufficiently relieve the stress caused by the difference in thermal expansion coefficient at the joint between the insulating member 1 and the electrode member 2. As a result, cracks and cracks are likely to occur near the joint portion of the insulating member 1 without being able to withstand the stress. If it exceeds 70%, the area that contacts the electrode member 2 at the end face of the insulating member 1 becomes small, the mechanical strength of the electrode member 2 against vibration or impact due to an external force is reduced, and the electrode member 2 is easily deformed.
[0022]
Moreover, it is preferable that the thickness (diameter direction thickness) of the wall part 2b of the electrode member 2 is 0.3-1 mm. If it is less than 0.3 mm, the strength of the joint portion between the insulating member 1 and the electrode member 2 against vibration or impact due to an external force is lowered, and the insulating member 1 and the electrode member 2 are easily detached. If it exceeds 1 mm, the insulating member 1 cannot withstand the stress caused by the difference in thermal expansion coefficient with the electrode member 2, and cracks, cracks, and the like are likely to occur near the joint portion of the insulating member 1.
[0023]
【Example】
Examples of the insulator of the present invention will be described below.
[0024]
(Example 1)
As Example 1, the structure shown in FIG. 5 was manufactured as follows. A cylindrical insulating member 6 made of an aluminum oxide sintered body having a purity of 99% by weight and having an inner diameter of 20 mm, an outer diameter of 40 mm, and a length of 40 mm was prepared. A metal paste made by mixing an organic binder and solvent with Mo powder, Mn powder and silicon oxide (SiO2) powder is printed and applied on the outer peripheral surfaces of both ends of the insulating member 6 so as to have a thickness of 10 to 15 μm. Then, it was baked at a temperature of 1400 ° C. in a forming gas humidified after drying. In this way, a metallized layer made of a Mo—Mn alloy was deposited on the outer peripheral surfaces of both end portions of the insulating member 6. Thereafter, a Ni plating layer was deposited on the metallized layer to a thickness of about 2 μm by electrolytic plating.
[0025]
Next, the inner peripheral surface of the wall part 7b of the electrode member 7 which consists of an Fe-Ni-Co alloy was brazed to the outer peripheral surface of the both ends of the insulating member 6. FIG. In the electrode member 7, the radial thickness of the circular wall portion 7b is 0.7 mm, the height of the wall portion 7b is 5 mm, the outer diameter of the annular portion 7c is 60 mm, the inner diameter is 20 mm, and the annular portion 7c The thickness is 15 mm, the depth D of the groove 7a is 4 mm, and the width W of the groove 7a is 6 mm.
[0026]
At this time, a preform of the brazing material 8 made of a linear Ag—Cu alloy having a diameter of 0.7 mm is installed on the end surface of the wall 7b of the electrode member 7, and heated to 820 ° C., The brazing material 8 was caused to enter the gap between the outer peripheral surface of both ends of the insulating member 6 and the inner peripheral surface of the wall portion 7b by capillary action, and the insulating member 6 and the electrode member 7 were joined. The product thus manufactured was designated as Sample A.
[0027]
As Comparative Example 1, Sample B was prepared in the same manner as in Example 1 except that the depth D of the groove 7a was 2 mm and the width W was 4 mm.
[0028]
As Comparative Example 2, Sample C was prepared in the same manner as in Example 1 except that the depth D of the groove 7a was 6 mm and the width W was 8 mm (80% of the thickness 10 mm of the insulating member 6).
[0029]
Table 1 shows the results of observing the joints of Samples A to C using a binocular microscope to check for abnormalities.
[0030]
[Table 1]

[0031]
From Table 1, no abnormality was observed in Sample A and Sample C. In the sample B, occurrence of cracks was confirmed in the vicinity of the joint portion of the insulating member 6 over about two thirds of the circumference.
[0032]
Separate samples A to C manufactured in the same manner as above were prepared, and an impact test {MIL-STD (Military Standard: US Military Standard) -202F METHOD213A} was performed at room temperature in an air atmosphere. ), An impact of about 50 G (G: gravitational acceleration) was applied once in the waveform of a half sine wave, and each joint was observed using a binocular microscope to test for abnormalities. The results are shown in Table 2.
[0033]
[Table 2]

[0034]
From Table 2, sample A showed no abnormality. In sample B, it was confirmed that cracks were generated in the vicinity of the joint portion of the insulating member 6 over about two thirds in the step of brazing the insulating member 6 and the electrode member 7. In sample C, it was confirmed that the electrode member 7 was deformed. In addition, when the depth D of the groove 7a is 6 mm, there is a problem in that, when machining, the tool runout becomes large and it is difficult to process with a uniform depth, the machining yield decreases, and the cost increases. It was.
[0035]
Separate samples A to C manufactured in the same manner as described above are prepared, and a vibration test {MIL-STD-202F METHOD201A} is performed at room temperature in an air atmosphere. The frequency is 10 to 55 Hz (hertz), and the maximum swing width is 1.52. A vibration of mm was sequentially applied in three directions of X, Y, and Z for 2 hours, and each joint was observed and inspected for any abnormality using a binocular microscope. The results are shown in Table 3.
[0036]
[Table 3]

[0037]
From Table 3, sample A showed no abnormality. In sample B, it was confirmed that cracks were generated in the vicinity of the joint portion of the insulating member 6 over about two thirds in the step of brazing the insulating member 6 and the electrode member 7. In sample C, it was confirmed that the electrode member 7 was deformed. In addition, when the depth D of the groove 7a is 6 mm, there is a problem in that the deflection of the cutting tool becomes large during processing, making it difficult to make the depth D uniform, and processing yield decreases and costs increase. occured.
[0038]
(Example 2)
In the second embodiment, the sample A of the first embodiment, the wall portion 7b of the electrode member 7 having a thickness of 0.2 mm (sample D), and the wall portion 7b having a thickness of 1.2 mm (sample E), respectively. The configurations other than the thickness of the wall portion 7b for the samples D and E were the same as those in Example 1.
[0039]
For each of Samples A, D, and E, an impact test {MIL-STD (Military Standard: American Military Standard) -202F METHOD213A} is performed at room temperature in an air atmosphere, and a sine half-wave waveform for 11 ms (milliseconds). Then, an impact of about 50 G (G: gravitational acceleration) was applied once, and each joint was observed with a binocular microscope to test for abnormalities. The results are shown in Table 4.
[0040]
[Table 4]

[0041]
From Table 4, sample A showed no abnormality at the joint. In Sample D, it was confirmed that the electrode member 7 was deformed. In sample E, it was confirmed that cracks were generated in the vicinity of the joint portion of the insulating member 6 over about two thirds in the step of brazing the insulating member 6 and the electrode member 7.
[0042]
Separate samples A to E manufactured in the same manner as described above are prepared, and vibration test {MIL-STD-202F METHOD 201A} is performed at room temperature in an air atmosphere. The frequency is 10 to 55 Hz (Hertz), and the maximum swing width is 1.52. A vibration of mm was sequentially applied in the three directions of X, Y, and Z for 2 hours each, and each junction was observed and inspected using a binocular microscope for any abnormality. The results are shown in Table 5.
[0043]
[Table 5]

[0044]
From Table 5, sample A showed no abnormality at the joint. In Sample D, it was confirmed that the electrode member 7 was deformed. In sample E, it was confirmed that cracks were generated in the vicinity of the joint portion of the insulating member 6 over about two thirds in the step of brazing the insulating member 6 and the electrode member 7.
[0045]
From the above results, it was found that Sample A was excellent in impact and vibration, etc., without causing cracks or cracks due to stress caused by the difference in thermal expansion coefficient between the insulating member 6 and the electrode member 7. .
[0046]
In addition, this invention is not limited to the said embodiment and Example, A various change may be performed in the range which does not deviate from the summary of this invention.
[0047]
【The invention's effect】
The insulator according to the present invention includes an electrode member in which two substantially annular metal members are arranged to face each other, and a wall portion is formed on each of the main surfaces on the opposite sides of the metal member, and outer circumferences of both end portions. A cylindrical insulating member brazed to each inner peripheral surface of the wall portion, and the electrode member has a side surface continuous with the inner peripheral surface of the wall portion along the inner periphery of the wall portion In addition, since the groove having a width smaller than the thickness of the insulating member is formed over the entire circumference, the stress generated due to the difference in the thermal expansion coefficient between the insulating member and the electrode member can be greatly relieved. Thus, the occurrence of cracks and cracks in the insulating member can be effectively suppressed. As a result, a highly reliable insulator in which the electrode member is firmly fixed to the insulating member is obtained.
[0048]
In the insulator according to the present invention, preferably, the groove has a depth of 3 to 5 mm, and the width is 50 to 70% of the thickness of the insulating member, so that the thermal expansion coefficient difference between the insulating member and the electrode member is reduced. As a result, the stress generated at both ends of the insulating member can be relaxed, and the occurrence of cracks and cracks at both ends of the insulating member can be more effectively suppressed.
[0049]
In the insulator of the present invention, preferably, the electrode member has a wall thickness of 0.3 to 1 mm, so that the bonding strength between the insulating member and the electrode member is maintained and the thermal expansion between the insulating member and the electrode member is achieved. It is possible to more effectively suppress the occurrence of cracks and cracks at both ends of the insulating member due to the stress caused by the coefficient difference.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of an insulator according to the present invention.
FIG. 2 is an enlarged cross-sectional view of a brazed portion in the insulator of FIG.
FIG. 3 is a cross-sectional view of a conventional insulator.
4 is an enlarged cross-sectional view of a brazed portion in the insulator of FIG. 3. FIG.
FIG. 5 is a cross-sectional view showing another example of the embodiment of the insulator of the present invention.
[Explanation of symbols]
1: Insulating member 2: Electrode member 2a: Groove 2b: Wall 2c: Annulus

Claims

An electrode member in which two substantially annular metal members are arranged to face each other, and a wall portion is formed on each of the main surfaces on the opposite sides of the metal members.
The outer peripheral surface of both ends comprises a cylindrical insulating member brazed to each inner peripheral surface of the wall portion,
A main surface opposite to the main surface on the opposite side of the metal member is substantially parallel to the main surface on the opposite side,
The main surface of the opposing side of the metal member has a groove having a side surface continuous with the inner peripheral surface of the wall portion along the inner periphery of the wall portion and having a width smaller than the thickness of the insulating member. Formed all around,
The insulator is characterized in that a depth of the groove is not less than 40% and not more than 60% of a thickness of the insulating member , and a width is not less than 60% and not more than 80% of the thickness of the insulating member.

The insulator according to claim 1, wherein the groove has a depth of 4 mm or more and 5 mm or less and a width of 6 mm or more and 7 mm or less .

The insulator according to claim 1 or 2, wherein the electrode member has a thickness of the wall portion of 0.3 to 1 mm.