JP3955702B2

JP3955702B2 - Circuit breaker

Info

Publication number: JP3955702B2
Application number: JP34418999A
Authority: JP
Inventors: 孝夫三橋; 満月間; 征浩伏見; 茂樹幸本
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1999-12-03
Filing date: 1999-12-03
Publication date: 2007-08-08
Anticipated expiration: 2019-12-03
Also published as: JP2001160348A

Description

【０００１】
【発明の属する技術分野】
この発明は遮断動作時に優れた限流機能を有する回路遮断器に関するものである。
【０００２】
【従来の技術】
図２１は、例えば特公平１―４３９７３号公報に示された従来の回路遮断器を示す部分断面図であり、図において、１３０は導体２９０により遮断器部１４０と電気的に直列接続された限流素子部、１は可動接点２と磁性材料からなる支持体７１を有する上記限流素子部１３０の可動子、５は固定接点６を有する上記限流素子部１３０の固定子で、上記可動子１と上記固定子５により接触子対が構成されている。２８０は上記接触子対と電気的に直列に接続された励磁コイル、１１は上記接触子対に適切な接触圧力を発生させるバネである。図２２は図２１の右側面図である。
【０００３】
次に動作を説明する。通常通電時、回路遮断器には遮断器部１４０、導体２９０、励磁コイル２８０、可動子１、固定子５、端子部１５の経路で電流が流れる。限流素子部１３０が限流動作を行うべき大きさの電流が流れると、可動接点２と固定接点６との間の電磁反発力により接点が開極しアークが発生する。このアークにより接点間の圧力が上昇するので、可動子１のピストン１３５がバネ１１の力に抗して押し動かされる。さらに、可動子１の一部は磁性材料の支持体７１により構成されているので、コイルプランジャを構成する励磁コイル２８０からも同時にその開極を支援する力を受ける。この可動子１が開極方向に移動するときに、可動接点背面側の気体が排気穴１１０より排気され、アークにより上昇した圧力が付加的に排出される。そして、バネ１１の力に抗して開極を保持するのに十分な圧力を維持できなくなるまで開極が保持される。
【０００４】
続いて、限流素子部１３０を通過する電流が減少し、アークの圧力がある値以下に減少すると、バネ１１の力により可動子１は閉極動作を開始する。この時、閉極過程を遅延させるために、排気穴１１０は閉極方向に対して鋭角をなすように設けられており、排気の流体抵抗を大きくしている。また、この排気穴１１０の方向は、開極動作時の排気の流体抵抗が小さくなる傾斜となる。上記のように構成した限流素子部１３０では、主に接点２、６間に発生する電気抵抗と励磁コイル２８０のインダクタンスとにより、回路を流れる事故電流が限流される。この接触子対はシリンダー状の狭い空間に設けられているので、限流動作時に発生するアークの圧力が上昇し、アークの抵抗率が高くなる。従って、限流に必要な高いアーク電圧が得られる。上記のように限流された電流は、最終的に限流素子部１３０と直列接続されている遮断器部１４０により遮断される。
【０００５】
【発明が解決しようとする課題】
従来の回路遮断器の限流素子部では、可動接点が常に狭い筒状の空間内にあるため、アーク発生に伴い上記空間内に充満する電極金属蒸気により電流遮断時の接点間の絶縁回復が十分得られない。また、可動子のブレにより可動接点が筒状の壁面に接触しやすく、壁面での絶縁破壊の可能性が高い。このような理由により、上記限流素子部単独では電流の遮断機能を有することが困難であり、別途電流を遮断する機能を有する遮断部を設ける必要がある。そのため、回路遮断器全体のサイズが大きくなり、構造が複雑になり、コストが高くなるという問題がある。
【０００６】
さらに、前述のように限流素子部と遮断部を直列に接続すると、遮断器全体のインピーダンスが大きくなる。特に、限流素子部には限流動作時の可動子の開極を助けるために励磁コイルを設けており、インピーダンスが高い構成となっている。このような高インピーダンスの回路遮断器では、大きな通電ロスや通電による異常温度上昇が発生しやすい。従って、大きな通電容量を必要とする場合、この従来の回路遮断器を用いることができないという問題点があった。
【０００７】
さらに、従来の回路遮断器の限流素子部では、可動子の開極動作が直線的に行われるため、接点開離距離の確保のために可動子が開閉動作する方向（接点の開閉動作方向）のサイズが大きくなりやすい。図２１に示すように、上記方向のサイズは、端子部、固定子、可動子、可動子が移動する空間、可とう導体を収納する空間、および、筐体壁厚の合計となる。因って、可動子が直動する方向のサイズに制限がある場合には、十分な開離距離を確保できず、高圧力を効果的にアーク電圧上昇に結び付けられないという問題がある。
【０００８】
さらに、上記のように高圧力を効果的にアーク電圧上昇に結び付けられないと、不必要な圧力上昇が生じ、これを押さえ込むため、非常に大きな筐体強度が必要となりコストが高くなるという問題が生じる。
【０００９】
さらに、従来の回路遮断器の限流素子部では、限流動作中、常に、アークスポットが両接点にあるので、短絡遮断時の大電流アークによる接点の消耗が多くなるという問題がある。
【００１０】
この発明は上記のような問題点を解消するためになされたもので、一つの消弧装置にて優れた限流機能を有し、定格通電電流等の小電流から短絡電流等の大電流までの広い電流範囲での遮断動作可能回数を増やし、低コスト、小形、且つ、比較的大きな通電容量を必要とする回路へも適用できる回路遮断器を得ることを目的としている。
【００１１】
さらに、この発明は、固定接点のアークによる消耗量を減らして、回路遮断器の繰り返し遮断動作可能回数を増加させることを目的としている。
【００１２】
さらに、この発明は、短絡電流遮断時の限流性能をより向上させ、且つ、短絡電流遮断時の固定接点のアークによる消耗量を減らすことを目的としている。
【００１３】
さらに、この発明は、短絡遮断時の可動子に働く電磁開極力を強化して開極速度を向上させ、且つ、固定子接点の消耗を低減することを目的としている。
【００１４】
さらに、この発明は、固定接点の位置決めを簡単に行うことを目的としている。
【００１５】
さらに、この発明は、比較的小電流、多回数の遮断動作時の固定接点のアークによる消耗量を減らすことを目的としている。
【００１６】
さらに、この発明は、可動接点のアークによる消耗量を減らし、且つ、消弧板によるアーク冷却、分断作用を有効に利用することを目的としている。
【００１７】
さらに、この発明は、アークを消弧する空間のアークランナが伸びる方向の寸法が小さい場合においても、短絡電流遮断時の固定接点のアークによる消耗量を減らして繰り返し遮断動作が行える回路遮断器を得ることを目的としている。
【００１８】
さらに、この発明は、電源電圧が比較的高い回路においても、事故電流を確実に遮断できる信頼性の高い回路遮断器を得ることを目的としている。
【００１９】
【課題を解決するための手段】
この発明に係る回路遮断器は、アーム水平部と可動接点とを有し可動子回転軸を中心として回動する可動子、上記可動接点と接点対をなす固定接点と閉成状態において上記可動子のアームの一部とほぼ平行で且つ反対方向に電流が流れる電路とを有すると共に一端が上記可動子回転軸から遠い側の端子部に引き出される固定子、この固定子に電気的に接続され上記固定接点近傍から反可動子回転軸方向へ延びるアークランナ、上記接点対に接触圧を発生させる付勢手段、上記可動接点の反可動子回転軸側に配置された消弧板、上記固定接点の上方を開放し周囲を筒状に取り囲む絶縁物、および上記各構成部材を収納する絶縁物筐体を備え、上記接点対の閉成状態において上記可動接点の接触面が上記絶縁物が囲む筒状空間内に位置し、開成状態において上記可動子の上記可動接点を有する端部が上記絶縁物が囲む筒状空間外に位置するように構成し、かつ上記絶縁物の上記固定接点の反アークランナ側の壁面は上記固定接点に隣接して配置され、上記アーム水平部の反可動子回転軸側の端部に上記可動接点が一端部に固着されたアーム垂直部の他端部を固着して上記可動子を略Ｌ字状に構成したものである。
【００２０】
また、固定子は、導体をほぼＵ字形状に曲げてその一端を反可動子回転軸側の端子部に接続すると共に、そのＵ字形状の他端の内側に固定接点が設けられたものからなり、且つ、可動子のアーム水平部と反対方向の電流が流れる、上記固定接点を設けた固定子電路の一部を、閉成状態の可動子のアーム水平部に近接するように屈曲させ、また、上記固定接点に向かい合う固定子電路には可動子の回転軌跡と交差する部位に可動子の開閉を許すスリットを設けたものである。
【００２１】
また、固定接点の反アークランナ側で発生直後の接点間のアークに直接触れる位置に配置された絶縁物部位を、他の３方に配置された絶縁物部位よりアークに触れた時に蒸気を発生しやすい材質にしたものである。
【００２２】
また、固定接点の固定子回転軸側に配置された絶縁物部位を黒色にしたものである。
【００２５】
また、固定子は、一端に固定接点を有し、可動子のアーム水平部と反対方向に電流が流れる電路と、この電路の他端に接続されこの電路の両側を通り端子部に至る左右対称の電路と、この電路と端子部とを接続し、可動子回転軌跡面を含む面にスリットを有する２叉に分かれた垂直電路とからなり、上記固定接点を設けた電路には上記左右対称の電路より上記可動子のアーム水平部側に突出するように屈曲した部位を設けたものである。
【００２６】
また、固定接点が、可動子のアーム側に突出した部位により位置決めされて伝路に固着されているものである。
【００２８】
また、固定子は、一端に固定接点を有し、閉成状態の可動アーム水平部と対向して反対方向の電流成分が流れる電路と、この電路の他端に接続されこの電路の両側を通り端子部に至る左右対称の電路と、この電路と端子部とを接続し、可動子回転軌跡面を含む面にスリットを有する２叉に分かれた垂直電路とからなり、上記固定接点を有する電路の上記固定接点が固着された部位を上記左右対称の電路より下方（可動子のアーム水平部から遠い方向）に位置させるように上記固定接点を固着した電路の一部を下方に屈曲させたものである。
【００３０】
また、アークランナを反可動子回転軸側へ延長した線とほぼ直交するようセラミック板を配置し、上記アークランナの先端部から見て上記セラミック板背面に位置する絶縁物にアークが触れないようにしたものである。
【００３１】
また、固定接点を設けた固定子電路の両側に、可動子の開閉軌跡を含む面に平行な一対の絶縁板を配置し、上記絶縁板のアークランナ先端部側端部と上記アークランナ先端部と対向する部材との間に空隙を設け、且つ、上記空隙と連通する流路を固定接点からみて上記絶縁板の背面に設けたものである。
【００３２】
【発明の実施の形態】
実施の形態１．
以下、この発明の実施の形態１を図について説明する。図１は、実施の形態１に係る回路遮断器の開成状態の消弧ユニット２５の内部構造を示す部分断面斜視図であり、内部構成が分かるように絶縁物８とロータ２２の一部を切り取っている。消弧ユニット２５の構成部品は、図２に示すように、端子部１５ａ、１５ｂを除き、消弧ユニット筐体本体２３と消弧ユニット筐体蓋２４に収納されている。さらに、図３に示すように、複数の消弧ユニット２５をクロスバー２７により連結し、クロスバー２７を介して接点を開閉させる機構部２８、異常電流を検出し機構部２８を動作させるリレー部２９、および、機構部２８を手動で動作させるハンドル３２を付加し、これらをベース３０とカバー３１にて収納すれば配線用遮断器となる。
【００３３】
図１において、１は、可動接点２とこの可動接点２が固着されている可動アーム垂直部３とこの可動アーム垂直部３とほぼ直交する可動アーム水平部４により構成されるほぼＬ字状の可動子である。この可動子１は、固定接点６、第１導体部７ａ、第２導体部７ｂおよび第３導体部７ｃとにより構成されるほぼＵ字状の固定子５と１対の接触子対をなしており、可動子１はバネ１１により固定子５方向に付勢されている。また、可動子１は、可動子回動軸１３を中心に回動自在に支持されており、摺動接触子１０を介して端子１５ｂと電気的に接続されている。
【００３４】
一方、固定子５は、第１導体部７ａの一端で端子部１５ａと接続されており、固定接点６を固着している第３導体部７ｃの端部にアークランナ９が延設されている。さらに、可動子１の開閉を妨げないように、第１導体部７ａおよび第２導体部７ｂにスリット２１が設けられている。また、固定子５は、固定接点６を除いて、開成状態の可動接点２の接触面から見渡せる部位が絶縁物８によって覆われている。
【００３５】
この絶縁物８は、主に第１導体部７ａと第２導体部７ｂの可動子側の面を覆う絶縁カバー部８ａと、固定接点６の左右両側面側と反端子１５ａ側の３方向を囲む第１の絶縁物部位８ｂと、アークランナ９の上部空間を端子部１５ａ側から囲み且つスリット２１内面を覆うほぼＵ字状の第２の絶縁物の部位８ｃとにより構成されており、上記第１の絶縁物部位８ｂと上記第２の絶縁物部位８ｃとによりほぼ筒状の空間が形成されている。この筒状空間を開成状態の可動接点２より見渡すと、固定接点６およびアークランナ９が露出して配置されている。
【００３６】
また、閉成状態において、可動アーム水平部４の電流と第３導体部７ｃの電流は、ほぼ平行且つ反対方向になるように配置され、接点対２、６は上記第１の絶縁物部位８ｂに囲まれた空間内に配置される。一方、開成時には、可動接点２が上記筒状空間外に移動し、可動子先端部が最上部の消弧板１９ａに近接する。
【００３７】
本実施の形態では、通常の開閉動作はハンドル３２を手動にて操作することにより行う。ハンドル３２の操作により、機構部２８とクロスバー２７を介してロータ２２が回動し、可動子１が開閉動作する。また、過負荷電流遮断時には、リレー部２９が異常電流を検出し、リレー部２９よりトリップ信号が機構部２８へ伝わり、機構部２８が動作してロータ２２が回動し、可動子１が引き上げられ接点が開極する。
【００３８】
しかし、短絡事故等の大電流遮断時には、ロータ２２の回動に先立ち、接点接触部への電流集中による電磁反発力Ｆ１と、可動アーム水平部４の電流と第３導体部７ｃのほぼ平行且つ反対方向の電流による電磁反発力Ｆ２と、第１導体部７ａおよび第２導体部７ｂの電流が可動子１に発生させる電磁力の可動子開極方向の電磁力Ｆ３とにより、バネ１１による接圧に抗して接点が開極し、接点間にアークが発生する。
【００３９】
これら開極力Ｆ１、Ｆ２、Ｆ３について、図４（ａ）、図４（ｂ）、図４（ｃ）、および図４（ｄ）にてさらに詳細に説明する。図４（ｂ）に示すように、可動接点２と固定接点６との接触はこれら両接点の接触面の一部にて行われる。そのため、上記両接点には、同図中、ｉｍ、ｉｆで示すように、接点接触面に電流が集中することにより両接点間に近接したほぼ平行且つ反対方向の電流成分が発生するので、可動接点２を有する可動子１には開極方向の電磁力Ｆ１が働く。また、同図中に示すように、遮断動作初期においては、第３導体部７ｃを流れる電流Ｉｃと可動アーム水平部４を流れる電流Ｉｍとはほぼ平行且つ反対方向となり、可動アーム水平部４を有する可動子１には開極方向に電磁力Ｆ２が働く。さらに、遮断動作初期には、可動アーム水平部４の電流Ｉｍが第１導体部７ａの電流Ｉａより固定接点６側に位置して電流Ｉｍと電流Ｉａとがほぼ平行且つほぼ同方向となり、可動アーム水平部４は第１導体部７ａに吸引される。
【００４０】
図４（ｃ）は、図４（ｂ）のＣ−Ｃ線に沿う断面を示しており、第１導体部７ａと可動アーム水平部４との間に働く電磁吸引力Ｆａ１、Ｆａ２を矢印で示している。第１導体部７ａは可動子１が開閉動作時に通過するスリットを有しているので、第１導体部７ａの電路は可動子開極軌跡を含む平面から左右にずれた位置にあり、第１導体部の電流Ｉａ１、Ｉａ２と可動アーム水平部４の電流Ｉｍ間に各々働く吸引力Ｆａ１、Ｆａ２は斜め上方となる。従って、上記吸引力Ｆａ１、Ｆａ２の上向きの分力Ｆ３₁、Ｆ３₂の和Ｆ３’が可動子１に働く開極力となる。
【００４１】
これ以外に、図４（ｂ）に示した第２導体部７ｂを流れる電流Ｉｂが固定接点６側空間につくる磁場Ｂｂが、可動アーム水平部４の第２導体部より固定接点側の部位の電流に作用して、上記部位に開極方向の電磁力Ｆ３”が生じる。図４（ｂ）ではこのＦ３”と先述のＦ３’の和をＦ３として示している。アークの発生にともない、上記接点接触面での電流集中による電磁反発力Ｆ１は消滅するが、電磁反発力Ｆ２および電磁力Ｆ３は引き続き可動子１を開極方向へと回動させる。
【００４２】
また、アーク発生にともない、アークの熱により筒状空間を形成する絶縁物８内面から大量の蒸気が発生し、絶縁物８と可動子１とで囲まれた空間に高圧雰囲気が発生する。上記空間での高圧の発生により、可動子１は圧力差による開極力Ｆｐを受ける。この状態を示したのが図４（ｄ）である。同図は、アーク発生直後における図４（ｂ）のＣ−Ｃ断面に相当する位置の固定子５、可動子１、および絶縁物８の断面図であり、可動子１と絶縁物８に囲まれる空間内でアークＡが発生している。これにより、可動子１の固定接点６側空間の方が開極方向側の空間より高圧となり、圧力差による開極力Ｆｐが可動子１に作用する。これらの電磁力Ｆ１、Ｆ２、Ｆ３および圧力差による力Ｆｐにより、可動子１が高速に回動し、接点が高速開極する。この高速開極によりアーク長が高圧雰囲気中にて急激に伸びるのでアーク電圧が急速に立ち上がり、事故電流がピーク値をむかえる。
【００４３】
ここで、回路遮断器内で限流遮断動作時に発生する比較的短ギャップの大電流アークの高圧力下でのアーク電圧上昇条件について述べる。図６に示す実験装置において、４００は電極、４０１は密閉容器、４０２は交流電源、４０３は投入スイッチ、４０４は加圧用ボンベである。この実験装置にて、密閉容器４０１内で、数ｃｍ以下の短ギャップ大電流アークの雰囲気圧Ｐを変化させてアーク電圧変化を測定した結果を図７のグラフに示す。図６の実験装置では、丸棒状の電極４００を対向させてアークを発生させているので、電極間距離はアーク長Ｌと等しくなる。
【００４４】
図７（ａ）より明らかなように、アーク電流値が比較的小さい場合、アーク雰囲気圧Ｐが高くなるとアーク電圧は殆どのアーク長Ｌにおいてアーク雰囲気圧Ｐが低い場合より高くなる。一方、図７（ｂ）に示すように、アーク電流値が比較的大きい場合、アーク雰囲気圧Ｐが高くなってもアーク電圧はアーク長Ｌが比較的長い場合を除いてアーク雰囲気圧Ｐが低い場合に対して殆ど変化しない。図７に示した雰囲気圧Ｐが高い場合のアーク電圧Ｖ（ｐ＝高）と雰囲気圧Ｐが低い場合のアーク電圧Ｖ（ｐ＝低）との比Ｒをとり、グラフ化すると図８に示すようになる。
【００４５】
図８より明らかなように、アーク電流値が比較的小さい場合のアーク電圧上昇率Ｒは、アーク長が長いほど高い。一方、アーク電流値が比較的大きい場合のアーク電圧上昇率Ｒは、アーク長がある値以上にならないと殆ど増加しないことが分かる。以上より、短ギャップ大電流アークにおいて、アーク雰囲気圧を上げることによりアーク電圧を効果的に上げるための条件とは、（ａ）アーク電流が比較的小さい、（ｂ）アーク長が長い、という２つを同時に満足する必要がある。
【００４６】
短絡等の事故が発生した場合、事故発生直後から回路電流は急激に増大する。従って、上記２つの条件を満たして高い雰囲気圧にてアーク電圧を上げて事故電流を限流するには、（１）少なくともアーク発生直後（事故発生直後）に高圧雰囲気をつくる、（２）アーク電流が比較的小さい時（事故発生直後）にアーク長を長くする、必要がある。事故電流が増大した後では、雰囲気圧を上げてもあまり限流性能は向上しない。さらに、事故電流が増大した後の高圧雰囲気は、限流性能向上にあまり寄与しないだけでなく、筐体等の破損の原因となる。
【００４７】
この発明では、先述のように、閉成状態の接点対の周りに筒状空間を形成する絶縁物８を配置し、事故発生直後に接点間に発生したアークの熱により絶縁物８より大量の蒸気を発生させて高圧雰囲気を形成するとともに、電磁力と圧力による高速開極にてアーク長を急速に引き伸して、アーク電圧を高めている。
【００４８】
図９は、（ａ）高速開極手段を用いない場合と、（ｂ）高速開極手段を用いた場合の筒状の絶縁物を用いた効果を示している。同図において、ｔｓは事故発生時刻、ｔ０は接点開極時刻、Ｖ０は接点間の電極降下電圧、破線は電源電圧波形である。図９（ａ）は、高速開極手段を用いない場合であり、アーク電圧が電源電圧に追い付いた時刻ｔ１（筒状絶縁物有の時）、ｔ２（筒状絶縁物無しの時）に電流ピークＩｐ１、Ｉｐ２をそれぞれむかえる。高速開極手段を用いないと、事故電流の立上りに比べアーク長さの立上りが遅いので、筒状の絶縁物にて高圧雰囲気を作り出しても、アーク長が短く、アーク電圧が上昇する上記条件を満たすことが難しい。
【００４９】
従って、図９（ａ）では、筒状絶縁物を用いても、電流ピークＩｐの改善の度合いΔＩｐ= Ｉｐ２- Ｉｐ１は小さい。一方、図９（ｂ）に示す高速開極手段を用いた場合では、事故電流が大きくなる前にアーク長が十分長くなるので、高圧雰囲気にてアーク電圧が上昇する上記条件を満たすことができる。アーク電圧が電源電圧に追い付いた時刻ｔ１’（筒状絶縁物有の時）、ｔ２’（筒状絶縁物無しの時）の電流ピークＩｐをそれぞれＩｐ１’、Ｉｐ２’とすると、電流ピークＩｐの改善の度合いΔＩｐ’＝Ｉｐ２’−Ｉｐ１’は、高速開極手段を用いなかった場合の電流ピークＩｐの改善の度合いΔＩｐより劇的に大きいことが分かる。
【００５０】
先述の電流ピーク後、可動子１はさらに回動し接点間距離が増大する。この接点間距離の増大により、アーク電圧がさら大きくなり事故電流は急速に零へと向かう。事故電流が小さく絞られると、アークは鉄製の消弧板１９、１９ａに引き込まれ、アークが分断、冷却され消弧される。このとき可動接点２は上記筒状空間外にあり、たとえ筒状空間を形成する絶縁物８の沿面での絶縁耐力が低下していたとしても、接点間の絶縁は十分回復しているので、電極間に電源電圧が印加されても電流が再び流れることはない。この時点までには、リレー部２９からの信号によって機構部２８が動作しており、この可動接点２が上記筒状空間外の位置にて保持され、遮断動作が完了する。上記電流ピーク以降の長い接点間距離による高いアーク電圧により遮断時間は大幅に短くなる。従って、限流性能を示す指標の一つである通過エネルギーＩ²ｔ（電流の二乗の時間積分）が小さくなる。
【００５１】
ところで、アークを筒状空間内で発生させることにより高圧力雰囲気を発生させる場合、上記筒状空間を小さくするほど、アークと絶縁物壁の距離が小さくなり絶縁物蒸気発生量が増えるとともに、可動接点２と絶縁物８との間隙が小さくなり上記蒸気が筒状空間から逃げ難くなり、且つ、圧力をあげる空間の容積がより小さくなるので、アーク雰囲気圧力の上昇の度合いがより大きくなる。そのため、アーク電圧がより急激に立ち上がり、限流性能が大幅に向上する。
【００５２】
このとき、上記筒状空間を取り囲む絶縁物８の筒状部に作用する圧力差による力は、筒状空間内の圧力と絶縁物８の筒状部の周りの圧力の差であり、絶縁物８の筒状部が脹らむ方向である。この力はスリット２１の両側の固定子を形成する導体や、消弧ユニット筐体２３、蓋２４にて受けることができ、一般的に用いられている樹脂（例えば、ナイロン樹脂等）にて絶縁物８を形成したとしても、圧力により絶縁物８が破損することが問題となることは少ない。
【００５３】
一方、消弧ユニット筐体２３、蓋２４は絶縁物８の筒状部と比べて内面積が大きく、筒状空間で発生して筐体内空間に広がった圧力と大気圧との差が力として作用するので、絶縁物８に比べて非常に大きな力が加わり、筐体破損が生じることがある。これを防ぐため、筐体には強化繊維にて強化された高価なモールド材を用いたり、筐体を金属部品（例えば、ネジとナット、リベット等）にて強化しているので、遮断器が高価となっている。
【００５４】
また、上記筒状空間をほぼ固定接点６と同じ筒断面まで小さくしてしまうと、固定子側アークスポットは遮断動作中常に固定接点６上にあるので、定格通電電流等の比較的小電流の多回数通電開閉による接点消耗が多くなり、さらに、短絡遮断時においても、固定接点６上にあるアークスポットでの電流密度が上昇して接点損耗が大きくなる。これらの固定接点消耗により、再通電不能が生じることがある。
【００５５】
さらに、固定接点６上にアークスポットが拘束されることにより、アークが消弧板１９、１９ａに触れ難い構成となるので、定格電流遮断、過負荷電流遮断等の比較的電流値が小さい遮断電流領域（アーク径が小さく絶縁物からの蒸気発生が少ないので、絶縁物蒸気流による電流遮断作用を得られない領域）では、消弧板１９、１９ａによるアーク分断、冷却効果を利用できず、上記電流領域での遮断性能を確保できないという問題が発生することがある。
【００５６】
そこで、この発明では、筒状空間の大きさを固定接点６とアークランナ９の上部空間とを含む大きさとし、固定子側アークスポットが固定接点６からアークランナ９へと移動するように構成している。このように比較的大きな筒形状を用いても、絶縁物８をアークに触れた時に大量の蒸気を発生する樹脂等の素材にて成形すれば、アーク電圧を上昇させるのに充分な圧力上昇を生じさせることができる。
【００５７】
図４（ａ）は、開極直後の可動子１および固定子５近傍の状態を示した主要部の部分断面図であり、接点間に発生したアークＡは、図中白抜きの矢印で示した第２導体部７ｂと第３導体部７ｃを流れる電流により電磁駆動力を受ける。さらに、固定接点６近傍のアークは、第１の絶縁物部位８ｂにより、アークランナ９側を除いて取り囲まれているので、アークの可動子回転軸１３側の圧力が、端子部１５ａ側の圧力より大きくなり、アークはアークランナ９側へと圧力差による駆動力（図４（ａ）中、黒塗りの矢印にて示す）を受ける。これらの駆動力の内、定格電流遮断時等の電流が小さい領域においては電磁駆動力の方がより有効であり、過負荷電流遮断、短絡電流遮断など遮断電流が大きくなるに従って圧力差による力がより有効となる。この発明では、電磁駆動力と圧力差による駆動力が同時にアークに働くので、電流領域に関わらず開極直後に固定子側アークスポットをアークランナ９へと移動させることができる。
【００５８】
アークランナ９に移動した固定子側アークスポットは、アークランナ９を流れる電流等によりアークランナ９先端部へと駆動される。短絡電流遮断時のアーク電流瞬時値が大きい間は、端子部１５ａ側へと駆動されたアークが、筒状空間の端子部１５ａ側の壁８ｄ面から発生する蒸気流により可動子回転軸１３側へと逆方向の駆動力を受けるので、上記電磁駆動力と上記逆方向の駆動力の関係で、固定子側アークスポットがアークランナ９先端部へ到達するとは限らない。しかし、可動子１の開極動作が進み、事故電流が小さく絞られてくると、アークが発生する熱量が減少し、上記逆方向の圧力差による駆動力が相対的に小さくなるので、固定子側アークスポットはアークランナ９先端部へと達する。この状態を示したのが、図５である。アークランナ９先端部と可動子１間のアークＡは、絶縁物８の上部に設けられた複数の消弧板１９、１９ａにて分断、冷却されて消弧される。
【００５９】
ところで、前述のように、ほぼＬ字状の可動子１を用いた場合、可動接点２のアークスポットが可動子１先端部の消弧板と対向する面へ移動し難い。そのため、複数の消弧板の内、可動子側に位置する上部の消弧板にアークが触れ難く、消弧板によるアーク分断、冷却効果が充分発揮できない場合がある。そこで、本実施の形態では、最上部の鉄製の消弧板１９ａの容積を他の消弧板１９より大きくし、且つ、馬蹄形の足の部分（中央にスリットを有する部分）を可動接点２を挟み込む位置まで延ばして、最大開極位置の可動接点２近傍アークへの磁性体による電磁吸引力を強化し、可動子側アークスポットが確実に可動子１先端部へと移動するように構成している。
【００６０】
また、本実施の形態では、筒状空間の端子部１５ａ側の壁高さを可動子回転軸１３側の壁高さより高くしている。遮断動作時に接点間に発生するアークには、主に第２導体部７ｂ、第３導体部７ｃ、および可動アーム水平部４を流れる電流により、端子部１５ａ側に電磁駆動力が発生する。従って、筒状空間内にあるアークは端子部１５ａ側の壁により強く触れる。また、可動子１を高速開極するためには可動子１の慣性モーメントを小さくした方が有利であるが、筒状空間の可動子回転軸１３側の壁高さにより決まる可動アーム垂直部３が長くなると、可動子慣性モーメントは増加する。そこで、本実施の形態では、端子部１５ａ側の壁高さを可動子回転軸１３側の壁高さより高くすることにより、可動アーム垂直部３の長さを短くして慣性モーメントを低減し、且つ、十分な絶縁物蒸気を発生させて十分な高圧雰囲気を作る構成としている。
【００６１】
また、本実施の形態では、排気口２６が接点２、６間からみて消弧板１９側のみに設けられている。このような配置をとると、電流遮断動作時において、アーク電流の増加にともない筐体内のアークよりロータ２２側の空間に圧力が蓄積される。アーク電流がピークをむかえアーク電流値が減少していくと、上記蓄積された圧力により電極間ではロータ２２側から排気口２６側へと気流が生じ、アークを消弧板１９へと引き伸ばす。さらに、電流零点近傍では、上記流れによる接点間の荷電粒子を吹き飛ばす作用で、接点間の絶縁回復が大幅に改善される。従って、高電圧の回路に用いても遮断失敗が起こり難い、信頼性の高い回路遮断器を得ることができる。
【００６２】
この蓄積圧による気流の絶縁回復作用は、電流遮断時の上記気流の流速が大きいほど大きい。流速を大きくするには、蓄積圧を上げるか流路断面を小さくすればよく、そのために排気口面積を小さくする必要がある。本実施の形態では、比較的面積の小さい排気口２６を開成状態の可動接点２側に設けている。筒状の絶縁物８を用いて限流性能を向上させる場合、固定接点側アークスポット近傍のアークは筒状の絶縁物８にて動きが制限されるので、上記ロータ側空間の蓄積圧による気流にてアークを構成する金属粒子を吹き飛ばすことはできない。一方、可動子側アークスポット近傍のアークは、電流遮断時には筒状空間外に位置しており、上記気流の作用を受けやすい。因って、比較的面積の小さい排気口２６を開成状態の可動接点２側に設けることにより、効果的に電流遮断時の電極間の絶縁回復を確保できる。
【００６３】
また、前述のように本実施の形態では、消弧装置を消弧ユニット筐体２３、蓋２４内に収納しているので、遮断動作時の遮断器内の圧力上昇をベース３０およびカバー３１で直接受けることがなくなる。消弧ユニット筐体２３、蓋２４の受圧面積は、ベース３０およびカバー３１の受圧面積より小さい。そのため、たとえベース３０およびカバー３１と同一材料、同一肉厚の消弧ユニット筐体２３、蓋２４を用いても、より大きな内圧上昇に耐えることができ、アーク雰囲気圧を上げてアーク電圧を上昇させる限流手法を用いるのに適している。また、従来、遮断動作時の内圧上昇に耐えるため、機械的強度の大きな高価なモールド材にてベース３０およびカバー３１を構成していたが、消弧ユニット筐体２３、蓋２４を用いることにより、圧力を受ける筐体の材料の量を減らすことができコスト低減が可能となる。
【００６４】
また、前述のように本実施の形態では、消弧装置を構成する部品を消弧ユニット筐体本体２３と消弧ユニット筐体蓋２４により収納し、全体で消弧ユニット２５を構成している。また、機構部２８、リレー部２９等の各構成部品をユニット化しており、これらを組み合わせて配線用遮断器を構成するので、組立が簡単となりコスト低減が可能となる。
【００６５】
また、本実施の形態では、図２１に示した従来例と異なり、可動子１の開極を助けるための励磁コイルを設ける必要がないので、低インピーダンスの限流性能に優れた限流器が得られ、大きな通電容量が求められる回路への適用が可能となる。
【００６６】
さらに、可動子１を回動させて開極するため、可動接点２が開閉する方向の必要寸法は、固定子５の導体厚さ、固定接点６の厚さ、可動子１が移動する空間、可動接点２の厚さ、および、可動アーム垂直部３の和となり、従来の直動型限流器より上記方向の必要寸法を小さくすることができる。従って、外形寸法に制限がある場合でも、高圧力を効果的にアーク電圧上昇に結び付けるのに必要な開極距離を容易に確保できる。
【００６７】
なお、図１では、筒状空間を、固定子５の可動接点２側の面を覆う絶縁物８の一部である第１の絶縁物部位８ｂと第２の絶縁物部位８ｃとで構成したが、例えば、第２の絶縁物部位８ｃを絶縁物８の一部とせず、固定子５近傍に配置される消弧ユニット筐体本体２３および消弧ユニット筐体２４の部位にて構成しても同様な効果が得られる。
【００６８】
実施の形態２．
この発明の実施の形態２を図１０、図１１に示す。図１０は、本実施の形態の固定子５を示す斜視図であり、実施の形態１の固定子の第２導体部７ｂの一部を水平方向の電路７ｃ’と上下方向の電路７ｂ’に置き換えている。図１１は、閉成状態の可動子１、図１０に示した固定子５、絶縁物８を示した部分断面図であり、図中、矢印にて電流方向を示している。同図から明らかなように、図１０の固定子形状を用いることにより、可動アーム水平部４と固定子５の電路７ｃ’が大幅に近付き、事故電流の遮断時の電磁開極力が実施の形態１より増大する。これにより、アーク電圧の立ち上がりがより早くなり、限流性能が向上する。
【００６９】
実施の形態３．
図１２は、この発明の実施の形態３に係る固定子５と絶縁物８を示す斜視図であり、固定接点６を３方向から取り囲む絶縁物８ｂの上記固定接点６より反アークランナ９側に位置する部位８ｅを、アークが発生する光を吸収しやすいように黒色としている。アークから外部に放出されるエネルギーの一部は放射によって放出されており、特に、短絡遮断時等に発生する大電流短ギャップアークでは、その割合が大きい。そこで、このように固定子接点６のアークランナ９と反対側の絶縁物の部位８ｅを黒色とすると、絶縁物の部位８ｅでのアークからの放射エネルギーの吸収が高まり、蒸気発生量が増大する。これにともない、固定接点側のアークスポットのアークランナ９への移動およびアークランナ先端部への走行が早まる。
【００７０】
また、上記８ｅに相当する部位を、固定接点近傍の絶縁物部位８ｅを除く絶縁物の部位よりアークに触れたときに蒸気を発生しやすい材料（例えば、比較的分解温度の低い樹脂材）にて構成しても、アークランナ側へ走行するアークの背面圧と前面圧の圧力差が生じるので、絶縁物の部位８ｅを黒色とした場合と同様に、固定接点側のアークスポットのアークランナ９への移動およびアークのアークランナ先端部への走行が早まる。これにより、アーク発生時の固定接点損耗が低減され、回路遮断器の繰り返し遮断動作可能回数を増加させることができる。
【００７１】
実施の形態４．
図１３（ａ）は、この発明の実施の形態４に係る固定子５と絶縁物８を示す斜視図であり、主要構成部が分かるよう一部を切り欠いている。また、図１３（ｂ）は、図１３（ａ）の固定接点６を固着した第３導体部７ｃおよびアークランナ９近傍を示す図である。図１３では、第３導体部７ｃの固定接点６を固着した面の固定接点以外の部位と、アークランナ９の可動接点２（図示せず）と対向する面の固定接点６側の一部とを絶縁物１４にて覆っている。図１３（ｂ）に示すように、アークランナ９の可動接点側面の露出部は、固定接点６側の固定接点の左右方向の幅より狭い幅の走行路と、アークランナ先端側の上記走行路より広い幅のアーク保持部にてほぼＴ字状に形成されている。
【００７２】
定格電流遮断等の比較的電流の小さな遮断動作時には、接点間に発生するアークスポット径は電流ピーク時においても充分小さく、固定子５を流れる電流による電磁駆動力にて容易に上記走行路を走行し、アークランナ９先端部へと移行する。一方、短絡電流遮断時等の大電流遮断では、事故電流の立ち上がりにともなってアークスポットが急激に大きくなるので、上記幅の狭い走行路にてアークを可動子先端部へと移行させるためには、事故電流が増大する前にアークを走行させる必要がある。そこでこの実施の形態では、先述の第２導体部７ｂと第３導体部７ｃを流れる電流による電磁力と筒状の絶縁物の一部８ｂが発生させる圧力差による力にて、開極直後の比較的電流の小さなアークを駆動し、アークランナ９先端部側へと移行させる。その後の電流増加により、アークランナ９先端部に移行した固定子側アークスポットの径が増大し、アークスポットの一部は固定子６側へと戻ろうとするが、上記幅の狭い走行路にてアークスポット径の増大が阻止され、アークはほぼ安定してアークランナ９先端部に留まる。
【００７３】
このようにアークスポット径が制限されることにより、アーク抵抗が上昇し限流性能が向上する。また、遮断動作中の比較的電流が大きな期間中も固定子側アークスポットがアークランナ９先端部に安定して留まるので、固定接点６のアークによる消耗が低減できる。さらに、先述の図５に示したようなアーク状態が、遮断直前だけでなく遮断動作中の比較的電流が大きな期間においても実現できるので、消弧板のアーク冷却作用を最大限に利用できる。
【００７４】
実施の形態５．
図１４は、この発明の実施の形態５に係る接触子対近傍の主要部を示す部分断面図（ａ）およびこの実施の形態で使用される金属板を示す斜視図（ｂ）である。本実施の形態では、絶縁物８に囲まれる筒状空間内の端子部１５ａ側にアークと直交する向きに金属板１７を設けている。遮断動作では、慣性モーメントの大きい可動子１の移動速度よりアークの移動速度が速く、可動子１が最大開離距離に到達する時刻より固定子側アークスポットがアークランナ９先端に移行する時刻の方が早い。従って、固定子側アークスポットがアークランナ９先端部へ移行しても、可動子１の開離距離が増大するまでは、絶縁物８の上部に設けられた消弧板１９のアーク冷却、分断の効果は利用されない。そこで、本実施の形態では、筒状空間内に金属板１７を設けることにより、可動子１の開離距離の増大を待たず、金属板１７によりアークを冷却、分断し、筐体内圧の上昇を低減している。
【００７５】
実施の形態６．
図１５は、この発明の実施の形態６に係る固定子５と一対のコア３４を示す斜視図であり、固定子５の形状が分かるように手前側のコアを省略している。また、図１６は、図１５の固定子５および一対のコア３４に絶縁物８を被せた図であり、絶縁物８の一部を切り欠いている。この絶縁物８は筒状空間を形成し、開成状態の可動接点２よりこの筒状空間内部を見渡すと固定接点６およびアークランナ９が配置されていることは、実施の形態１と同様であるが、本実施の形態では、コア３４の絶縁も兼ねている。
【００７６】
固定子５の電路は、端子部１５ａ、電路７ｆ、７ｅ、７ｃ”、７ｂ”、固定接点６の順で構成されており、可動子１が回転する軌跡を含む面に対して面対称である。この固定子５には、電路７ｅ、７ｆの電流が発生する可動子１の開極を妨げる磁場成分を少なくするため、スリット３３が設けられており、電路７ｅ、７ｆは、可動子１が回転する軌跡を含む面から左右にずれた位置に配置される。電路７ｃ”と電路７ｂ”には固定接点６が固着され、端子部１５ａ側へと延びる舌片の根元部を打上げることにより成形されており、上記舌片は、電路７ｃ”、電路７ｂ”、固定接点６固着部位およびアークランナ９とによって構成される。
【００７７】
また、固定接点６は、上記電路７ｂ”と固定接点固着部位との境界である屈曲部にて位置決めされ、ロウ付けにて固着されている。電路７ｃ”と電路７ｂ”で形成される打上げ部は、閉成状態で上記舌片と対向してほぼ平行に配置される可動アーム水平部４との距離が近づくように打上げられており、開極初期の可動アーム水平部４に働く電磁反発力が強化される。また、固定接点６近傍に位置する電路７ｂ”には、接点開極方向（上下方向）成分の電流が流れ、この電流の上下方向成分は、接点間に発生したアークと逆方向となり、アークを端子部１５ａ側へと押し出す。従って、接点間に発生したアークは素早くアークランナ９へと移行するので、接点消耗が改善される。
【００７８】
ところで、電路７ｅの上部に設けられた一対のコア３４は、鉄などの磁性体にて構成されており、絶縁物８により接点間に発生するアークに直接触れないよう配置されている。このコアは、電路７ｃ”、７ｂ”の電流が作る可動子１を開極させる磁場成分を強化するとともに、電路７ｅを流れる電流がつくる可動子１の開極を妨げ且つアークを反端子部１５ａ側へ押し戻す作用をする磁束を遮蔽する役割をになっている。また、コア３４の端子部１５ａ側端部が電路７ｆに近接するように構成されており、上記端部に電路７ｆの電流がつくる可動子１の開極を妨げ且つアークを反端子部１５ａ側へ押し戻す作用をする磁束が吸収される。なお、図１５では、コア３４をほぼＬ字状の２枚の磁性体板に構成したが、２枚の磁性体板をＬ字の最も上部にて接続して一体化したコアを用いてもよい。このようにコアを一体化することより、磁性体コアによる可動子１の開極を促進する効果が向上する。
【００７９】
実施の形態７．
図１７は、この発明の実施の形態７に係る固定子５と馬蹄形アークランナ１８を示す斜視図であり、図示していないが、筒状空間を形成する絶縁物８が、固定接点６近傍を除く固定子５の可動接点側の面を覆うことは、実施の形態１と同様である。また、固定子５の導体７ｆ、７ｅ、７ｃ”、７ｂ”および固定接点６の配置は基本的に実施の形態６と同様である。本実施の形態では、鉄製の馬蹄形アークランナ１８を端子部１５ａ側から固定接点６を囲むように配置しており、馬蹄形アークランナ１８は馬蹄形アークランナの足１８ａにて導体７ｅと電気的に接続されている。
【００８０】
接点間に発生したアークが、固定接点６近傍に位置する電路７ｂ”の接点開極方向（上下方向）成分の電流により、端子部１５ａ側へと押し出されることは実施の形態６と同様であるが、本実施の形態では、それに加え馬蹄形アークランナ１８による磁気吸引力が働く。この磁性体によるアークを端子部１５ａ側へと吸引する作用は、磁性体の磁気飽和が発生しない比較的小電流領域でより有効である。また、上記馬蹄形アークランナ１８は、電路７ｅ、７ｆの電流によるアークを接点側へおしもどす磁場成分を遮蔽する効果があるので、アークのアークランナ１８への移行が早くなる。因って、定格電流の多頻度開閉時の接点消耗を低減させることできる。また、アークが消弧板１９に触れる時刻を早めることができ、消弧板のアーク冷却、分断作用を有効に利用できる。
【００８１】
実施の形態８．
この発明の実施の形態８を図について説明する。図１８は、本実施の形態に係る固定子５と一対のコア３４と鉄製の遮蔽板３５を示す斜視図であり。固定子５の形状が分かるように、固定接点６の左右に設けられている電路７ｅの一方と遮蔽板３５の一部を切り欠いている。その他の部品については、図示していないが、基本的に実施の形態６と同様の構成である。図１８の固定子形状は、図１５に示したものと比較して、電路７ｅの配置が異なり、電路７ｅが電路７ｃより上方に設けられている。電路７ｅの中心線は固定接点６接触面より上方に位置する。
【００８２】
このような構成とすると、電路７ｃ’が閉成状態の可動アーム水平部４と近付き電磁開極力が強化されること、および電路７ｂ”の電流の上下方向成分によりアークがアークランナ９側へと駆動され、消弧板１９によるアーク冷却、分断作用が向上することは実施の形態６と同様であるが、電路７ｅが固定接点接触面より上方に位置することから、電路７ｅの電流による電磁駆動力により固定接点側のアークスポットがアークランナ９側へより移動しやすくなる。また、電路７ｅを上方へ配置することにより、可動子１の開極を妨げ且つアークを可動子回転中心側へと押し戻す作用をする電路７ｆが必然的に短くなるので、アークランナ９へ移行したアークが固定接点６側へと戻ることを防止できる。
【００８３】
ところで、図１８には、一部断面をとった遮蔽板３５と電路７ｅの上部に設けられた一対のコア３４の一方を示している。遮蔽板３５およびコア３４は鉄などの磁性体にて構成されており、絶縁物８により接点間に発生するアークに直接触れないよう配置されている。遮蔽板３５は、主に、電路７ｆを流れる電流が発生する磁束（可動子１の開極を妨げ、且つ、アークを可動子回転中心側へと押し戻す作用をする）を遮蔽する役割をはたしている。一方、コア３４は、電路７ｃ’、７ｂ”、７ｃの電流が作る可動子１を開極させる磁場成分を強化するとともに、電路７ｅを流れる電流がつくる可動子１の開極を妨げる磁束を遮蔽する役割をになっている。
【００８４】
実施の形態９．
この発明の実施の形態９を図について説明する。図１９は、本実施の形態に係る可動子１の先端部３６を示す図であり、図１９（ａ）が可動子先端部３６を上方（可動接点２が固定接点６から開極する方向）から見た図、図１９（ｂ）が可動子先端部３６を左右方向（可動子１が回動する軌跡を含む面に直交する方向）から見た図である。本実施の形態では、可動子１の可動接点２より先端部寄りの部位を扇形とし、先端部端面に近づくほど左右方向の幅が狭くなるよう構成されている。
【００８５】
先述のように、この発明ではほぼＬ字状の可動子１を用いるため、可動子側アークスポットが可動接点２から可動子先端部の消弧板１９と対向する面へと移行し難く、複数の消弧板の内、上部に配置された消弧板はアークに触れず、アーク冷却、分断に寄与しない。そこで本実施の形態では、可動接点２から可動子先端部へのアークスポットの移行を促進するため、可動子先端部の消弧板１９と対向する面を可動接点２接触面から垂直に切り上げるのではなく、可動接点２と近接する部分では上記接触面とほぼ平行とし、可動子先端になるに従い徐々に可動接点接触面と直交するよう、可動子先端部形状をほぼ扇形としている。
【００８６】
さらに、図１９（ａ）に示すように、可動子先端部３６を尖鋭化することにより、先端部の電界強度を上げ、アークの接点から先端部への移行を促進している。このような可動子先端形状を用いることにより、ほぼＬ字状の可動子１においても、アークスポットを確実に可動子先端部３６へ移行できるので、可動接点２の消耗を減らし、且つ、消弧板１９によりアーク冷却、分断作用を有効に利用できる。
【００８７】
実施の形態１０．
この発明の実施の形態１０を図について説明する。図２０は、本実施の形態の消弧ユニット内の主要部を示す部分断面図であり、図２０（ａ）は図２０（ｂ）のＣ１−Ｃ１線に沿う断面図、図２０（ｂ）は図２０（ａ）のＣ２−Ｃ２線に沿う断面図である。本実施の形態の固定子５およびコア３４の形状は、実施の形態６で示したものと基本的に同じあり、接点間に発生したアークが、固定子５を流れる電流による電磁力と絶縁物の一部８ｂによる圧力効果にて、アークランナ９先端部へと駆動されることは同様である。
【００８８】
しかし、実施の形態６では、アークランナ９先端部へ駆動されたアークが、電路７ｆを覆う絶縁物の部位８ｄが発生する蒸気により接点間側へと押し戻される作用を受ける。そこで、本実施の形態では、上記絶縁物の部位８ｄをセラミック化して蒸気発生量を減らすことにより、アークを接点間に押し戻す力を低減している。このようにアークを接点間に押し戻す力が小さいと、回路遮断器を小形化するために消弧空間のアークランナ９が伸びる方向の寸法を短くした場合においても、短絡遮断時に固定接点６へアークスポットが広がることがなく、アークによる固定接点６の消耗量が減り、回路遮断器の繰り返し遮断動作可能な回数が増える。
【００８９】
また、本実施の形態では、一対のコア３４と絶縁物の部位８ｄとの間、および、一対のコア３４と消弧ユニット筐体本体２３および消弧ユニット筐体蓋２４との間にそれぞれ間隙を設けて流路３９を構成している。この流路３９には、アークランナ９先端側へのアークの移動にともない、図２０（ａ）に白抜き矢印で示した流れが生じ、走行するアークの前面側の圧力上昇が低減され、アーク走行速度が速まる効果がある。また、絶縁物８に囲まれた空間に充満する金属蒸気等を上記空間外へと排気できるので、接点間の絶縁回復が促進される。従って、電源電圧が比較的高い回路においても事故電流を確実に遮断でき、信頼性の高い回路遮断器を得ることができる。
【００９０】
【発明の効果】
以上のように、この発明によれば、１つの消弧装置にて優れた限流機能を有し、定格通電電流等の小電流から短絡電流等の大電流までの広い電流範囲での遮断動作可能回数を増やし、低コスト、小形、且つ、比較的大きな通電容量を必要とする回路へも適用できる回路遮断器が得られる効果がある。
【００９１】
また、固定接点の反アークランナ側に配置された絶縁物を、他の２方に配置された絶縁物よりアークに触れた時に蒸気を発生しやすいようにしたので、固定接点のアークによる消耗量を減らして、回路遮断器の繰り返し遮断動作可能回数を増やす効果がある。
【００９２】
また、アークランナの可動接点側の面の一部を、上記面でのアークランナ露出部がほぼＴ字状となるように絶縁物で覆い、上記露出部の内、固定接点に近接する部位の可動子の軌跡を含む面に直交する方向の幅が上記固定接点の幅より狭く、上記固定接点に近接する部位の上記方向の幅よりアークランナ先端部での露出部の上記方向の幅を広くしたので、短絡電流遮断時の限流性能をより向上させ、且つ、短絡電流遮断時の固定接点のアークによる消耗量を減らす効果がある。
【００９３】
また、短絡遮断時の可動子に働く電磁開極力を強化して開極速度を向上し、且つ、固定子接点の消耗を低減できる効果がある。
【００９４】
また、固定接点が可動アーム側に突出した部位のアークランナ側屈曲部にて位置決めされるので、新たな固定接点位置決めための加工の必要なく、固定接点が容易に位置決めできる効果がある。
【００９５】
また、比較的小電流、多回数の遮断動作時の固定接点のアークによる消耗量を低減できる効果がある。
【００９６】
また、消弧板と対向する上記可動アームの先端部を可動子の軌跡を含む面と直交する方向から見てほぼ扇形としたので、可動接点の消耗量を減らし、且つ、消弧板によるアーク冷却、分断作用を有効に利用できる効果がある。
【００９７】
また、アークを消弧する空間のアークランナが伸びる方向の寸法が小さい場合においても、短絡電流遮断時の固定接点のアークによる消耗量を減らして繰り返し遮断動作が行える回路遮断器が得られる効果がある。
【００９８】
また、固定接点が固着した接点板の左右に、可動子の開閉軌跡を含む面に平行な一対の絶縁板を配置し、上記絶縁板のアークランナ先端部側端部と上記アークランナ先端部と対向する部材との間に空隙を設け、且つ、上記空隙と連通する流路を固定接点からみて上記絶縁板の背面に設けたので、電源電圧が比較的高い回路においても、事故電流を確実に遮断できる信頼性の高い回路遮断器が得られる効果がある。
【図面の簡単な説明】
【図１】この発明の実施の形態１に係る開成状態の消弧ユニット内部構造を示す部分断面斜視図である。
【図２】実施の形態１の開成状態の消弧ユニット内部構造を示す斜視図である。
【図３】実施の形態１の回路遮断器の構成を示す斜視図である。
【図４】実施の形態１の動作を説明する主要部の部分断面図（ａ）、およびその動作を説明するための要部断面図（ｂ）（ｃ）（ｄ）である。
【図５】実施の形態１の動作を説明する主要部の部分断面図である。
【図６】アーク電圧の基礎的特性測定した実験装置を示す構成図である。
【図７】雰囲気圧力のアーク電圧への影響を示したグラフである。
【図８】電流値のアーク電圧上昇率への影響を示したグラフである。
【図９】実施の形態１の効果を説明するグラフである。
【図１０】この発明の実施の形態２に係る固定子形状を示す斜視図である。
【図１１】実施の形態２の動作を説明する主要部の部分断面図である。
【図１２】この発明の実施の形態３に係る固定子と絶縁物の形状を示す斜視図である。
【図１３】この発明の実施の形態４に係る固定子の主要部を示す部分断面斜視図（ａ）、および実施の形態４の固定接点板近傍を示す部分断面図（ｂ）である。
【図１４】この発明の実施の形態５に係る可動子および固定子の主要部を示す部分断面図（ａ）、および金属板の斜視図（ｂ）である。
【図１５】この発明の実施の形態６に係る固定子側電路とコアを示す斜視図である。
【図１６】実施の形態６の固定子側電路と絶縁物を示す部分断面斜視図である。
【図１７】この発明の実施の形態７に係る固定子とアークランナを示す斜視図である。
【図１８】この発明の実施の形態８に係る固定子近傍の主要部の構成を示す部分断面斜視図である。
【図１９】この発明の実施の形態９に係る可動子先端部を示す上面図（ａ）、および実施の形態９の可動子先端部を示す正面図（ｂ）である。
【図２０】この発明の実施の形態１０に係る回路遮断器の主要部を示す図２０（ｂ）のＣ１−Ｃ１線に沿う断面図（ａ）、および図２０（ａ）のＣ２−Ｃ２線に沿う断面図（ｂ）である。
【図２１】従来の限流機能付き遮断器を示す部分断面正面図である。
【図２２】図２１の右側面図である。
【符号の説明】
Ａアーク、１可動子、
２可動接点、３可動アーム垂直部、
４可動アーム水平部、５固定子、
６固定接点、７ａ第１導体部、
７ｂ第２導体部、７ｃ第３導体部、
７ｂ’、７ｂ”、７ｃ’、７ｃ”、７ｅ、７ｆ電路、
８絶縁物、８ａ絶縁カバー部、
８ｂ第１の絶縁物部位、８ｃ第２の絶縁物部位、
８ｄ第２の絶縁物部位の一部、８ｅ第１の絶縁物部位の一部、
９アークランナ、１０摺動接触子、
１１バネ、１２バネ掛け、
１３可動子回転軸、１４絶縁物、
１５ａ、１５ｂ、１６端子部、１７金属板、
１８馬蹄形アークランナ、１８ａ馬蹄形アークランナの一部、
１９、１９ａ消弧板、２０消弧側板、
２１スリット、２２ロータ、
２３消弧ユニット筐体本体、２４消弧ユニット筐体蓋、
２５消弧ユニット、２６排気口、
２７クロスバー、２８機構部、
２９リレー部、３０ベース、
３１カバー、３２ハンドル、
３３スリット、３４コア、
３５遮蔽板、３６可動子先端部、
３７セラミック、３８絶縁物、
３９流路、４００電極、
４０１密閉容器、４０２交流電源、
４０３投入スイッチ、４０４加圧ボンベ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit breaker having an excellent current limiting function during a breaking operation.
[0002]
[Prior art]
FIG. 21 is a partial cross-sectional view showing a conventional circuit breaker disclosed in, for example, Japanese Patent Publication No. 1-43973. In the figure, 130 is electrically connected to the breaker unit 140 by a conductor 290. In Connected in series The Current limiting element unit 1 is a movable element of the current limiting element unit 130 having a movable contact 2 and a support 71 made of a magnetic material, and 5 is a stator of the current limiting element unit 130 having a fixed contact 6. so, By the mover 1 and the stator 5 Contact pair Composed ing. 280 is electrically connected to the above contact pair In Connected in series The An exciting coil 11 is a spring that generates an appropriate contact pressure for the contact pair. 22 is a right side view of FIG.
[0003]
Next, the operation will be described. During normal energization, the circuit breaker includes a circuit breaker section 140, a conductor 290, an exciting coil 280, a mover 1, a stator 5, and a terminal section. 15 Current flows through the path. When a current of a magnitude that should cause the current-limiting element unit 130 to perform a current-limiting operation flows, the contact is opened due to the electromagnetic repulsive force between the movable contact 2 and the fixed contact 6 to generate an arc. Since the pressure between the contacts increases due to this arc, the piston 135 of the mover 1 is pushed against the force of the spring 11. Further, since a part of the mover 1 is composed of a support 71 made of a magnetic material, it receives a force for supporting the opening simultaneously from the exciting coil 280 constituting the coil plunger. When the mover 1 moves in the opening direction, the gas on the back side of the movable contact is exhausted from the exhaust hole 110, and the pressure increased by the arc is additionally discharged. The opening is held until a pressure sufficient to hold the opening against the force of the spring 11 cannot be maintained.
[0004]
Subsequently, when the current passing through the current limiting element unit 130 decreases and the arc pressure decreases below a certain value, the mover 1 starts closing operation by the force of the spring 11. At this time, in order to delay the closing process, the exhaust hole 110 is provided so as to form an acute angle with respect to the closing direction, thereby increasing the fluid resistance of the exhaust. The direction of the exhaust hole 110 is inclined so that the fluid resistance of the exhaust during the opening operation is small. In the current limiting element unit 130 configured as described above, the fault current flowing through the circuit is limited mainly by the electrical resistance generated between the contacts 2 and 6 and the inductance of the exciting coil 280. Since this contact pair is provided in a narrow cylindrical space, the pressure of the arc generated during the current limiting operation increases, and the arc resistivity increases. Therefore, a high arc voltage necessary for current limiting can be obtained. The current limited as described above is finally interrupted by the circuit breaker unit 140 connected in series with the current limiting element unit 130.
[0005]
[Problems to be solved by the invention]
In the current limiting element part of the conventional circuit breaker, since the movable contact is always in a narrow cylindrical space, the insulation between the contacts at the time of current interruption is restored by the electrode metal vapor that fills the space as the arc occurs. Not enough. In addition, the movable contact tends to come into contact with the cylindrical wall surface due to the movement of the mover, and the possibility of dielectric breakdown on the wall surface is high. For these reasons, it is difficult for the current limiting element unit alone to have a current blocking function, and it is necessary to provide a separate blocking unit having a function of blocking current. Therefore, there is a problem that the size of the entire circuit breaker is increased, the structure is complicated, and the cost is increased.
[0006]
Furthermore, when the current limiting element portion and the breaking portion are connected in series as described above, the impedance of the entire breaker increases. In particular, the current limiting element portion is provided with an exciting coil to assist the opening of the mover during the current limiting operation, and has a high impedance configuration. In such a high-impedance circuit breaker, large energization loss and abnormal temperature rise due to energization are likely to occur. Therefore, there is a problem that this conventional circuit breaker cannot be used when a large energization capacity is required.
[0007]
Furthermore, in the current limiting element part of the conventional circuit breaker, the opening movement of the mover is performed linearly, ensuring the contact opening distance. of For this reason, the size in the direction in which the mover opens and closes (the contact opening and closing direction) tends to increase. As shown in FIG. 21, the size in the above direction is the sum of the terminal portion, the stator, the mover, the space in which the mover moves, the space in which the flexible conductor is accommodated, and the casing wall thickness. Therefore, when the size in the direction in which the mover moves linearly is limited, there is a problem that a sufficient separation distance cannot be secured and high pressure cannot be effectively linked to an increase in arc voltage.
[0008]
Furthermore, if high pressure cannot be effectively linked to an increase in arc voltage as described above, an unnecessary increase in pressure occurs, and this is suppressed. Arise.
[0009]
Further, in the current limiting element portion of the conventional circuit breaker, since the arc spot is always present at both contacts during the current limiting operation, there is a problem that the contact is consumed due to a large current arc when the short circuit is interrupted.
[0010]
The present invention has been made to solve the above problems, and has an excellent current limiting function in one arc extinguishing device, from a small current such as a rated current to a large current such as a short circuit current. An object of the present invention is to obtain a circuit breaker that can be applied to a circuit that increases the number of times that a breaking operation can be performed in a wide current range, and that requires a low cost, a small size, and a relatively large current carrying capacity.
[0011]
Another object of the present invention is to increase the number of times that a circuit breaker can be repeatedly interrupted by reducing the amount of consumption due to arcing of a fixed contact.
[0012]
Furthermore, an object of the present invention is to further improve the current-limiting performance when a short-circuit current is interrupted, and to reduce the amount of consumption due to arcing of a fixed contact when the short-circuit current is interrupted.
[0013]
Another object of the present invention is to enhance the electromagnetic opening force acting on the mover at the time of short-circuit interruption to improve the opening speed and reduce the consumption of the stator contact.
[0014]
Furthermore, an object of the present invention is to easily perform the positioning of the fixed contact.
[0015]
Another object of the present invention is to reduce the amount of consumption due to arcing of the fixed contact during a relatively small current and many interruption operations.
[0016]
Another object of the present invention is to reduce the amount of wear of the movable contact due to the arc, and to effectively use the arc cooling and dividing action by the arc extinguishing plate.
[0017]
Furthermore, the present invention provides a circuit breaker capable of repeatedly performing a breaking operation by reducing the amount of consumption due to the arc of a fixed contact at the time of breaking a short-circuit current even when the dimension of the arc runner extending in the space where the arc is extinguished is small. The purpose is that.
[0018]
Another object of the present invention is to provide a highly reliable circuit breaker that can reliably cut off an accident current even in a circuit having a relatively high power supply voltage.
[0019]
[Means for Solving the Problems]
The circuit breaker according to the present invention includes a movable element having a horizontal arm part and a movable contact, and rotating about a movable element rotation axis, and a fixed contact forming a contact pair with the movable contact and the movable element in a closed state. A stator that is substantially parallel to a part of the arm of the arm and through which an electric current flows in the opposite direction, and one end of which is drawn out to the terminal portion on the side far from the movable shaft, and is electrically connected to the stator and is connected to the stator An arc runner extending in the direction of the anti-mover rotation axis from the vicinity of the fixed contact, an urging means for generating contact pressure on the contact pair, an arc-extinguishing plate disposed on the anti-mover rotation axis side of the movable contact, and above the fixed contact And a cylindrical space in which the contact surface of the movable contact is surrounded by the insulator when the contact pair is closed. Located in the opening End with the movable contact of said movable member is configured to be located outside the cylindrical space in which the insulator surrounds the And the wall surface of the insulator on the side opposite to the arc runner of the fixed contact is disposed adjacent to the fixed contact, and the movable contact is fixed to one end of the horizontal arm portion on the side opposite to the rotary axis of the armature. The other end of the arm vertical part was fixed, and the mover was configured in a substantially L shape. Is.
[0020]
In addition, the stator is formed by bending the conductor into a substantially U shape and connecting one end thereof to the terminal portion on the side opposite to the rotary shaft of the anti-moveable element, and having a fixed contact inside the other end of the U shape. And a part of the stator electric circuit provided with the fixed contact, in which a current in the direction opposite to the arm horizontal part of the mover flows, is bent so as to be close to the arm horizontal part of the closed mover, The stator electric circuit facing the fixed contact is provided with a slit that allows the mover to be opened and closed at a portion that intersects the rotation locus of the mover.
[0021]
In addition, the fixed contact on the non-arc runner side In the position where you can directly touch the arc between the contacts The disposed insulator portion is made of a material that is liable to generate steam when it touches the arc from the other three insulator portions.
[0022]
Further, the insulator portion arranged on the stator rotating shaft side of the fixed contact is made black.
[0025]
Also fixed Child Has a fixed contact at one end, an electric circuit through which current flows in the opposite direction to the arm horizontal part of the mover, a symmetrical electric circuit connected to the other end of the electric circuit and passing through both sides of the electric circuit to the terminal part, This electric circuit is connected to the terminal part, and is composed of a bifurcated vertical electric circuit having a slit on the surface including the mover rotation locus surface. From the above symmetrical circuit Projects to the arm horizontal part of the mover Bent like A part is provided.
[0026]
Further, the fixed contact is positioned by a portion protruding to the arm side of the mover and is fixed to the transmission path.
[0028]
Also fixed Child Has a fixed contact at one end, Closed With movable arm horizontal part Opposite Opposite direction of Current component The electric circuit through which the current flows, the symmetrical electric circuit connected to the other end of the electric circuit and passing through the both sides of the electric circuit to the terminal part, and the electric circuit and the terminal part are connected. Of the electric circuit having the above-mentioned fixed contact. Fixed above Position the part where the contact is fixed below the symmetrical electric circuit (in the direction far from the arm horizontal part of the mover). As shown in the figure, a part of the electric circuit to which the fixed contact was fixed was bent downward. Is.
[0030]
In addition, a ceramic plate is disposed so as to be substantially orthogonal to a line extending the arc runner to the anti-mover rotation axis side, and is located on the back surface of the ceramic plate as viewed from the tip of the arc runner. Insulator The arc is not touched.
[0031]
In addition, a pair of insulating plates parallel to the plane including the open / close locus of the mover are arranged on both sides of the stator circuit provided with the fixed contact, and the arc runner tip side end of the insulation plate and the arc runner tip are opposed to each other. A gap is provided between the insulating plate and a flow path communicating with the gap is provided on the back surface of the insulating plate as viewed from the fixed contact.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional perspective view showing the internal structure of the arc-extinguishing unit 25 in the open state of the circuit breaker according to the first embodiment, and a part of the insulator 8 and the rotor 22 are cut out so that the internal structure can be understood. ing. As shown in FIG. 2, the components of the arc-extinguishing unit 25 are accommodated in the arc-extinguishing unit casing body 23 and the arc-extinguishing unit casing lid 24 except for the terminal portions 15a and 15b. Further, as shown in FIG. 3, a plurality of arc extinguishing units 25 are connected by a cross bar 27, a mechanism unit 28 that opens and closes contacts via the cross bar 27, and a relay unit that detects an abnormal current and operates the mechanism unit 28. 29 and a handle 32 for manually operating the mechanism portion 28 are added, and if these are housed in the base 30 and the cover 31, a circuit breaker for wiring is obtained.
[0033]
In FIG. 1, reference numeral 1 denotes a substantially L-shape composed of a movable contact 2, a movable arm vertical portion 3 to which the movable contact 2 is fixed, and a movable arm horizontal portion 4 substantially orthogonal to the movable arm vertical portion 3. It is a mover. The mover 1 forms a pair of contact with a substantially U-shaped stator 5 composed of a fixed contact 6, a first conductor portion 7a, a second conductor portion 7b, and a third conductor portion 7c. The mover 1 is biased toward the stator 5 by a spring 11. The mover 1 is supported so as to be rotatable about a mover rotating shaft 13 and is electrically connected to a terminal 15 b via a sliding contact 10.
[0034]
On the other hand, the stator 5 is connected to the terminal portion 15a at one end of the first conductor portion 7a, and an arc runner 9 is extended to the end portion of the third conductor portion 7c to which the fixed contact 6 is fixed. Furthermore, the slit 21 is provided in the 1st conductor part 7a and the 2nd conductor part 7b so that opening and closing of the needle | mover 1 may not be prevented. In addition, the stator 5 is covered with an insulator 8 except for the fixed contact 6, and the part that can be seen from the contact surface of the opened movable contact 2.
[0035]
This insulator 8 is mainly composed of an insulating cover portion 8a that covers the surface on the mover side of the first conductor portion 7a and the second conductor portion 7b, and the three directions of the left and right side surfaces of the fixed contact 6 and the opposite terminal 15a side. The first insulator part 8b that surrounds and a substantially U-shaped second insulator part 8c that surrounds the upper space of the arc runner 9 from the terminal portion 15a side and covers the inner surface of the slit 21 are configured as described above. A substantially cylindrical space is formed by the one insulator portion 8b and the second insulator portion 8c. When this cylindrical space is looked over from the movable contact 2 in the open state, the fixed contact 6 And the arc runner 9 is exposed and arranged.
[0036]
In the closed state, the current of the movable arm horizontal portion 4 and the current of the third conductor portion 7c are arranged so as to be substantially parallel and in opposite directions, and the contact pairs 2 and 6 are connected to the first insulator portion 8b. It is arranged in the space surrounded by. On the other hand, at the time of opening, the movable contact 2 moves out of the cylindrical space, and the tip of the movable element comes close to the uppermost arc extinguishing plate 19a.
[0037]
In the present embodiment, the normal opening / closing operation is performed by manually operating the handle 32. By operating the handle 32, the rotor 22 is rotated via the mechanism portion 28 and the cross bar 27, and the movable element 1 is opened and closed. When the overload current is interrupted, the relay unit 29 detects an abnormal current, and a trip signal is transmitted from the relay unit 29 to the mechanism unit 28. The mechanism unit 28 operates to rotate the rotor 22, and the mover 1 is pulled up. Contact is opened.
[0038]
However, when a large current is interrupted due to a short circuit accident or the like, prior to the rotation of the rotor 22, the electromagnetic repulsive force F1 due to the current concentration on the contact contact portion, the current of the movable arm horizontal portion 4 and the third conductor portion 7c are substantially parallel and The contact by the spring 11 is caused by the electromagnetic repulsive force F2 caused by the current in the opposite direction and the electromagnetic force F3 in the armature opening direction of the electromagnetic force generated by the current in the first conductor portion 7a and the second conductor portion 7b. The contact opens against the pressure, and an arc is generated between the contacts.
[0039]
These opening forces F1, F2, and F3 will be described in more detail with reference to FIGS. 4 (a), 4 (b), 4 (c), and 4 (d). As shown in FIG. 4B, the contact between the movable contact 2 and the fixed contact 6 is performed on a part of the contact surface of these both contacts. For this reason, as shown by im and if in the drawing, currents in the parallel and opposite directions that are close to each other are generated by concentrating the current on the contact surface. Electromagnetic force F1 in the opening direction acts on the mover 1 having the contact 2. As shown in the figure, at the beginning of the breaking operation, the current Ic flowing through the third conductor portion 7c and the current Im flowing through the movable arm horizontal portion 4 are substantially parallel and opposite to each other. An electromagnetic force F2 acts on the movable element 1 in the opening direction. Furthermore, at the initial stage of the breaking operation, the current Im of the movable arm horizontal portion 4 is located closer to the fixed contact 6 than the current Ia of the first conductor portion 7a, and the current Im and the current Ia are substantially parallel and substantially in the same direction. The arm horizontal part 4 is attracted to the first conductor part 7a.
[0040]
FIG. 4C shows a cross section taken along the line CC of FIG. 4B, and electromagnetic attraction forces Fa1 and Fa2 acting between the first conductor portion 7a and the movable arm horizontal portion 4 are indicated by arrows. Show. Since the first conductor portion 7a has a slit through which the mover 1 passes during the opening / closing operation, the electric path of the first conductor portion 7a is shifted to the left and right from the plane including the mover opening locus, The attractive forces Fa1 and Fa2 acting between the currents Ia1 and Ia2 of the conductor part and the current Im of the movable arm horizontal part 4 are obliquely upward. Therefore, the upward component force F3 of the suction forces Fa1 and Fa2 ₁ , F3 ₂ Is the opening force that acts on the mover 1.
[0041]
In addition to this, the current flowing through the second conductor portion 7b shown in FIG. Ib The magnetic field Bb produced in the space on the fixed contact 6 side acts on the current in the portion on the fixed contact side from the second conductor portion of the movable arm horizontal portion 4, and an electromagnetic force F3 ″ in the opening direction is generated in the portion. In FIG. 4B, the sum of F3 ″ and the above-mentioned F3 ′ is shown as F3. As the arc is generated, the electromagnetic repulsion force F1 due to the current concentration on the contact contact surface disappears, but the electromagnetic repulsion force F2 and the electromagnetic force F3 continue to rotate the mover 1 in the opening direction.
[0042]
Further, along with the generation of the arc, a large amount of steam is generated from the inner surface of the insulator 8 forming the cylindrical space by the heat of the arc, and the insulator 8 and the mover 1 so A high-pressure atmosphere is generated in the enclosed space. Due to the generation of high pressure in the space, the mover 1 receives an opening force Fp due to a pressure difference. This state is shown in FIG. This figure is a cross-sectional view of the stator 5, the mover 1 and the insulator 8 at a position corresponding to the CC cross section of FIG. 4B immediately after the occurrence of the arc, and is surrounded by the mover 1 and the insulator 8. Arc in the space A Has occurred. As a result, the space on the fixed contact 6 side of the mover 1 has a higher pressure than the space on the opening direction side, and the opening force Fp due to the pressure difference acts on the mover 1. By these electromagnetic forces F1, F2, F3 and the force Fp due to the pressure difference, the mover 1 rotates at a high speed, and the contact opens at high speed. Due to this high-speed opening, the arc length rapidly increases in a high-pressure atmosphere, so that the arc voltage rises rapidly and the accident current reaches its peak value.
[0043]
Here, the arc voltage increase condition under a high pressure of a relatively short gap high current arc generated during the current limiting interruption operation in the circuit breaker will be described. In the experimental apparatus shown in FIG. 6, 400 is an electrode, 401 is a sealed container, 402 is an AC power source, 403 is a closing switch, and 404 is a pressurizing cylinder. The graph of FIG. 7 shows the results of measuring the arc voltage change by changing the atmospheric pressure P of a short gap high current arc of several centimeters or less in this sealed apparatus 401 in this experimental apparatus. In the experimental apparatus of FIG. 6, since the arc is generated by making the round bar-shaped electrodes 400 face each other, the distance between the electrodes becomes equal to the arc length L.
[0044]
As is clear from FIG. 7A, when the arc current value is relatively small, the arc voltage is almost equal to the arc length L when the arc atmospheric pressure P is increased. Than when the arc atmosphere pressure P is low Get higher. On the other hand, as shown in FIG. 7 (b), when the arc current value is relatively large, the arc voltage is high except when the arc length L is relatively long even when the arc atmospheric pressure P is high. For the case where the arc atmosphere pressure P is low Almost no change. FIG. 8 is a graph showing the ratio R of the arc voltage V (p = high) when the atmospheric pressure P is high and the arc voltage V (p = low) when the atmospheric pressure P is low, as shown in FIG. It becomes like this.
[0045]
As is clear from FIG. 8, the arc voltage increase rate R when the arc current value is relatively small is higher as the arc length is longer. On the other hand, it can be seen that the arc voltage increase rate R when the arc current value is relatively large hardly increases unless the arc length exceeds a certain value. From the above, in a short gap high current arc, the conditions for effectively increasing the arc voltage by increasing the arc atmospheric pressure are (a) a relatively small arc current and (b) a long arc length. It is necessary to satisfy one at the same time.
[0046]
When an accident such as a short circuit occurs, the circuit current rapidly increases immediately after the accident occurs. Therefore, to satisfy the above two conditions and increase the arc voltage at a high atmospheric pressure to limit the accident current, (1) at least immediately after the occurrence of the arc (accident occurrence) Living It is necessary to create a high-pressure atmosphere immediately after (2), and to increase the arc length when the arc current is relatively small (immediately after the accident). After the accident current increases, the current limiting performance is not improved much even if the atmospheric pressure is increased. Furthermore, the high-pressure atmosphere after the increase in the accident current not only contributes to the improvement in the current limiting performance, but also causes damage to the housing and the like.
[0047]
In the present invention, as described above, the insulator 8 that forms the cylindrical space is disposed around the contact pair in the closed state, and a larger amount than the insulator 8 due to the heat of the arc generated between the contacts immediately after the accident occurs. Steam is generated to create a high-pressure atmosphere, and the arc voltage is increased by rapidly extending the arc length by high-speed opening with electromagnetic force and pressure.
[0048]
FIG. 9 shows the effect of using a cylindrical insulator when (a) the high-speed opening means is not used and (b) when the high-speed opening means is used. In the figure, ts is the accident occurrence time, t0 is the contact opening time, V0 is the electrode drop voltage between the contacts, and the broken line is the power supply voltage waveform. FIG. 9 (a) shows a case where the high-speed opening means is not used, and the current at time t1 (when the cylindrical insulator is present) and t2 (when the cylindrical insulator is absent) when the arc voltage catches up with the power supply voltage. The peaks Ip1 and Ip2 are respectively changed. If high-speed opening means is not used, the rise of the arc length is slower than the rise of the accident current, so even if a high pressure atmosphere is created with a cylindrical insulator, the arc length is short and the arc voltage rises. It is difficult to meet.
[0049]
Therefore, in FIG. 9A, even if a cylindrical insulator is used, the degree of improvement ΔIp = Ip2−Ip1 of the current peak Ip is small. On the other hand, in the case of using the high-speed electrode opening means shown in FIG. 9B, the arc length becomes sufficiently long before the accident current becomes large, so that the above condition that the arc voltage rises in a high-pressure atmosphere can be satisfied. . Assuming that the current peaks Ip at times t1 ′ (when the cylindrical insulator is present) and t2 ′ (when there is no cylindrical insulator) when the arc voltage catches up with the power supply voltage are Ip1 ′ and Ip2 ′, respectively, It can be seen that the degree of improvement ΔIp ′ = Ip2′−Ip1 ′ is dramatically larger than the degree of improvement ΔIp of the current peak Ip when the high-speed opening means is not used.
[0050]
After the above-described current peak, the mover 1 further rotates and the distance between the contacts increases. As the distance between the contacts is increased, the arc voltage is further increased, and the fault current rapidly goes to zero. When the fault current is reduced, the arc is drawn into the iron arc extinguishing plates 19 and 19a, and the arc is divided, cooled and extinguished. At this time, the movable contact 2 is outside the cylindrical space, and even if the dielectric strength at the creeping surface of the insulator 8 forming the cylindrical space is reduced, the insulation between the contacts has sufficiently recovered, Even if the power supply voltage is applied between the electrodes, the current does not flow again. Up to this point, the mechanism portion 28 has been operated by a signal from the relay portion 29, the movable contact 2 is held at a position outside the cylindrical space, and the interruption operation is completed. The interruption time is significantly shortened by the high arc voltage due to the long distance between the contacts after the current peak. Therefore, the passing energy I, which is one of the indexes indicating the current limiting performance ² t (time integration of square of current) becomes small.
[0051]
By the way, when generating a high-pressure atmosphere by generating an arc in a cylindrical space, the smaller the cylindrical space, the smaller the distance between the arc and the insulator wall, and the more the amount of insulator vapor generated, the more movable Since the gap between the contact 2 and the insulator 8 is reduced, the vapor is less likely to escape from the cylindrical space, and the volume of the space in which the pressure is increased is reduced, so that the degree of increase in the arc atmosphere pressure is increased. Therefore, the arc voltage rises more rapidly and the current limiting performance is greatly improved.
[0052]
At this time, the force due to the pressure difference acting on the cylindrical portion of the insulator 8 surrounding the cylindrical space is the difference between the pressure in the cylindrical space and the pressure around the cylindrical portion of the insulator 8. This is the direction in which the 8 cylindrical portion expands. This force can be received by the conductor forming the stator on both sides of the slit 21, the arc extinguishing unit housing 23, and the lid 24, and is insulated with a commonly used resin (for example, nylon resin). Even if the object 8 is formed, it is unlikely that the insulator 8 is damaged by pressure.
[0053]
On the other hand, the arc extinguishing unit housing 23 and the lid 24 have a larger inner area than the cylindrical portion of the insulator 8, and the difference between the pressure generated in the cylindrical space and spreading in the inner space of the casing is the force. Since it acts, a very large force is applied as compared with the insulator 8, and the casing may be damaged. In order to prevent this, an expensive mold material reinforced with reinforcing fibers is used for the casing, or the casing is reinforced with metal parts (for example, screws and nuts, rivets, etc.). It is expensive.
[0054]
Further, if the cylindrical space is reduced to substantially the same cylinder cross section as the fixed contact 6, the stator side arc spot is always on the fixed contact 6 during the breaking operation, so that a relatively small current such as a rated energization current is reduced. Contact consumption due to frequent energization switching increases, and even when a short circuit is interrupted, the current density at the arc spot on the fixed contact 6 increases and contact wear increases. Due to the consumption of these fixed contacts, re-energization may occur.
[0055]
Further, since the arc spot is constrained on the fixed contact 6 so that the arc is difficult to touch the arc extinguishing plates 19 and 19a, the breaking current having a relatively small current value such as rated current interruption and overload current interruption is obtained. In the region (the region where the arc diameter is small and the generation of steam from the insulator is small, the current blocking action due to the insulator vapor flow cannot be obtained), the arc division by the arc extinguishing plates 19 and 19a, and the cooling effect cannot be used. There may be a problem that the interruption performance in the current region cannot be secured.
[0056]
Therefore, in the present invention, the size of the cylindrical space is set to include the fixed contact 6 and the upper space of the arc runner 9 so that the stator-side arc spot moves from the fixed contact 6 to the arc runner 9. . Even if a relatively large cylindrical shape is used in this way, if the insulator 8 is formed of a material such as a resin that generates a large amount of steam when it touches the arc, a sufficient pressure increase to increase the arc voltage can be obtained. Can be generated.
[0057]
FIG. 4A is a partial cross-sectional view of the main part showing a state in the vicinity of the mover 1 and the stator 5 immediately after opening, and an arc A generated between the contacts is indicated by a white arrow in the figure. Further, an electromagnetic driving force is received by the current flowing through the second conductor portion 7b and the third conductor portion 7c. Furthermore, since the arc in the vicinity of the fixed contact 6 is surrounded by the first insulator portion 8b except for the arc runner 9 side, the pressure of the arc on the mover rotating shaft 13 side is greater than the pressure on the terminal portion 15a side. The arc becomes larger, and the arc receives a driving force (indicated by a black arrow in FIG. 4A) due to a pressure difference toward the arc runner 9 side. Of these driving forces, the electromagnetic driving force is more effective in the region where the current is small, such as when the rated current is cut off, and the force due to the pressure difference increases as the breaking current increases, such as overload current interruption and short-circuit current interruption. It becomes more effective. In the present invention, since the electromagnetic driving force and the driving force due to the pressure difference simultaneously act on the arc, the stator-side arc spot can be moved to the arc runner 9 immediately after the opening regardless of the current region.
[0058]
The stator-side arc spot that has moved to the arc runner 9 is driven to the tip of the arc runner 9 by a current flowing through the arc runner 9 or the like. While the instantaneous value of the arc current when the short-circuit current is interrupted is large, the arc driven to the terminal portion 15a side is moved toward the mover rotating shaft 13 by the steam flow generated from the wall 8d surface on the terminal portion 15a side of the cylindrical space. Therefore, the stator-side arc spot does not always reach the tip of the arc runner 9 because of the relationship between the electromagnetic driving force and the reverse driving force. However, when the opening operation of the mover 1 proceeds and the accident current is reduced, the amount of heat generated by the arc decreases, and the driving force due to the pressure difference in the reverse direction becomes relatively small. The side arc spot reaches the tip of the arc runner 9. FIG. 5 shows this state. The arc A between the tip of the arcrunner 9 and the mover 1 is divided by a plurality of arc extinguishing plates 19, 19 a provided on the top of the insulator 8, cooled and extinguished.
[0059]
By the way, as described above, when the substantially L-shaped mover 1 is used, the arc spot of the movable contact 2 is difficult to move to the surface facing the arc extinguishing plate at the tip of the mover 1. For this reason, it is difficult for the arc to touch the upper arc extinguishing plate located on the movable element side among the plurality of arc extinguishing plates, and there are cases in which the arc division and cooling effect by the arc extinguishing plate cannot be sufficiently exhibited. Therefore, in the present embodiment, the volume of the uppermost iron arc extinguishing plate 19a is made larger than that of the other arc extinguishing plates 19, and the horseshoe-shaped foot portion (the portion having a slit in the center) is used as the movable contact 2. Extending to the pinching position, the magnetic attracting force by the magnetic material to the arc near the movable contact 2 at the maximum opening position is strengthened, and the movable element side arc spot is surely moved to the tip of the movable element 1 Yes.
[0060]
Moreover, in this Embodiment, the wall height by the side of the terminal part 15a of cylindrical space is made higher than the wall height by the side of the needle | mover rotating shaft 13. FIG. In the arc generated between the contacts during the interruption operation, an electromagnetic driving force is generated on the terminal portion 15a side mainly by the current flowing through the second conductor portion 7b, the third conductor portion 7c, and the movable arm horizontal portion 4. Therefore, the cylinder Empty The arc in the space touches the wall on the terminal portion 15a side strongly. In order to open the mover 1 at high speed, it is advantageous to reduce the moment of inertia of the mover 1, but the movable arm vertical portion 3 determined by the wall height on the mover rotating shaft 13 side of the cylindrical space. As becomes longer, the moment of inertia of the mover increases. Therefore, in the present embodiment, by making the wall height on the terminal portion 15a side higher than the wall height on the mover rotating shaft 13 side, the length of the movable arm vertical portion 3 is shortened to reduce the moment of inertia, And it is set as the structure which generate | occur | produces sufficient insulator vapor | steam and produces sufficient high-pressure atmosphere.
[0061]
In the present embodiment, the exhaust port 26 is provided only on the arc-extinguishing plate 19 side when viewed from between the contacts 2 and 6. With such an arrangement, pressure is accumulated in the space closer to the rotor 22 than the arc in the housing as the arc current increases during the current interruption operation. When the arc current reaches its peak and the arc current value decreases, an air flow is generated between the electrodes from the rotor 22 side to the exhaust port 26 side due to the accumulated pressure, and the arc is stretched to the arc extinguishing plate 19. Furthermore, in the vicinity of the current zero point, the insulation recovery between the contacts is greatly improved by the action of blowing off charged particles between the contacts due to the above flow. Therefore, it is possible to obtain a highly reliable circuit breaker in which breakage failure hardly occurs even when used in a high voltage circuit.
[0062]
The insulation recovery action of the airflow due to the accumulated pressure is greater as the flow velocity of the airflow at the time of current interruption is larger. In order to increase the flow velocity, it is only necessary to increase the accumulated pressure or to reduce the cross section of the flow path. For this purpose, it is necessary to reduce the exhaust port area. In the present embodiment, the exhaust port 26 having a relatively small area is provided on the movable contact 2 side in the opened state. When the current limiting performance is improved by using the cylindrical insulator 8, the movement of the arc in the vicinity of the fixed contact side arc spot is restricted by the cylindrical insulator 8, so that the air flow caused by the accumulated pressure in the rotor side space is used. The metal particles constituting the arc cannot be blown away. On the other hand, the arc in the vicinity of the mover side arc spot is located outside the cylindrical space when the current is interrupted, and is easily affected by the airflow. Therefore, by providing the exhaust port 26 having a relatively small area on the movable contact 2 side in the opened state, it is possible to effectively ensure insulation recovery between the electrodes when the current is interrupted.
[0063]
Further, as described above, in the present embodiment, the arc extinguishing device is housed in the arc extinguishing unit casing 23 and the lid 24, so that the pressure increase in the circuit breaker during the breaking operation is caused by the base 30 and the cover 31. You will not receive it directly. The pressure receiving areas of the arc extinguishing unit housing 23 and the lid 24 are smaller than the pressure receiving areas of the base 30 and the cover 31. Therefore, even if the arc extinguishing unit housing 23 and the lid 24 having the same material and the same thickness as the base 30 and the cover 31 are used, it is possible to withstand a larger increase in internal pressure, and the arc voltage is increased to increase the arc voltage. It is suitable to use the current limiting method. Conventionally, the base 30 and the cover 31 are made of an expensive mold material having high mechanical strength in order to withstand an increase in internal pressure during the shut-off operation. However, by using the arc extinguishing unit housing 23 and the lid 24, The amount of the housing material that receives pressure can be reduced, and the cost can be reduced.
[0064]
Further, as described above, in the present embodiment, the parts constituting the arc extinguishing device are accommodated by the arc extinguishing unit casing main body 23 and the arc extinguishing unit casing lid 24 to constitute the arc extinguishing unit 25 as a whole. . Further, each component such as the mechanism section 28 and the relay section 29 is unitized, and these are combined to configure a circuit breaker for wiring, so that assembly is simplified and cost reduction is possible.
[0065]
Further, in the present embodiment, unlike the conventional example shown in FIG. 21, there is no need to provide an exciting coil for helping to open the mover 1, so that a current limiting device with low impedance and excellent current limiting performance is provided. As a result, it can be applied to a circuit requiring a large current carrying capacity.
[0066]
Further, since the movable element 1 is rotated and opened, the required dimensions in the direction in which the movable contact 2 opens and closes are the conductor thickness of the stator 5, the thickness of the fixed contact 6, the space in which the movable element 1 moves, It becomes the sum of the thickness of the movable contact 2 and the movable arm vertical portion 3, and the required dimension in the above direction can be made smaller than that of the conventional linear motion type current limiting device. Therefore, even when the outer dimensions are limited, it is possible to easily secure the opening distance necessary for effectively connecting the high pressure to the increase of the arc voltage.
[0067]
In FIG. 1, the cylindrical space is divided into a first insulator portion 8 b and a second insulator portion 8 c that are part of the insulator 8 that covers the surface of the stator 5 on the movable contact 2 side. so Although configured, for example, the second insulator portion 8 c is not part of the insulator 8, and is configured by the arc extinguishing unit housing body 23 and the arc extinguishing unit housing 24 disposed in the vicinity of the stator 5. However, the same effect can be obtained.
[0068]
Embodiment 2. FIG.
A second embodiment of the present invention is shown in FIGS. FIG. 10 is a perspective view showing the stator 5 of the present embodiment, and a part of the second conductor portion 7b of the stator of the first embodiment is connected to the horizontal electric circuit 7c ′ and the vertical electric circuit 7b ′. Replaced. FIG. 11 is a partial sectional view showing the movable element 1 in the closed state, the stator 5 and the insulator 8 shown in FIG. 10, and the current direction is indicated by an arrow in the figure. As is apparent from FIG. 10, by using the stator shape of FIG. 10, the electric arm 7c ′ of the movable arm horizontal portion 4 and the stator 5 is greatly brought close, and the electromagnetic opening force at the time of interruption of the accident current is the embodiment. Increase from 1. Thereby, the rise of the arc voltage becomes faster and the current limiting performance is improved.
[0069]
Embodiment 3 FIG.
FIG. 12 is a perspective view showing the stator 5 and the insulator 8 according to Embodiment 3 of the present invention, and is located on the side opposite to the arc runner 9 from the fixed contact 6 of the insulator 8b surrounding the fixed contact 6 from three directions. The part 8e to be performed is black so as to easily absorb light generated by the arc. Part of the energy released to the outside from the arc is released by radiation, and particularly in a large current short gap arc generated when a short circuit is interrupted, the ratio is large. Thus, when the insulator portion 8e on the opposite side of the arc runner 9 of the stator contact 6 is black, the absorption of radiation energy from the arc at the insulator portion 8e is increased, and the amount of steam generated is increased. Accordingly, the movement of the arc spot on the fixed contact side to the arc runner 9 and the traveling to the tip end of the arc runner are accelerated.
[0070]
Further, the portion corresponding to 8e is made of a material that easily generates vapor when it touches the arc from an insulating portion excluding the insulating portion 8e in the vicinity of the fixed contact (for example, a resin material having a relatively low decomposition temperature). Even if configured, there is a pressure difference between the back pressure and the front pressure of the arc traveling to the arc runner side, so that the arc spot on the fixed contact side to the arc runner 9 is the same as when the insulating portion 8e is black. The movement and traveling of the arc to the tip of the arc runner are accelerated. Thereby, the fixed contact wear at the time of arc generation is reduced, and the number of times that the circuit breaker can be repeatedly interrupted can be increased.
[0071]
Embodiment 4 FIG.
FIG. 13A is a perspective view showing a stator 5 and an insulator 8 according to Embodiment 4 of the present invention, and a part is cut away so that the main components can be seen. FIG. 13B is a view showing the vicinity of the third conductor portion 7c and the arc runner 9 to which the fixed contact 6 of FIG. 13A is fixed. In FIG. 13, a portion other than the fixed contact on the surface where the fixed contact 6 of the third conductor portion 7 c is fixed, and a part on the fixed contact 6 side of the surface facing the movable contact 2 (not shown) of the arc runner 9. It is covered with an insulator 14. As shown in FIG. 13B, the exposed portion of the side surface of the movable contact of the arc runner 9 is wider than the width of the fixed contact on the fixed contact 6 side in the left-right direction and wider than the travel path on the tip end side of the arc runner. It is formed in a substantially T shape at the arc holding portion having a width.
[0072]
During a breaking operation with a relatively small current, such as rated current breaking, the diameter of the arc spot generated between the contacts is sufficiently small even at the peak of the current, and it easily travels on the above-mentioned traveling path by the electromagnetic driving force generated by the current flowing through the stator 5. Then, it moves to the tip of the arc runner 9. On the other hand, when a large current is interrupted, such as when a short circuit current is interrupted, the arc spot suddenly increases with the rise of the accident current, so in order to transfer the arc to the tip of the mover on the narrow travel path. It is necessary to run the arc before the accident current increases. Therefore, in this embodiment, the electromagnetic force due to the current flowing through the second conductor portion 7b and the third conductor portion 7c described above and the force due to the pressure difference generated by the part 8b of the cylindrical insulator immediately after opening the electrode. An arc having a relatively small current is driven to shift to the tip end side of the arc runner 9. Due to the subsequent increase in current, the diameter of the stator-side arc spot that has moved to the tip of the arc runner 9 increases, and a part of the arc spot tends to return to the stator 6 side. The increase in the spot diameter is prevented, and the arc remains almost stably at the tip of the arc runner 9.
[0073]
By limiting the arc spot diameter in this way, the arc resistance is increased and the current limiting performance is improved. Further, since the stator side arc spot remains stably at the tip of the arc runner 9 even during a period when the current is relatively large during the breaking operation, the consumption of the fixed contact 6 due to the arc can be reduced. Furthermore, since the arc state as shown in FIG. 5 can be realized not only immediately before the interruption but also in a period in which the current is relatively large during the interruption operation, the arc cooling action of the arc extinguishing plate can be utilized to the maximum.
[0074]
Embodiment 5 FIG.
FIG. 14: is the fragmentary sectional view (a) which shows the principal part of the contact pair vicinity which concerns on Embodiment 5 of this invention, and a perspective view (b) which shows the metal plate used by this embodiment. In the present embodiment, the metal plate 17 is provided on the terminal portion 15a side in the cylindrical space surrounded by the insulator 8 in a direction orthogonal to the arc. In the breaking operation, the moving speed of the arc is faster than the moving speed of the mover 1 having a large moment of inertia, and the time at which the stator side arc spot shifts to the tip of the arc runner 9 than the time at which the mover 1 reaches the maximum separation distance. Is early. Therefore, even if the stator-side arc spot moves to the tip of the arc runner 9, arc cooling and separation of the arc extinguishing plate 19 provided on the top of the insulator 8 are continued until the separation distance of the mover 1 increases. The effect is not used. Therefore, in the present embodiment, by providing the metal plate 17 in the cylindrical space, the arc is cooled and divided by the metal plate 17 without waiting for an increase in the separation distance of the mover 1, thereby increasing the internal pressure of the housing. Is reduced.
[0075]
Embodiment 6 FIG.
FIG. 15 is a perspective view showing the stator 5 and the pair of cores 34 according to Embodiment 6 of the present invention, and the front core is omitted so that the shape of the stator 5 can be seen. FIG. 16 is a diagram in which the insulator 5 and the pair of cores 34 in FIG. 15 are covered with the insulator 8, and a part of the insulator 8 is cut away. The insulator 8 forms a cylindrical space, and when the inside of the cylindrical space is looked over from the opened movable contact 2, the fixed contact 6 and the arc runner 9 are arranged as in the first embodiment. In this embodiment, the core 34 is also insulated.
[0076]
The electric path of the stator 5 is composed of the terminal portion 15a, the electric paths 7f, 7e, 7c ″, 7b ″, and the fixed contact 6 in this order, and is plane-symmetric with respect to the plane including the locus of rotation of the mover 1. . The stator 5 is provided with a slit 33 in order to reduce a magnetic field component that hinders the opening of the mover 1 in which electric currents of the electric paths 7e and 7f are generated. The electric paths 7e and 7f are rotated by the mover 1. It is arranged at a position shifted to the left and right from the plane including the locus to be moved. The fixed contact 6 is fixed to the electric circuit 7c ″ and the electric circuit 7b ″, and is formed by driving up the base of the tongue piece extending toward the terminal portion 15a. The tongue pieces are formed by the electric circuit 7c ″ and the electric circuit 7b ″. The fixed contact 6 is attached to the fixed portion and the arc runner 9.
[0077]
The fixed contact 6 is positioned at a bent portion which is a boundary between the electric path 7b ″ and the fixed contact fixing portion, and is fixed by brazing. A launch portion formed by the electric path 7c ″ and the electric path 7b ″. Is launched so that the distance between the movable arm horizontal portion 4 and the movable arm horizontal portion 4 arranged substantially in parallel with each other in the closed state is closer to the electromagnetic arm. In addition, a current in the contact opening direction (vertical direction) component flows in the electric circuit 7b ″ located in the vicinity of the fixed contact 6. The vertical component of this current is opposite to the arc generated between the contacts. Direction and pushes the arc toward the terminal portion 15a. Therefore, since the arc generated between the contacts quickly moves to the arc runner 9, contact wear is improved.
[0078]
By the way, the pair of cores 34 provided on the upper portion of the electric circuit 7e is made of a magnetic material such as iron, and is disposed so as not to directly touch the arc generated between the contacts by the insulator 8. This core reinforces the magnetic field component that opens the movable element 1 generated by the electric currents of the electric paths 7c ″ and 7b ″, prevents the opening of the movable element 1 generated by the current flowing through the electric path 7e, and prevents the arc from the anti-terminal portion 15a. It serves to shield the magnetic flux that acts to push back to the side. Moreover, the terminal part 15a side edge part of the core 34 is comprised so that it may adjoin to the electric circuit 7f, and the opening of the needle | mover 1 which the electric current of the electric circuit 7f produces in the said edge part is prevented, and an arc is counter terminal part 15a side. The magnetic flux acting to push back is absorbed. In FIG. 15, the core 34 is composed of two substantially L-shaped magnetic plates, but a core in which the two magnetic plates are connected at the top of the L-shape may be used. Good. By integrating the cores in this way, the effect of promoting the opening of the mover 1 by the magnetic core is improved.
[0079]
Embodiment 7 FIG.
FIG. 17 is a perspective view showing the stator 5 and the horseshoe-shaped arc runner 18 according to Embodiment 7 of the present invention. Although not shown, the insulator 8 forming the cylindrical space excludes the vicinity of the fixed contact 6. Covering the surface of the stator 5 on the movable contact side is the same as in the first embodiment. The arrangement of the conductors 7f, 7e, 7c ″, 7b ″ and the fixed contact 6 of the stator 5 is basically the same as that of the sixth embodiment. In the present embodiment, an iron horseshoe-shaped arc runner 18 is arranged so as to surround the fixed contact 6 from the terminal portion 15a side, and the horseshoe-shaped arc runner 18 is electrically connected to the conductor 7e by the legs 18a of the horseshoe-shaped arc runner. .
[0080]
The arc generated between the contacts is pushed out toward the terminal portion 15a side by the current in the contact opening direction (vertical direction) component of the electric circuit 7b ″ positioned in the vicinity of the fixed contact 6 as in the sixth embodiment. However, in this embodiment, in addition to this, a magnetic attraction force is exerted by the horseshoe-shaped arc runner 18. The action of attracting the arc by the magnetic material toward the terminal portion 15a is a relatively small current region in which magnetic saturation of the magnetic material does not occur. Further, the horseshoe-shaped arc runner 18 has an effect of shielding a magnetic field component that returns the arc caused by the currents in the electric paths 7e and 7f to the contact side, so that the transition of the arc to the arc runner 18 is accelerated. Therefore, contact consumption during frequent switching of the rated current can be reduced, and the time when the arc touches the arc-extinguishing plate 19 can be shortened, so that arc cooling of the arc-extinguishing plate can be achieved. It can be effectively utilized the divided action.
[0081]
Embodiment 8 FIG.
Embodiment 8 of the present invention will be described with reference to the drawings. FIG. 18 is a perspective view showing the stator 5, the pair of cores 34, and the iron shielding plate 35 according to the present embodiment. In order to understand the shape of the stator 5, one of the electric paths 7 e provided on the left and right sides of the fixed contact 6 and a part of the shielding plate 35 are cut out. Other components are not shown, but basically have the same configuration as that of the sixth embodiment. The stator shape in FIG. 18 differs from the one shown in FIG. 15 in the arrangement of the electric circuit 7e, and the electric circuit 7e is provided above the electric circuit 7c. The center line of the electric circuit 7e is located above the contact surface of the fixed contact 6.
[0082]
With such a configuration, the electromagnetic arm opening force is strengthened by approaching the movable arm horizontal portion 4 in the closed state of the electric circuit 7c ′, and the arc is driven to the arc runner 9 side by the vertical component of the electric current of the electric circuit 7b ″. The arc cooling and dividing action by the arc extinguishing plate 19 is improved as in the sixth embodiment, but since the electric circuit 7e is located above the fixed contact surface, the electromagnetic driving force due to the electric current of the electric circuit 7e This makes it easier for the arc spot on the fixed contact side to move toward the arc runner 9. Further, by arranging the electric path 7e upward, the opening of the mover 1 is prevented and the arc is pushed back toward the mover rotation center. Since the electric circuit 7f for performing the above is inevitably shortened, it is possible to prevent the arc transferred to the arc runner 9 from returning to the fixed contact 6 side.
[0083]
Incidentally, FIG. 18 shows one of a shielding plate 35 having a partial cross section and a pair of cores 34 provided on the upper portion of the electric circuit 7e. The shielding plate 35 and the core 34 are made of a magnetic material such as iron, and are arranged so as not to directly touch the arc generated between the contacts by the insulator 8. The shielding plate 35 mainly serves to shield the magnetic flux generated by the current flowing through the electric path 7f (which prevents the opening of the mover 1 and pushes the arc back toward the mover rotation center). . On the other hand, the core 34 reinforces the magnetic field component that opens the movable element 1 generated by the currents of the electric paths 7c ′, 7b ″, and 7c, and shields the magnetic flux that prevents the opening of the movable element 1 generated by the current flowing through the electric path 7e. Have a role to play.
[0084]
Embodiment 9 FIG.
Embodiment 9 of the present invention will be described with reference to the drawings. FIG. 19 is a view showing the distal end portion 36 of the mover 1 according to the present embodiment, and FIG. 19 (a) is above the mover distal end portion 36 (the direction in which the movable contact 2 opens from the fixed contact 6). FIG. 19B is a view of the mover tip 36 viewed from the left-right direction (a direction perpendicular to the plane including the trajectory where the mover 1 rotates). In the present embodiment, the portion closer to the tip than the movable contact 2 of the mover 1 is formed in a fan shape, and the width in the left-right direction becomes narrower as it approaches the end surface of the tip.
[0085]
As described above, since the substantially L-shaped mover 1 is used in the present invention, the mover-side arc spot hardly shifts from the movable contact 2 to the surface facing the arc extinguishing plate 19 at the tip of the mover. Among the arc extinguishing plates, the arc extinguishing plate arranged at the top does not touch the arc and does not contribute to arc cooling or division. Therefore, in this embodiment, in order to promote the transition of the arc spot from the movable contact 2 to the tip of the mover, the surface facing the arc extinguishing plate 19 at the tip of the mover is vertically rounded up from the contact surface of the movable contact 2. Rather, the shape of the tip of the mover is substantially fan-shaped so that the portion close to the movable contact 2 is substantially parallel to the contact surface and gradually becomes perpendicular to the contact surface of the movable contact as the tip of the mover is reached.
[0086]
Further, as shown in FIG. 19A, the tip of the mover 36 is sharpened to increase the electric field strength at the tip, and promote the transition from the arc contact point to the tip. By using such a mover tip shape, even in the substantially L-shaped mover 1, the arc spot can be reliably transferred to the mover tip 36, so that the consumption of the movable contact 2 is reduced and the arc is extinguished. The plate 19 can effectively use the arc cooling and the dividing action.
[0087]
Embodiment 10 FIG.
Embodiment 10 of the present invention will be described with reference to the drawings. 20 is a partial cross-sectional view showing the main part in the arc extinguishing unit of the present embodiment, FIG. 20 (a) is a cross-sectional view taken along line C1-C1 of FIG. 20 (b), and FIG. 20 (b). These are sectional drawings which follow the C2-C2 line of Fig.20 (a). The shapes of the stator 5 and the core 34 according to the present embodiment are basically the same as those shown in the sixth embodiment, and an arc generated between the contacts causes an electromagnetic force and an insulator due to a current flowing through the stator 5. It is the same that the arc runner 9 is driven to the tip by the pressure effect of the part 8b.
[0088]
However, in the sixth embodiment, the arc driven to the tip of the arc runner 9 is subjected to an action of being pushed back to the contact side by the steam generated by the insulating portion 8d covering the electric path 7f. Therefore, in the present embodiment, the force of pushing back the arc between the contacts is reduced by converting the insulating portion 8d into a ceramic to reduce the amount of steam generated. Thus, if the force for pushing back the arc between the contacts is small, even if the dimension in the direction in which the arc runner 9 extends in the arc extinguishing space is shortened in order to reduce the size of the circuit breaker, Is not spread, the amount of consumption of the fixed contact 6 due to arc is reduced, and the number of times the circuit breaker can be repeatedly interrupted increases.
[0089]
In the present embodiment, a gap is provided between the pair of cores 34 and the insulating portion 8d, and between the pair of cores 34 and the arc-extinguishing unit housing body 23 and the arc-extinguishing unit housing lid 24, respectively. The flow path 39 is configured by providing the above. As the arc moves toward the tip end side of the arc runner 9 in the flow path 39, the flow indicated by the white arrow in FIG. 20A is generated, and the pressure rise on the front side of the traveling arc is reduced, and the arc traveling It has the effect of speeding up. In addition, since metal vapor or the like that fills the space surrounded by the insulator 8 can be exhausted out of the space, recovery of insulation between the contacts is promoted. Therefore, even in a circuit having a relatively high power supply voltage, an accident current can be reliably interrupted, and a highly reliable circuit breaker can be obtained.
[0090]
【The invention's effect】
As described above, according to the present invention, a single arc-extinguishing device has an excellent current limiting function, and a breaking operation in a wide current range from a small current such as a rated current to a large current such as a short-circuit current. There is an effect that a circuit breaker that can be applied to a circuit that increases the number of possible times, is low-cost, small-sized, and requires a relatively large current-carrying capacity is obtained.
[0091]
In addition, since the insulator arranged on the anti-arc runner side of the fixed contact is more likely to generate steam when it touches the arc than the other two arranged insulators, the consumption of the fixed contact by the arc is reduced. This has the effect of increasing the number of times that the circuit breaker can be repeatedly interrupted.
[0092]
Further, a part of the surface of the arc runner on the movable contact side is covered with an insulator so that the arc runner exposed portion on the surface is substantially T-shaped, and the movable element in the exposed portion in the vicinity of the fixed contact Since the width in the direction perpendicular to the plane including the locus of the fixed contact is narrower than the width of the fixed contact, the width of the exposed portion at the tip of the arc runner is wider than the width in the direction of the portion adjacent to the fixed contact. The current-limiting performance at the time of short-circuit current interruption is further improved, and the amount of consumption due to arcing of the fixed contact at the time of short-circuit current interruption is reduced.
[0093]
In addition, there is an effect that the electromagnetic opening force acting on the mover at the time of short-circuit interruption is enhanced to improve the opening speed and reduce the consumption of the stator contacts.
[0094]
In addition, since the fixed contact is positioned at the arc runner-side bent portion that protrudes toward the movable arm, there is an effect that the fixed contact can be easily positioned without the need for a new process for positioning the fixed contact.
[0095]
In addition, there is an effect that it is possible to reduce the amount of wear due to the arc of the fixed contact at the time of relatively small current and many interruption operations.
[0096]
In addition, since the tip of the movable arm facing the arc-extinguishing plate is substantially fan-shaped when viewed from the direction perpendicular to the plane including the trajectory of the moving element, the consumption of the movable contact is reduced and the arc by the arc-extinguishing plate is used. There is an effect that the cooling and dividing action can be effectively used.
[0097]
Moreover, even when the dimension of the arc runner extending direction of the space where the arc is extinguished is small, it is possible to obtain a circuit breaker that can repeatedly perform a breaking operation by reducing the amount of consumption due to the arc of the fixed contact at the time of breaking the short-circuit current .
[0098]
In addition, a pair of insulating plates parallel to the plane including the opening / closing locus of the mover are arranged on the left and right sides of the contact plate to which the fixed contact is fixed, and the arc runner tip side end of the insulating plate and the arc runner tip are opposed to each other. Since an air gap is provided between the members and a flow path communicating with the air gap is provided on the back surface of the insulating plate as viewed from the fixed contact, the accident current can be reliably interrupted even in a circuit having a relatively high power supply voltage. There is an effect that a highly reliable circuit breaker can be obtained.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional perspective view showing an internal structure of an arc extinguishing unit in an open state according to Embodiment 1 of the present invention.
FIG. 2 is a perspective view showing the internal structure of the arc extinguishing unit in the open state according to the first embodiment.
FIG. 3 is a perspective view showing a configuration of a circuit breaker according to the first embodiment.
4 is a partial cross-sectional view (a) of a main part for explaining the operation of the first embodiment, and main part cross-sectional views (b), (c), and (d) for explaining the operation. FIG.
FIG. 5 is a partial cross-sectional view of the main part for explaining the operation of the first embodiment.
FIG. 6 is a block diagram showing an experimental apparatus for measuring basic characteristics of arc voltage.
FIG. 7 is a graph showing the influence of the atmospheric pressure on the arc voltage.
FIG. 8 is a graph showing the influence of the current value on the rate of increase in arc voltage.
FIG. 9 is a graph illustrating the effect of the first embodiment.
FIG. 10 is a perspective view showing a stator shape according to Embodiment 2 of the present invention.
FIG. 11 is a partial cross-sectional view of the main part for explaining the operation of the second embodiment.
FIG. 12 is a perspective view showing shapes of a stator and an insulator according to Embodiment 3 of the present invention.
FIG. 13 is a partial cross-sectional perspective view (a) showing the main part of the stator according to Embodiment 4 of the present invention, and a partial cross-sectional view (b) showing the vicinity of the fixed contact plate of Embodiment 4.
FIG. 14 is a partial cross-sectional view (a) showing main parts of a mover and a stator according to Embodiment 5 of the present invention, and a perspective view (b) of a metal plate.
FIG. 15 is a perspective view showing a stator side electric circuit and a core according to Embodiment 6 of the present invention;
FIG. 16 is a partial cross-sectional perspective view showing a stator side electric circuit and an insulator according to the sixth embodiment.
FIG. 17 is a perspective view showing a stator and an arc runner according to Embodiment 7 of the present invention.
FIG. 18 is a partial cross-sectional perspective view showing a configuration of a main part near a stator according to Embodiment 8 of the present invention.
FIG. 19 is a top view (a) showing the tip of the mover according to the ninth embodiment of the present invention, and a front view (b) showing the tip of the mover according to the ninth embodiment.
20 is a cross-sectional view (a) taken along line C1-C1 in FIG. 20 (b) and showing a main part of a circuit breaker according to Embodiment 10 of the present invention, and C2-C2 line in FIG. 20 (a). It is sectional drawing (b) which follows this.
FIG. 21 is a partial cross-sectional front view showing a conventional circuit breaker with a current limiting function.
22 is a right side view of FIG. 21. FIG.
[Explanation of symbols]
A arc, 1 mover,
2 movable contact, 3 movable arm vertical part,
4 horizontal part of movable arm, 5 stator,
6 fixed contact, 7a 1st conductor part,
7b 2nd conductor part, 7c 3rd conductor part,
7b ', 7b ", 7c', 7c", 7e, 7f Electric circuit,
8 Insulator, 8a Insulation cover,
8b first insulator part, 8c second insulator part,
8d part of the second insulator part, 8e part of the first insulator part,
9 Arcrunner, 10 Sliding contact,
11 spring, 12 spring hook,
13 mover rotation shaft, 14 insulator,
15a, 15b, 16 terminal part, 17 metal plate,
18 Horseshoe Arcrunner, 18a Part of Horseshoe Arcrunner,
19, 19a arc extinguishing plate, 20 arc extinguishing side plate,
21 slits, 22 rotors,
23 arc extinguishing unit housing body, 24 arc extinguishing unit housing lid,
25 arc extinguishing unit, 26 exhaust port,
27 Crossbar, 28 Mechanical part,
29 relay section, 30 base,
31 cover, 32 handle,
33 slits, 34 cores,
35 shielding plate, 36 mover tip,
37 ceramics, 38 insulators,
39 channels, 400 electrodes,
401 airtight container, 402 AC power supply,
403 input switch, 404 pressure cylinder.

Claims

A movable element having a horizontal part of the arm and a movable contact and rotating around a rotation axis of the movable element, a fixed contact forming a contact pair with the movable contact, and being substantially parallel to a part of the arm of the movable element in a closed state. A stator having an electric path through which current flows in the opposite direction and having one end pulled out to a terminal portion on the side farther from the movable element rotation shaft, and an anti-mover rotation shaft from the vicinity of the fixed contact that is electrically connected to the stator Arc runner extending in the direction, urging means for generating contact pressure on the contact pair, an arc extinguishing plate disposed on the anti-movement rotor shaft side of the movable contact, and opening the upper side of the fixed contact to surround the periphery in a cylindrical shape And an insulator housing for housing each of the constituent members, and the contact surface of the movable contact is located in a cylindrical space surrounded by the insulator in the closed state of the contact pair. The above mover is allowed End having contacts is configured to be located outside the cylindrical space in which the insulator surrounds and the wall surface of the counter-arc runner side of the fixed contacts of the insulating material is positioned adjacent to said stationary contact, said arm The movable element is configured in a substantially L shape by fixing the other end of the arm vertical part with the movable contact fixed to one end to the end of the horizontal part opposite to the rotary axis of the movable element. Circuit breaker.

The stator is composed of a conductor bent in a substantially U shape and having one end connected to the terminal portion on the anti-mover rotating shaft side and a fixed contact provided inside the other end of the U shape, In addition, a part of the stator electric circuit provided with the fixed contact, in which a current in a direction opposite to the arm horizontal part of the mover flows, is bent so as to be close to the arm horizontal part of the closed mover, 2. The circuit breaker according to claim 1, wherein the stator electric circuit facing the fixed contact is provided with a slit that allows opening and closing of the mover at a portion intersecting with the rotation locus of the mover.

A material that is likely to generate steam when it touches the arc from the insulator part arranged in the other three sides , where the insulator part placed directly in contact with the arc between the contacts immediately after the occurrence on the anti-arc runner side of the fixed contact circuit breaker according to claim 1, characterized in that the.

Circuit breaker according to claim 1, wherein an insulator portion disposed to the movable member rotary shaft side of the fixed contact, characterized in that the black.

The stator has a fixed contact at one end, an electric circuit through which current flows in the opposite direction to the arm horizontal part of the mover, and a symmetrical electric circuit that is connected to the other end of the electric circuit and passes through both sides of the electric circuit to reach the terminal part And a bifurcated vertical electric circuit having a slit on the surface including the mover rotation trajectory plane, and the electric circuit provided with the fixed contact from the symmetrical electric circuit. 2. The circuit breaker according to claim 1, wherein a portion bent so as to protrude toward the arm horizontal portion of the mover is provided.

6. The circuit breaker according to claim 5 , wherein the fixed contact is positioned by a bent portion protruding toward the arm side of the mover and fixed to the electric circuit.

The stator has a fixed contact at one end, an electric circuit through which a current component in the opposite direction flows opposite to the movable arm horizontal part in the closed state, and a terminal part connected to the other end of the electric circuit and passing through both sides of the electric circuit and path symmetrical leading to, and coupling the electrical path and the terminal section consists of a vertical path, divided into 2 or having a slit on the surface including the movable member rotation trajectory plane, the fixed path with the fixed contact characterized in that the site contacts are secured by bending a portion of the path which is fixed to the fixed contacts so that is positioned below the path of the symmetric (direction away from the arm horizontal portion of the movable element) downward The circuit breaker according to claim 1.

The ceramic plate was placed so that it was almost perpendicular to the line extending the arcrunner to the anti-movement rotor axis , and the arc was not touched by the insulator located on the back of the ceramic plate when viewed from the tip of the arc runner. The circuit breaker according to claim 1, wherein:

A pair of insulating plates parallel to the plane including the open / close locus of the mover are arranged on both sides of the stator electrical circuit provided with the fixed contacts, and the arc runner tip side end of the insulating plate and the arc runner tip are opposed to each other 2. A circuit breaker according to claim 1, wherein a gap is provided between the insulating plate and a flow path communicating with the gap is provided on a back surface of the insulating plate as viewed from a fixed contact.