JP2005038675A

JP2005038675A - Current breaking unit

Info

Publication number: JP2005038675A
Application number: JP2003199193A
Authority: JP
Inventors: Shingi Hagyuda; 進義萩生田; Teruyoshi Chin; 照祥陳
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 2003-07-18
Filing date: 2003-07-18
Publication date: 2005-02-10

Abstract

<P>PROBLEM TO BE SOLVED: To provide a current breaking unit which can be easily mounted on a printed board. <P>SOLUTION: The current breaking unit has a conductive spring part as a part of an electric circuit mounted on the printed board, a conductive first mounting part connected to one end side of the spring part, a conductive second mounting part connected to the other end side of the spring part, a supporting part connected to the opposite side of the spring part of the second mounting part, and a cut-off part formed at a second mounting part side of the supporting part. The first mounting part and the supporting part are inserted into a through-hole and a supporting hole of the printed board respectively. The second mounting part contacts with a wiring pattern in a state of restraining spring force of the spring part for making the second mounting part separate from the wiring pattern connected to heat radiating parts of the printed board. The cut-off part is cut off in order to cut off the supporting part from the second mounting part after soldering the first and second mounting parts. By the above, the current breaking unit can be easily mounted on the printed board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、プリント基板における発熱部品の過熱を防止するための電流遮断具に関する。
【０００２】
【従来の技術】
例えば、周知のモータ駆動回路では、モータがロックしてしまった場合にモータへの通電が継続されると、モータの回転および停止を制御する駆動部品が徐々に発熱し、最悪の場合、モータ駆動回路全体が故障してしまう恐れがある。このため、通常、電気回路が実装されたプリント基板には、前述の駆動部品等の発熱部品が異常に発熱したときに、発熱部品を流れる電流を遮断する電流遮断具が設けられている。
【０００３】
電流遮断具は、例えば、導電性を有する半円弧状の板ばね部材で構成され、板ばね部材の両端を配線パターンにそれぞれ半田付けすることでプリント基板に取り付けられる（例えば、特許文献１参照）。この電流遮断具は、以下のような手順でプリント基板に取り付けられる。
まず、板ばね部材の一端から延在する段差部をプリント基板の通孔に挿入する。板ばね部材の一端は、段差部が通孔に挿入されると、配線パターンに接触する。次に、板ばね部材を外力により押し下げて、板ばね部材の他端を別の配線パターンに接触させる。そして、板ばね部材を外力により押し下げた状態（板ばね部材の他端を配線パターンに接触させた状態）で、板ばね部材の他端を配線パターンに半田付けする。この後、必要であれば、板ばね部材の一端を配線パターンに半田付けする。
【０００４】
このようにしてプリント基板に取り付けられた電流遮断具では、発熱部品の異常な発熱に伴って板ばね部材の他端の半田が溶融すると、板ばね部材の他端は、板ばね部材の復元力により配線パターンから離脱する。これにより、発熱部品を流れる電流は遮断され、発熱部品の過熱が防止される。
【特許文献１】
特開平８−２９８０５８号公報
【０００５】
【発明が解決しようとする課題】
前述の電流遮断具では、板ばね部材を外力により押し下げながら、板ばね部材の他端を配線パターンに半田付けしなけれならない。このため、半田付け作業時に、ばね部のばね力を規制するための治工具が必要となる。また、半田付けのための熱が治工具を介して逃げてしまうため、電流遮断具をプリント基板に短時間で取り付ることができない。従って、プリント基板の組立コストが増大してしまう。
【０００６】
本発明の目的は、プリント基板に容易に取り付けできる電流遮断具を提供することにある。本発明の別の目的は、プリント基板の組立コストを低減することにある。
【０００７】
【課題を解決するための手段】
前述の課題を解決するために、本発明は、以下のように構成される。
【０００８】
請求項１の電流遮断具は、プリント基板に実装される電気回路の一部を構成する導電性のばね部と、前記ばね部の一端側に接続され、前記プリント基板の貫通穴に挿入された状態で半田付けされる導電性の第１取付部と、前記ばね部の他端側に接続され、前記プリント基板の発熱部品に接続される配線パターンに半田付けされる導電性の第２取付部と、前記第２取付部の前記ばね部とは反対側に接続され、前記第２取付部を前記配線パターンから離脱させるために作用する前記ばね部のばね力を規制した状態で前記第２取付部を前記配線パターンに接触させるために、前記プリント基板の支持穴に挿入される支持部と、前記支持部の前記第２取付部側に形成され、前記第２取付部の前記配線パターンへの半田付け後に、前記支持部を前記第２取付部から切り離すための切断部とを備えていることを特徴とする。
【０００９】
請求項２の電流遮断具は、請求項１記載の電流遮断具において、前記ばね部、前記第１取付部、前記第２取付部および前記支持部は、線材を折曲加工して一体形成されていることを特徴とする。
請求項３の電流遮断具は、請求項１記載の電流遮断具において、前記ばね部は、コイル状に形成され、軸方向が前記プリント基板に沿った状態で配置され、前記第１および第２取付部は、前記ばね部の前記軸方向の両端に配置されていることを特徴とする。
【００１０】
請求項４の電流遮断具は、請求項３記載の電流遮断具において、前記プリント基板上に配置され、前記ばね部を収納する絶縁性の収納部材を備え、前記第１および第２取付部は、前記ばね部を伸張した状態でそれぞれ前記プリント基板に半田付けされ、前記第２取付部は、前記発熱部品の発熱に伴う半田の溶融により前記配線パターンから離脱したときに、前記ばね部の復元力により、前記収納部材内に前記ばね部と共に収納されることを特徴とする。
【００１１】
請求項５の電流遮断具は、請求項１記載の電流遮断具において、前記第２取付部の前記配線パターンへの半田付けに用いられる半田の融点は、前記発熱部品の前記配線パターンへの半田付けに用いられる半田の融点より低いことを特徴とする。
【００１２】
請求項６の電流遮断具は、請求項１記載の電流遮断具において、前記ばね部は、絶縁材料で被覆されていることを特徴とする。
【００１３】
【発明の実施の形態】
以下、図面を用いて本発明の実施形態を説明する。
【００１４】
図１は、本発明の電流遮断具の第１の実施形態を示している。
電流遮断具１００は、プリント基板ＰＣＢに実装される電気回路の一部を構成するばね部１０と、ばね部１０の一端に形成された第１取付部１２と、ばね部１０の他端に形成された第２取付部１４と、第２取付部１４から延在するコ字状の支持部１６と、支持部１２の第２取付部１４側に形成された切断部１８とを有している。ばね部１０、第１取付部１２、第２取付部１４および支持部１６は、りん青銅等の導電性の線材を折曲加工して一体形成されている。
【００１５】
ばね部１０は、ループ状の本体部１０ａと、本体部１０ａの一端から第１取付部１２まで延在する第１脚部１０ｂと、本体部１０ａの他端から第２取付部１４まで延在する第２脚部１０ｃを有している。ばね部１０は、本体部１０ａのループ面、第１脚部１０ｂおよび第２脚部１０ｃがプリント基板ＰＣＢに沿った状態で、プリント基板ＰＣＢ上に配置される。このため、プリント基板ＰＣＢ上にスペースを確保できない製品（筐体）に適用すると効果的である。
【００１６】
第１取付部１２は、ばね部１０の第１脚部１０ｂの先端側を、プリント基板ＰＣＢに向かって折り曲げて形成されている。第１取付部１２は、自身を配線パターンＷ１に半田付けするために、プリント基板ＰＣＢの貫通穴Ｈ１に挿入される。貫通穴Ｈ１は、例えば、プリント基板ＰＣＢ上に形成された銅箔の配線パターンＷ１内に貫通するスルーホールである。なお、貫通穴Ｈ１は、スルーホールには限定されない。例えば、貫通穴Ｈ１内には、導電体を形成しなくてもよい。また、貫通穴Ｈ１の周囲に形成されるランドは、プリント基板ＰＣＢの表面のみに形成されてもよい。第２取付部１４は、ばね部１０の第２脚部１０ｃの先端側に形成されている。支持部１６は、第２取付部１４のばね部１０の反対側を、プリント基板ＰＣＢとは反対側に折り曲げ、さらに、コ字状に折り曲げて形成されている。
【００１７】
第２取付部１４は、第１取付部１２および支持部１６がそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入されたときに、ばね部１０の外側へ広がろうとするばね力を発生させた状態で配線パターンＷ２に接触する位置に形成されている。図中の破線は、第１取付部１２および支持部１６をそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入するために、本体部１０ａを弾性変形させて第２脚部１０ｃを第１脚部１０ｂに近づけた状態を示している。なお、プリント基板ＰＣＢの発熱部品ＦＰは、プリント基板ＰＣＢ上に形成された銅箔の配線パターンＷ２に半田Ｓ３により半田付けされている。
【００１８】
電流遮断具１００は、例えば、以下のような手順でプリント基板ＰＣＢに取り付けられる。図２〜図４は、第１の実施形態における電流遮断具１００のプリント基板ＰＣＢへの取付方法を示している。図２および図３は、半田付け作業前の電流遮断具１００を示している。図４は、半田付け作業後の電流遮断具１００を示している。
【００１９】
まず、図２および図３に示すように、ばね部１０のばね力を外力により規制した状態、すなわち、ばね部１０の第１脚部１０ｂおよび第２脚部１０ｃを外力により互いに近づけた状態で、第１取付部１２および第２取付部１４をそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入する。なお、第１取付部１２および支持部１６の貫通穴Ｈ１および支持穴Ｈ２への挿入は、作業者がばね部１０の第１脚部１０ｂおよび第２脚部１０ｃを直接つまんで実施してもよいし、簡易な治工具を用いて実施してもよい。これにより、第２取付部１４は、貫通穴Ｈ１および支持穴Ｈ２がばね部１０のばね力を受けた状態で、配線パターンＷ２に接触する。
【００２０】
次に、図４に示すように、第１取付部１２を半田Ｓ１により配線パターンＷ１に半田付けし、第２取付部１４を半田Ｓ２により配線パターンＷ２に半田付けする。なお、半田Ｓ１〜Ｓ３の融点は同一である。この際、電流遮断具１００は、第１取付部１２および支持部１６がそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入された状態でプリント基板ＰＣＢに支持されているため、第１取付部１２および第２取付部１４を半田付けするためにばね部１０のばね力を外力により規制する必要はない。このため、第１取付部１２および第２取付部１４の半田付け作業は容易になる。具体的には、第１取付部１２および第２取付部１４の半田付け作業を、特別な治工具を用いることなく実施できる。
【００２１】
この後、工具等を用いて切断部１８を切断し、支持部１６を第２取付部１４から切り離すとともに、支持穴Ｈ２から取り外す。これにより、電流遮断具１００のプリント基板ＰＣＢへの取付作業は完了する。
図５は、第１の実施形態における電流遮断具１００の電流遮断動作を示している。
【００２２】
前述のようにしてプリント基板ＰＣＢに取り付けられた電流遮断具１００では、発熱部品ＦＰが異常に発熱し、発熱部品ＦＰの熱が配線パターンＷ２を介して半田Ｓ１に伝達されることで半田Ｓ２が溶融すると、第２取付部１４は、ばね部１０の復元力により、プリント基板ＰＣＢに沿って配線パターンＷ２から離れた位置に移動する。これにより、配線パターンＷ１、Ｗ２は非導通状態となり、発熱部品ＦＰを流れる電流は遮断され、発熱部品ＦＰの発熱は停止する。
【００２３】
電流遮断具１００は、例えば、図６に示すような周知のモータ駆動回路に適用される。発熱部品ＦＰは、モータＭの回転および停止を制御するパワートランジスタである。電流遮断具１００は、モータＭと発熱部品ＦＰ（パワートランジスタ）との間に接続される。
以上、第１の実施形態では、次の効果が得られる。
【００２４】
第１取付部１２および第２取付部１４を半田付けするときに、ばね部１０のばね力を外力により規制しなくてもよいため、第１取付部１２および第２取付部１４を容易に半田付けできる。具体的には、半田付け作業時に、ばね部１０のばね力を規制するための治工具は不要になる。すなわち、半田付けのための熱が治工具を介して逃げることはない。このため、電流遮断具１００をプリント基板ＰＣＢに短時間で取り付けることができる。半田付け時間を短縮でき、かつ治工具を不要にできるため、プリント基板ＰＣＢの組立コストを削減できる。
【００２５】
ばね部１０、第１取付部１２、第２取付部１４および支持部１６は、線材を折曲加工して一体形成されているため、電流遮断具１００を簡易に形成でき、部品コストを低減できる。
ばね部１０のばね力は、切断部１８が切断されるまで、第２取付部１４の半田Ｓ２には作用しない。このため、第２取付部１４の半田付けとその他の半田付けとの実施順序に対する制限を無くすことができる。これに対して、従来の電流遮断具では、ばね部１０のばね力が第２取付部１４の半田Ｓ２に常に作用するため、第２取付部１４の半田付けを最後に実施する必要があった。従って、電流遮断具１００では、プリント基板ＰＣＢの組立工程の自由度を向上できる。
【００２６】
図７は、本発明の電流遮断具の第２の実施形態を示している。第１の実施形態で説明した要素と同一の要素については、同一の符号を付し、詳細な説明は省略する。
電流遮断具２００は、プリント基板ＰＣＢａに実装される電気回路の一部を構成するばね部２０と、ばね部２０の一端側に形成された第１取付部２２と、ばね部２０の他端側に形成された第２取付部２４と、第２取付部２４から延在するコ字状の支持部２６と、支持部２６の第２取付部２４側に形成された切断部２８とを有している。ばね部２０、第１取付部２２、第２取付部２４および支持部２６は、りん青銅等の導電性の線材を折曲加工して一体形成されている。なお、プリント基板ＰＣＢａは、配線パターンＷ１、Ｗ２、貫通穴Ｈ１および支持穴Ｈ２の形状および位置が異なることを除いて、第１の実施形態のプリント基板ＰＣＢと同一である。
【００２７】
ばね部２０は、ループ状の本体部２０ａと、本体部２０ａの一端から延在する第１脚部２０ｂと、本体部２０ａの他端から延在する第２脚部２０ｃと、第１脚部２０ｂの先端側を円弧状に折り曲げて形成された規制部２０ｄとを有している。ばね部２０は、規制部２０ｄを除いて、絶縁材料２０ｅで被覆されている。ばね部２０は、本体部２０ａのループ面、第１脚部２０ｂおよび第２脚部２０ｃがプリント基板ＰＣＢａに直立した状態で、プリント基板ＰＣＢａ上に配置される。このため、プリント基板ＰＣＢａ上にスペースを十分に確保できる製品（筐体）に適用すると効果的である。
【００２８】
第１取付部２２は、ばね部２０の規制部２０ｄの先端から延在し、自身を配線パターンＷ１に半田付けするために、プリント基板ＰＣＢａの貫通穴Ｈ１に挿入される。ばね部２０に規制部２０ｄが形成されているため、第１取付部２２は、規制部２０が配線パターンＷ１に当接するまで貫通穴Ｈ１に挿入される。第２取付部２４は、ばね部２０の第２脚部２０ｃの先端側を、プリント基板ＰＣＢａに沿って折り曲げて形成されている。支持部２６は、第２取付部２４のばね部２０の反対側を、プリント基板ＰＣＢａとは反対側に折り曲げ、さらに、コ字状に折り曲げて形成されている。
【００２９】
第２取付部２４は、第１取付部２２および支持部２６がそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入されたときに、ばね部２０の外側へ広がろうとするばね力（第２取付部２４を図の上側に持ち上げようとする力）を発生させた状態で配線パターンＷ２に接触する位置に形成されている。
電流遮断具２００は、例えば、以下のような手順でプリント基板ＰＣＢａに取り付けられる。
【００３０】
まず、ばね部２０のばね力を外力により規制した状態、すなわち、ばね部２０の第１脚部２０ｂおよび第２脚部２０ｃを外力により互いに近づけた状態で、第１取付部２２および第２取付部２４をそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入する。なお、第１取付部２２および支持部２６の貫通穴Ｈ１および支持穴Ｈ２への挿入は、作業者がばね部２０の第１脚部２０ｂおよび第２脚部２０ｃを直接つまんで実施してもよいし、簡易な治工具を用いて実施してもよい。これにより、第２取付部２４は、貫通穴Ｈ１および支持穴Ｈ２がばね部２０のばね力を受けた状態で、配線パターンＷ２に接触する。
【００３１】
次に、第１取付部２２を半田Ｓ１により配線パターンＷ１に半田付けし、第２取付部１４を半田Ｓ２ａにより配線パターンＷ２に半田付けする。なお、半田Ｓ２ａの融点は、半田Ｓ１の融点（第１の実施形態の半田Ｓ２、Ｓ３の融点と等しい）より低い。この際、電流遮断具２００は、第１取付部２２および支持部２６がそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入された状態でプリント基板ＰＣＢａに支持されているため、第１取付部２２および第２取付部２４を半田付けするためにばね部２０のばね力を外力により規制する必要はない。このため、第１の実施形態と同様に、第１取付部２２および第２取付部２４の半田付け作業は容易になる。
【００３２】
この後、工具等を用いて切断部２８を切断し、支持部２６を第２取付部２４から切り離すとともに、支持部２６を支持穴Ｈ２から取り外す。これにより、電流遮断具２００のプリント基板ＰＣＢａへの取付作業は完了する。
図８は、第２の実施形態における電流遮断具２００の電流遮断動作を示している。
【００３３】
前述のようにしてプリント基板ＰＣＢａに取り付けられた電流遮断具２００では、プリント基板ＰＣＢａに搭載された発熱部品ＦＰが異常に発熱し、発熱部品ＦＰの熱が配線パターンＷ２を介して半田Ｓ２ａに伝達されることで半田Ｓ２ａが溶融すると、第２取付部２４は、ばね部２０の復元力により、プリント基板ＰＣＢａ上方の配線パターンＷ２から離れた位置に移動する。これにより、配線パターンＷ１、Ｗ２は非導通状態となり、発熱部品ＦＰを流れる電流は遮断され、発熱部品ＦＰの発熱は停止する。
【００３４】
半田Ｓ２ａの融点は、発熱部品ＦＰの半田Ｓ３の融点より低いため、半田Ｓ２ａは、半田Ｓ３より先に溶融する。このため、発熱部品ＦＰが半田Ｓ３の溶融に伴って移動することはない。
【００３５】
また、ばね部２０は、絶縁材料２０ｅで被覆されているため、第２取付部２４が配線パターンＷ２から離脱したときに、ばね部２０がその他の実装部品または配線パターンに電気的に接触することはない。
電流遮断具２００は、例えば、図９に示すような周知のＤＣ−ＤＣコンバータ回路に適用される。発熱部品ＦＰは、ＤＣ−ＤＣコンバータのスイッチングトランジスタである。電流遮断具２００は、トランスＴの一次側と発熱部品ＦＰ（スイッチングトランジスタ）との間に接続される。
【００３６】
以上、第２の実施形態でも、第１の実施形態と同様の効果が得られる。さらに、ばね部２０は絶縁材料２０ｅで被覆されているため、第２取付部２４が配線パターンＷ２から離脱したときに、ばね部２０がその他の実装部品に接触するなどして電気回路がショートすることを防止できる。
ばね部２０は、本体部２０ａのループ面、第１脚部２０ｂおよび第２脚部２０ｃがプリント基板ＰＣＢａに直立した状態で、プリント基板ＰＣＢａ上に配置されるため、電流遮断具２００の実装面積を低減できる。このため、プリント基板ＰＣＢａの部品実装密度および配線自由度を向上できる。
【００３７】
第２取付部２４の半田Ｓ２ａは、発熱部品ＦＰの半田Ｓ３より先に溶融するため、発熱部品ＦＰが半田Ｓ３の溶融により移動することを防止できる。この結果、発熱部品ＦＰがその他の実装部品に接触するなどして電気回路がショートすることを防止できる。
図１０は、本発明の電流遮断具の第３の実施形態を示している。第１および第２の実施形態で説明した要素と同一の要素については、同一の符号を付し、詳細な説明は省略する。
【００３８】
電流遮断具３００は、プリント基板ＰＣＢｂに実装される電気回路の一部を構成するばね部３０と、ばね部３０の一端側に形成された第１取付部３２と、ばね部２０の他端側に形成された第２取付部３４と、第２取付部３４から延在するコ字状の支持部３６と、支持部２６の第２取付部２４側に形成された切断部３８と、ばね部３０を収納する絶縁チューブ４０（収納部材）とを有している。ばね部３０、第１取付部３２、第２取付部３４および支持部３６は、りん青銅等の導電性の線材を折曲加工して一体形成されている。なお、プリント基板ＰＣＢｂは、配線パターンＷ１、Ｗ２、貫通穴Ｈ１および支持穴Ｈ２の形状および位置が異なることを除いて、第１の実施形態のプリント基板ＰＣＢと同一である。
【００３９】
ばね部３０は、絶縁チューブ４０に収納されたコイル状の本体部３０ａと、本体部３０ａの一端から延在する第１脚部３０ｂと、本体部３０ａの他端から延在する第２脚部３０ｃとを有している。ばね部３０は、本体部３０ａ（および絶縁チューブ４０）の軸方向がプリント基板ＰＣＢｂに沿った状態で、プリント基板ＰＣＢｂ上に配置される。
【００４０】
第１取付部３２は、ばね部３０の第１脚部３０ｂの先端側に形成され、自身を配線パターンＷ１に半田付けするために、プリント基板ＰＣＢｂの貫通穴Ｈ１に挿入される。第２取付部３４は、ばね部３０の第２脚部３０ｃの先端側をプリント基板ＰＣＢｂに沿って折り曲げて形成されている。支持部３６は、第２取付部３４のばね部３０の反対側を、プリント基板ＰＣＢｂとは反対側に折り曲げ、さらに、コ字状に折り曲げて形成されている。
【００４１】
第２取付部３４は、第１取付部３２および支持部３６がそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入されたときに、ばね部３０の縮まろうとするばね力を発生させた状態（ばね部３０を伸張した状態）で配線パターンＷ２に接触する位置に形成されている。
電流遮断具３００は、例えば、以下のような手順でプリント基板ＰＣＢａに取り付けられる。
【００４２】
まず、ばね部３０のばね力を外力により規制した状態、すなわち、ばね部３０を外力により伸張した状態で、第１取付部３２および第２取付部３４をそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入する。なお、第１取付部３２および支持部３６の貫通穴Ｈ１および支持穴Ｈ２への挿入は、作業者がばね部３０の第１脚部３０ｂおよび第２脚部３０ｃを直接つまんで実施してもよいし、簡易な治工具を用いて実施してもよい。これにより、第２取付部３４は、貫通穴Ｈ１および支持穴Ｈ２がばね部３０のばね力を受けた状態で、配線パターンＷ２に接触する。
【００４３】
次に、第１取付部３２を半田Ｓ１により配線パターンＷ１に半田付けし、第２取付部３４を半田Ｓ２により配線パターンＷ２に半田付けする。この際、電流遮断具３００は、第１取付部３２および支持部３６がそれぞれ貫通穴Ｈ１および支持穴Ｈ２に挿入された状態でプリント基板ＰＣＢｂに支持されているため、第１取付部３２および第２取付部３４を半田付けするためにばね部３０を外力により伸張させる必要はない。このため、第１の実施形態と同様に、第１取付部３２および第２取付部３４の半田付け作業は容易になる。
【００４４】
この後、工具等を用いて切断部３８を切断し、支持部３６を第２取付部３４から切り離すとともに、支持部３６を支持穴Ｈ２から取り外す。これにより、電流遮断具３００のプリント基板ＰＣＢａへの取付作業は完了する。
図１１は、第２の実施形態における電流遮断具３００の電流遮断動作を示している。
【００４５】
前述のようにしてプリント基板ＰＣＢａに取り付けられた電流遮断具３００では、プリント基板ＰＣＢｂに搭載された発熱部品ＦＰが異常に発熱し、発熱部品ＦＰの熱が配線パターンＷ２を介して半田Ｓ２に伝達されることで半田Ｓ２が溶融すると、第２取付部３４は、ばね部３０の復元力により配線パターンＷ２から離れた位置（絶縁チューブ４０内）に移動する。これにより、配線パターンＷ１、Ｗ２は非導通状態となり、発熱部品ＦＰを流れる電流は遮断され、発熱部品ＦＰの発熱は停止する。
【００４６】
また、第２取付部３４は、配線パターンＷ２から離脱したときに、絶縁チューブ４０内にばね部３０とともに収納されるため、振動等に伴ってばね部３０が伸縮するなどしても、第２取付部３４がその他の実装部品または配線パターンに接触することはない。
【００４７】
電流遮断具３００は、例えば、第２の実施形態の電流遮断具２００と同様に、図９に示すような周知のＤＣ−ＤＣコンバータ回路に適用される。
以上、第３の実施形態でも、第１の実施形態と同様の効果が得られる。さらに、ばね部３０の本体部３０ａはコイル状に形成されているため、ばね部３０のばね力を長期間持続させることができる。
【００４８】
第２取付部３４は、配線パターンＷ２から離脱したときに、絶縁チューブ４０内にばね部３０とともに収納される。このため、第２取付部３４がその他の実装部品に接触するなどして電気回路がショートすることを防止できる。
以上、本発明を詳細に説明してきたが、前述の実施形態およびその変形例は発明の一例に過ぎず、本発明はこれに限定されるものではない。本発明を逸脱しない範囲で変形可能であることは明らかである。
【００４９】
【発明の効果】
本発明の電流遮断具では、第１および第２取付部の半田付けの際に、ばね部のばね力を外力により規制しなくてもよいため、第１および第２取付部を容易に半田付けできる。このため、電流遮断具をプリント基板に容易に取り付けることができ、プリント基板の組立コストを削減できる。
【図面の簡単な説明】
【図１】本発明の電流遮断具の第１の実施形態を示す斜視図である。
【図２】第１の実施形態における半田付け作業前の電流遮断具を示す斜視図である。
【図３】第１の実施形態における半田付け作業前の電流遮断具を示す断面図である。
【図４】第１の実施形態における半田付け作業後の電流遮断具を示す斜視図である。
【図５】第１の実施形態における電流遮断具の電流遮断動作を示す説明図である。
【図６】第１の実施形態の電流遮断具が適用されるモータ駆動回路を示す回路図である。
【図７】本発明の電流遮断具の第２の実施形態を示す断面図である。
【図８】第２の実施形態における電流遮断具の電流遮断動作を示す説明図である。
【図９】第２の実施形態の電流遮断具が適用されるＤＣ−ＤＣコンバータ回路を示す回路図である。
【図１０】本発明の電流遮断具の第３の実施形態を示す断面図である。
【図１１】第３の実施形態における電流遮断具の電流遮断動作を示す説明図である。
【符号の説明】
１００、２００、３００電流遮断具
１０、２０、３０ばね部
１０ａ、２０ａ、３０ａ本体部
１０ｂ、２０ｂ、３０ｂ第１脚部
１０ｃ、２０ｃ、３０ｃ第２脚部
１２、２２、３２第１取付部
１４、２４、３４第２取付部
１６、２６、３６支持部
１８、２８、３８切断部
２０ｄ規制部
２０ｅ絶縁材料
４０絶縁チューブ（収納部材）
ＦＰ発熱部品
ＰＣＢ、ＰＣＢａ、ＰＣＢｂプリント基板
Ｓ１、Ｓ２、Ｓ２ａ、Ｓ３半田
Ｈ１貫通穴
Ｈ２支持穴
Ｗ１、Ｗ２配線パターン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a current interrupter for preventing overheating of heat generating components on a printed circuit board.
[0002]
[Prior art]
For example, in a known motor drive circuit, when the motor is locked and the power supply to the motor is continued, the drive parts that control the rotation and stop of the motor gradually generate heat, and in the worst case, the motor drive The entire circuit may break down. For this reason, normally, a printed circuit board on which an electric circuit is mounted is provided with a current interrupter that interrupts a current flowing through the heat-generating component when the heat-generating component such as the drive component described above abnormally generates heat.
[0003]
The current breaker is made of, for example, a semicircular plate spring member having conductivity, and is attached to a printed circuit board by soldering both ends of the plate spring member to a wiring pattern (see, for example, Patent Document 1). . This current interrupter is attached to the printed circuit board in the following procedure.
First, the stepped portion extending from one end of the leaf spring member is inserted into the through hole of the printed board. One end of the leaf spring member comes into contact with the wiring pattern when the step portion is inserted into the through hole. Next, the leaf spring member is pushed down by an external force, and the other end of the leaf spring member is brought into contact with another wiring pattern. Then, the other end of the leaf spring member is soldered to the wiring pattern in a state where the leaf spring member is pushed down by an external force (the other end of the leaf spring member is in contact with the wiring pattern). Thereafter, if necessary, one end of the leaf spring member is soldered to the wiring pattern.
[0004]
In the current breaker attached to the printed circuit board in this manner, when the solder at the other end of the leaf spring member melts due to abnormal heat generation of the heat generating component, the other end of the leaf spring member is restored to the restoring force of the leaf spring member. To leave the wiring pattern. Thereby, the electric current which flows through a heat-emitting component is interrupted | blocked and overheating of a heat-generating component is prevented.
[Patent Document 1]
JP-A-8-298058
[0005]
[Problems to be solved by the invention]
In the above-described current breaker, the other end of the leaf spring member must be soldered to the wiring pattern while pushing down the leaf spring member with an external force. For this reason, a jig for regulating the spring force of the spring portion is required during the soldering operation. Moreover, since the heat for soldering escapes through the jig, the current breaker cannot be attached to the printed circuit board in a short time. Therefore, the assembly cost of the printed circuit board increases.
[0006]
An object of the present invention is to provide a current interrupter that can be easily attached to a printed circuit board. Another object of the present invention is to reduce the assembly cost of a printed circuit board.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention is configured as follows.
[0008]
The current interrupter according to claim 1 is connected to one end side of the spring part and a conductive spring part constituting a part of an electric circuit mounted on the printed board, and is inserted into a through hole of the printed board. Conductive first mounting portion soldered in a state, and conductive second mounting portion connected to the other end side of the spring portion and soldered to a wiring pattern connected to the heat generating component of the printed circuit board And the second mounting portion in a state in which the spring force of the spring portion, which is connected to the opposite side of the second mounting portion from the wiring pattern and acts to detach the second mounting portion from the wiring pattern, is regulated. In order to bring the portion into contact with the wiring pattern, a support portion that is inserted into a support hole of the printed circuit board and a second attachment portion side of the support portion are formed, and the second attachment portion is connected to the wiring pattern. After the soldering, the support part is Characterized in that it includes a cutting portion for separating from the urging unit.
[0009]
The current breaker according to claim 2 is the current breaker according to claim 1, wherein the spring portion, the first attachment portion, the second attachment portion, and the support portion are integrally formed by bending a wire. It is characterized by.
The current breaker according to claim 3 is the current breaker according to claim 1, wherein the spring portion is formed in a coil shape, and is arranged in a state in which an axial direction is along the printed circuit board. The attachment parts are arranged at both ends of the spring part in the axial direction.
[0010]
The current breaker according to claim 4 is the current breaker according to claim 3, further comprising an insulating housing member disposed on the printed circuit board for housing the spring portion, wherein the first and second mounting portions are The spring part is soldered to the printed circuit board in an extended state, and the second attachment part is restored when the spring part is detached from the wiring pattern due to melting of the solder accompanying the heat generation of the heat-generating component. It is housed together with the spring part in the housing member by force.
[0011]
The current breaker according to claim 5 is the current breaker according to claim 1, wherein the melting point of the solder used for soldering the second mounting portion to the wiring pattern is the solder to the wiring pattern of the heat-generating component. It is characterized by being lower than the melting point of the solder used for attachment.
[0012]
The current breaker according to claim 6 is the current breaker according to claim 1, wherein the spring portion is covered with an insulating material.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 shows a first embodiment of the current interrupter of the present invention.
The current breaker 100 is formed at the other end of the spring part 10, the spring part 10 constituting a part of the electric circuit mounted on the printed circuit board PCB, the first attachment part 12 formed at one end of the spring part 10. The second mounting portion 14, a U-shaped support portion 16 extending from the second mounting portion 14, and a cutting portion 18 formed on the second mounting portion 14 side of the support portion 12. . The spring portion 10, the first attachment portion 12, the second attachment portion 14, and the support portion 16 are integrally formed by bending a conductive wire such as phosphor bronze.
[0015]
The spring portion 10 includes a loop-shaped main body portion 10a, a first leg portion 10b extending from one end of the main body portion 10a to the first attachment portion 12, and an extension from the other end of the main body portion 10a to the second attachment portion 14. The second leg portion 10c is provided. The spring part 10 is arranged on the printed circuit board PCB in a state where the loop surface of the main body part 10a, the first leg part 10b, and the second leg part 10c are along the printed circuit board PCB. For this reason, it is effective when applied to a product (housing) in which a space cannot be secured on the printed circuit board PCB.
[0016]
The first attachment portion 12 is formed by bending the distal end side of the first leg portion 10b of the spring portion 10 toward the printed circuit board PCB. The first attachment portion 12 is inserted into the through hole H1 of the printed circuit board PCB in order to solder itself to the wiring pattern W1. The through hole H1 is, for example, a through hole that penetrates into a copper foil wiring pattern W1 formed on the printed circuit board PCB. The through hole H1 is not limited to the through hole. For example, a conductor need not be formed in the through hole H1. Moreover, the land formed around the through hole H1 may be formed only on the surface of the printed circuit board PCB. The second attachment portion 14 is formed on the distal end side of the second leg portion 10 c of the spring portion 10. The support portion 16 is formed by bending the opposite side of the spring portion 10 of the second attachment portion 14 to the opposite side of the printed circuit board PCB, and further bending it in a U shape.
[0017]
The second mounting portion 14 is in a state in which a spring force is generated to spread outside the spring portion 10 when the first mounting portion 12 and the support portion 16 are inserted into the through hole H1 and the support hole H2, respectively. It is formed at a position in contact with the wiring pattern W2. The broken lines in the figure indicate that the main body portion 10a is elastically deformed and the second leg portion 10c is changed to the first leg portion 10b in order to insert the first attachment portion 12 and the support portion 16 into the through hole H1 and the support hole H2, respectively. The close state is shown. The heat generating component FP of the printed circuit board PCB is soldered to the copper foil wiring pattern W2 formed on the printed circuit board PCB by the solder S3.
[0018]
The current interrupter 100 is attached to the printed circuit board PCB by the following procedure, for example. 2 to 4 show a method of attaching the current interrupter 100 to the printed circuit board PCB in the first embodiment. 2 and 3 show the current interrupter 100 before the soldering operation. FIG. 4 shows the current interrupter 100 after the soldering operation.
[0019]
First, as shown in FIGS. 2 and 3, the spring force of the spring portion 10 is regulated by an external force, that is, the first leg portion 10b and the second leg portion 10c of the spring portion 10 are brought closer to each other by an external force. The first attachment portion 12 and the second attachment portion 14 are inserted into the through hole H1 and the support hole H2, respectively. The first mounting portion 12 and the support portion 16 may be inserted into the through hole H1 and the support hole H2 even if an operator directly pinches the first leg portion 10b and the second leg portion 10c of the spring portion 10. It may be carried out using a simple jig or tool. Thereby, the 2nd attachment part 14 contacts the wiring pattern W2 in the state in which the through-hole H1 and the support hole H2 received the spring force of the spring part 10. FIG.
[0020]
Next, as shown in FIG. 4, the first mounting portion 12 is soldered to the wiring pattern W1 with solder S1, and the second mounting portion 14 is soldered to the wiring pattern W2 with solder S2. The melting points of the solders S1 to S3 are the same. At this time, the current breaker 100 is supported by the printed circuit board PCB with the first attachment portion 12 and the support portion 16 inserted into the through hole H1 and the support hole H2, respectively. 2 It is not necessary to restrict the spring force of the spring portion 10 by an external force in order to solder the attachment portion 14. For this reason, the soldering work of the 1st attachment part 12 and the 2nd attachment part 14 becomes easy. Specifically, the soldering operation of the first attachment portion 12 and the second attachment portion 14 can be performed without using a special jig.
[0021]
Thereafter, the cutting portion 18 is cut using a tool or the like, and the support portion 16 is separated from the second mounting portion 14 and removed from the support hole H2. Thereby, the mounting operation of the current interrupter 100 to the printed circuit board PCB is completed.
FIG. 5 shows a current interrupting operation of the current interrupter 100 according to the first embodiment.
[0022]
In the current breaker 100 attached to the printed circuit board PCB as described above, the heat generating component FP generates heat abnormally, and the heat of the heat generating component FP is transmitted to the solder S1 via the wiring pattern W2, whereby the solder S2 is generated. When melted, the second mounting portion 14 moves to a position away from the wiring pattern W2 along the printed circuit board PCB by the restoring force of the spring portion 10. As a result, the wiring patterns W1 and W2 are turned off, the current flowing through the heat generating component FP is interrupted, and the heat generation of the heat generating component FP is stopped.
[0023]
The current interrupter 100 is applied to, for example, a known motor drive circuit as shown in FIG. The heat generating component FP is a power transistor that controls rotation and stop of the motor M. The current interrupter 100 is connected between the motor M and the heat generating component FP (power transistor).
As described above, in the first embodiment, the following effects can be obtained.
[0024]
When the first mounting portion 12 and the second mounting portion 14 are soldered, the spring force of the spring portion 10 does not have to be regulated by an external force, so that the first mounting portion 12 and the second mounting portion 14 can be easily soldered. Can be attached. Specifically, a jig for restricting the spring force of the spring portion 10 is not required during the soldering operation. That is, the heat for soldering does not escape through the jig. For this reason, the current interrupter 100 can be attached to the printed circuit board PCB in a short time. Since the soldering time can be shortened and a jig or tool can be dispensed with, the assembly cost of the printed circuit board PCB can be reduced.
[0025]
Since the spring part 10, the first attachment part 12, the second attachment part 14, and the support part 16 are integrally formed by bending a wire, the current interrupter 100 can be easily formed, and the component cost can be reduced. .
The spring force of the spring part 10 does not act on the solder S2 of the second attachment part 14 until the cutting part 18 is cut. For this reason, the restriction | limiting with respect to the execution order of soldering of the 2nd attachment part 14 and other soldering can be eliminated. On the other hand, in the conventional current breaker, since the spring force of the spring portion 10 always acts on the solder S2 of the second mounting portion 14, the second mounting portion 14 needs to be soldered last. . Therefore, in the current interrupter 100, the degree of freedom in the assembly process of the printed circuit board PCB can be improved.
[0026]
FIG. 7 shows a second embodiment of the current interrupter of the present invention. The same elements as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The current breaker 200 includes a spring part 20 constituting a part of an electric circuit mounted on the printed circuit board PCBa, a first attachment part 22 formed on one end side of the spring part 20, and the other end side of the spring part 20 A second mounting portion 24 formed on the second mounting portion 24, a U-shaped support portion 26 extending from the second mounting portion 24, and a cutting portion 28 formed on the second mounting portion 24 side of the support portion 26. ing. The spring portion 20, the first attachment portion 22, the second attachment portion 24, and the support portion 26 are integrally formed by bending a conductive wire such as phosphor bronze. The printed circuit board PCBa is the same as the printed circuit board PCB of the first embodiment except that the wiring patterns W1, W2, the through holes H1, and the support holes H2 are different in shape and position.
[0027]
The spring portion 20 includes a loop-shaped main body portion 20a, a first leg portion 20b extending from one end of the main body portion 20a, a second leg portion 20c extending from the other end of the main body portion 20a, and a first leg portion. And a restricting portion 20d formed by bending the tip end side of 20b into an arc shape. The spring part 20 is covered with an insulating material 20e except for the restricting part 20d. The spring part 20 is disposed on the printed circuit board PCBa with the loop surface of the main body part 20a, the first leg part 20b and the second leg part 20c standing upright on the printed circuit board PCBa. For this reason, it is effective when applied to a product (housing) that can secure a sufficient space on the printed circuit board PCBa.
[0028]
The first attachment portion 22 extends from the tip of the restricting portion 20d of the spring portion 20, and is inserted into the through hole H1 of the printed circuit board PCBa in order to solder itself to the wiring pattern W1. Since the restricting portion 20d is formed in the spring portion 20, the first attachment portion 22 is inserted into the through hole H1 until the restricting portion 20 contacts the wiring pattern W1. The second attachment portion 24 is formed by bending the distal end side of the second leg portion 20c of the spring portion 20 along the printed circuit board PCBa. The support portion 26 is formed by bending the opposite side of the spring portion 20 of the second attachment portion 24 to the opposite side of the printed circuit board PCBa and further bending it in a U shape.
[0029]
The second mounting portion 24 has a spring force (second mounting portion 24) that tends to spread outside the spring portion 20 when the first mounting portion 22 and the support portion 26 are inserted into the through hole H1 and the support hole H2, respectively. Is formed at a position in contact with the wiring pattern W2 in a state where a force to lift the upper side of the figure is generated.
The current interrupter 200 is attached to the printed circuit board PCBa by the following procedure, for example.
[0030]
First, in a state where the spring force of the spring portion 20 is regulated by an external force, that is, in a state where the first leg portion 20b and the second leg portion 20c of the spring portion 20 are brought closer to each other by an external force, the first attachment portion 22 and the second attachment portion. The parts 24 are inserted into the through holes H1 and the support holes H2, respectively. The first mounting portion 22 and the support portion 26 may be inserted into the through hole H1 and the support hole H2 even if the operator directly pinches the first leg portion 20b and the second leg portion 20c of the spring portion 20. It may be carried out using a simple jig or tool. Thereby, the 2nd attachment part 24 contacts the wiring pattern W2 in the state in which the through-hole H1 and the support hole H2 received the spring force of the spring part 20. FIG.
[0031]
Next, the first mounting portion 22 is soldered to the wiring pattern W1 with the solder S1, and the second mounting portion 14 is soldered to the wiring pattern W2 with the solder S2a. The melting point of the solder S2a is lower than the melting point of the solder S1 (equal to the melting points of the solders S2 and S3 of the first embodiment). At this time, the current breaker 200 is supported by the printed circuit board PCBa with the first attachment portion 22 and the support portion 26 inserted into the through hole H1 and the support hole H2, respectively. 2 In order to solder the mounting portion 24, it is not necessary to restrict the spring force of the spring portion 20 with an external force. For this reason, as in the first embodiment, the soldering work of the first mounting portion 22 and the second mounting portion 24 is facilitated.
[0032]
Thereafter, the cutting portion 28 is cut using a tool or the like, the support portion 26 is separated from the second attachment portion 24, and the support portion 26 is removed from the support hole H2. Thereby, the mounting operation of the current breaker 200 to the printed circuit board PCBa is completed.
FIG. 8 shows a current interrupting operation of the current interrupter 200 in the second embodiment.
[0033]
In the current interrupter 200 attached to the printed circuit board PCBa as described above, the heat generating component FP mounted on the printed circuit board PCBa abnormally generates heat, and the heat of the heat generating component FP is transmitted to the solder S2a through the wiring pattern W2. Thus, when the solder S2a is melted, the second mounting portion 24 is moved to a position away from the wiring pattern W2 above the printed circuit board PCBa by the restoring force of the spring portion 20. As a result, the wiring patterns W1 and W2 are turned off, the current flowing through the heat generating component FP is interrupted, and the heat generation of the heat generating component FP is stopped.
[0034]
Since the melting point of the solder S2a is lower than the melting point of the solder S3 of the heat generating component FP, the solder S2a is melted before the solder S3. For this reason, the heat generating component FP does not move as the solder S3 melts.
[0035]
Further, since the spring portion 20 is covered with the insulating material 20e, when the second mounting portion 24 is detached from the wiring pattern W2, the spring portion 20 is in electrical contact with other mounted components or wiring patterns. There is no.
The current breaker 200 is applied to, for example, a well-known DC-DC converter circuit as shown in FIG. The heat generating component FP is a switching transistor of a DC-DC converter. The current breaker 200 is connected between the primary side of the transformer T and the heat generating component FP (switching transistor).
[0036]
As described above, also in the second embodiment, the same effect as in the first embodiment can be obtained. Further, since the spring portion 20 is covered with the insulating material 20e, when the second mounting portion 24 is detached from the wiring pattern W2, the electric circuit is short-circuited by the spring portion 20 coming into contact with other mounted components. Can be prevented.
Since the spring part 20 is arranged on the printed circuit board PCBa in a state where the loop surface of the main body part 20a, the first leg part 20b and the second leg part 20c stand upright on the printed circuit board PCBa, the mounting area of the current interrupter 200 Can be reduced. For this reason, the component mounting density and wiring flexibility of the printed circuit board PCBa can be improved.
[0037]
Since the solder S2a of the second mounting portion 24 is melted before the solder S3 of the heat generating component FP, the heat generating component FP can be prevented from moving due to melting of the solder S3. As a result, it is possible to prevent the electric circuit from short-circuiting due to the heat-generating component FP contacting other mounting components.
FIG. 10 shows a third embodiment of the current interrupter of the present invention. The same elements as those described in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.
[0038]
The current breaker 300 includes a spring portion 30 that forms part of an electric circuit mounted on the printed circuit board PCBb, a first attachment portion 32 formed on one end side of the spring portion 30, and the other end side of the spring portion 20. A second mounting portion 34 formed on the second mounting portion 34, a U-shaped support portion 36 extending from the second mounting portion 34, a cutting portion 38 formed on the second mounting portion 24 side of the support portion 26, and a spring portion. And an insulating tube 40 (housing member) for housing 30. The spring portion 30, the first attachment portion 32, the second attachment portion 34, and the support portion 36 are integrally formed by bending a conductive wire such as phosphor bronze. The printed circuit board PCBb is the same as the printed circuit board PCB of the first embodiment except that the wiring patterns W1, W2, the through holes H1, and the support holes H2 are different in shape and position.
[0039]
The spring 30 includes a coil-shaped main body 30a housed in the insulating tube 40, a first leg 30b extending from one end of the main body 30a, and a second leg extending from the other end of the main body 30a. 30c. The spring part 30 is disposed on the printed circuit board PCBb in a state where the axial direction of the main body part 30a (and the insulating tube 40) is along the printed circuit board PCBb.
[0040]
The first attachment portion 32 is formed on the distal end side of the first leg portion 30b of the spring portion 30, and is inserted into the through hole H1 of the printed circuit board PCBb in order to solder itself to the wiring pattern W1. The second attachment portion 34 is formed by bending the distal end side of the second leg portion 30c of the spring portion 30 along the printed circuit board PCBb. The support portion 36 is formed by bending the opposite side of the spring portion 30 of the second attachment portion 34 to the opposite side of the printed circuit board PCBb and further bending it in a U shape.
[0041]
The second mounting portion 34 is in a state in which a spring force that causes the spring portion 30 to contract is generated when the first mounting portion 32 and the support portion 36 are inserted into the through hole H1 and the support hole H2, respectively (the spring portion 30). Is formed at a position in contact with the wiring pattern W2.
The current interrupter 300 is attached to the printed circuit board PCBa by the following procedure, for example.
[0042]
First, the first attachment portion 32 and the second attachment portion 34 are inserted into the through hole H1 and the support hole H2, respectively, in a state where the spring force of the spring portion 30 is regulated by an external force, that is, in a state where the spring portion 30 is extended by an external force. To do. The first mounting portion 32 and the support portion 36 may be inserted into the through hole H1 and the support hole H2 even if the operator directly pinches the first leg portion 30b and the second leg portion 30c of the spring portion 30. It may be carried out using a simple jig or tool. Thereby, the 2nd attachment part 34 contacts the wiring pattern W2 in the state in which the through-hole H1 and the support hole H2 received the spring force of the spring part 30. FIG.
[0043]
Next, the first mounting portion 32 is soldered to the wiring pattern W1 with the solder S1, and the second mounting portion 34 is soldered to the wiring pattern W2 with the solder S2. At this time, the current breaker 300 is supported by the printed circuit board PCBb with the first attachment portion 32 and the support portion 36 inserted into the through hole H1 and the support hole H2, respectively. 2 It is not necessary to extend the spring portion 30 by an external force in order to solder the attachment portion 34. For this reason, as in the first embodiment, the soldering work of the first mounting portion 32 and the second mounting portion 34 is facilitated.
[0044]
Thereafter, the cutting portion 38 is cut using a tool or the like, the support portion 36 is separated from the second attachment portion 34, and the support portion 36 is removed from the support hole H2. Thereby, the mounting operation of the current breaker 300 to the printed circuit board PCBa is completed.
FIG. 11 shows a current interrupting operation of the current interrupter 300 in the second embodiment.
[0045]
In the current breaker 300 attached to the printed circuit board PCBa as described above, the heat generating component FP mounted on the printed circuit board PCBb abnormally generates heat, and the heat of the heat generating component FP is transmitted to the solder S2 via the wiring pattern W2. Thus, when the solder S2 is melted, the second mounting portion 34 moves to a position (inside the insulating tube 40) away from the wiring pattern W2 by the restoring force of the spring portion 30. As a result, the wiring patterns W1 and W2 are turned off, the current flowing through the heat generating component FP is interrupted, and the heat generation of the heat generating component FP is stopped.
[0046]
Further, since the second mounting portion 34 is housed in the insulating tube 40 together with the spring portion 30 when it is detached from the wiring pattern W2, even if the spring portion 30 expands or contracts due to vibration or the like, the second mounting portion 34 is The attachment portion 34 does not come into contact with other mounting parts or wiring patterns.
[0047]
The current breaker 300 is applied to a known DC-DC converter circuit as shown in FIG. 9, for example, similarly to the current breaker 200 of the second embodiment.
As described above, also in the third embodiment, the same effect as in the first embodiment can be obtained. Furthermore, since the main body portion 30a of the spring portion 30 is formed in a coil shape, the spring force of the spring portion 30 can be maintained for a long period of time.
[0048]
The second attachment portion 34 is housed together with the spring portion 30 in the insulating tube 40 when detached from the wiring pattern W2. For this reason, it is possible to prevent the electric circuit from being short-circuited by the second mounting portion 34 coming into contact with other mounting components.
As mentioned above, although this invention was demonstrated in detail, above-mentioned embodiment and its modification are only examples of this invention, and this invention is not limited to this. Obviously, modifications can be made without departing from the scope of the present invention.
[0049]
【The invention's effect】
In the current interrupter according to the present invention, when the first and second mounting portions are soldered, the spring force of the spring portion does not have to be regulated by an external force, and therefore the first and second mounting portions can be easily soldered. it can. For this reason, the current breaker can be easily attached to the printed circuit board, and the assembly cost of the printed circuit board can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of a current interrupter of the present invention.
FIG. 2 is a perspective view showing a current interrupter before soldering work in the first embodiment.
FIG. 3 is a cross-sectional view showing a current interrupter before soldering work in the first embodiment.
FIG. 4 is a perspective view showing a current interrupter after soldering work in the first embodiment.
FIG. 5 is an explanatory diagram showing a current interrupting operation of the current interrupter in the first embodiment.
FIG. 6 is a circuit diagram showing a motor drive circuit to which the current interrupter of the first embodiment is applied.
FIG. 7 is a cross-sectional view showing a second embodiment of the current interrupter of the present invention.
FIG. 8 is an explanatory diagram showing a current interrupting operation of the current interrupter in the second embodiment.
FIG. 9 is a circuit diagram showing a DC-DC converter circuit to which the current interrupter of the second embodiment is applied.
FIG. 10 is a cross-sectional view showing a third embodiment of the current interrupter of the present invention.
FIG. 11 is an explanatory diagram showing a current interrupting operation of a current interrupter in the third embodiment.
[Explanation of symbols]
100, 200, 300 Current interrupter
10, 20, 30 Spring part
10a, 20a, 30a body
10b, 20b, 30b 1st leg
10c, 20c, 30c Second leg
12, 22, 32 First mounting portion
14, 24, 34 Second mounting portion
16, 26, 36 support
18, 28, 38 Cutting part
20d Regulatory Department
20e Insulating material
40 Insulating tube (storage member)
FP exothermic parts
PCB, PCBa, PCBb Printed circuit board
S1, S2, S2a, S3 Solder
H1 through hole
H2 support hole
W1, W2 wiring pattern

Claims

A conductive spring part constituting a part of an electric circuit mounted on a printed circuit board;
A conductive first attachment portion connected to one end of the spring portion and soldered in a state of being inserted into a through hole of the printed circuit board;
A conductive second mounting portion connected to the other end of the spring portion and soldered to a wiring pattern connected to the heat generating component of the printed circuit board;
The second mounting portion is connected to the side opposite to the spring portion of the second mounting portion, and the second mounting portion is controlled in a state in which the spring force of the spring portion acting to separate the second mounting portion from the wiring pattern is restricted. In order to make contact with the wiring pattern, a support part inserted into a support hole of the printed circuit board,
A cutting portion that is formed on the second mounting portion side of the support portion, and that separates the support portion from the second mounting portion after the second mounting portion is soldered to the wiring pattern. A current breaker characterized by.

The current interrupter according to claim 1,
The current interrupter, wherein the spring portion, the first attachment portion, the second attachment portion, and the support portion are integrally formed by bending a wire.

The current interrupter according to claim 1,
The spring portion is formed in a coil shape, and the axial direction is arranged along the printed board,
The current interrupter, wherein the first and second attachment portions are disposed at both ends of the spring portion in the axial direction.

The current interrupter according to claim 3,
An insulating storage member disposed on the printed circuit board for storing the spring portion;
The first and second mounting portions are each soldered to the printed circuit board with the spring portion extended,
The second mounting portion is housed together with the spring portion in the housing member by a restoring force of the spring portion when the second mounting portion is separated from the wiring pattern due to melting of solder accompanying heat generation of the heat-generating component. And current interrupter.

The current interrupter according to claim 1,
The current breaker characterized in that the melting point of solder used for soldering the second mounting portion to the wiring pattern is lower than the melting point of solder used for soldering the heat-generating component to the wiring pattern.

The current interrupter according to claim 1,
The current interrupter is characterized in that the spring part is covered with an insulating material.