JP2004266217A

JP2004266217A - Direct current reactor

Info

Publication number: JP2004266217A
Application number: JP2003057349A
Authority: JP
Inventors: Tomonori Mizutani; 友徳水谷
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2003-03-04
Filing date: 2003-03-04
Publication date: 2004-09-24

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a direct current reactor having a structure in which it is easy to assemble permanent magnets, further the whole fixing can be made including the permanent magnets without varying the performance or dimensions, and further it is easy to fix to an external unit. <P>SOLUTION: A "square frame"-shaped core 3 is constituted of an upper side 3a, both-side legs 3b, 3b and a lower side 3c, and a recess 3d is provided at the center of the lower side 3c so that, when an I core 1 with a wound a coil 2 is inserted thereinto, the coil 2 of the I core 1 keeps a predetermined magnetic air gap 4 relative to an unwound side. Further, a groove 3e is provided at the center of the recess 3d so as to fix a biasing permanent magnet 5 with a magnet width Lm1. An upper surface of the I core 1 comes into contact with an abutment surface 6 of the upper side 3a of the "square frame"-shaped core 3, and further the permanent magnet 5 is provided so as to directly come into contact with a lower surface of the I core 1 and the groove 3e of the "square frame"-shaped core 3, respectively. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
この発明は、電源の電流波形を改善するためスイッチング電源やインバータに用いる、磁気バイアスを有する直流リアクトルに関する。
【０００２】
【従来の技術】
永久磁石を用いて磁気バイアスを与える直流リアクトルとして、特許文献１（特公昭４６−３７１２８号公報）に開示されたものがある。
特許文献１では、Ｅ形コアの中央脚にコイルを巻回し、中央脚の高さを側面脚より低くし、Ｅ形コアの側面脚をＩ形コアによりブリッジし、Ｅ形コアの中央脚とＩ形コア間の空隙に磁気バイアスを与える永久磁石を挟んだものである。
【０００３】
また、永久磁石が減磁せず、かつ磁束がコア内で飽和し難い直流リアクトルを提供することを目的としたものとして、特許文献２（特開平８−３１６０４９号公報）に開示されたものがある。
特許文献２では、軟磁性体からなるＥ形コアと軟磁性体からなるＩ形コアを合わせ面で組み合わせてＥＩ形コア構体を構成するもので、所定のインダクタンスが得られるよう、Ｅ形コアの中央脚を側面脚より短くし、磁気的空隙を作る。また、中央脚の磁気的空隙部の両側面には、所定のバイアス磁束を発生する幅の２枚の矩形の永久磁石を接する辺同士が異極となる極異性に着磁し、Ｉ形コアと平行させ、同極が中央脚を挟んで同極性同士が対向するように配置する。
【０００４】
また、Ｅ形コアをＣ形コアに、Ｉ形コアをＴ形コアに変えてＣＴ形コア構体を構成する。Ｔ形コアの脚部には、コイルを巻回してある。Ｔ形コアの脚とＣ形コアの中央部の間に磁気的空隙を形成してある。磁気的空隙の両側面には、バイアス磁束を発生する一対の永久磁石を対向するもの同士が同極性になるように設けてある。このように構成することにより、巻線がしやすくなる。
【０００５】
【発明が解決しようとする課題】
特許文献１では、空隙に磁石を挿入するため、コイルの作る磁束により減磁を受けない磁石材料にする必要があり、また直流リアクトルのインダクタンスは空隙長さが小さいほど大となるが、空隙長さを小さくすると必然的に磁石が薄くなり、加工し難くなるとともに減磁しやすくなる。したがって、わずかでも大電流を流す可能性があれば磁石を厚くすることが不可欠となりこのため空隙長さが長くなるので、コアの断面積も大きくする必要が生じて結果としてリアクトルが大きくなってしまうという問題点があった。
【０００６】
また、特許文献２では、巻線の作る磁束は永久磁石内を流れないので、永久磁石が減磁することがなく、かつ磁束がコア内で飽和し難い直流リアクトルを得られるが、バイアス用の一対の永久磁石を使用する構成であり、直流リアクトルの製造における２個の永久磁石の組立が困難であるという問題点があった。
【０００７】
また、従来の直流リアクトルは上述のように、Ｅ形コアとＩ形コアとを組み合わせてＥＩ形コア構体を、またはＣ形コアとＴ形コアとを組み合わせてＣＴ形コア構体を構成する構造のため、永久磁石をも含め一体となるように固定するには、大きな留め具が必要となり、リアクトルの形状が大きくなるという問題点があった。
【０００８】
この発明は上述のような課題を解決するためになされたもので、第１の目的は直流リアクトルの製造において、直流リアクトルを構成する永久磁石の組立が容易な構造の直流リアクトルを得るものである。
【０００９】
また、第２の目的は、リアクトルの性能や大きさを変えることなく、永久磁石をも含め一体に固定することができ、また外部機器等への固定が容易な構造の直流リアクトルを得るものである。
【００１０】
【課題を解決するための手段】
この発明の直流リアクトルは、巻線を巻回するＩ形状の第１のコアと、この第１のコアと組み合わせて閉磁路を形成する□形状の第２のコアと、巻線の作る磁束と対向するように着磁したバイアス用の永久磁石と、を有する直流リアクトルにおいて、
第２のコアの□形状の下辺部中央に、第１のコアの前記巻線を巻回しない側面側および永久磁石の側面側との間に所定の磁気的空隙を形成するための凹部を設け、第１のコアの上面部を第２のコアの□形状の上辺部中央の下面部と接触させ、また第１のコアの下面部を永久磁石の上面部と接触させ、さらに永久磁石の下面部を第２のコアの□形状の下辺部中央の凹部に接触させることにより、巻線の作る磁束の経路を第１のコアの巻線を巻回しない側面側と第２のコアの□形状の下辺部中央に設けた凹部の間に形成した磁気的空隙を通る経路とし、永久磁石の作る磁束の経路を第２のコアの□形状の下辺部中央に設けた凹部の溝を経由し、磁気的空隙を通らない経路としたものである。
【００１１】
また、第１のコアの巻線を巻回しない側面部の寸法を、巻線を巻回する側面部の寸法よりも大きくしたものである。
【００１２】
さらに、第２のコアの□形状の下辺部中央に設けた凹部の中央に、永久磁石を挿入するための溝を設けたものである。
【００１３】
さらにまた、第１のコアの上面部と第２のコアの□形状の上辺部中央の下面部とを、凹凸形状とし、はめ合わせるようにしたものである。
【００１４】
また、第２のコアの□形状の下辺部にこのコアを固定するための貫通穴を設けたものである。
【００１５】
【発明の実施の形態】
実施の形態１．
図１はこの発明の実施の形態１に係る直流リアクトルの正断面図である。図において、第１のコアとしてのＩ形状コア１は、所定の形状に打ち抜き加工した電磁鋼板を複数枚積層して形成され、巻線２が巻回される。また、所定の形状に打ち抜き加工した電磁鋼板を複数枚積層して形成される第２のコアとしての□形状コア３は、上辺部３ａ、両側脚部３ｂ，３ｂおよび下辺部３ｃから構成され、下辺部３ｃ中央には、巻線２を巻回したＩ形状コア１を挿入したとき、Ｉ形状コア１の巻線２が巻回されていない側面との間に所定の磁気的空隙４を保つように凹部３ｄを設けてある。また、凹部３ｄの中央には磁石幅Ｌｍ１のバイアス用の永久磁石５を固定するための溝３ｅが設けられている。また、下辺部３ｃには、巻線２の作る磁束φｅおよび永久磁石５の作るバイアス磁束φｍの経路を妨げない位置に貫通穴３ｆ、３ｆを設ける。
【００１６】
Ｉ形状コア１の上面部は□形状コア３の上辺部３ａの合わせ面６で接触し、また、永久磁石５はＩ形状コア１の下面部と□形状コア３の溝３ｅとにそれぞれ直に接触して設けるようにしたので、Ｉ形状コア１と□形状コア３と永久磁石５とがそれぞれ上下に分離するのを防ぐための留め具は不要である。
【００１７】
実施の形態１に係る直流リアクトルの磁束の流れについて説明する。
巻線２の作る磁束φｅは図中に実線で示すように、Ｉ形状コア１を通り、Ｉ形状コア１の上面部→合わせ面６→□形状コア３の上辺部３ａ→□形状コア３の側脚部３ｂ→□形状コア３の下辺部３ｃ（□形状コア３の凹部３ｄ）→磁気的空隙４を通ってＩ形状コア１に帰還する。
また、永久磁石５の作るバイアス磁束φｍは図中に破線で示すように、永久磁石５から、□形状コア３の溝３ｅ→□形状コア３の下辺部３ｃ→□形状コア３の側脚部３ｂ→□形状コア３の上辺部３ａ→合わせ面６→Ｉ形状コア１の上面部→Ｉ形状コア１→Ｉ形状コア１の下面部を通って永久磁石５に帰還する経路となり、磁気的空隙４を通らない。
【００１８】
また、図に示すように、Ｉ形状コア１内および□形状コア３内では、巻線２の作る磁束φｅと永久磁石５の作るバイアス磁束φｍは対向して流れるので、Ｉ形状コア１および□形状コア３の磁気的飽和が緩和され、巻線２の作る磁束φｅは永久磁石５内を通らないので、永久磁石５が減磁することもない。
【００１９】
図２はこの発明の実施の形態１に係る直流リアクトルの組立例を示す斜視図である。図において、１〜３、３ａ、３ｂ、３ｃ、３ｄ、３ｅ、３ｆ、５は図１と同様であり、その説明を省略する。
所定の形状に打ち抜き加工した電磁鋼板を複数枚積層して形成されたＩ形状コア１に巻線２を巻回した後、バイアス用の永久磁石５とともに、所定の形状に打ち抜き加工した電磁鋼板を複数枚積層して形成された□形状コア３に挿入することにより、巻線２を巻回したＩ形状コア１とバイアス用の永久磁石５とが、□形状コア３の上辺部３ａと下辺部３ｃとの間に支持される。
【００２０】
実施の形態１の直流リアクトルは、バイアス用の永久磁石は１個で構成するようにしたので、直流リアクトルの製造における永久磁石の組立が容易となり、またバイアス用の永久磁石を１個としたことにより、コストを下げることができる。
また、□形状コア３の下辺部３ｃ中央の凹部３ｄの中央には、永久磁石５を挿入するための溝３ｅを設けたので、直流リアクトルの製造において永久磁石５を□形状コア３の下辺部３ｃ中央への設置作業が容易となる。
【００２１】
実施の形態２．
図３はこの発明の実施の形態２に係る直流リアクトルの正断面図である。図において、巻線を巻回しない側面部の寸法を、巻線を巻回する側面部の寸法よりも大きくした第１のコアである凸形状コア１１は、所定の形状に打ち抜き加工した電磁鋼板を複数枚積層して形成され、巻線１２が巻回される。また、所定の形状に打ち抜き加工した電磁鋼板を複数枚積層して形成される□形状コア１３は、上辺部１３ａ、両側脚部１３ｂ，１３ｂおよび下辺部１３ｃから構成され、下辺部１３ｃ中央には、巻線１２を巻回した凸形状コア１１を挿入したとき、凸形状コア１１の巻線１２が巻回されていない凸形状の下部側面との間に所定の磁気的空隙１４を保つように凹部１３ｄを設けてある。また、凹部１３ｄ中央には磁石幅Ｌｍ１１のバイアス用の永久磁石１５を固定するための溝１３ｅが設けられている。また、下辺部１３ｃには、巻線１２の作る磁束φｅおよび永久磁石１５の作るバイアス磁束φｍの経路を妨げない位置に貫通穴１３ｆ、１３ｆを設ける。
【００２２】
凸形状コア１１の上面部は□形状コア１３の上辺部１３ａの合わせ面１６で接触し、また、永久磁石１５は凸形状コア１１の下面部と□形状コア１３の溝１３ｅとにそれぞれ直に接触して設けるようにしたので、凸形状コア１１と□形コア１３と永久磁石１５とがそれぞれ上下に分離するのを防ぐための留め具は不要である。
【００２３】
実施の形態２に係る直流リアクトルの磁束の流れについて説明する。
巻線１２の作る磁束φｅは図中に実線で示すように、凸形状コア１１を通り、凸形状コア１１の上面部→合わせ面１６→□形状コア１３の上辺部１３ａ→□形状コア１３の側脚部１３ｂ→□形状コア１３の下辺部１３ｃ（□形状コア１３の凹部１３ｄ）→磁気的空隙１４を通って凸形状コア１１に帰還する。
また、永久磁石１５の作るバイアス磁束φｍは図中に破線で示すように、永久磁石１５から、□形状コア１３の溝１３ｅ→□形状コア１３の下辺部１３ｃ→□形状コア１３の側脚部１３ｂ→□形状コア１３の上辺部１３ａ→合わせ面１６→凸形状コア１１の上面部→凸形状コア１１→凸形状コア１１の下面部を通って永久磁石１５に帰還する。
【００２４】
実施の形態２に係る直流リアクトルは、実施の形態１に係る直流リアクトルのＩ形状コア１の巻線２が巻回されていない側面の部分の寸法を大きくし、凸形状コア１１（逆Ｔ字形状コア）としたもので、実施の形態１における永久磁石５の磁石幅をＬｍ１とし、実施の形態２における永久磁石１５の磁石幅をＬｍ１１とした場合に、Ｌｍ１１＞Ｌｍ１と磁石幅を大きく取ることができる。したがって、実施の形態１に係る直流リアクトルの永久磁石５の作るバイアス磁束φｍと比べ、実施の形態２に係る直流リアクトルの永久磁石１５の作るバイアス磁束φｍが増大する。
すなわち、Ｉ形状コアを使用した実施の形態１と比較して、さらに大きな励磁電流に対しても、凸形状コア１１内および□形状コア１３内は磁気的飽和が生じることなく、使用状態に適合したインダクタンスが得られる。
【００２５】
実施の形態３．
図４はこの発明の実施の形態３に係る直流リアクトルの正断面図である。図において、２、４、５は図１と同様であり、その説明を省略する。Ｉ形状コア２１は□形状コア２３との合わせ面２６を凸形状とし、□形状コア２３はＩ形状コア２１との合わせ面２６を凹形状とし、Ｉ形状コアと□形状コアとをすきまばめ、またはしまりばめにより結合する。
【００２６】
実施の形態３では、直流リアクトルを構成する、Ｉ形状コアと□形状コアとの合わせ面を凹凸形状とし、Ｉ形状コアと□形状コアとをすきまばめ、またはしまりばめにより結合するようにしたので、
Ｉ形状コアの位置が固定され、Ｉ形状コアの両側に形成する２ヶ所の磁気的空隙溝の幅を容易に均等とすることができ、またリアクトルの特性が安定する。
【００２７】
ところで、上記説明では、Ｉ形状コア２１は□形状コア２３との合わせ面２６を凸形状とし、□形状コア２３はＩ形状コア２１との合わせ面２６を凹形状とした例について述べたが、Ｉ形状コアの□形状コアとの合わせ面を凹形状とし、□形状コアのＩ形状コアとの合わせ面を凸形状としても同様の効果が得られる。
【００２８】
また、上記説明では、第１のコアとしてＩ形状コアの上面部と、第２のコアの□形状の上辺部中央の下面部とを、凹凸形状とし、はめ合わせるようにした例について述べたが、第１のコアとして凸形状コアの上面部と、第２のコアの□形状の上辺部中央の下面部とを、凹凸形状とし、はめ合わせるようにしても同様の効果が得られる。
【００２９】
実施の形態４．
図５はこの発明の実施の形態４に係る直流リアクトルの正面図で、直流リアクトルを構成するＩ形状コアと永久磁石とを□形状コアに固定した例である。図において、１〜３は図１と同様であり、その説明を省略する。また、側板７は非磁性体で作られ、Ｉ形状コア１の永久磁石と接する側および永久磁石とを覆う大きさとする。Ｉ形状コア１および永久磁石５とが□形状コア３の内部から飛び出すことがないよう、□形状コア３の下辺部に設けられた貫通穴（３ｆ、図示せず）を利用し、２枚の側板７、７を使用して□形状コア３の両側から、ボルト、ナット等の締付具８により固定する。
【００３０】
上述の実施の形態１〜３における直流リアクトルでは、□形状コアの内部空間に、巻線が巻回されたＩ形状コアまたは凸形状コアと永久磁石を配置するようにしたので、従来の２個のコアと永久磁石がそれぞれ上下に分離するのを防ぐための留め具が不要となり、リアクトルの小型化ならびに低コスト化が可能となる。
また、□形状コア３の下辺部３ｃは、□形状コア３の側脚部３ｂと比べ、磁路断面積が広いため、リアクトルの特性を損なわない程度の貫通穴３ｆを開けることができ、リアクトルの性能や大きさを変えることなく、永久磁石をも含め一体に固定することが容易となる。
【００３１】
ところで、上記説明では、□形状コア３の下辺部３ｃに設けられた２箇所の貫通穴３ｆを利用し、２枚の側板７を使用して、直流リアクトルの両側から、Ｉ形コア１の永久磁石と接する側および永久磁石とを□形コア３に固定した例について述べたが、□形状コア３の下辺部３ｃに設ける貫通穴３ｆを１箇所とし、２枚の側板７の代りにＵ字形の板を使用し、直流リアクトルを挟み込んで固定する様にしてもよい。
【００３２】
実施の形態５．
図６はこの発明の実施の形態５に係る直流リアクトルの正面図で、直流リアクトルを固定した例である。図において、１〜３、５は図１と同様であり、その説明を省略する。□形状コア３の下辺部に設けられた貫通穴（３ｆ、図示せず）を利用してＬ形金具９等により、外部機器１０等にボルト、ナット等の締付具８により固定する。
【００３３】
上述の実施の形態１〜３における直流リアクトルでは、□形状コア３の下辺部３ｃは、□形状コア３の側脚部３ｂと比べ、磁路断面積が広いため、リアクトルの特性を損なわない程度の貫通穴３ｆを開けることができ、リアクトルの性能や大きさを変えることなく、リアクトルの外部機器１０等への固定が容易にできる。
【００３４】
ところで、上記説明では、図４において、□形状コア３の下辺部３ｃに設けられた貫通穴３ｆを利用して、直流リアクトルの両側から、Ｉ形状コア１の永久磁石と接する側および永久磁石とを□形状コア３に固定する例を説明し、図５において、□形状コア３の下辺部３ｃに設けられた貫通穴３ｆを利用してＬ形金具９等により、外部機器１０等に固定する例を説明したが、Ｉ形状コア１の永久磁石と接する側および永久磁石の□形状コア３への固定と、直流リアクトルの外部機器１０等への固定とを、同時に行っても良い。
【００３５】
【発明の効果】
この発明は、以上説明したように構成されているので、以下に示すような効果を奏する。
【００３６】
この発明の直流リアクトルは、巻線を巻回するＩ形状の第１のコアと、この第１のコアと組み合わせて閉磁路を形成する□形状の第２のコアと、巻線の作る磁束と対向するように着磁したバイアス用の永久磁石と、を有する直流リアクトルにおいて、第２のコアの□形状の下辺部中央に、第１のコアの前記巻線を巻回しない側面側および永久磁石の側面側との間に所定の磁気的空隙を形成するための凹部を設け、第１のコアの上面部を第２のコアの□形状の上辺部中央の下面部と接触させ、また第１のコアの下面部を永久磁石の上面部と接触させ、さらに永久磁石の下面部を第２のコアの□形状の下辺部中央の凹部に接触させることにより、巻線の作る磁束の経路を第１のコアの巻線を巻回しない側面側と第２のコアの□形状の下辺部中央に設けた凹部の間に形成した磁気的空隙を通る経路とし、永久磁石の作る磁束の経路を第２のコアの□形状の下辺部中央に設けた凹部の溝を経由し、磁気的空隙を通らない経路としたので、
直流リアクトルを構成するバイアス用の永久磁石が１個となり、直流リアクトルの製造における永久磁石の組立が容易となるとともに、コストを下げることができる。
【００３７】
また、第１のコアの巻線を巻回しない側面部の寸法を、巻線を巻回する側面部の寸法よりも大きくしたので、永久磁石の磁石幅を大きく取ることができ、永久磁石の作るバイアス磁束を増大することができる。
【００３８】
さらに、第２のコアの□形状の下辺中央部に設けた凹部の中央に、永久磁石を挿入するための溝を設けたので、直流リアクトルの製造において第２のコアの下辺部中央位置への永久磁石の設置が容易となる。
【００３９】
さらにまた、第１のコアの上面部と第２のコアの□形状の上辺部中央の下面部とを、凹凸形状とし、はめ合わせるようにしたので、
第１のコアの位置が固定され、第１のコアの両側に形成する２ヶ所の磁気的空隙溝の幅を容易に均等とすることができ、またリアクトルの特性が安定する。
【００４０】
また、第２のコアの□形状の下辺部にこのコアを固定するための貫通穴を設けたので、永久磁石をも含め一体に固定することが容易となるとともにリアクトルの外部機器等への固定が容易にできる。
【図面の簡単な説明】
【図１】この発明の実施の形態１に係る直流リアクトルの正断面図である。
【図２】この発明の実施の形態１に係る直流リアクトルの組立例を示す斜視図である。
【図３】この発明の実施の形態２に係る直流リアクトルの正断面図である。
【図４】この発明の実施の形態３に係る直流リアクトルの正断面図である。
【図５】この発明の実施の形態４に係る直流リアクトルの正面図で、直流リアクトルを構成するＩ形状コアと永久磁石とを□形状コアに固定した例である。
【図６】この発明の実施の形態５に係る直流リアクトルの正面図である。
【符号の説明】
１Ｉ形状コア、２巻線、３ □形状コア、３ａ □形状コア３の上辺部、３ｂ □形状コア３の側脚部、３ｃ □形状コア３の下辺部、３ｄ下辺部３ｃ中央に設けた凹部、３ｅ凹部３ｄ中央に設けた溝、３ｆ貫通穴、４磁気的空隙、５バイアス用の永久磁石、６Ｉ形状コア１と□形状コア３の上辺部３ａとの合わせ面、７側板、８締付具、９Ｌ形金具、１０外部機器、１１凸形状コア、１２巻線、１３ □形状コア、１３ａ □形状コア３の上辺部、１３ｂ □形状コア１３の側脚部、１３ｃ □形状コア１３の下辺部、１３ｄ下辺部１３ｃ中央に設けた凹部、１３ｅ凹部１３ｄ中央に設けた溝、１３ｆ貫通穴、１４磁気的空隙、１５バイアス用の永久磁石、１６凸形状コア１１と□形状コア１３の上辺部１３ａとの合わせ面、２１Ｉ形状コア、２３ □形状コア、２６Ｉ形状コア２１と□形状コア２３との合わせ面、Ｌｍ１、Ｌｍ１１磁石幅、 φｅ巻線２の作る磁束、 φｍ永久磁石５の作るバイアス磁束。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a DC reactor having a magnetic bias and used for a switching power supply and an inverter to improve a current waveform of a power supply.
[0002]
[Prior art]
As a DC reactor that applies a magnetic bias using a permanent magnet, there is one disclosed in Patent Document 1 (Japanese Patent Publication No. 46-37128).
In Patent Literature 1, a coil is wound around a central leg of an E-shaped core, the height of the central leg is made lower than that of a side leg, and the side leg of the E-shaped core is bridged by an I-shaped core. A permanent magnet that applies a magnetic bias to the gap between the I-shaped cores is sandwiched.
[0003]
Patent Document 2 (Japanese Patent Application Laid-Open No. H8-316049) discloses a DC reactor in which a permanent magnet is not demagnetized and a magnetic flux is hardly saturated in a core. is there.
In Patent Literature 2, an E-shaped core structure is formed by combining an E-shaped core made of a soft magnetic material and an I-shaped core made of a soft magnetic material on a mating surface. The center leg is shorter than the side legs, creating a magnetic gap. On both sides of the magnetic gap of the center leg, two sides of two rectangular permanent magnets having a width for generating a predetermined bias magnetic flux are magnetized in opposite polarities so that the sides contacting each other have different polarities. And the same polarity is arranged so that the same polarity faces each other with the center leg interposed therebetween.
[0004]
Further, the E-shaped core is changed to a C-shaped core, and the I-shaped core is changed to a T-shaped core to form a CT-shaped core structure. A coil is wound around the leg of the T-shaped core. A magnetic gap is formed between the legs of the T-shaped core and the center of the C-shaped core. On both sides of the magnetic air gap, a pair of permanent magnets that generate a bias magnetic flux are provided so as to have the same polarity. This configuration facilitates winding.
[0005]
[Problems to be solved by the invention]
In Patent Document 1, since a magnet is inserted into the gap, it is necessary to use a magnet material that is not demagnetized by the magnetic flux generated by the coil. The inductance of the DC reactor increases as the gap length decreases, but the gap length increases. When the size is reduced, the magnet is inevitably thinned, which makes it difficult to process and demagnetizes easily. Therefore, if there is a possibility that a large amount of current may flow, it is indispensable to increase the thickness of the magnet. For this reason, the length of the air gap becomes longer, and the cross-sectional area of the core needs to be increased. As a result, the reactor becomes larger. There was a problem.
[0006]
Further, in Patent Document 2, since the magnetic flux generated by the winding does not flow through the permanent magnet, a DC reactor can be obtained in which the permanent magnet does not demagnetize and the magnetic flux hardly saturates in the core. This is a configuration using a pair of permanent magnets, and there is a problem that it is difficult to assemble two permanent magnets in manufacturing a DC reactor.
[0007]
As described above, the conventional DC reactor has a structure in which an E-type core and an I-type core are combined to form an EI-type core structure, or a C-type core and a T-type core are combined to form a CT-type core structure. For this reason, in order to fix them together including the permanent magnet, a large fastener is required, and there is a problem that the shape of the reactor becomes large.
[0008]
The present invention has been made to solve the above-described problems, and a first object of the present invention is to obtain a DC reactor having a structure in which a permanent magnet constituting the DC reactor can be easily assembled in the production of the DC reactor. .
[0009]
A second object is to obtain a DC reactor having a structure that can be integrally fixed including a permanent magnet without changing the performance and size of the reactor and that can be easily fixed to an external device or the like. is there.
[0010]
[Means for Solving the Problems]
A DC reactor according to the present invention includes an I-shaped first core for winding a winding, a □ -shaped second core that forms a closed magnetic circuit in combination with the first core, and a magnetic flux generated by the winding. And a permanent magnet for bias magnetized so as to face each other,
At the center of the lower side of the square shape of the second core, a concave portion for forming a predetermined magnetic gap is provided between the side surface of the first core where the winding is not wound and the side surface of the permanent magnet. Contacting the upper surface of the first core with the lower surface of the center of the upper side of the second core, contacting the lower surface of the first core with the upper surface of the permanent magnet, By contacting the part with the central concave portion of the lower side of the second core, the path of the magnetic flux generated by the winding is changed to the side surface of the first core where the winding is not wound and the square of the second core. A path through a magnetic gap formed between the concave portions provided in the center of the lower side, and a magnetic flux path created by the permanent magnet via a groove of the concave portion provided in the center of the lower side of the □ shape of the second core; The path does not pass through the magnetic gap.
[0011]
Further, the size of the side surface of the first core where the winding is not wound is larger than the size of the side surface where the winding is wound.
[0012]
Further, a groove for inserting a permanent magnet is provided at the center of a concave portion provided at the center of the lower side of the square shape of the second core.
[0013]
Furthermore, the upper surface of the first core and the lower surface at the center of the □ -shaped upper side of the second core have an uneven shape and are fitted together.
[0014]
Further, a through hole for fixing the core is provided in the lower side of the square shape of the second core.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a front sectional view of the DC reactor according to Embodiment 1 of the present invention. In the figure, an I-shaped core 1 as a first core is formed by laminating a plurality of electromagnetic steel sheets punched into a predetermined shape, and a winding 2 is wound. The □ -shaped core 3 as a second core formed by laminating a plurality of electromagnetic steel sheets punched into a predetermined shape is composed of an upper side 3a, both side legs 3b, 3b, and a lower side 3c, When the I-shaped core 1 on which the winding 2 is wound is inserted into the center of the lower side portion 3c, a predetermined magnetic gap 4 is maintained between the I-shaped core 1 and the side surface on which the winding 2 is not wound. Recess 3d is provided as described above. A groove 3e for fixing the biasing permanent magnet 5 having the magnet width Lm1 is provided at the center of the recess 3d. In the lower side 3c, through holes 3f, 3f are provided at positions not obstructing the path of the magnetic flux φe generated by the winding 2 and the bias magnetic flux φm generated by the permanent magnet 5.
[0016]
The upper surface of the I-shaped core 1 is in contact with the mating surface 6 of the upper side 3a of the □ -shaped core 3, and the permanent magnet 5 is directly in contact with the lower surface of the I-shaped core 1 and the groove 3e of the □ -shaped core 3, respectively. Since they are provided in contact with each other, a fastener for preventing the I-shaped core 1, the □ -shaped core 3, and the permanent magnet 5 from being vertically separated from each other is unnecessary.
[0017]
The flow of the magnetic flux of the DC reactor according to the first embodiment will be described.
The magnetic flux φe generated by the winding 2 passes through the I-shaped core 1 as shown by a solid line in the figure, and the upper surface of the I-shaped core 1 → the mating surface 6 → the upper side 3a of the □ -shaped core 3 → the □ -shaped core 3 Side leg 3b → bottom side 3c of □ -shaped core 3 (recess 3d of □ -shaped core 3) → returns to I-shaped core 1 through magnetic gap 4.
Further, the bias magnetic flux φm generated by the permanent magnet 5 is, as shown by a broken line in the figure, from the permanent magnet 5, the groove 3 e of the □ -shaped core 3 → the lower side 3 c of the □ -shaped core 3 → the side leg of the □ -shaped core 3. 3b → the upper side 3a of the □ -shaped core 3 → the mating surface 6 → the upper surface of the I-shaped core 1 → the I-shaped core 1 → the path to return to the permanent magnet 5 through the lower surface of the I-shaped core 1; Do not pass 4.
[0018]
Further, as shown in the figure, in the I-shaped core 1 and the □ -shaped core 3, the magnetic flux φe generated by the winding 2 and the bias magnetic flux φm generated by the permanent magnet 5 flow in opposition, so that the I-shaped core 1 and the □ Since the magnetic saturation of the shape core 3 is relaxed and the magnetic flux φe generated by the winding 2 does not pass through the permanent magnet 5, the permanent magnet 5 is not demagnetized.
[0019]
FIG. 2 is a perspective view showing an example of assembling the DC reactor according to Embodiment 1 of the present invention. In the figure, 1 to 3, 3a, 3b, 3c, 3d, 3e, 3f, and 5 are the same as those in FIG.
After winding the winding 2 around an I-shaped core 1 formed by laminating a plurality of electromagnetic steel sheets punched into a predetermined shape, the electromagnetic steel sheet punched into a predetermined shape is formed together with a permanent magnet 5 for bias. By inserting into the □ -shaped core 3 formed by laminating a plurality of pieces, the I-shaped core 1 on which the winding 2 is wound and the biasing permanent magnet 5 are connected to the upper side 3 a and the lower side of the □ -shaped core 3. 3c.
[0020]
Since the DC reactor according to the first embodiment has a single permanent magnet for bias, assembly of the permanent magnet in the production of the DC reactor is easy, and one permanent magnet for bias is used. Thereby, costs can be reduced.
Further, since a groove 3e for inserting the permanent magnet 5 is provided at the center of the concave portion 3d at the center of the lower side 3c of the square core 3, the permanent magnet 5 is used for manufacturing the DC reactor. Installation work in the center of 3c becomes easy.
[0021]
Embodiment 2 FIG.
FIG. 3 is a front sectional view of the DC reactor according to Embodiment 2 of the present invention. In the figure, a convex core 11 which is a first core in which the size of a side surface portion on which a winding is not wound is larger than the size of a side surface portion on which a winding is wound is an electromagnetic steel sheet punched into a predetermined shape. Are laminated, and the winding 12 is wound. The □ -shaped core 13 formed by laminating a plurality of electromagnetic steel sheets punched into a predetermined shape is composed of an upper side portion 13a, both side legs 13b, 13b, and a lower side portion 13c. When the convex core 11 around which the winding 12 is wound is inserted, a predetermined magnetic gap 14 is maintained between the convex core 11 and the lower side surface of the convex shape where the winding 12 is not wound. A recess 13d is provided. A groove 13e for fixing the biasing permanent magnet 15 having the magnet width Lm11 is provided at the center of the recess 13d. Further, through holes 13f, 13f are provided in the lower side portion 13c at positions not obstructing the path of the magnetic flux φe generated by the winding 12 and the bias magnetic flux φm generated by the permanent magnet 15.
[0022]
The upper surface of the convex core 11 contacts the mating surface 16 of the upper side 13a of the square core 13, and the permanent magnet 15 directly contacts the lower surface of the convex core 11 and the groove 13e of the square core 13, respectively. Since they are provided in contact with each other, a fastener for preventing the convex core 11, the square core 13, and the permanent magnet 15 from being vertically separated from each other is unnecessary.
[0023]
The flow of the magnetic flux of the DC reactor according to the second embodiment will be described.
The magnetic flux φe generated by the winding 12 passes through the convex core 11 as shown by a solid line in the figure, and the upper surface portion of the convex core 11 → the mating surface 16 → the upper side portion 13a of the □ -shaped core 13 → the □ -shaped core 13 Side leg 13b → bottom side 13c of □ -shaped core 13 (recess 13d of □ -shaped core 13) → returns to convex core 11 through magnetic gap 14.
Further, the bias magnetic flux φm generated by the permanent magnet 15 is, as shown by the broken line in the figure, from the permanent magnet 15 to the groove 13e of the square core 13 → the lower side 13c of the square core 13 → the side leg of the square core 13. 13b → the upper side 13a of the □ -shaped core 13 → the mating surface 16 → the upper surface of the convex core 11 → the convex core 11 → the return to the permanent magnet 15 through the lower surface of the convex core 11.
[0024]
The DC reactor according to the second embodiment increases the dimension of the side of the DC reactor according to the first embodiment where the winding 2 of the I-shaped core 1 is not wound, and increases the convex core 11 (inverted T-shape). When the magnet width of the permanent magnet 5 in the first embodiment is Lm1 and the magnet width of the permanent magnet 15 in the second embodiment is Lm11, the magnet width is large as Lm11> Lm1. be able to. Therefore, the bias magnetic flux φm generated by the permanent magnet 15 of the DC reactor according to the second embodiment is larger than the bias magnetic flux φm generated by the permanent magnet 5 of the DC reactor according to the first embodiment.
That is, as compared with the first embodiment using the I-shaped core, even in the case of an even larger exciting current, the inside of the convex core 11 and the inside of the □ -shaped core 13 do not cause magnetic saturation and conform to the use state. The obtained inductance is obtained.
[0025]
Embodiment 3 FIG.
FIG. 4 is a front sectional view of a DC reactor according to Embodiment 3 of the present invention. In the figure, reference numerals 2, 4, and 5 are the same as those in FIG. 1, and a description thereof will be omitted. The I-shaped core 21 has a convex shape at the mating surface 26 with the □ -shaped core 23, the □ -shaped core 23 has a concave shape at the mating surface 26 with the I-shaped core 21, and a loose fit between the I-shaped core and the □ -shaped core. Or by an interference fit.
[0026]
In the third embodiment, the mating surface of the I-shaped core and the □ -shaped core constituting the DC reactor is made to have an uneven shape, and the I-shaped core and the □ -shaped core are joined together by loose fit or tight fit. Because
The position of the I-shaped core is fixed, the width of two magnetic gap grooves formed on both sides of the I-shaped core can be easily made uniform, and the characteristics of the reactor are stabilized.
[0027]
By the way, in the above description, the example is described in which the I-shaped core 21 has a mating surface 26 with the □ -shaped core 23 and the □ -shaped core 23 has a mating surface 26 with the I-shaped core 21. Similar effects can be obtained by making the mating surface of the I-shaped core with the □ -shaped core concave, and making the mating surface of the □ -shaped core with the I-shaped core convex.
[0028]
In the above description, an example was described in which the upper surface of the I-shaped core as the first core and the lower surface of the center of the upper side of the □ -shaped second core were formed into an uneven shape and fitted. The same effect can be obtained by fitting the upper surface of the convex core as the first core and the lower surface of the center of the □ -shaped upper side of the second core into an uneven shape and fitting them.
[0029]
Embodiment 4 FIG.
FIG. 5 is a front view of a DC reactor according to Embodiment 4 of the present invention, in which an I-shaped core and a permanent magnet constituting the DC reactor are fixed to a □ -shaped core. In the figure, 1 to 3 are the same as in FIG. 1 and the description thereof is omitted. The side plate 7 is made of a non-magnetic material and has a size that covers the side of the I-shaped core 1 that contacts the permanent magnet and the permanent magnet. In order to prevent the I-shaped core 1 and the permanent magnet 5 from protruding from the inside of the □ -shaped core 3, two through-holes (3f, not shown) provided on the lower side of the □ -shaped core 3 are used. Using the side plates 7, 7, fix from both sides of the □ -shaped core 3 with fasteners 8 such as bolts and nuts.
[0030]
In the DC reactors according to the first to third embodiments, the I-shaped core or the convex-shaped core having the winding wound thereon and the permanent magnet are arranged in the internal space of the □ -shaped core. A fastener for preventing the core and the permanent magnet from being vertically separated from each other is not required, and the size and cost of the reactor can be reduced.
Further, since the lower side 3c of the □ -shaped core 3 has a larger magnetic path cross-sectional area than the side leg 3b of the □ -shaped core 3, a through hole 3f that does not impair the characteristics of the reactor can be formed. It is easy to integrally fix them including the permanent magnets without changing the performance and size.
[0031]
By the way, in the above description, the permanent magnets of the I-shaped core 1 are used from both sides of the DC reactor by using two side plates 7 using two through holes 3f provided in the lower side 3c of the □ -shaped core 3. Although the example in which the side in contact with the magnet and the permanent magnet are fixed to the □ -shaped core 3 has been described, the through hole 3 f provided in the lower side 3 c of the □ -shaped core 3 is made one, and a U-shape is used instead of the two side plates 7. The DC reactor may be sandwiched and fixed by using the above plate.
[0032]
Embodiment 5 FIG.
FIG. 6 is a front view of a DC reactor according to Embodiment 5 of the present invention, in which the DC reactor is fixed. In the figure, 1 to 3 and 5 are the same as those in FIG. Using a through hole (3f, not shown) provided in the lower side of the shaped core 3, the core 3 is fixed to an external device 10 or the like by a fastener 8 such as a bolt or a nut using an L-shaped bracket 9 or the like.
[0033]
In the DC reactor according to the first to third embodiments, the lower side 3c of the □ -shaped core 3 has a wider magnetic path cross-sectional area than the side leg 3b of the □ -shaped core 3, so that the characteristics of the reactor are not impaired. 3f can be opened, and the reactor can be easily fixed to the external device 10 or the like without changing the performance and size of the reactor.
[0034]
By the way, in the above description, in FIG. 4, the side in contact with the permanent magnet of the I-shaped core 1 and the permanent magnet are used from both sides of the DC reactor using the through holes 3 f provided in the lower side 3 c of the □ -shaped core 3. 5 is fixed to the □ -shaped core 3 and, in FIG. 5, the □ -shaped core 3 is fixed to the external device 10 or the like by the L-shaped fitting 9 or the like using the through hole 3 f provided in the lower side portion 3 c. Although the example has been described, the fixing of the side of the I-shaped core 1 in contact with the permanent magnet and the permanent magnet to the □ -shaped core 3 and the fixing of the DC reactor to the external device 10 or the like may be performed simultaneously.
[0035]
【The invention's effect】
Since the present invention is configured as described above, it has the following effects.
[0036]
A DC reactor according to the present invention includes an I-shaped first core for winding a winding, a □ -shaped second core that forms a closed magnetic circuit in combination with the first core, and a magnetic flux generated by the winding. And a permanent magnet for bias, which is magnetized so as to face each other, in the center of the □ -shaped lower side of the second core, the side surface and the permanent magnet on which the winding of the first core is not wound. A concave portion for forming a predetermined magnetic gap between the first core and the side surface of the second core, the upper surface of the first core is brought into contact with the lower surface of the center of the upper side of the second core; The lower surface of the core is brought into contact with the upper surface of the permanent magnet, and the lower surface of the permanent magnet is brought into contact with the central concave portion of the lower side of the second core, so that the path of the magnetic flux generated by the windings becomes At the side of the first core where the winding of the core is not wound and at the center of the □ -shaped lower side of the second core The path of the magnetic flux created by the permanent magnet passes through the groove of the recess provided at the center of the lower side of the square shape of the second core and does not pass through the magnetic gap. Because it was a route,
Since the number of permanent magnets for bias constituting the DC reactor is one, assembling of the permanent magnets in the production of the DC reactor becomes easy, and the cost can be reduced.
[0037]
In addition, since the size of the side portion of the first core where the winding is not wound is made larger than the size of the side portion where the winding is wound, the magnet width of the permanent magnet can be increased, and The generated bias magnetic flux can be increased.
[0038]
Furthermore, since a groove for inserting a permanent magnet is provided at the center of the concave portion provided at the center of the lower side of the □ -shape of the second core, the center of the lower side of the second core is located at the center of the lower side of the second core in manufacturing a DC reactor. Installation of the permanent magnet is facilitated.
[0039]
Furthermore, the upper surface of the first core and the lower surface of the center of the upper side of the □ -shape of the second core were formed into a concave-convex shape and fitted together.
The position of the first core is fixed, the width of the two magnetic gap grooves formed on both sides of the first core can be easily made uniform, and the characteristics of the reactor are stabilized.
[0040]
In addition, since a through hole for fixing this core is provided in the lower side of the □ -shape of the second core, it is easy to integrally fix it including the permanent magnet, and the reactor is fixed to an external device or the like. Can be easily done.
[Brief description of the drawings]
FIG. 1 is a front sectional view of a DC reactor according to Embodiment 1 of the present invention.
FIG. 2 is a perspective view showing an example of assembling the DC reactor according to Embodiment 1 of the present invention.
FIG. 3 is a front sectional view of a DC reactor according to Embodiment 2 of the present invention.
FIG. 4 is a front sectional view of a DC reactor according to Embodiment 3 of the present invention.
FIG. 5 is a front view of a DC reactor according to Embodiment 4 of the present invention, showing an example in which an I-shaped core and a permanent magnet constituting the DC reactor are fixed to a □ -shaped core.
FIG. 6 is a front view of a DC reactor according to Embodiment 5 of the present invention.
[Explanation of symbols]
1 I-shaped core, 2 winding, 3 □ -shaped core, 3a □ -shaped core 3 upper side, 3b □ -shaped core 3 side leg, 3c □ shaped core 3 lower side, 3d provided at center of lower side 3c Concave portion 3e groove provided in the center of concave portion 3d 3f through hole 4 magnetic gap 5 permanent magnet for bias 6 mating surface of I-shaped core 1 and upper side 3a of □ -shaped core 3 7 side plate 8 Fastener, 9 L-shaped bracket, 10 external equipment, 11 convex core, 12 winding, 13 □ shaped core, 13 a □ Upper side of 3 shaped core 3, 13 b □ Side leg of 13 shaped core 13, 13 c □ shaped core 13 lower side portion, 13d concave portion provided in the center of lower side portion 13c, 13e groove provided in the center of concave portion 13d, 13f through hole, 14 magnetic gap, 15 permanent magnet for bias, 16 convex core 11 and □ -shaped core 13 With the upper side 13a Surface, 21 I-shaped core, 23 □ -shaped core, 26 Mating surface of I-shaped core 21 and □ -shaped core 23, Lm1, Lm11 Magnet width, φe Magnetic flux generated by winding 2, φm Bias magnetic flux generated by permanent magnet 5 .

Claims

An I-shaped first core for winding a winding;
A □ -shaped second core that forms a closed magnetic circuit in combination with the first core;
A permanent magnet for bias, which is magnetized so as to face the magnetic flux generated by the winding,
In a DC reactor having
In order to form a predetermined magnetic gap between the side of the first core where the winding is not wound and the side of the permanent magnet, in the center of the lower side of the square shape of the second core. Provide a recess,
Bringing the upper surface of the first core into contact with the lower surface at the center of the □ -shaped upper side of the second core; and bringing the lower surface of the first core into contact with the upper surface of the permanent magnet; By bringing the lower surface of the permanent magnet into contact with the central concave portion of the lower side of the □ -shape of the second core,
A magnetic air gap formed between a side surface of the first core, on which the winding is not wound, and a concave portion provided at the center of the lower side of the square of the second core has a magnetic flux path formed by the winding. The path of the magnetic flux created by the permanent magnet may be a path that does not pass through the magnetic gap through a groove of a concave portion provided at the center of the lower side of the □ shape of the second core. DC reactor.

2. The DC reactor according to claim 1, wherein a size of a side surface of the first core where the winding is not wound is larger than a size of a side surface of the first core around which the winding is wound. 3.

3. The DC reactor according to claim 1, wherein a groove for inserting the permanent magnet is provided at a center of a concave portion provided at a center of a lower side of the square shape of the second core.

4. The method according to claim 1, wherein an upper surface of the first core and a lower surface of a center of an upper side of the second core have a concave-convex shape and are fitted to each other. DC reactor described in Crab.

The direct current reactor according to any one of claims 1 to 4, wherein a through hole for fixing the core is provided in a lower side of the square shape of the second core.