JP3774436B2

JP3774436B2 - Inductor manufacturing method

Info

Publication number: JP3774436B2
Application number: JP2002373881A
Authority: JP
Inventors: 和雄小林; 健佐藤; 勝彦西村; 耕介原田; 京宣新谷; 佐武秀機; 和臣渡辺; 循二影山
Original assignee: Seiko Epson Corp; Fujitsu Telecom Networks Ltd
Current assignee: Seiko Epson Corp; Fujitsu Telecom Networks Ltd
Priority date: 2002-12-25
Filing date: 2002-12-25
Publication date: 2006-05-17
Anticipated expiration: 2022-12-25
Also published as: JP2004207443A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば、電源などに使用するパワーインダクタ、ノイズフィルタ用コイル、スイッチングトランスなどに適用される中空の芯を有するインダクタの製造方法に関する。
【０００２】
【従来の技術】
従来、インダクタやトランスとしては、種々のものが知られている。
例えば、磁粉を混入した結着材から成る磁性媒体中に、巻線の全体もしくは一部分を埋設して成るコイルとその製造方法が知られている（例えば、特許文献１参照）。
所定形状の中空部を設けた型材に巻線を施し、中空部に薄片状磁性粉末を充填しまたは充填しつつ巻線に直流を間欠通電し、さらに絶縁性樹脂を含浸固化せしめて所定形状に成型した圧粉磁心を得る圧粉磁心の製造方法が知られている（例えば、特許文献２参照）。
【０００３】
心部が中心となる絶縁性ボビンに巻線を施したコイルと、一端が開口した収納ケースとを用意し、コイルを、収納ケース内に、両者の中心軸が一致するように装入した後、コイル全体が埋設するように強磁性粉末を充填し、しかる後収納ケースの開口部を封止するインダクタおよびその製造方法が知られている（例えば、特許文献３参照）。
【０００４】
軟磁性粉末と熱可塑性ポリマーから成る被覆層を芯線の外周部に具備する電線を用意し、これを空芯コイル形状に巻線加工したインダクタおよびその製造方法が知られている（例えば、特許文献４参照）。
粘土状の弾性および粘性を有し、さらに熱もしくは紫外線などを照射すると凝固する絶縁性の材料に、透磁率が高く、かつ抵抗率の高い磁性材料を混入させて成るＥＭＩ対策用コアが知られている（例えば、特許文献５参照）。
【０００５】
【特許文献１】
特開昭５４−１６３３５４号公報
【特許文献２】
特開昭５７−３９５１６号公報
【特許文献３】
特開平５−１５９９３４号公報
【特許文献４】
特開平６−３６９３７号公報
【特許文献５】
特開平１０−２７５９９４号公報
【０００６】
【発明が解決しようとする課題】
しかしながら、特許文献１に係るコイルとその製造方法では、磁性媒体を固化することによって磁性媒体の中に巻線の全体もしくは一部分を埋設するので、磁性体が方向性を持つ場合、磁性体の方向を均一とすることが難しい。また、磁性体の特性に偏差があるため、インダクタンスなど特性がばらついてしまうという問題があった。
また、特許文献２に係る圧粉磁心および圧粉磁心コイルの製造方法では、絶縁性樹脂を含浸固化せしめて所定形状に成型した圧粉磁心を得るので、磁性体が方向性を持つ場合、磁性体の方向を均一とすることが難しい。また、磁性体の特性に偏差があるため、インダクタンスなど特性がばらついてしまうという問題があった。
【０００７】
また、特許文献３に係るインダクタおよびその製造方法では、コイルを、収納ケース内に、両者の中心軸が一致するように装入した後、コイル全体が埋設するように強磁性粉末を充填し、しかる後収納ケースの開口部を封止するので、強磁性粉末の充填を正確に行い難く、充填ムラを起こし易いという問題がある。
また、特許文献４に係るインダクタおよびその製造方法では、軟磁性粉末が熱可塑性ポリマーによって固化されているので、磁性体が方向性を持つ場合、磁性体の方向を均一とすることが難しい。また、磁性体の特性に偏差があるため、インダクタンスなど特性がばらついてしまうという問題があった。
【０００８】
また、特許文献５に係るＥＭＩ対策用コアでは、凝固する絶縁性の材料に、透磁率が高く、かつ抵抗率の高い磁性材料を混入させて成るので、磁性体が方向性を持つ場合、磁性体の方向を均一とすることが難しい。また、磁性体の特性に偏差があるため、インダクタンスなど特性がばらついてしまうという問題があった。
【０００９】
一方、従来のトロイダルコアでは、プレスによりトロイダル形状に巻回するための複雑な工数を要するという問題があった。そのため、トロイダルコアが高価となるという不具合があった。
また、従来のトロイダルコアでは、磁性体にギャップがあるため、漏れ磁束が生じ、ギャップ近傍において磁束の偏りが生じ易いという問題があった。そのため、スイッチングコンバータとして用いた場合、ギャップによる漏れ磁束は、スイッチ・オフに伴うサージとノイズ発生の原因となる。
なお、トランスにおいても、インダクタと同様の問題があった。
【００１０】
本発明は斯かる従来の問題点を解決するために為されてもので、その目的は、製作が容易で磁性体が方向性を持つ場合に磁性体の方向を均一にすることが可能なインダクタの製造方法を提供することにある。
【００１１】
【課題を解決するための手段】
請求項１に係る発明は、磁性粉末を入れた容器に線材を螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布する工程と、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布した状態で、前記コイル部への電流値を高め、前記コイル部からの発熱で前記結着材を硬化させ、前記磁性粉末と前記コイル部とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１２】
請求項２に係る発明は、磁性粉末を入れた容器に線材を螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布する工程と、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布した状態で、前記コイル部を加熱器にて加熱し、前記結着材を加熱硬化して前記磁性粉末と前記コイル部とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１３】
請求項３に係る発明は、結着材を付着した磁性粉末を入れた容器内に線材を螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を前記コイル部に電磁吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、前記コイル部への電流値を高めて前記結着材を加熱硬化して前記磁性粉末と前記コイル部とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１４】
請求項４に係る発明は、結着材を付着した磁性粉末を入れた容器内に線材を螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を前記コイル部に電磁吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、前記コイル部を加熱器にて加熱し、前記結着材を加熱硬化して前記磁性粉末と前記コイル部とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１５】
請求項５に係る発明は、磁性粉末を入れた容器に複数の線材を同時に螺旋状に巻回するとともにドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布する工程と、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布した状態で、前記コイル部への電流値を高め、前記線材からの発熱で前記結着材を硬化させ、前記磁性粉末と前記線材とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１６】
請求項６に係る発明は、磁性粉末を入れた容器に複数の線材を同時に螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布する工程と、電磁吸着されている前記磁性粉末とともに前記コイル部に結着材を塗布した状態で、加熱器にて前記結着材を加熱硬化して前記磁性粉末と前記線材とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１７】
請求項７に係る発明は、結着材を付着した磁性粉末を入れた容器内に複数の線材を同時に螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を前記コイル部に電磁吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、前記コイル部への電流値を高めて前記結着材を加熱硬化して前記磁性粉末と前記コイル部とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１８】
請求項８に係る発明は、結着材を付着した磁性粉末を入れた容器内に複数の線材を同時に螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部を配し、前記コイル部に電流を通電して該コイル部の周囲に電磁吸着により前記磁性粉末を前記コイル部に電磁吸着してコア部を形成する工程と、前記コア部を形成した状態で、前記コイル部を前記容器より取り出し、前記コイル部を加熱器にて加熱し、前記結着材を加熱硬化して前記磁性粉末と前記コイル部とを前記結着材で被覆して成る結着材層を形成する工程とを備えたことを特徴とする。
【００１９】
請求項９に係る発明は、請求項１ないし請求項８の何れか１項記載のインダクタの製造方法において、前記結着材層は、外装のみが硬化し、内部の前記磁性粉末が前記結着材により拘束されていないことを特徴とする。
請求項１０に係る発明は、請求項１ないし請求項８の何れか１項記載のインダクタの製造方法において、前記結着材層は、外装および内部の前記磁性粉末が前記結着材により拘束されていることを特徴とする。
請求項１１に係る発明は、請求項１ないし請求項８の何れか１項載のインダクタの製造方法において、前記コイル部に通電する電流は、直流、交流、脈流、矩形あるいは直流を重畳した交流であることを特徴とする。
請求項１２に係る発明は、請求項１、請求項２、請求項５、請求項６の何れか１項記載のインダクタの製造方法において、前記コイル部を電磁吸着している磁性粉末とともに前記結着材に浸漬することを特徴とする。
【００２０】
【発明の実施の形態】
以下、本発明を図面に示す実施形態に基づいて説明する。
図１および図３は、本発明の一実施形態に係るインダクタ１を示す。
本実施形態に係るインダクタ１は、線材２を螺旋状に巻回して成る直線状の巻線をドーナツ状に形成して成るコイル部４への通電時に生じる電磁吸着によりコイル部４に電磁吸着されている磁性粉末３をコア部とし、このコア部に、コイル部４への通電を継続してコイル部４とともに結着材５を塗布し、その後にコイル部４による発熱で結着材５を硬化して形成される結着材層９で被覆することによって形成されている。
【００２１】
コイル部４は、図２に示すように、例えば、線径（直径）１ｍｍのエナメル被覆銅線を同心円の直径１１ｍｍ、ピッチ２ｍｍで螺旋状に３０回巻回して形成した直線状の巻線を、内径８ｍｍ、外径３０ｍｍのドーナツ形状に形成することによって構成されている。
ここで、線材２としては、例えば、エナメル、ポリウレタンなどの絶縁皮膜を施した銅線、アルミニウム線などで構成されている。なお、その径および長さは、用途目的に応じて任意に決定できる。
また、磁性粉末３としては、例えば、原子比で示す化学量論組成が（Ｆｅ０．９７Ｃｒ０．０３）７６（Ｓｉ０．５Ｂ０．５）２２Ｃ２などのＦｅ−Ｓｉ−Ｂ系のアモルファス合金粉末を用いた。粉末粒径としては、４５μｍ以下または１５０μｍ以下である。また、４５μｍ以下のアモルファス合金と１５０μｍ以下のアモルファス合金とで形成したコイルのインダクタンス、直流重畳特性を比較したところ、１５０μｍ以下のアモルファス合金が優れていた。
また、結着材５としては、例えば、熱硬化性樹脂、溶剤系接着剤、水ガラスなどで構成されている。
【００２２】
本実施形態に係るインダクタ１においては、例えば、図３に示すように、コイル部４への通電によって磁性粉末３がコイル部４の内側４ａと外側４ｂとに吸着されてコア部を形成し、このコア部が結着材層９によって囲繞されて形成されている。
従って、本実施形態に係るインダクタ１によれば、従来のトロイダルコアとは異なって、コア部にギャップがないリアクトルを実現することができる。
このように、ギャップレスにすれば、漏れ磁束を低減することが可能となり、近接効果による巻緑抵抗増大を防ぎ銅損を低減できる。
また、ギャップ近傍における磁束の偏りを無くしコアロス鉄損の増大を防ぐことができる。
さらに、スイッチングコンバータとして用いた場合、ギャップによる漏れ磁束はスイッチングのスイッチオフに伴うサージとノイズ発生の原因ともなるが、本実施形態に係るインダクタ１によれば、このような不具合も解消することが可能となる。
【００２３】
上述したように、すでに成形されたトロイダルコアに巻線を施すことは容易ではなく、特に、機械化による量産に問題がある。このため、リアクトルが高価となるという不具合があった。
これに対し、本実施形態に係るインダクタ１によれば、コイル部４に磁性粉末３を用い、トロイダルコアに巻線を施す手順を省略し、殆ど材料費のみの低価格でトロイダルにリアクトルを構成できるという利点がある。
本実施形態に係るインダクタ１によれば、コア部を形成する磁性粉末３は、コイル部４の内側４ａと外側４ｂとに吸着されてコア部を形成し、このコア部が結着材層９によって囲繞されて形成されているので、漏れ出ることがない。
しかも、コア内部の磁性粉末３は、電磁吸着時に磁性粉末３の磁性の方向が均一化されているので、従来のように、磁性体が方向性を持つ場合、磁性体の方向が均一にできないという問題が発生しない。
【００２４】
なお、本実施形態では、結着材層９は、外装を形成し、コア内部の磁性粉末３が結着材５によって拘束されることがない場合について説明したが、結着材がコア内部にまで浸透して磁性粉末３をともに結着しても良い。
この場合、コア内部の磁性粉末３は、電磁吸着時に磁性粉末３の磁性の方向が均一化された状態を保って結着材５で磁性粉末３を結着するので、従来のように、磁性体が方向性を持つ場合、磁性体の方向が均一にできないという問題が発生しない。
【００２５】
次に、図５に基づいて本実施形態に係るインダクタ１の製造方法を説明する（請求項１ないし請求項４、請求項９に対応する）。
先ず、図５（ａ）に示すように、磁性粉末３を入れた容器６にコイル部４を配し、コイル部４を導線８を介して電源７に接続し、コイル部４に電流６Ａで通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成する。
ここで、図６に基づいて磁性粉末３の吸着について説明する。コイル部４への電流が３Ａ以下では、吸着力が悪かった。コイル部４への電流が３Ａを超えて８Ａまでの間では好適な吸着量が得られた。コイル部４への電流が８Ａを超えると、吸着力が強くなり、コイル部４の外側から磁性粉末３が漏れるようになってきた。以上の結果から、本実施形態においては、通電電流値は４Ａ〜８Ａ、好ましくは６Ａ〜８Ａとすることが望ましいと判断した。
【００２６】
次に、図５（ｂ）に示すように、磁性粉末３を電磁吸着した状態で、コイル部４を容器６より取り出し、電磁吸着されている磁性粉末３とともに線材２に結着材５を塗布する。
次に、図５（ｃ）に示すように、コイル部４への電流値を高め、コイル部４からの発熱で結着材５を硬化させ、結着材層９を形成する。結着材層９の硬化後、電源を切る。ここでの操作は、常温下で行う。
ここで、結着材５としてエポキシ樹脂を用い、電磁吸着時の電流値６Ａを２０Ａに上げたところ、約２分でエポキシ樹脂が硬化した。
斯くして、図１に示すように、目的とするインダクタ１を得ることができる。
得られたインダクタ１と、公知の同型のインダクタとについて、チョークコイルの直流重畳特性（１００ｋＨｚ、１Ｖ）を取ったところ、図７に示すように、得られたインダクタ１は必要直流重畳値で必要インダクタンス値が取れることを確認できた。ここでは、例えば、直流重畳値ＩＬ＝２０Ａ時、インダクタンス値が５μＨ以上あることを確認した。
ここで、線材２に通電する電流は、図８（ａ）に示す直流、図８（ｂ）に示す交流、図４（ｃ）に示す脈流、図８（ｄ）に示す矩形を重畳した交流、図８（ｅ）に示す直流を重畳した交流の何れでも良い（請求項１１）。
【００２７】
また、本実施形態では、磁性粉末３を入れた容器６にコイル部４を配し、コイル部４に電流を通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成した後に、磁性粉末３を電磁吸着した状態で、容器６より取り出し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布した状態で、コイル部４への電流値を高め、コイル部４からの発熱で結着材５を硬化させ、磁性粉末５とコイル部４とを結着材５で被覆して成る結着材層９を形成したが、磁性粉末３を入れた容器６にコイル部４を配し、コイル部４に電流を通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成した後に、磁性粉末３を電磁吸着した状態で、容器６より取り出し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布した状態で、コイル部４を、例えば、オーブンなどの加熱器（図示せず）にて加熱し結着材５を加熱硬化して磁性粉末３とコイル部４とを結着材５で被覆するようにしても良い（請求項２）。
【００２８】
また、本実施形態では、磁性粉末３を入れた容器６にコイル部４を配し、コイル部４に電流を通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成した後に、磁性粉末３を電磁吸着した状態で、容器６より取り出し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布した状態で、コイル部４への電流値を高め、コイル部４からの発熱で結着材５を硬化させ、磁性粉末５とコイル部４とを結着材５で被覆して成る結着材層９を形成したが、例えば、噴霧や浸漬などにて結着材５を付着した磁性粉末３を入れた容器６にコイル部４を配し、コイル部４に電流を通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成した後に、磁性粉末３を電磁吸着した状態で、容器６より取り出し、コイル部４への電流値を高めて結着材５を加熱硬化して磁性粉末３とコイル部４とを結着材５で被覆して成る結着材層９を形成するようにしても良い（請求項３）。
【００２９】
また、本実施形態では、磁性粉末３を入れた容器６にコイル部４を配し、コイル部４に電流を通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成した後に、磁性粉末３を電磁吸着した状態で、容器６より取り出し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布し、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布した状態で、コイル部４への電流値を高め、コイル部４からの発熱で結着材５を硬化させ、磁性粉末５とコイル部４とを結着材５で被覆して成る結着材層９を形成したが、例えば、噴霧や浸漬などにて結着材５を付着した磁性粉末３を入れた容器６にコイル部４を配し、コイル部４に電流を通電し、コイル部４の周囲に電磁吸着により磁性粉末３を吸着したコア部を形成した後に、磁性粉末３を電磁吸着した状態で、容器６より取り出し、コイル部４を、例えば、オーブンなどの加熱器（図示せず）にて加熱し、結着材５を加熱硬化して磁性粉末３とコイル部４とを結着材５で被覆して成る結着材層９を形成するようにしても良い（請求項４）。
【００３０】
なお、本実施形態において、例えば、図９に示すように、容器６に機械的振動を加えることができるカム機構１０Ａ，１０Ｂを取り付け、電磁吸着時に磁性粉末３に機械的振動を与えて磁性粉末３の充填度を高めても良い。また、図１０に示すように、容器６に真空ポンプ１１を取り付け、電磁吸着時に容器６内を真空状態にして磁性粉末３の充填度を高めても良い。
また、本実施形態では、結着材層９は、外装を形成し、内部の磁性粉末３が結着材５によって拘束されることがない場合について説明したが、結着材５が内部にまで浸透して磁性粉末３をともに結着しても良い（請求項１０）。
また、本実施形態では、磁性粉末３を電磁吸着した状態で、電磁吸着されている磁性粉末３とともにコイル部４に結着材５を塗布したが、結着材５に浸漬しても良い（請求項１２）。
【００３１】
また、本実施形態では、１本の線材２を螺旋状に巻回して形成したコイル部４を用いる場合について説明したが、図４に示すように、例えば、２本の線材２を同時に螺旋状に巻回してコイル部４を形成しても良い（請求項５〜請求項８）。勿論、線材２の本数は、２本以上であれば任意である。
また、本実施形態では、直線状の巻線をドーナツ形状に形成する場合について説明したが、線材２を螺旋状に巻回しながらドーナツ形状に形成することも可能である。
本発明におけるトランスは、一次巻線および二次巻線の少なくとも何れか一方にインダクタ１を用いることによって達成される。
なお、その基本構成は、従来のトランスと同様であるので、具体的な開示は省略する。
【００３２】
【発明の効果】
本発明によれば、磁束のなかでコアを形成するため、磁性体が方向性を持つ場合、磁性体の方向が均一となる。
また、磁性粉末を電磁吸着しながら通電して硬化させるため、磁性粉末を理想的な分布で固定できる。
また、磁束のなかでコアを形成させるため、磁束密度を保つのに必要な最小量の磁性粉末だけを使用するので、材料費のコストを低減できる。
また、吸着する時の電流の値を変化することで完成したコイルのインダクタンスをコントロールできる。
【００３３】
また、本発明をトロイダルコイルに適用した場合には、螺旋状に巻回した巻線をドーナツ形状にしてコアを形成するため、従来のようにドーナツ状のコアにコイルを巻く必要がなく工数が大幅に低減できる。
また、磁性粉末が緻密に充填できる。
また、磁性粉末に電気的振動が加わるため、さらに緻密に充填できる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係るインダクタ１を示す平面図である。
【図２】図１に用いるコイル部を示す平面図である。
【図３】図１のインダクタ１の縦断面図である。
【図４】図１に用いる別のコイル部を示す平面図である。
【図５】図１のインダクタ１の製造方法を示す説明図である。
【図６】図１のインダクタ１の製造時の磁性粉末の吸着量と電流との関係を示すグラフである。
【図７】図１のインダクタと従来のインダクタとの直流重畳特性を示すグラフである。
【図８】本発明の一実施形態に係るインダクタ１の製造方法に使用する通電条件を示す説明図である。
【図９】図１のインダクタ１を製造する際の容器への機械的振動を与える例を示す説明図である。
【図１０】図１のインダクタ１を製造する際の容器内を真空状態にするための例を示す説明図である。
【符号の説明】
１インダクタ
２線材
３磁性粉末
４コイル部
５結着材
６容器
７電源
８導線
９結着材層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing an inductor having a hollow core applied to, for example, a power inductor used for a power source, a noise filter coil, a switching transformer, and the like.
[0002]
[Prior art]
Conventionally, various inductors and transformers are known.
For example, a coil formed by embedding the whole or a part of a winding in a magnetic medium made of a binder mixed with magnetic powder and a manufacturing method thereof are known (for example, see Patent Document 1).
Winding a mold with a hollow part of a predetermined shape, filling the hollow part with flaky magnetic powder or intermittently passing a direct current through the winding, and further impregnating and solidifying with an insulating resin into a predetermined shape A method of manufacturing a dust core for obtaining a molded dust core is known (see, for example, Patent Document 2).
[0003]
After preparing a coil with winding on an insulating bobbin centered on the center and a storage case with one open end, insert the coil into the storage case so that the central axes of both are aligned An inductor that fills with ferromagnetic powder so that the entire coil is embedded and then seals the opening of the storage case and a method for manufacturing the same are known (for example, see Patent Document 3).
[0004]
2. Description of the Related Art An inductor in which an electric wire having a coating layer made of soft magnetic powder and a thermoplastic polymer is prepared on the outer periphery of a core wire, and this is wound into an air core coil shape, and a manufacturing method thereof are known (for example, Patent Documents) 4).
A core for EMI countermeasures is known, which is made by mixing a magnetic material with high permeability and high resistivity into an insulating material that has clay-like elasticity and viscosity and solidifies when irradiated with heat or ultraviolet rays. (For example, see Patent Document 5).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 54-163354 [Patent Document 2]
JP-A-57-39516 [Patent Document 3]
JP-A-5-159934 [Patent Document 4]
JP-A-6-36937 [Patent Document 5]
JP-A-10-275994 [0006]
[Problems to be solved by the invention]
However, in the coil and the manufacturing method thereof according to Patent Document 1, since the whole or a part of the winding is embedded in the magnetic medium by solidifying the magnetic medium, the direction of the magnetic body is determined when the magnetic body has directionality. It is difficult to make uniform. In addition, since there is a deviation in the characteristics of the magnetic material, there is a problem that characteristics such as inductance vary.
Further, in the method of manufacturing a dust core and a dust core coil according to Patent Document 2, a dust core obtained by impregnating and solidifying an insulating resin and molded into a predetermined shape is obtained. It is difficult to make the body direction uniform. In addition, since there is a deviation in the characteristics of the magnetic material, there is a problem that characteristics such as inductance vary.
[0007]
In addition, in the inductor and the manufacturing method thereof according to Patent Document 3, after the coil is inserted into the storage case so that the central axes of both coincide, the ferromagnetic powder is filled so that the entire coil is embedded, After that, since the opening of the storage case is sealed, there is a problem that it is difficult to accurately fill the ferromagnetic powder and uneven filling tends to occur.
In addition, in the inductor and the manufacturing method thereof according to Patent Document 4, since the soft magnetic powder is solidified by the thermoplastic polymer, it is difficult to make the direction of the magnetic body uniform when the magnetic body has directionality. In addition, since there is a deviation in the characteristics of the magnetic material, there is a problem that characteristics such as inductance vary.
[0008]
In the EMI countermeasure core according to Patent Document 5, a magnetic material having a high magnetic permeability and a high resistivity is mixed in the insulating material to be solidified. It is difficult to make the body direction uniform. In addition, since there is a deviation in the characteristics of the magnetic material, there is a problem that characteristics such as inductance vary.
[0009]
On the other hand, the conventional toroidal core has a problem that it requires a complicated man-hour for winding into a toroidal shape by pressing. For this reason, there is a problem that the toroidal core is expensive.
Further, in the conventional toroidal core, there is a problem in that since there is a gap in the magnetic body, a leakage magnetic flux is generated, and the magnetic flux is easily biased in the vicinity of the gap. Therefore, when used as a switching converter, the leakage magnetic flux due to the gap causes a surge and noise due to switching off.
The transformer has the same problem as the inductor.
[0010]
The present invention has been made in order to solve such a conventional problem, and the object thereof is an inductor capable of making the direction of the magnetic body uniform when it is easy to manufacture and the magnetic body has directionality. It is in providing the manufacturing method of.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, a coil portion formed by forming a linear winding formed by spirally winding a wire rod in a container containing magnetic powder in a donut shape is arranged, and current is passed through the coil portion. Then, the step of forming the core part by adsorbing the magnetic powder by electromagnetic adsorption around the coil part, and with the core part formed, the coil part is taken out of the container and electromagnetically adsorbed. A step of applying a binder to the coil portion together with the magnetic powder, and increasing a current value to the coil portion in a state where the binder is applied to the coil portion together with the magnetic powder that is electromagnetically adsorbed; And the step of curing the binder with heat generated from a portion to form a binder layer formed by coating the magnetic powder and the coil portion with the binder.
[0012]
According to a second aspect of the present invention, a coil portion formed by forming a linear winding formed by spirally winding a wire rod in a container containing magnetic powder in a donut shape is arranged, and current is passed through the coil portion. Then, the step of forming the core part by adsorbing the magnetic powder by electromagnetic adsorption around the coil part, and with the core part formed, the coil part is taken out of the container and electromagnetically adsorbed. A step of applying a binder to the coil part together with the magnetic powder, and heating the coil part with a heater in a state where the binder is applied to the coil part together with the magnetic powder that is electromagnetically adsorbed; And a step of forming a binder layer formed by heating and curing the binder and covering the magnetic powder and the coil portion with the binder.
[0013]
In the invention according to claim 3, a coil portion formed by forming a linear winding formed by spirally winding a wire in a donut shape in a container containing magnetic powder with a binder attached thereto, A step of forming a core part by passing an electric current through the coil part and electromagnetically attracting the magnetic powder to the coil part by electromagnetic adsorption around the coil part; and the coil part in a state where the core part is formed. Is removed from the container, the current value to the coil part is increased, and the binder is heated and cured to form a binder layer formed by coating the magnetic powder and the coil part with the binder. And a process.
[0014]
In the invention according to claim 4, a coil portion formed by forming a linear winding formed by spirally winding a wire in a donut shape in a container containing magnetic powder with a binder attached thereto, A step of forming a core part by passing an electric current through the coil part and electromagnetically attracting the magnetic powder to the coil part by electromagnetic adsorption around the coil part; and the coil part in a state where the core part is formed. Is removed from the container, the coil part is heated with a heater, and the binder is heated and cured to form a binder layer formed by coating the magnetic powder and the coil part with the binder. And a step of performing.
[0015]
According to a fifth aspect of the present invention, a coil portion formed by winding a plurality of wires simultaneously in a spiral shape in a container containing magnetic powder and forming a donut shape is provided, and a current is passed through the coil portion. A step of forming the core part by adsorbing the magnetic powder around the coil part by electromagnetic adsorption, and with the core part formed, the coil part is taken out of the container and together with the magnetic powder being electromagnetically adsorbed A step of applying a binding material to the coil portion, and a state in which the binding material is applied to the coil portion together with the magnetic powder that has been electromagnetically adsorbed to increase the current value to the coil portion and generate heat from the wire. And the step of curing the binder and forming a binder layer formed by coating the magnetic powder and the wire with the binder.
[0016]
According to a sixth aspect of the present invention, a coil portion formed by forming a linear winding formed by spirally winding a plurality of wire rods into a container containing magnetic powder in a donut shape is disposed, and the coil portion is disposed in the coil portion. A step of forming a core part by energizing an electric current and adsorbing the magnetic powder around the coil part by electromagnetic adsorption, and with the core part formed, the coil part is taken out from the container and electromagnetically adsorbed. Applying the binder to the coil portion together with the magnetic powder, and applying the binder to the coil portion together with the magnetically adsorbed magnetic powder in a heater. And a step of forming a binder layer formed by heating and curing to coat the magnetic powder and the wire with the binder.
[0017]
According to a seventh aspect of the present invention, there is provided a coil portion formed by forming a linear winding formed by spirally winding a plurality of wire rods in a container containing a magnetic powder having a binding material attached thereto in a donut shape. A step of forming a core portion by energizing a current to the coil portion and electromagnetically attracting the magnetic powder to the coil portion by electromagnetic adsorption around the coil portion; A binder layer formed by taking out the coil portion from the container, increasing the current value to the coil portion, heat-curing the binder, and coating the magnetic powder and the coil portion with the binder. And a step of forming the structure.
[0018]
According to an eighth aspect of the present invention, there is provided a coil portion formed by forming a linear winding formed by spirally winding a plurality of wire rods in a container containing a magnetic powder having a binding material attached thereto in a donut shape. A step of forming a core portion by energizing a current to the coil portion and electromagnetically attracting the magnetic powder to the coil portion by electromagnetic adsorption around the coil portion; The coil part is taken out from the container, the coil part is heated with a heater, the binder is heated and cured, and the magnetic powder and the coil part are covered with the binder. And a step of forming a layer.
[0019]
The invention according to claim 9 is the inductor manufacturing method according to any one of claims 1 to 8, wherein only the exterior of the binder layer is cured, and the magnetic powder inside is bound to the binder. It is characterized by not being restrained by the material.
The invention according to claim 10 is the method of manufacturing an inductor according to any one of claims 1 to 8, wherein the binder layer includes an outer sheath and the magnetic powder in the inside being restrained by the binder. It is characterized by.
According to an eleventh aspect of the present invention, in the inductor manufacturing method according to any one of the first to eighth aspects, a direct current, an alternating current, a pulsating current, a rectangle, or a direct current is superimposed on the current supplied to the coil portion. It is characterized by alternating current.
The invention according to claim 12 is the inductor manufacturing method according to any one of claims 1, 2, 5, and 6, wherein the coil portion is coupled with the magnetic powder that is electromagnetically adsorbed. It is characterized by being immersed in a dressing.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
1 and 3 show an inductor 1 according to an embodiment of the present invention.
The inductor 1 according to the present embodiment is electromagnetically attracted to the coil portion 4 by electromagnetic attraction generated when the coil portion 4 formed by forming a linear winding formed by spirally winding the wire 2 into a donut shape is energized. The magnetic powder 3 is used as a core portion, and the coil portion 4 is continuously energized and the binder material 5 is applied to the core portion together with the coil portion 4. Thereafter, the binder material 5 is heated by the heat generated by the coil portion 4. It is formed by covering with a binder layer 9 formed by curing.
[0021]
As shown in FIG. 2, the coil portion 4 includes, for example, a linear winding formed by spirally winding an enamel-coated copper wire having a wire diameter (diameter) of 1 mm with a concentric diameter of 11 mm and a pitch of 2 mm 30 times. And a donut shape having an inner diameter of 8 mm and an outer diameter of 30 mm.
Here, the wire 2 is made of, for example, a copper wire, an aluminum wire or the like having an insulating film such as enamel or polyurethane. The diameter and length can be arbitrarily determined according to the purpose of use.
Further, as the magnetic powder 3, for example, an Fe—Si—B amorphous alloy powder having a stoichiometric composition represented by an atomic ratio of (Fe0.97Cr0.03) 76 (Si0.5B0.5) 22C2 or the like was used. . The powder particle size is 45 μm or less or 150 μm or less. Further, when comparing the inductance and direct current superposition characteristics of a coil formed of an amorphous alloy of 45 μm or less and an amorphous alloy of 150 μm or less, the amorphous alloy of 150 μm or less was excellent.
The binder 5 is made of, for example, a thermosetting resin, a solvent-based adhesive, water glass, or the like.
[0022]
In the inductor 1 according to the present embodiment, for example, as shown in FIG. 3, the magnetic powder 3 is attracted to the inner side 4 a and the outer side 4 b of the coil part 4 by energizing the coil part 4 to form a core part, The core portion is formed so as to be surrounded by the binder layer 9.
Therefore, according to the inductor 1 which concerns on this embodiment, unlike the conventional toroidal core, a reactor without a gap in a core part is realizable.
Thus, if it is made gapless, it becomes possible to reduce a leakage magnetic flux, and it can prevent the increase in winding green resistance by a proximity effect, and can reduce a copper loss.
In addition, it is possible to prevent an increase in core loss iron loss by eliminating magnetic flux bias in the vicinity of the gap.
Further, when used as a switching converter, the leakage magnetic flux due to the gap causes a surge and noise due to switching off of the switching. However, according to the inductor 1 according to the present embodiment, such a problem can be solved. It becomes possible.
[0023]
As described above, it is not easy to wind the already formed toroidal core, and there is a problem in mass production by mechanization in particular. For this reason, there existed a malfunction that a reactor became expensive.
On the other hand, according to the inductor 1 according to the present embodiment, the magnetic powder 3 is used for the coil portion 4, the procedure for winding the toroidal core is omitted, and the toroidal reactor is configured at a low price with almost only material costs. There is an advantage that you can.
According to the inductor 1 according to the present embodiment, the magnetic powder 3 forming the core portion is adsorbed on the inner side 4a and the outer side 4b of the coil portion 4 to form the core portion, and this core portion is the binder layer 9. Because it is surrounded and formed by, it does not leak out.
In addition, since the magnetic direction of the magnetic powder 3 in the core is made uniform during electromagnetic adsorption, the direction of the magnetic body cannot be made uniform when the magnetic body has directionality as in the prior art. Does not occur.
[0024]
In the present embodiment, the case where the binder layer 9 forms an exterior and the magnetic powder 3 inside the core is not restrained by the binder 5 has been described. However, the binder is inside the core. The magnetic powder 3 may be bonded together.
In this case, the magnetic powder 3 inside the core binds the magnetic powder 3 with the binder 5 while keeping the magnetic direction of the magnetic powder 3 uniform during electromagnetic adsorption. When the body has directionality, the problem that the direction of the magnetic body cannot be made uniform does not occur.
[0025]
Next, a method for manufacturing the inductor 1 according to the present embodiment will be described with reference to FIG. 5 (corresponding to claims 1 to 4 and claim 9).
First, as shown in FIG. 5 (a), a coil part 4 is arranged in a container 6 containing magnetic powder 3, and the coil part 4 is connected to a power source 7 via a conducting wire 8, and the coil part 4 is supplied with a current 6A. Energization is performed to form a core portion that adsorbs the magnetic powder 3 by electromagnetic adsorption around the coil portion 4.
Here, adsorption | suction of the magnetic powder 3 is demonstrated based on FIG. When the current to the coil part 4 was 3 A or less, the attractive force was poor. A suitable amount of adsorption was obtained when the current to the coil part 4 exceeded 3A and reached 8A. When the current to the coil part 4 exceeds 8 A, the attractive force becomes strong, and the magnetic powder 3 has leaked from the outside of the coil part 4. From the above results, in the present embodiment, it was determined that the energization current value is 4A to 8A, preferably 6A to 8A.
[0026]
Next, as shown in FIG. 5B, the coil portion 4 is taken out from the container 6 with the magnetic powder 3 electromagnetically adsorbed, and the binder 5 is applied to the wire 2 together with the magnetic powder 3 that has been electromagnetically adsorbed. To do.
Next, as shown in FIG. 5C, the current value to the coil portion 4 is increased, and the binder 5 is cured by heat generated from the coil portion 4 to form the binder layer 9. After the binder layer 9 is cured, the power is turned off. This operation is performed at room temperature.
Here, when an epoxy resin was used as the binder 5 and the current value 6A during electromagnetic adsorption was increased to 20A, the epoxy resin was cured in about 2 minutes.
Thus, the target inductor 1 can be obtained as shown in FIG.
When the DC superposition characteristics (100 kHz, 1 V) of the choke coil were taken with respect to the obtained inductor 1 and the known same type inductor, the obtained inductor 1 is required to have the necessary DC superposition value as shown in FIG. It was confirmed that the inductance value was obtained. Here, for example, when the DC superimposition value IL = 20 A, it was confirmed that the inductance value is 5 μH or more.
Here, the current applied to the wire 2 is superimposed on the direct current shown in FIG. 8 (a), the alternating current shown in FIG. 8 (b), the pulsating flow shown in FIG. 4 (c), and the rectangle shown in FIG. 8 (d). Either an alternating current or an alternating current obtained by superimposing the direct current shown in FIG. 8E may be used.
[0027]
Moreover, in this embodiment, the coil part 4 is arranged in the container 6 containing the magnetic powder 3, the current is supplied to the coil part 4, and the core part that adsorbs the magnetic powder 3 by electromagnetic adsorption around the coil part 4. After the formation, the magnetic powder 3 is taken out from the container 6 in the state of electromagnetic adsorption, and the binder 5 is applied to the coil portion 4 together with the magnetic powder 3 that is electromagnetically adsorbed. In a state in which the binder 5 is applied to the part 4, the current value to the coil part 4 is increased, the binder 5 is cured by heat generated from the coil part 4, and the magnetic powder 5 and the coil part 4 are bound to each other. 5 is formed, the coil part 4 is arranged in the container 6 containing the magnetic powder 3, the current is supplied to the coil part 4, and the coil part 4 is surrounded by electromagnetic adsorption. After forming the core that adsorbs the magnetic powder 3, the magnetic powder 3 is electromagnetically adsorbed. In the state, it is taken out from the container 6, and the binder 5 is applied to the coil portion 4 together with the magnetic powder 3 that is electromagnetically adsorbed, and the binder 5 is applied to the coil portion 4 together with the magnetic powder 3 that is electromagnetically adsorbed Then, the coil part 4 is heated by, for example, a heater (not shown) such as an oven to heat and cure the binder 5 so that the magnetic powder 3 and the coil part 4 are covered with the binder 5. (Claim 2).
[0028]
Moreover, in this embodiment, the coil part 4 is arranged in the container 6 containing the magnetic powder 3, the current is supplied to the coil part 4, and the core part that adsorbs the magnetic powder 3 by electromagnetic adsorption around the coil part 4. After the formation, the magnetic powder 3 is taken out from the container 6 in the state of electromagnetic adsorption, and the binder 5 is applied to the coil portion 4 together with the magnetic powder 3 that is electromagnetically adsorbed. In a state in which the binder 5 is applied to the part 4, the current value to the coil part 4 is increased, the binder 5 is cured by heat generated from the coil part 4, and the magnetic powder 5 and the coil part 4 are bound to each other. 5 is formed. For example, the coil part 4 is arranged in a container 6 containing the magnetic powder 3 to which the binder 5 is adhered by spraying or dipping. The magnetic powder 3 was adsorbed around the coil part 4 by electromagnetic adsorption. After the magnetic part 3 is formed, the magnetic powder 3 and the coil part 4 are taken out from the container 6 with the magnetic powder 3 electromagnetically adsorbed, and the current value to the coil part 4 is increased to heat and cure the binder 5. A binder layer 9 formed by covering with the binder 5 may be formed (claim 3).
[0029]
Moreover, in this embodiment, the coil part 4 is arranged in the container 6 containing the magnetic powder 3, the current is supplied to the coil part 4, and the core part that adsorbs the magnetic powder 3 by electromagnetic adsorption around the coil part 4. After the formation, the magnetic powder 3 is taken out from the container 6 in the state of electromagnetic adsorption, and the binder 5 is applied to the coil portion 4 together with the magnetic powder 3 that is electromagnetically adsorbed. In a state in which the binder 5 is applied to the part 4, the current value to the coil part 4 is increased, the binder 5 is cured by heat generated from the coil part 4, and the magnetic powder 5 and the coil part 4 are bound to each other. 5 is formed. For example, the coil part 4 is arranged in a container 6 containing the magnetic powder 3 to which the binder 5 is adhered by spraying or dipping. The magnetic powder 3 was adsorbed around the coil part 4 by electromagnetic adsorption. After forming the portion, the magnetic powder 3 is taken out from the container 6 while being electromagnetically adsorbed, and the coil portion 4 is heated by a heater (not shown) such as an oven to heat the binder 5. The binder layer 9 may be formed by curing and coating the magnetic powder 3 and the coil portion 4 with the binder 5 (claim 4).
[0030]
In this embodiment, for example, as shown in FIG. 9, cam mechanisms 10A and 10B capable of applying mechanical vibration are attached to the container 6, and the magnetic powder 3 is mechanically vibrated during electromagnetic adsorption to provide magnetic powder. The filling degree of 3 may be increased. Further, as shown in FIG. 10, a vacuum pump 11 may be attached to the container 6 to increase the filling degree of the magnetic powder 3 by making the container 6 in a vacuum state during electromagnetic adsorption.
Further, in the present embodiment, the case where the binder layer 9 forms an exterior and the internal magnetic powder 3 is not restrained by the binder 5 has been described. The magnetic powder 3 may penetrate and bind together (claim 10).
In the present embodiment, the binding material 5 is applied to the coil portion 4 together with the magnetic powder 3 that is electromagnetically adsorbed in a state where the magnetic powder 3 is electromagnetically adsorbed, but may be immersed in the binding material 5 ( Claim 12).
[0031]
Moreover, although this embodiment demonstrated the case where the coil part 4 formed by spirally winding the one wire 2 was used, as shown in FIG. 4, for example, two wires 2 are simultaneously spiraled. The coil part 4 may be formed by being wound around (Claim 5 to Claim 8). Of course, the number of the wires 2 is arbitrary as long as it is two or more.
Moreover, although this embodiment demonstrated the case where a linear coil | winding was formed in a donut shape, it is also possible to form in a donut shape, winding the wire 2 helically.
The transformer in the present invention is achieved by using the inductor 1 for at least one of the primary winding and the secondary winding.
Since the basic configuration is the same as that of a conventional transformer, a specific disclosure is omitted.
[0032]
【The invention's effect】
According to the present invention, since the core is formed in the magnetic flux, when the magnetic body has directionality, the direction of the magnetic body becomes uniform.
In addition, since the magnetic powder is cured by energization while electromagnetically adsorbing, the magnetic powder can be fixed in an ideal distribution.
Further, since the core is formed in the magnetic flux, only the minimum amount of magnetic powder necessary to maintain the magnetic flux density is used, so that the material cost can be reduced.
Moreover, the inductance of the completed coil can be controlled by changing the value of the current when attracted.
[0033]
In addition, when the present invention is applied to a toroidal coil, since the core is formed by forming a spirally wound winding in a donut shape, it is not necessary to wind the coil around the donut-shaped core as in the conventional case, and man-hours are increased. It can be greatly reduced.
Also, the magnetic powder can be densely filled.
Further, since electric vibration is applied to the magnetic powder, it can be filled more densely.
[Brief description of the drawings]
FIG. 1 is a plan view showing an inductor 1 according to an embodiment of the present invention.
FIG. 2 is a plan view showing a coil portion used in FIG.
3 is a longitudinal sectional view of the inductor 1 of FIG.
4 is a plan view showing another coil unit used in FIG. 1. FIG.
FIG. 5 is an explanatory diagram showing a method for manufacturing the inductor 1 of FIG. 1;
6 is a graph showing the relationship between the amount of magnetic powder adsorbed and the current when the inductor 1 of FIG. 1 is manufactured. FIG.
FIG. 7 is a graph showing DC superposition characteristics of the inductor of FIG. 1 and a conventional inductor.
FIG. 8 is an explanatory diagram showing energization conditions used in the method for manufacturing the inductor 1 according to one embodiment of the present invention.
FIG. 9 is an explanatory view showing an example in which mechanical vibration is applied to the container when the inductor 1 of FIG. 1 is manufactured.
10 is an explanatory view showing an example for making the inside of the container in a vacuum state when the inductor 1 of FIG. 1 is manufactured; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inductor 2 Wire material 3 Magnetic powder 4 Coil part 5 Binder 6 Container 7 Power supply 8 Conductor 9 Binder layer

Claims

A coil part formed by forming a linear winding formed by winding a wire in a spiral shape in a container containing magnetic powder in a donut shape is arranged, and a current is passed through the coil part to surround the coil part. Forming a core portion by adsorbing the magnetic powder by electromagnetic adsorption;
With the core portion formed, the step of taking out the coil portion from the container and applying a binder to the coil portion together with the magnetic powder that is electromagnetically adsorbed;
In a state where the binder is applied to the coil part together with the magnetic powder that is electromagnetically adsorbed, the current value to the coil part is increased, and the binder is cured by heat generated from the coil part, and the magnetic powder And a step of forming a binder layer formed by coating the coil portion with the binder.

A coil part formed by forming a linear winding formed by winding a wire in a spiral shape in a container containing magnetic powder in a donut shape is arranged, and a current is passed through the coil part to surround the coil part. Forming a core portion by adsorbing the magnetic powder by electromagnetic adsorption;
With the core portion formed, the step of taking out the coil portion from the container and applying a binder to the coil portion together with the magnetic powder that is electromagnetically adsorbed;
In a state where a binder is applied to the coil part together with the magnetic powder that is electromagnetically adsorbed, the coil part is heated with a heater, and the binder is heated and cured to provide the magnetic powder and the coil part. And a step of forming a binder layer formed by coating the binder with the binder.

A coil part formed by forming a linear winding formed by spirally winding a wire in a donut shape is placed in a container containing magnetic powder with a binder attached thereto, and a current is passed through the coil part. Forming a core part by electromagnetically adsorbing the magnetic powder to the coil part by electromagnetic adsorption around the coil part;
In a state where the core portion is formed, the coil portion is taken out from the container, the current value to the coil portion is increased, the binder is heated and cured, and the magnetic powder and the coil portion are bonded to the binder. And a step of forming a binder layer formed by coating with an inductor.

A coil part formed by forming a linear winding formed by spirally winding a wire in a donut shape is placed in a container containing magnetic powder with a binder attached thereto, and a current is passed through the coil part. Forming a core part by electromagnetically adsorbing the magnetic powder to the coil part by electromagnetic adsorption around the coil part;
With the core portion formed, the coil portion is taken out from the container, the coil portion is heated with a heater, the binder is heat-cured, and the magnetic powder and the coil portion are bound together. And a step of forming a binder layer formed by coating with a material.

A coil portion formed by winding a plurality of wires simultaneously in a spiral shape in a container containing magnetic powder and forming a donut shape is arranged, and an electric current is passed through the coil portion to cause electromagnetic adsorption around the coil portion. Adsorbing the magnetic powder to form a core part;
With the core portion formed, the step of taking out the coil portion from the container and applying a binder to the coil portion together with the magnetic powder that is electromagnetically adsorbed;
In a state where a binder is applied to the coil part together with the magnetic powder that is electromagnetically adsorbed, the current value to the coil part is increased, and the binder is cured by heat generated from the wire, and the magnetic powder And a step of forming a binder layer formed by coating the wire with the binder. A method for manufacturing an inductor, comprising:

A coil part formed by forming a linear winding formed by spirally winding a plurality of wires in a container containing magnetic powder in a donut shape is arranged, and a current is passed through the coil part to supply the coil part. Forming a core part by adsorbing the magnetic powder by electromagnetic adsorption around
With the core portion formed, the step of taking out the coil portion from the container and applying a binder to the coil portion together with the magnetic powder that is electromagnetically adsorbed;
In a state where the binder is applied to the coil portion together with the magnetic powder that is electromagnetically adsorbed, the binder is heated and cured with a heater to coat the magnetic powder and the wire with the binder. And a step of forming a binder layer comprising: a method of manufacturing an inductor.

A coil portion formed by forming a linear winding formed by spirally winding a plurality of wire rods in a donut shape in a container containing magnetic powder with a binder attached thereto is arranged, and current is supplied to the coil portion. And forming a core part by electromagnetically adsorbing the magnetic powder to the coil part by electromagnetic adsorption around the coil part;
In a state where the core portion is formed, the coil portion is taken out from the container, the current value to the coil portion is increased, the binder is heated and cured, and the magnetic powder and the coil portion are bonded to the binder. And a step of forming a binder layer formed by coating with an inductor.

A coil portion formed by forming a linear winding formed by spirally winding a plurality of wire rods in a donut shape in a container containing magnetic powder with a binder attached thereto is arranged, and current is supplied to the coil portion. And forming a core part by electromagnetically adsorbing the magnetic powder to the coil part by electromagnetic adsorption around the coil part;
With the core portion formed, the coil portion is taken out from the container, the coil portion is heated with a heater, the binder is heat-cured, and the magnetic powder and the coil portion are bound together. And a step of forming a binder layer formed by coating with a material.

In the manufacturing method of the inductor according to any one of claims 1 to 8,
In the method of manufacturing an inductor, only the exterior of the binder layer is cured, and the magnetic powder inside is not constrained by the binder.

In the manufacturing method of the inductor according to any one of claims 1 to 8,
The manufacturing method of an inductor, wherein the binder layer has the outer and inner magnetic powders restrained by the binder.

In the manufacturing method of the inductor given in any 1 paragraph of Claims 1 thru / or 8,
A method of manufacturing an inductor, wherein the current to be passed through the coil section is a direct current, an alternating current, a pulsating current, a rectangle, or an alternating current in which a direct current is superimposed.

In the manufacturing method of the inductor according to any one of claims 1, 2, 5, and 6,
The inductor is manufactured by immersing the coil part in the binder together with magnetic powder that is electromagnetically adsorbed.