JP2004311757A

JP2004311757A - Manufacturing method of coil parts

Info

Publication number: JP2004311757A
Application number: JP2003103954A
Authority: JP
Inventors: Kiyoshi Takagi; 潔高木; Osamu Shimomura; 理下村
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2003-04-08
Filing date: 2003-04-08
Publication date: 2004-11-04
Anticipated expiration: 2023-04-08
Also published as: JP4269753B2

Abstract

【課題】コイル部を磁性粉末に内包して外装部を形成しても、外装部にクラックが発生することを抑制して、生産性を向上したコイル部品の製造方法を提供することを目的としている。
【解決手段】扁平状の電線２１を上下方向にエッジワイズに巻回したコイル部２３を、磁性粉末からなる圧粉体２４で内包するとともに圧粉体２４を再加圧成形して外装部２５を形成したコイル部品において、コイル部２３の巻幅の中央から両端部にかけて径寸法を大きくした巻軸４５に扁平状の電線２１を巻回し、電線２１は、外周側の厚み寸法２７を内周側の厚み寸法２８より小さくしており、コイル部２３は、隣接する電線２１の内周側側辺の中点の間隔２９より隣接する電線の外周側側辺の中点の間隔３０を小さくするとともに、外周側の巻幅寸法３１を内周側の巻幅寸法３２より小さくした方法としたものである。
【選択図】図１An object of the present invention is to provide a method of manufacturing a coil component in which the occurrence of cracks in the exterior part is suppressed and the productivity is improved even when the exterior part is formed by enclosing the coil part in magnetic powder. I have.
A coil part (23) in which a flat electric wire (21) is wound edgewise in a vertical direction is enclosed by a compact (24) made of magnetic powder, and the compact (24) is pressed again to form an exterior part (25). The flat wire 21 is wound around a winding shaft 45 having a larger diameter from the center of the winding width of the coil portion 23 to both ends, and the wire 21 has an inner circumferential thickness 27 on the outer circumferential side. The thickness of the coil portion 23 is smaller than the thickness 29 on the side, and the coil portion 23 makes the interval 30 between the middle points on the outer peripheral side of the adjacent electric wire smaller than the interval 29 between the midpoints on the inner peripheral side of the adjacent electric wire 21. At the same time, the winding width dimension 31 on the outer peripheral side is smaller than the winding width dimension 32 on the inner peripheral side.
[Selection diagram] Fig. 1

Description

【０００１】
【発明の属する技術分野】
本発明は、各種電子機器に使用するコイル部品の製造方法に関するものである。
【０００２】
【従来の技術】
従来のコイル部品について、図面を参照しながら説明する。
【０００３】
図９は従来のコイル部品の断面図、図１０は同斜視図である。
【０００４】
図９、図１０において従来のコイル部品は、絶縁層を被覆した扁平状の電線１を上下方向にエッジワイズに巻回するとともに貫通孔２を有したコイル部３と、絶縁樹脂を被覆した磁性粉体でコイル部３を内包した外装部４と、コイル部３の両端部を外装部４から突出させた端子部５とを備えていた。
【０００５】
このとき、コイル部３を形成した電線１は、図１１（ａ）のコイル部形成前の電線の断面図、図１１（ｂ）のコイル部形成後の電線の断面図に示すように、コイル部３形成前の断面長方形形状の電線１をエッジワイズに巻回したことで、コイル部３の外周側が引き伸ばされて電線１の外周側の厚み６が内周側の厚み７より薄くなっており、コイル部３の外周側の隣接した電線１の間に隙間８が形成されていた。
【０００６】
そして、磁性粉末でこのコイル部３を内包するとともに加圧成形して外装部４を形成してコイル部品を構成していた。
【０００７】
尚、この出願の発明に関連する先行技術文献情報としては、例えば、特許文献１が知られている。
【０００８】
【特許文献１】
特開２００２−２０３７３１号公報
【０００９】
【発明が解決しようとする課題】
上記従来の構成では、コイル部３の外周側の隣接する電線１の間に隙間８があるので、磁性粉末を加圧成形して外装部４を形成する際に、図１２の従来のコイル部品の外装部成形時の加圧状態を示した断面図に示すように、コイル部３の隣接した電線１の間の隙間８が加圧９によって押し潰されて小さくなり、加圧成形時の加圧９がなくなると、図１３の従来のコイル部品の外装部成形時の除圧した状態を示す断面図に示すように、コイル部３のスプリングバックによって、コイル部３の隣接した電線１間の隙間８が元に戻ろうとする力が働き、外装部４を外方に押し戻して外装部４にクラック１０が発生する恐れがあった。
【００１０】
このように、隣接する電線１の外周側に隙間８を有したコイル部３を磁性粉末で内包しているので、外装部４の加圧成形後にコイル部３のスプリングバックによって、外装部４にクラック１０が発生して、生産上の歩留まりが悪いといった問題点を有していた。
【００１１】
本発明は上記従来の問題点を解決するもので、コイル部を磁性粉末に内包して外装部を形成しても、外装部にクラックが発生することを抑制して、生産性を向上したコイル部品の製造方法を提供することを目的としている。
【００１２】
【課題を解決するための手段】
上記目的を達成するために本発明は以下の構成を有する。
【００１３】
本発明の請求項１に記載の発明は、扁平状の電線を上下方向にエッジワイズに巻回するコイル部形成工程と、絶縁材を被覆した磁性粉末を加圧成形して圧粉体を形成する圧粉体形成工程と、コイル部の両端部を突出させるとともに圧粉体にコイル部を内包するように圧粉体を再加圧成形して外装部を形成した外装部形成工程とを備え、コイル部形成工程は、コイル部の巻幅の中央から両端部にかけて径寸法を大きくした巻軸に扁平状の電線を巻回し、隣接する電線の内周側側辺の中点の間隔より隣接する電線の外周側側辺の中点の間隔を小さくするとともに、外周側の巻幅寸法を内周側の巻幅寸法より小さくして巻回した方法である。
【００１４】
上記構成により、コイル部形成工程は、コイル部の巻幅の中央から両端部にかけて径寸法を大きくした巻軸に扁平状の電線を巻回し、隣接する電線の内周側側辺の中点の間隔より隣接する電線の外周側側辺の中点の間隔を小さくするとともに外周側の巻幅寸法を内周側の巻幅寸法より小さくして巻回したので、コイル部の隣接した電線の間の隙間を小さくして、圧粉体を再加圧成形して外装部を形成した後にコイル部のスプリングバックによる外装部を外方に押出す力を小さくすることができ、外装部にクラックが発生することを抑制することができる。
【００１５】
本発明の請求項２に記載の発明は、特に、コイル部は、隣接する電線が密接するように巻回した方法である。
【００１６】
上記方法により、コイル部は、隣接する電線が密接するように巻回したので、コイル部の隣接した電線の間の隙間をなくして、圧粉体を再加圧成形して外装部を形成した後にコイル部のスプリングバックによる外装部を外方に押出す力をより小さくして、外装部にクラックが発生することをより抑制することができる。
【００１７】
本発明の請求項３に記載の発明は、電線を巻回する巻軸は、コイル部の径寸法の最小部で上下に分割可能な巻軸とした方法である。
【００１８】
上記方法により、電線を巻回する巻軸は、コイル部の径寸法の最小部で上下に分割可能な巻軸としたので、巻幅の中央より両端部の径寸法を大きくした巻軸に扁平状の電線を巻回した後に、巻軸を上下に分割すれば、巻軸からコイル部を容易に取り出すことができる。
【００１９】
本発明の請求項４に記載の発明は、特に、圧粉体形成工程は、熱硬化性樹脂を含有した結合材と磁性粉末とを熱硬化性樹脂が熱硬化しないように非加熱状態で混合するとともに加圧成形しており、外装部形成工程は、コイル部を被覆するように圧粉体を再加圧成形するとともに熱硬化性樹脂が熱硬化するように加熱成形した方法である。
【００２０】
上記方法により、圧粉体形成工程は、熱硬化性樹脂を含有した結合材と磁性粉末とを熱硬化性樹脂が熱硬化しないように非加熱状態で混合するとともに加圧成形しており、外装部形成工程は、コイル部を被覆するように圧粉体を再加圧成形するとともに熱硬化性樹脂が熱硬化するように加熱成形しているので、圧粉体でコイル部を内包するとともに圧粉体を再加圧成形して外装部を形成する際に、圧粉体を加熱成形すれば熱硬化性樹脂を含有した結合材を硬化することができ、外装部を形成後にクラックが発生することをより抑制することができる。
【００２１】
本発明の請求項５に記載の発明は、特に、圧粉体は、背面部に中脚部と外脚部を有した断面Ｅ字形状にするとともに２個形成した方法である。
【００２２】
上記方法により、圧粉体は、背面部に中脚部と外脚部を有した断面Ｅ字形状にするとともに２個形成したので、圧粉体でコイル部を内包する際に、圧粉体でコイル部を的確に位置決めすることができる。
【００２３】
本発明の請求項６に記載の発明は、特に、圧粉体は、２つの圧粉体の中脚部および外脚部の高さ寸法の総和をコイル部の内周側の巻幅寸法より大きくするとともに、中脚部の高さ寸法の総和より外脚部の高さ寸法の総和を大きくした方法である。
【００２４】
上記方法により、圧粉体は、２つの前記圧粉体の中脚部および外脚部の高さ寸法の総和をコイル部の内周側の巻幅寸法より大きくするとともに、中脚部の高さ寸法の総和より外脚部の高さ寸法の総和を大きくしているので、外脚部側の圧粉体の磁性粉末の量を多くして、コイル部の外周側の巻幅寸法が内周側の巻幅寸法より小さい寸法でも、外装部を形成する際に、外脚部の圧粉体がくずれてまわり込み的確にコイル部を内包することができる。
【００２５】
本発明の請求項７に記載の発明は、特に、圧粉体は、中脚部を根元側が太い断面台形形状にした方法である。
【００２６】
上記方法により、圧粉体は、中脚部を根元側が太い断面台形形状にしているので、貫通孔の内径を巻軸方向中央から両端にかけて大きくしても、コイル部を的確に内包することができる。
【００２７】
本発明の請求項８に記載の発明は、圧粉体は、コイル部の内周側に対応する背面部よりコイル部の外周部に対応する背面部の厚み寸法を大きくした構成である。
【００２８】
上記方法により、圧粉体は、コイル部の内周側に対応する背面部よりコイル部の外周部に対応する背面部の厚み寸法を大きくしているので、コイル部の外周側の巻幅寸法が内周側の巻幅寸法より小さい寸法でも、コイル部を的確に内包することができる。
【００２９】
【発明の実施の形態】
以下、本発明の一実施の形態におけるコイル部品について図面を参照しながら説明する。
【００３０】
図１は本発明の一実施の形態のコイル部品の断面図、図２は同斜視図、図３（ａ）は同要部であるコイル部の断面図、図３（ｂ）は同要部であるコイル部の平面図、図４（ａ）は同要部である圧粉体の斜視図、図４（ｂ）は同要部である圧粉体の断面図、図５は同要部である外装部形成後の斜視図である。
【００３１】
図１〜図５において、本発明の一実施の形態におけるコイル部品は、扁平状の電線２１を上下方向にエッジワイズに巻回するとともに貫通孔２２を有したコイル部２３と、絶縁材を被覆した磁性粉末からなる圧粉体２４でコイル部２３を内包するとともに圧粉体２４を再加圧成形した外装部２５と、コイル部２３の両端部を外装部２５から突出させた端子部２６とを備えている。
【００３２】
このとき、コイル部２３を形成した電線２１は、外周側の厚み寸法２７を内周側の厚み寸法２８より小さくしており、コイル部２３は、隣接する電線２１の内周側側辺の中点の間隔２９より隣接する電線の外周側側辺の中点の間隔３０を小さくするとともに、外周側の巻幅寸法３１を内周側の巻幅寸法３２より小さくしている。
【００３３】
また、コイル部２３は、電線２１を３ターン以上巻回するとともに貫通孔２２の内径３３を巻軸方向中央から両端にかけて大きくしており、隣接する電線２１が密接している。
【００３４】
そして、圧粉体２４は、熱硬化性樹脂を含有した結合材と磁性粉末とを非加熱状態で混合するとともに、背面部３４に中脚部３５と外脚部３６を有した断面Ｅ字形状に加圧成形しており、圧粉体２４は２個形成している。
【００３５】
さらに、圧粉体２４は、２つの圧粉体２４の中脚部３５および外脚部３６の高さ寸法３７，３８の総和をコイル部２３の内周側の巻幅寸法３２より大きくするとともに、中脚部３５の高さ寸法３７の総和より外脚部の高さ寸法３８の総和を大きくして形成している。
【００３６】
また、圧粉体２４は、コイル部２３の内周側に対応する背面部３９よりコイル部２３の外周側に対応する背面部４０の厚み寸法を大きくしており、中脚部３５は根元側が太い断面台形形状に形成している。
【００３７】
そして、外装部２５から突出した端子部２６は適宜折り曲げて外装部２５に沿わす等してコイル部品を構成している。
【００３８】
次に、上記本発明の一実施の形態のコイル部品の製造方法について図面を参照しながら説明する。
【００３９】
図６は本発明の一実施の形態のコイル部品の製造工程図、図７（ａ）〜図７（ｃ）は同要部であるコイル部形成工程を示す図、図８（ａ）〜図８（ｅ）は同要部である外装部形成工程を示す図である。
【００４０】
図６〜図８において、本発明の一実施の形態におけるコイル部品の製造工程は、扁平状の電線２１を上下方向にエッジワイズに巻回するコイル部形成工程４１と、絶縁材を被覆した磁性粉末を加圧成形して圧粉体２４を形成する圧粉体形成工程４２と、コイル部２３の両端部を突出させるとともに圧粉体２４にコイル部２３を内包するように圧粉体２４を再加圧成形して外装部２５を形成する外装部形成工程４３と端子部２６を適宜折り曲げ加工する端子加工工程４４とを設けている。
【００４１】
コイル部形成工程４１では、コイル部２３の内周側の巻幅の中央より両端部の径寸法を大きくした巻軸４５に扁平状の電線２１を巻回し、隣接する電線２１の内周側側辺の中点の間隔２９より隣接する電線の外周側側辺の中点の間隔３０を小さくするとともに、外周側の巻幅寸法３１を内周側の巻幅寸法３２より小さくして、隣接する電線２１を密接させて巻回している。
【００４２】
また、扁平状の電線２１を巻回する際に使用する巻軸４５は、径寸法の最小部４６で上下に分割可能な巻軸４５にしており、電線２１を巻軸４５に巻回後、巻軸４５を上下に分割して、巻軸４５からコイル部２３を取り出している。
【００４３】
そして、圧粉体形成工程４２は、熱硬化性樹脂を含有した結合材と磁性粉末とを熱硬化性樹脂が熱硬化しないように非加熱状態で混合するとともに加圧成形しており、外装部形成工程４３では、コイル部２３を内包するように圧粉体２４を再加圧成形するとともに熱硬化性樹脂が熱硬化するように加熱成形している。
【００４４】
このとき、外装部形成工程４３では圧粉体２４が再加圧成形されて、圧粉体２４が一端くずれ、くずれた圧粉体２４でコイル部２３を被覆するように再加圧成形され外装部２５が形成されるとともに加熱成形によって熱硬化性樹脂が熱硬化して外装部２５の形状が強固に維持される。
【００４５】
また、外装部形成工程４３では、加熱成形後に熱硬化性樹脂の硬化反応を促進するために再度加熱工程を設けてもよい。
【００４６】
そして、圧粉体形成工程４２では、圧粉体２４は、背面部３４に中脚部３５と外脚部３６を有した断面Ｅ字形状にするとともに２個形成しており、圧粉体２４は、２つの圧粉体２４の中脚部３５および外脚部３６の高さ寸法の総和をコイル部２３の内周側の巻幅寸法３２より大きくするとともに、中脚部３５の高さ寸法３７の総和より外脚部３６の高さ寸法３８の総和を大きくして形成している。
【００４７】
さらに、圧粉体２４は、中脚部３５を根元側が太い断面台形形状にしており、また、コイル部２３の内周側に対応する背面部３９よりコイル部２３の外周側に対応する背面部４０の厚み寸法を大きくして形成している。
【００４８】
上記構成および方法により、電線２１は、外周側の厚み寸法２７を内周側の厚み寸法２８より小さくしており、コイル部２３は、隣接する電線２１の内周側側辺の中点の間隔２９より隣接する電線２１の外周側側辺の中点の間隔３０を小さくするとともに、外周側の巻幅寸法３１を内周側の巻幅寸法３２より小さくしているので、コイル部２３の隣接した電線２１の間の隙間を小さくして、圧粉体２４を再加圧成形して外装部２５を形成した後にコイル部２３のスプリングバックによる外装部２５を外包に押出す力を小さくすることができ、外装部にクラックが発生することを抑制することができる。
【００４９】
また、コイル部２３は隣接する電線２１が密接しているので、コイル部２３の隣接した電線２１の間の隙間をなくして、外装部２５にクラックが発生することをより抑制することができる。
【００５０】
そして、コイル部２３は、貫通孔２２の内径３３を巻軸方向中央から両端にかけて大きくしているので、電線２１を３ターン以上巻回した場合でも、隣接した電線２１が互いにずれることを防止して、コイル部２３の隣接した電線２１の間の隙間を的確に小さくして、外装部２５にクラックが発生することを抑制することができる。
【００５１】
さらに、圧粉体２４は、熱硬化性樹脂を含有した結合材と磁性粉末との混合材としているので、圧粉体２４でコイル部２３を内包するとともに圧粉体を再加圧成形して外装部２５を形成する際に、加熱成形すれば熱硬化性樹脂を含有した結合材を硬化することができ、外装部２５を形成後にクラックが発生することをより抑制することができる。
【００５２】
また、圧粉体２４は、背面部３４に中脚部３５と外脚部３６を有した断面Ｅ字形状にするとともに２個形成したので、圧粉体２４でコイル部２３を内包する際に、圧粉体２４でコイル部２３を的確に位置決めすることができる。
【００５３】
そして、圧粉体２４は、２つの圧粉体２４の中脚部３５および外脚部３６の高さ寸法３７，３８の総和をコイル部２３の内周側の巻幅寸法３２より大きくするとともに、中脚部３５の高さ寸法３７の総和より外脚部３６の高さ寸法３８の総和を大きくしているので、外脚部３６側の圧粉体２４の磁性粉末の量を多くして、コイル部２３の外周側の巻幅寸法３１が内周側の巻幅寸法３２より小さい寸法でも、外装部２５を形成する際に、外脚部３６の圧粉体２４がくずれてまわり込み的確にコイル部２３を内包することができる。
【００５４】
さらに、圧粉体２４は、コイル部２３の内周側に対応する背面部３９よりコイル部の外周側に対応する背面部４０の厚み寸法を大きくしているので、コイル部２３の外周側の巻幅寸法３１が内周側の巻幅寸法３２より小さい寸法でも、コイル部２３を的確に内包することができる。
【００５５】
また、圧粉体２４は、中脚部３５を根元側が太い断面台形形状に形成しているので、貫通孔２２の内径３３を巻軸方向中央から両端にかけて大きくした場合でも、コイル部２３を的確に内包することができる。
【００５６】
このように、本発明の一実施の形態によれば、コイル部２３の隣接した電線２１の間の隙間を小さくしているので、圧粉体２４を再加圧成形して外装部２５を形成した後に、コイル部２３のスプリングバックによる外装部２５を外方に押出す力を抑制して、外装部２５にクラックが発生することを抑制することができ、生産性を向上させることができる。
【００５７】
【発明の効果】
以上のように本発明によれば、電線は、外周側の厚み寸法を内周側の厚み寸法より小さくしており、コイル部は、隣接する電線の内周側側辺の中点の間隔より隣接する電線の外周側側辺の中点の間隔を小さくするとともに、外周部の巻幅寸法を内周側の巻幅寸法より小さく巻回した方法としているので、コイル部の隣接した電線の間の隙間を小さくして、外装部を加圧成形して形成した後にコイル部のスプリングバックによる外装部を外方に押出す力を小さくすることができ、外装部にクラックが発生することを抑制して、生産性を向上したコイル部品の製造方法を提供することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態におけるコイル部品の断面図
【図２】同斜視図
【図３】（ａ）同要部であるコイル部の断面図
（ｂ）同要部であるコイル部の平面図
【図４】（ａ）同要部である圧粉体の斜視図
（ｂ）同要部である圧粉体の断面図
【図５】同要部である外装部形成後の斜視図
【図６】同製造工程図
【図７】同要部であるコイル部形成工程を示す図
【図８】同要部である外装部形成工程を示す図
【図９】従来のコイル部品の断面図
【図１０】同斜視図
【図１１】（ａ）コイル部形成前の電線の断面図
（ｂ）コイル部形成後の電線の断面図
【図１２】従来のコイル部品の外装部形成時の加圧状態を示した断面図
【図１３】同外装部形成時の除圧した状態を示す断面図
【符号の説明】
２１電線
２２貫通孔
２３コイル部
２４圧粉体
２５外装部
２６端子部
２７外周側の厚み寸法
２８内周側の厚み寸法
２９内周側側辺の中点の間隔
３０外周側側辺の中点の間隔
３１外周側の巻幅寸法
３２内周側の巻幅寸法
３３内径
３４背面部
３５中脚部
３６外脚部
３７中脚部の高さ寸法
３８外脚部の高さ寸法
３９コイル部の内周側に対応する背面部
４０コイル部の外周側に対応する背面部
４１コイル部形成工程
４２圧粉体形成工程
４３外装部形成工程
４４端子加工工程
４５巻軸
４６径寸法の最小部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a coil component used for various electronic devices.
[0002]
[Prior art]
A conventional coil component will be described with reference to the drawings.
[0003]
FIG. 9 is a sectional view of a conventional coil component, and FIG. 10 is a perspective view of the same.
[0004]
9 and 10, a conventional coil component is composed of a coil portion 3 having a through-hole 2 while winding a flat electric wire 1 covered with an insulating layer vertically in an edgewise direction, and a magnetic material coated with an insulating resin. An exterior part 4 including the coil part 3 in powder was provided, and a terminal part 5 having both ends of the coil part 3 protruding from the exterior part 4.
[0005]
At this time, as shown in the cross-sectional view of the electric wire before forming the coil portion in FIG. 11A and the cross-sectional view of the electric wire after forming the coil portion in FIG. By winding the wire 1 having a rectangular cross section before forming the portion 3 in an edgewise manner, the outer peripheral side of the coil portion 3 is stretched, and the thickness 6 on the outer peripheral side of the wire 1 is smaller than the thickness 7 on the inner peripheral side. A gap 8 was formed between adjacent electric wires 1 on the outer peripheral side of the coil portion 3.
[0006]
Then, the coil part 3 is encapsulated with magnetic powder and molded under pressure to form the exterior part 4 to form a coil part.
[0007]
As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
[0008]
[Patent Document 1]
JP-A-2002-203731
[Problems to be solved by the invention]
In the above-described conventional configuration, there is a gap 8 between the adjacent electric wires 1 on the outer peripheral side of the coil portion 3. Therefore, when forming the exterior portion 4 by pressing the magnetic powder under pressure, the conventional coil component shown in FIG. As shown in the cross-sectional view showing the pressurized state during the molding of the exterior part, the gap 8 between the electric wires 1 adjacent to the coil part 3 is crushed by the pressurization 9 and becomes small, When the pressure 9 disappears, as shown in a cross-sectional view of FIG. 13 showing a state in which the pressure is removed at the time of forming the exterior part of the conventional coil part, the spring back of the coil part 3 causes There is a fear that a force acting to return the gap 8 to the original position acts to push the exterior part 4 outward and cracks 10 are generated in the exterior part 4.
[0010]
As described above, since the coil portion 3 having the gap 8 on the outer peripheral side of the adjacent electric wire 1 is included in the magnetic powder, the coil portion 3 is spring-backed after the pressure molding of the exterior portion 4 so that There was a problem that cracks 10 were generated and the production yield was poor.
[0011]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and suppresses the occurrence of cracks in the exterior portion even when the exterior portion is formed by enclosing the coil portion in magnetic powder, thereby improving the productivity. It is intended to provide a method for manufacturing a component.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
[0013]
The invention according to claim 1 of the present invention provides a step of forming a coil portion in which a flat electric wire is wound edgewise in a vertical direction, and forming a compact by pressing and molding magnetic powder coated with an insulating material. And a package forming step in which both ends of the coil section are projected and the package is formed by re-pressing the compact so as to include the coil section in the compact. In the coil portion forming step, the flat wire is wound around a winding shaft having a larger diameter from the center of the winding width of the coil portion to both end portions, and the wire is adjacent to the wire at an interval between the midpoints on the inner peripheral side of the adjacent wire. In this method, the distance between the middle points on the outer peripheral side of the electric wire to be made is reduced, and the winding width on the outer peripheral side is made smaller than the winding width on the inner peripheral side.
[0014]
With the above configuration, the coil part forming step is to wind a flat electric wire around a winding shaft having a larger diameter dimension from the center of the winding width of the coil part to both ends, and the midpoint of the middle point on the inner peripheral side of the adjacent electric wire. Since the distance between the midpoints on the outer peripheral side of the adjacent electric wire was made smaller than the interval and the winding width on the outer peripheral side was made smaller than the inner peripheral side winding width, the coil was wound between the adjacent electric wires. After forming the exterior part by re-pressing the green compact and forming the exterior part, the force of pushing out the exterior part by the spring back of the coil part can be reduced, and cracks may occur in the exterior part. This can be suppressed.
[0015]
The invention described in claim 2 of the present invention is a method in which the coil portion is wound so that adjacent electric wires come into close contact with each other.
[0016]
According to the above method, the coil portion was wound so that the adjacent electric wires were in close contact with each other, so that there was no gap between the adjacent electric wires of the coil portion, and the compact was again pressed and formed to form the exterior portion. Later, the force of pushing out the exterior part due to the spring back of the coil part can be made smaller, and the occurrence of cracks in the exterior part can be further suppressed.
[0017]
The invention described in claim 3 of the present invention is a method in which the winding shaft for winding the electric wire is a winding shaft that can be divided into upper and lower portions at the minimum diameter portion of the coil portion.
[0018]
According to the above method, the winding shaft for winding the electric wire is a winding shaft that can be divided into upper and lower portions at the minimum portion of the diameter of the coil portion. If the winding shaft is divided into upper and lower parts after winding the electric wire, the coil portion can be easily taken out from the winding shaft.
[0019]
In the invention according to claim 4 of the present invention, in particular, in the green compact forming step, the binder containing the thermosetting resin and the magnetic powder are mixed in a non-heated state so that the thermosetting resin is not thermoset. The external part forming step is a method in which the green compact is re-pressed and molded so as to cover the coil part and heat molded so that the thermosetting resin is thermoset.
[0020]
According to the above method, in the green compact forming step, the binder and the magnetic powder containing the thermosetting resin are mixed in a non-heated state so that the thermosetting resin is not thermoset, and are subjected to pressure molding. In the part forming step, the green compact is re-pressed so as to cover the coil part and the hot molding is performed so that the thermosetting resin is thermoset. When forming the exterior part by re-pressing the powder, the binder containing the thermosetting resin can be cured by heat molding the green compact, and cracks occur after the exterior part is formed. Can be further suppressed.
[0021]
The invention described in claim 5 of the present invention is a method in which two compacts are formed in an E-shaped cross section having a middle leg and an outer leg on the back surface.
[0022]
According to the above method, the green compact was formed into an E-shaped cross section having a middle leg portion and an outer leg portion on the back surface, and two compacts were formed. With this, the coil portion can be accurately positioned.
[0023]
In the invention described in claim 6 of the present invention, in particular, in the green compact, the sum of the heights of the middle leg and the outer leg of the two green compacts is made larger than the winding width on the inner peripheral side of the coil portion. This is a method in which the sum of the heights of the outer legs is made larger than the sum of the heights of the middle legs.
[0024]
According to the above method, the green compact makes the sum of the heights of the middle leg and the outer leg of the two green compacts larger than the winding width on the inner peripheral side of the coil portion, and increases the height of the middle leg. Since the sum of the heights of the outer legs is larger than the sum of the heights, the amount of magnetic powder of the compact on the outer legs is increased so that the winding width on the outer periphery of the coil is Even with a dimension smaller than the winding width dimension on the peripheral side, when forming the exterior part, the green compact of the outer leg part can be distorted, and the coil part can be wrapped around accurately.
[0025]
The invention as set forth in claim 7 of the present invention is a method in which the green leg has a trapezoidal cross section with a thicker base at the base.
[0026]
According to the above method, the green compact has a trapezoidal shape in which the middle leg portion has a thicker base side, so that even when the inner diameter of the through hole is increased from the center in the winding axis direction to both ends, the coil portion can be accurately included. it can.
[0027]
The invention described in claim 8 of the present invention has a configuration in which the thickness of the back surface portion corresponding to the outer peripheral portion of the coil portion is larger than that of the back surface portion corresponding to the inner peripheral side of the coil portion.
[0028]
According to the above method, since the thickness of the back portion corresponding to the outer peripheral portion of the coil portion is larger than that of the back portion corresponding to the inner peripheral side of the coil portion, the green compact has a winding width dimension on the outer peripheral side of the coil portion. Is smaller than the winding width dimension on the inner peripheral side, the coil portion can be accurately included.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a coil component according to an embodiment of the present invention will be described with reference to the drawings.
[0030]
FIG. 1 is a cross-sectional view of a coil component according to an embodiment of the present invention, FIG. 2 is a perspective view of the same, FIG. 3A is a cross-sectional view of a coil portion as the main part, and FIG. FIG. 4A is a perspective view of a green compact as the main part, FIG. 4B is a cross-sectional view of the green compact as the main part, and FIG. It is a perspective view after forming the exterior part.
[0031]
1 to 5, a coil part according to an embodiment of the present invention includes a coil part 23 having a through-hole 22 while winding a flat electric wire 21 vertically and edgewise, and covering an insulating material. And a terminal part 26 having both ends of the coil part 23 protruding from the exterior part 25. It has.
[0032]
At this time, the electric wire 21 on which the coil portion 23 is formed has a thickness dimension 27 on the outer peripheral side smaller than a thickness dimension 28 on the inner peripheral side, and the coil portion 23 is formed inside the inner peripheral side of the adjacent electric wire 21. The interval 30 between the middle points on the outer peripheral side of the adjacent electric wire is made smaller than the interval 29 between the points, and the winding width dimension 31 on the outer peripheral side is made smaller than the winding width dimension 32 on the inner peripheral side.
[0033]
Further, the coil portion 23 winds the electric wire 21 for three or more turns and increases the inner diameter 33 of the through hole 22 from the center in the winding axis direction to both ends, so that the adjacent electric wires 21 are in close contact.
[0034]
The green compact 24 mixes the binder containing the thermosetting resin and the magnetic powder in a non-heated state, and has an E-shaped cross section having a middle leg 35 and an outer leg 36 on the back surface 34. , And two compacts 24 are formed.
[0035]
Further, in the green compact 24, the sum of the heights 37 and 38 of the middle leg 35 and the outer leg 36 of the two green compacts 24 is made larger than the inner width 32 of the coil portion 23. The height of the outer leg 38 is larger than the sum of the height 37 of the middle leg 35.
[0036]
In the green compact 24, the thickness of the rear portion 40 corresponding to the outer peripheral side of the coil portion 23 is larger than the thickness of the rear portion 39 corresponding to the inner peripheral side of the coil portion 23. It has a large trapezoidal cross section.
[0037]
The terminal part 26 protruding from the exterior part 25 is bent as appropriate to form a coil component along the exterior part 25 or the like.
[0038]
Next, a method for manufacturing a coil component according to an embodiment of the present invention will be described with reference to the drawings.
[0039]
6A to 6C are views showing a manufacturing process of a coil component according to an embodiment of the present invention, and FIGS. FIG. 8 (e) is a view showing an exterior part forming step which is the main part.
[0040]
6 to 8, a coil component manufacturing process according to one embodiment of the present invention includes a coil portion forming process 41 of winding a flat electric wire 21 in an edgewise manner in a vertical direction, and a magnetic material coated with an insulating material. A green compact forming step 42 of molding the powder under pressure to form a green compact 24, and a step of projecting both ends of the coil portion 23 and forming the green compact 24 so as to include the coil portion 23 in the green compact 24. An exterior part forming step 43 for forming the exterior part 25 by re-press molding and a terminal processing step 44 for appropriately bending the terminal part 26 are provided.
[0041]
In the coil part forming step 41, the flat electric wire 21 is wound around a winding shaft 45 having both ends larger in diameter than the center of the winding width on the inner peripheral side of the coil part 23, and the inner peripheral side of the adjacent electric wire 21 The distance 30 between the midpoints of the outer peripheral sides of the adjacent electric wires is made smaller than the distance 29 between the midpoints of the sides, and the winding width dimension 31 on the outer peripheral side is made smaller than the winding width dimension 32 on the inner peripheral side. The electric wire 21 is wound closely.
[0042]
Further, the winding shaft 45 used when winding the flat electric wire 21 is a winding shaft 45 that can be divided into upper and lower portions at a minimum portion 46 having a diameter, and after the electric wire 21 is wound around the winding shaft 45, The winding shaft 45 is divided into upper and lower parts, and the coil part 23 is taken out from the winding shaft 45.
[0043]
In the green compact forming step 42, the binder containing the thermosetting resin and the magnetic powder are mixed in a non-heated state so as to prevent the thermosetting resin from being thermoset, and are molded under pressure. In the forming step 43, the green compact 24 is re-pressurized and molded so as to include the coil portion 23, and is thermoformed so that the thermosetting resin is thermoset.
[0044]
At this time, in the exterior part forming step 43, the green compact 24 is repressurized and molded, and the green compact 24 is once deformed. The portion 25 is formed and the thermosetting resin is thermoset by heat molding, and the shape of the exterior portion 25 is firmly maintained.
[0045]
In addition, in the exterior part forming step 43, a heating step may be provided again to promote the curing reaction of the thermosetting resin after the heat molding.
[0046]
Then, in the green compact forming step 42, the green compact 24 has an E-shaped cross section having a middle leg 35 and an outer leg 36 on the back surface portion 34, and two compacts 24 are formed. Makes the sum of the heights of the middle leg 35 and the outer leg 36 of the two compacts 24 larger than the winding width 32 on the inner peripheral side of the coil portion 23, and the height of the middle leg 35. The sum of the heights 38 of the outer leg portions 36 is larger than the sum of the 37.
[0047]
Further, in the green compact 24, the middle leg portion 35 has a trapezoidal shape in cross section at the base side, and the rear portion 39 corresponding to the outer peripheral side of the coil portion 23 from the rear portion 39 corresponding to the inner peripheral side of the coil portion 23. 40 is formed with a large thickness.
[0048]
With the above configuration and method, the electric wire 21 has the thickness 27 on the outer peripheral side smaller than the thickness 28 on the inner peripheral side, and the coil portion 23 has a gap between the midpoints on the inner peripheral side of the adjacent electric wire 21. Since the interval 30 between the midpoints on the outer peripheral side of the wire 21 adjacent to the wire 29 is made smaller and the winding width 31 on the outer circumference is made smaller than the winding width 32 on the inner circumference, The gap between the electric wires 21 thus formed is reduced, and the green compact 24 is repressurized to form the exterior portion 25, and thereafter the force for pushing the exterior portion 25 to the outer package by the spring back of the coil portion 23 is reduced. It is possible to suppress the occurrence of cracks in the exterior part.
[0049]
Further, since the adjacent electric wires 21 are in close contact with the coil portion 23, there is no gap between the adjacent electric wires 21 of the coil portion 23, and the occurrence of cracks in the exterior portion 25 can be further suppressed.
[0050]
And since the coil part 23 enlarges the inner diameter 33 of the through hole 22 from the center in the winding axis direction to both ends, even when the electric wire 21 is wound for three turns or more, it is possible to prevent the adjacent electric wires 21 from being shifted from each other. Thus, the gap between the electric wires 21 adjacent to the coil portion 23 can be accurately reduced, and the occurrence of cracks in the exterior portion 25 can be suppressed.
[0051]
Further, since the green compact 24 is a mixture of the binder and the magnetic powder containing the thermosetting resin, the green compact 24 includes the coil portion 23 and the green compact is pressed again. When the exterior part 25 is formed, by performing heat molding, the binder containing the thermosetting resin can be cured, and the occurrence of cracks after the exterior part 25 is formed can be further suppressed.
[0052]
Further, since the green compact 24 has an E-shaped cross section having a middle leg portion 35 and an outer leg portion 36 on the back surface portion 34 and is formed in two pieces, when the green compact 24 encloses the coil portion 23, Thus, the coil portion 23 can be accurately positioned by the green compact 24.
[0053]
In the green compact 24, the sum of the heights 37 and 38 of the middle leg portion 35 and the outer leg portion 36 of the two green compacts 24 is made larger than the inner width 32 of the coil portion 23. Since the sum of the heights 38 of the outer legs 36 is larger than the sum of the heights 37 of the middle legs 35, the amount of magnetic powder of the green compact 24 on the outer legs 36 is increased. Even when the winding width dimension 31 on the outer peripheral side of the coil part 23 is smaller than the winding width dimension 32 on the inner peripheral side, when forming the exterior part 25, the green compact 24 of the outer leg part 36 is distorted and can be accurately wrapped around. Can include the coil portion 23.
[0054]
Furthermore, since the compact 24 has a larger thickness of the rear portion 40 corresponding to the outer peripheral side of the coil portion than the rear portion 39 corresponding to the inner peripheral side of the coil portion 23, Even if the winding width dimension 31 is smaller than the winding width dimension 32 on the inner peripheral side, the coil portion 23 can be accurately included.
[0055]
Further, in the compact 24, since the middle leg portion 35 is formed in a trapezoidal shape with a thick base at the base side, even when the inner diameter 33 of the through hole 22 is increased from the center in the winding axis direction to both ends, the coil portion 23 is accurately formed. Can be included.
[0056]
As described above, according to the embodiment of the present invention, since the gap between the electric wires 21 adjacent to the coil portion 23 is reduced, the green compact 24 is re-pressed to form the exterior portion 25. After that, the force that pushes the exterior part 25 outward due to the springback of the coil part 23 is suppressed, so that the occurrence of cracks in the exterior part 25 can be suppressed, and the productivity can be improved.
[0057]
【The invention's effect】
As described above, according to the present invention, the electric wire has a thickness dimension on the outer peripheral side smaller than a thickness dimension on the inner peripheral side, and the coil portion is smaller than a gap between the midpoints on the inner peripheral side of the adjacent electric wire. Since the distance between the middle points on the outer peripheral side of the adjacent electric wire is reduced and the winding width of the outer peripheral portion is smaller than that of the inner peripheral side, the distance between the adjacent electric wires of the coil portion is reduced. After the outer part is formed by pressure molding, the force to push the outer part outward by the spring back of the coil part can be reduced, and the occurrence of cracks in the outer part can be suppressed. Thus, it is possible to provide a method for manufacturing a coil component with improved productivity.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a coil part according to an embodiment of the present invention. FIG. 2 is a perspective view of the coil part. FIG. 3A is a cross-sectional view of a coil part as the main part. FIG. 4A is a perspective view of the green compact as the main part, and FIG. 5B is a cross-sectional view of the green compact as the main part. FIG. FIG. 6 is a perspective view of the same manufacturing process. FIG. 7 is a diagram showing a coil portion forming process as the main portion. FIG. 8 is a diagram showing an exterior portion forming process as the main portion. FIG. 9 is a conventional coil component. FIG. 10 is a perspective view of the same. FIG. 11 (a) is a cross-sectional view of an electric wire before a coil portion is formed. (B) is a cross-sectional view of an electric wire after a coil portion is formed. FIG. 13 is a cross-sectional view showing a pressurized state at the time. FIG. 13 is a cross-sectional view showing a depressurized state at the time of forming the exterior part.
DESCRIPTION OF SYMBOLS 21 Electric wire 22 Through-hole 23 Coil part 24 Green compact 25 Exterior part 26 Terminal part 27 Outer peripheral side thickness dimension 28 Inner peripheral side thickness dimension 29 Interval of the midpoint of the inner peripheral side side 30 Midpoint of the outer peripheral side side The width 31 of the outer circumference side The winding width dimension 32 of the inner circumference side 33 The inner diameter 34 The rear part 35 The middle leg part 36 The outer leg part 37 The height dimension of the middle leg part 38 The height dimension of the outer leg part 39 The coil part Back part 40 corresponding to the inner peripheral side Back part 41 corresponding to the outer peripheral side of the coil part Coil part forming step 42 Green compact forming step 43 Exterior part forming step 44 Terminal processing step 45 Winding shaft 46 Minimum part of diameter dimension

Claims

A coil portion forming step of winding a flat electric wire in an edgewise manner in a vertical direction, a green compact forming step of forming a green compact by pressing and molding magnetic powder coated with an insulating material, An exterior part forming step of forming an exterior part by re-pressing the green compact so as to include the coil part in the green compact while projecting both ends, and the coil part forming step, The flat wire is wound around a winding shaft whose diameter is increased from the center to the both ends of the winding width of the coil portion, and the width of the wire adjacent to the wire is larger than the distance between the middle points on the inner peripheral side of the wire adjacent to the wire. A method for manufacturing a coil component in which the interval between the midpoints on the outer peripheral side is reduced, and the winding width on the outer peripheral side is made smaller than the winding width on the inner peripheral side.

The method for manufacturing a coil component according to claim 1, wherein the coil portion is wound such that adjacent electric wires are closely contacted.

The method for manufacturing a coil component according to claim 1, wherein the winding shaft for winding the electric wire is a winding shaft that can be divided into upper and lower portions at a minimum portion of the diameter of the coil portion.

In the green compact forming step, the binder containing the thermosetting resin and the magnetic powder are mixed in a non-heated state so as to prevent the thermosetting resin from being thermoset, and are molded under pressure. The method according to claim 1, wherein, in the step, the green compact is re-pressurized so as to cover the coil portion and heat-molded so that the thermosetting resin is thermoset.

The method for manufacturing a coil component according to claim 1, wherein the green compact has an E-shaped cross section having a middle leg portion and an outer leg portion on the back surface and two compacts are formed.

The green compact is such that the sum of the heights of the middle leg and the outer leg of the two green compacts is larger than the winding width on the inner peripheral side of the coil portion, and the sum of the heights of the middle leg is 6. The method for manufacturing a coil component according to claim 5, wherein the sum of the height dimensions of the outer leg portions is increased.

The method for manufacturing a coil component according to claim 5, wherein the green compact has a trapezoidal shape in which a middle leg portion has a thick root side.

6. The method of manufacturing a coil component according to claim 5, wherein the green compact has a thickness dimension of a back portion corresponding to an outer peripheral portion of the coil portion larger than a back portion corresponding to an inner peripheral side of the coil portion.