JP4711568B2 - Transformer - Google Patents

Description

【０００５】
【発明が解決しようとする課題】
変成器の小型化、軽量化を図るには、変成器を構成する部品のうちで寸法が大きく、かつ重量も重い巻鉄心４の寸法を縮小することが最も有効である。また、珪素鋼板等の電磁鋼板からなる巻鉄心４は、変成器を構成する他の部品よりも比較的高価であり、変成器の製造コストを低減する上でも、巻鉄心４の寸法はできる限り小さいことが好ましい。
【０００６】
上記式（１）から明らかなように、同一の起電力Ｅを維持しつつ、かつ磁束密度Ｂｍを低下させることなく、巻鉄心４の寸法、すなわち鉄心有効断面積Ａを低減するには、巻数Ｎを増加させればよい。また、巻鉄心４を大型化することなく、すなわち鉄心窓部の寸法を拡大することなく導線２ａ，３ａの巻数Ｎを増加させるには、導線２ａ，３ａの巻回方向と直交する方向の断面積を減少させる必要、すなわ導線２ａ，３ａの径を縮小する必要がある。一方、導線２ａ，３ａの断面積が減少すると電流密度が上昇するため、導線２ａ，３ａで生じるジュール熱に起因する温度上昇も顕著となる。そのため、従来は、一次巻線２及び二次巻線３の両方を含む巻線１全体での温度上昇を考慮し、この巻線１全体での温度上昇が許容範囲となるように導線２ａ，３ａの径を設定し、かつ一次巻線２と二次巻線３のそれぞれについて導線２ａ，３ａの径を一定としていた。
【０００７】
しかし、本発明者が種々の実験及び研究を行ったところ、巻線１の脚部１ａにおける巻回方向と直交する方向の断面（横断面）において、上記導線２ａ，３ａで生じるジュール熱に起因する温度上昇に分布が存在することを見出した。詳細には、図１２に示すように、巻線１の横断面における窓部１ｃ側の外周近傍の領域である内側外周領域Ａｒ１（図１１において位置Ｐ４〜位置Ｐ５間の領域）と、巻線１の横断面における窓部１ｃと反対側の外周近傍の領域である外側外周領域Ａｒ２（図１１において位置Ｐ１〜Ｐ２の領域）とでは、巻線１の横断面における中心近傍の領域である中心領域Ａｒ３（図１１において位置Ｐ２〜Ｐ４間の領域）と比較して導線２ａ，３ａに生じるジュール熱に起因する温度上昇の度合いが比較的低い。換言すれば、内側外周領域Ａｒ１と内側外周領域Ａｒ２は、中心領域Ａｒ３よりも巻線の冷却効果が高いことが判明した。
【０００８】
本発明は、かかる新たな知見に基づいて、巻線が備える一対の脚部に巻鉄心を形成してなる変成器の小型化、軽量化、及び製造コストの低減を図ることを課題としている。
【０００９】
【課題を解決するための手段】
本発明は、間隔を隔てて互いに対向する一対の脚部と、これら脚部の両端を連結する一対の連結部と、これら脚部及び連結部により囲まれた窓部とを備える巻線と、上記一対の脚部に電磁鋼板をそれぞれ巻き込でなる一対の巻鉄心とを備え、上記巻線は上記導体の巻回方向と直交する方向の断面である横断面の形状が略円形である、変成器であって、上記巻線は、断面円形の導線を複数回巻回してなる一次巻線と、単一の帯状導体を複数回巻回してなる二次巻線とにより構成され、上記帯状導体の上記巻回方向と直交する断面での断面積は、上記巻線の横断面における上記窓部側の外周近傍領域である内側外周領域と、上記巻線の横断面における上記窓部と反対側の外周近傍領域である外側外周領域とのうちの少なくとも一方の領域において、上記巻線の横断面における中心近傍の領域である中心領域よりも小さい、変成器を提供するものである。
【００１０】
本発明の変成器では、帯状導体に生じるジュール熱に対する冷却効果が比較的高い領域である巻線の横断面における内側外周領域と外側外周領域のうちの少なくとも一方において、中心領域よりも帯状導体の断面積を小さく設定している。従って、帯状導体の発熱による温度上昇の制約を充足しつつ、かつ巻線の横断面の面積を増加させることなく帯状導体の巻数を増大させ、それによって巻鉄心の小型化（鉄心有効断面積の低減）を図ることができる。巻鉄心は、変成器を構成する他の部品と比較し寸法も大きく、かつ重量も重いので巻鉄心の小型化により変成器全体として、小型化、軽量化を図ることができる。また、巻鉄心は変成器を構成する他の部品と比較して比較的高価である電磁鋼板からなるため、巻鉄心を小型化して電磁鋼板の使用量を低減することにより、変成器の製造コストを低減することができる。なお、「略円形」とは、真円に限らず、楕円、長円、多角形、及び自由曲線からなる閉曲線等の巻線の横断面の形状としては実質的に円形の範疇に含まれる平面図形をいう。
【００１１】
例えば、上記帯状導体は厚みが一定でかつ断面矩形であると共に、上記外側外周領域における幅と、上記内側外周領域における幅とのうちの少なくとも一方が、上記中心領域における幅よりも小さい。
【００１２】
具体的には、上記帯状導体の幅は、上記外側外周領域と、上記内側外周領域とのうちの少なくとも一方において、上記中心領域から離反するに伴って連続的又は段階的に縮小する。なお、帯状導体の厚みを、外側外周領域及び／又は内側外周領域と中心領域とで異ならせても良い。
【００１３】
【発明の実施の形態】
次に、図面に示す本発明の実施形態に基づいて、本発明を詳細に説明する。
【００１４】
（第１参考例）
図１から図３は、本発明の第１参考例に係る変成器を示している。
この変成器は、一次巻線１１と二次巻線１２からなる１個の巻線１０と、一対の巻鉄心１３とを備えている。なお、図において、１４は巻線１０の外周を被覆する絶縁テープ、１５は一次巻線１１と二次巻線１２とを絶縁するための絶縁スペーサである。
【００１５】
巻線１０は、間隔を隔てて互いに対向する一対の脚部１０ａと、これら脚部１０ａの両端を連結する一対の連結部１０ｂと、これら脚部１０ａ及び連結部１０ｂにより囲まれた窓部１０ｃとを備えている。また、巻線１０は後述する導線１１ａ〜１２ｂの巻回方向に直交する方向の断面（横断面）が円形である。一方、巻鉄心１３は、円筒状であって巻線１０が備える一対の脚部１０ａに電磁鋼板をそれぞれ巻き込んでなる。すなわち巻鉄心１３の断面円形の鉄心窓に巻線１０が収容されている。
【００１６】
巻線１０を構成する一次巻線１１と二次巻線１２は、それぞれ銅等の導電性を有する材料からなり断面円形の導線１１ａ〜１２ｂを多数回巻回して構成されている。図１１に示した従来の変成器では一次巻線２及び二次巻線３の導線２ａ，２ｂは断面積が一定であるが、本参考例では、一次巻線１１及び二次巻線１２の両方で導線の径を変化させて、それによって断面積を変化させている。図において、ｔ１，ｔ２，ｔ３，ｔ４は一次側及び二次側の入出力用の端子を示している。
【００１７】
まず、一次巻線１１は、一次側内導線１１ａと一次側外導線１１ｂからなる。一次側内導線１１ａは一次側外導線１１ｂよりも径が小さく、従って断面積が小さい。一次側内導線１１ａと一次側外導線１１ｂとは、図３に概略的に示すように、一方の端部が互いに電気的に接続されており、電気的には１本の導線を構成している。一次巻線１１は、これら一次側内導線１１ａ及び一次側外導線１１ｂを、図示しない巻型に対して巻回することにより形成される。この際、一次側内導線１１ａから巻型に巻き付け、窓部１０ｃ側に一次側内導線１１ａを配置する。なお、図２において矢印Ｙは巻線１０の横断面において導線が積み上げられる方向を示している。
【００１８】
次に、二次巻線１２は、二次側内導線１２ａと一次側外導線１１ｂからなる。二次側外導線１２ｂは二次側内導線１２ａよりも径が小さく、従って断面積が小さい。二次側内導線１２ａと二次側外導線１２ｂとは、図３に概略的に示すように、一方の端部が互いに電気的に接続されており、電気的には１本の導線を構成している。二次巻線１２は、これら二次側内導線１２ａ及び二次側外導線１２ｂを、巻型に巻回済みの一次巻線１１に絶縁スペーサ１５を介在させて巻回することにより形成される。この際、一次側内導線１１ａから巻き付けて、一次巻線１１側に二次側内導線１２ａを配置する。なお、二次巻線１２の形成後、巻線１０の外周に絶縁テープ１４が巻き付けられる。
【００１９】
図２に示すように、一次巻線１１については、巻線１０の横断面における窓部１０ｃ側の外周近傍の領域である内側外周領域Ａｒ１に径の小さい（断面積の小さい）一次側内導線１１ａが配置され、巻線１０の横断面における中心近傍の領域である中心領域Ａｒ３に径の大きい（断面積の大きい）一次側外導線１１ｂが配置されている。一方、二次巻線１２については、中心領域Ａｒ３に径の大きい（断面積の大きい）二次側内導線１２ａが配置され、巻線１０の横断面における窓部１０ｃとは反対側の外周近傍の領域である外側外周領域Ａｒ２には径の小さい（断面積の小さい）二次側外導線１２ｂが配置されている。すなわち、第１参考例では、導線１１ａ〜１２ｂに生じるジュール熱に対する冷却効果が比較的高い領域である内側外周領域Ａｒ１と外側外周領域Ａｒ２において、冷却効果の低い中心領域Ａｒ３よりも導線１１ａ〜１２ｂの面積を小さく設定している。従って、導線１１ａ〜１２ｂの発熱による温度上昇の制約を充足しつつ、かつ巻線１０の横断面の面積を増加させることなく導線１１ａ〜１２ｂの巻数を増大させ、それによって巻鉄心１３の小型化（鉄心有効断面積の低減）を図ることができる。巻鉄心１３は、変成器を構成する他の部品と比較し寸法も大きく、かつ重量も重いので巻鉄心１３の小型化により変成器全体として、小型化、軽量化を図ることができる。また、巻鉄心１３は変成器を構成する他の部品と比較して比較的高価である電磁鋼板からなるため、巻鉄心１３を小型化して電磁鋼板の使用量を低減することにより、変成器の製造コストを低減することができる。
【００２０】
（第２参考例）
図４は、本発明の第２参考例に係る変成器を示している。
この第２参考例では、巻線１０の一次巻線１１及び二次巻線１２は、導線ではなく銅等の導電性材料からなる断面矩形の帯状導体２１，２２を巻回してなる。まず、これらの帯状導体２１，２２は板厚が一定であり断面形状は矩形状である。また、図１０（Ａ）に示すように、帯状導体２１，２２は基端２１ａ，２２ａ側から一定の長さＬ１は幅Ｗが一定の平行部２１ｃ，２２ｃであり、この平行部２１ｃ，２２ｃから末端２１ｂ，２２ｂ側に向けて漸次幅Ｗが減少する長さＬ２のテーパ部２１ｄ，２２ｄを備えている。平行部２１ｃ，２２ｃでは帯状導体２１，２２の断面積は一定であるが、テーパ部２１ｄ，２２ｄでは帯状導体２１，２２の断面積は先端側に向けて漸次減少している。
【００２１】
一次巻線１１は、図示しない巻型に対して帯状導体２１を末端２１ｂ側から巻回することにより形成しており、窓部１０ｃ側にテーパ２１ｄを配置している。また、二次巻線１２は、巻型に巻回済みの一次巻線１１に絶縁スペーサ１５を介在させて帯状導体２２を基端２２ａ側から巻回することにより形成しており、窓部１０ｃとは反対側にテーパ部２２ｄを配置している。
【００２２】
図４に示すように、一次巻線１１の帯状導体２１については、内側外周領域Ａｒ１に幅Ｗが漸次縮小して断面積が漸次減少するテーパ部２１ｄが配置され、中心領域Ａｒ３に幅Ｗが一定の平行部２１ｃが配置されている。一方、二次巻線１２の帯状導体２２については、中心領域Ａｒ３に幅Ｗが一定で断面積の大きい平行部２２ｃが配置され、外側外周領域Ａｒ２には幅Ｗが漸次縮小して断面積が漸次減少するテーパ部２２ｄが配置されている。
【００２３】
内側外周領域Ａｒ１では帯状導体２１の幅方向の巻鉄心１３の鉄心窓の寸法が小さく、かつその減少率が大きいが、幅Ｗが漸次縮小するテーパ部２１ｄを配置しているため、幅一定の帯状導体を巻回する場合と比較して巻数が増大する。一方、内側外周領域Ａｒ１は、帯状導体２１に生じるジュール熱に対する冷却効果が高い。外側外周領域Ａｒ２も、上記内側外周領域Ａｒ３と同様に、帯状導体２２の幅方向の巻鉄心１３の鉄心窓の寸法が小さく、かつその減少率が大きいが、幅Ｗが漸次縮小するテーパ部２２ｄを配置しているため、幅一定の帯状導体を巻回する場合と比較して巻数が増大する。一方、外側外周領域Ａｒ２も、帯状導体２２に生じるジュール熱に対する冷却効果が高い。このように第２参考例では、帯状導体２１，２２に生じるジュール熱に対する冷却効果が比較的高い領域である内側外周領域Ａｒ１と外側外周領域Ａｒ２において、冷却効果の低い中心領域Ａｒ３よりも帯状導体２１，２２の断面積を小さく、かつこの断面積を漸次低減させることにより、帯状導体２１，２２の発熱による温度上昇の制約を充足しつつ、かつ巻線１０の横断面の面積を増加させることなく帯状導体２１，２２の巻数を増大させている。この巻数の増大により、巻鉄心１３の小型化し、変成器全体としても小型化、軽量化、及びコスト低減を図ることができる。
【００２４】
なお、図４では、巻鉄心１０の横断面を概略的に示しているため、巻鉄心１３の鉄心窓に隙間があるように見えるが、実際にはこの隙間は極めて微少であり、実質的に巻鉄心１０の横断面は円形である。第２参考例のその他の構成及び作用は第１参考例と同様であるので、同一の要素には同一の符号を付して説明を省略する。
【００２５】
（第１実施形態）
次に、図５から図７に示す本発明の第１実施形態について説明する。
この第１実施形態では、図７に示すコイルボビン２５に巻線を形成している。このコイルボビン２５は、共に樹脂製である外枠２６と、内枠２７とを備えている。外枠２６は巻鉄心１３に巻き込まれる一対の鉄心巻き込み部２６ａと、この鉄心巻き込み部２６ａを連結する一対の連結部２６ｂとを備え、全体として矩形枠状を呈している。また、外枠２６の外周には巻線を収容するための溝２６ｃが形成されている。上記内枠２７は、外枠２６と同様に、一対の鉄心巻き込み部２７ａと、一対の連結部２７ｂとを備えた矩形枠状であって、その外周に溝２７ｃが形成されている。外枠２６に対して内枠２７が一体に嵌め込まれる。
【００２６】
図５に示すように、外枠２６の溝２６ｃの断面は矩形状であり、内枠２７の溝２７ｃの断面は正六角形を２分割した形状である。従って、溝２６ｃ，２７ｃを合わせた断面形状、すなわち巻線１０の断面形状は、円形に近似した形状である。
【００２７】
図５に示すように、巻線１０は一次巻線１１と、二次巻線１２とにより構成され、一次巻線１１は、コイルボビン２５の内枠２７の溝２７ｃに径が一定（断面積が一定）の導線２８を巻回して形成されている。そのため、一次巻線１１については、内側領域Ａｒ１と中心領域Ａｒ３とで導線２８の断面積が一定である。一方、二次巻線１２は、コイルボビン２５の外枠２６の溝２６ｃに帯状導体２９を巻回して構成している。この帯状導体２９は上記第２参考例における帯状導体２１，２２と同様である。すなわち、帯状導体２９は板厚が一定で基端２９ａ側の平行部２９ｃと、末端２９ｂ側のテーパ部２９ｄとを備えている。帯状導体２９は基端２９ａ側からコイルボビン２５の外枠２６に巻回しており、中心領域Ａｒ３には平行部２９ｃが配置され、外側外周部Ａｒ２にはテーパ部２９ｄが配置されている。なお、図においてｔ６，ｔ７，ｔ８，ｔ９は一次側及び二次側の入出力用の端子を示している。
【００２８】
外側外周領域Ａｒ２では、帯状導体２２の幅方向の巻鉄心１３の鉄心窓の寸法が小さく、かつその減少率が大きいが、幅Ｗが漸次縮小するテーパ部２９ｄを配置しているため、幅一定の帯状導体を巻回する場合と比較して巻数が増大する。一方、外側外周領域Ａｒ２は、帯状導体２２に生じるジュール熱に対する冷却効果が高い。このように第１実施形態では、帯状導体２９に生じるジュール熱に対する冷却効果が比較的高い領域である外側外周領域Ａｒ２において、冷却効果の低い中心領域Ａｒ３よりも帯状導体２９の断面積を小さく、かつこの断面積を漸次低減させることにより、帯状導体２９の発熱による温度上昇の制約を充足しつつ、かつ巻線１０の横断面の面積を増加させることなく帯状導体２９の巻数を増大させている。この巻数の増大により、巻鉄心１３を小型化し、変成器全体としても小型化、軽量化、及びコスト低減を図ることができる。第１実施形態のその他の構成は第１参考例と同様であるので、同一の要素には同一の符号を付して説明を省略する。
【００２９】
（第２実施形態）
図８及び図９に示すように、本発明の第２実施形態に係る変成器の巻線１０は、１個の一次巻線４１を備え、この一次巻線４１よりも窓部１０ｃ側に２個の二次巻線４２，４３を備え、さらに一次巻線４１に対して窓部１０ｃと反対側に２個の二次巻線４４，４５を備えている。窓部１０ｃ側の２個の二次巻線４２，４４３と、窓部１０ｃと反対側の二次巻線４４，４５とは１個ずつ電気的に接続されている。従って、この変成器は１個の一次巻線と２個の二次巻線を有している。
【００３０】
一次巻線４１は径が一定（断面積が一定）である導線４１ａを巻回してなり、巻線１０の横断面の中心付近に配置されている。
この一次巻線４１よりも窓部１０ｃ側には配置されている２個の二次巻線４２，４３は、それぞれ絶縁スペーサ１５Ａにより一次巻線４１に対して絶縁されると共に、絶縁スペーサ１５Ｃにより二次巻線４２，４３どうしが互いに絶縁されている。また、これらの二次巻線４２，４３は、図１０（Ｂ），（Ｃ）に示すように、板厚が一定で断面が矩形状であって、基端４６ａ，４７ａ側の長さＬ１の平行部４６ｃ，４７ｃと、末端４６ｂ，４６ｂ側の長さＬ２のテーパ部４６ｄ，４７ｄとを備える帯状導体４６，４７からなる。これらの帯状導体４６，４７は、長手方向の一方の辺が折れ曲がりのない直線であり、他方の辺が一方の辺に向けて延びることによりテーパ部４６ｄ，４７ｄが形成されている。二次巻線４２，４３は、これらの帯状導体４６，４７を末端４６ｂ，４７ｂ側から巻回することにより形成され、それぞれ内側外周領域Ａｒ１に各帯状導体４６，４７のテーパ部４６ｄ，４７ｄが配置され、中心領域Ａｒ３に平行部４６ｃ，４７ｃが配置されている。
【００３１】
一次巻線４１に対して窓部１０ｃと反対側の二次巻線４４，４５も、図１０（Ｂ），（Ｃ）に示すように、板厚が一定で断面が矩形状であって、基端４８ａ，９ａ側の長さＬ１の平行部４８ｃ，４９ｃと長さＬ２のテーパ部４８ｄ，４９ｄとを備える帯状導体４８，４９からなる。二次巻線４４，４５は、これらの帯状導体４８，４９を基端４８ａ，４９ａ側から巻回することにより形成され、それぞれ外側外周領域Ａｒ２に各帯状導体４８，４９のテーパ部４８ｄ，４９ｄが配置され、中心領域Ａｒ３に平行部４８ｃ，４９ｃが配置されている。
【００３２】
図においてｔ１１からｔ２０は一次巻線４１及び二次巻線４２〜４５の端子を示している。これらのうち端子ｔ１１，ｔ１２，ｔ１３，ｔ１５，ｔ１８，ｔ２０は一次側及び二次側の入出力用の端子を示している。一方、端子ｔ１４，ｔ１６，ｔ１７，ｔ１９は二次巻線４２〜４５の相互接続用である。
【００３３】
まず、窓部１０ｃ側の２個の二次巻線４２，４３のうち、一方の二次巻線４２の端子ｔ１４と、巻線１０の横断面においてこの二次巻線４２と横断面の中心に対して点対称に配置されている窓部１０ｃと反対側の二次巻線４４の端子ｔ１７とが接続されている。従って、これらの二次巻線４２，４４は１本の巻線を構成している。
【００３４】
また、窓部１０ｃ側の２個の二次巻線４２，４３のうち、他方の二次巻線４３の端子ｔ１６と、巻線１０の横断面においてこの二次巻線４３と横断面の中心に対して点対称に配置されている窓部１０ｃとは反対側の二次巻線４５の端子ｔ１９とが接続されている。従って、これらの二次巻線４３，４５は１本の巻線を構成している。
【００３５】
この第２実施形態では、窓部１０ｃ側の二次巻線４２，４３においては、帯状導体４６，４７のテーパ部４６ｄ，４７ｄが内側外周領域Ａｒ１に配置され、平行部４６ｃ，４７ｃが中央領域Ａｒ３に配置されている。同様に、窓部１０ｃとは反対側の二次巻線４４，４５においては、帯状導体４８，４９のテーパ部４８ｄ，４９ｄが外側外周領域Ａｒ２に配置され、平行部４８ｃ，４９ｃが中央領域Ａｒ３に配置されている。このように第２実施形態では、帯状導体４６〜４９に生じるジュール熱に対する冷却効果が比較的高い領域である内側領域Ａｒ１及び外側外周領域Ａｒ２において、冷却効果の低い中心領域Ａｒ３よりも帯状導体４６〜４９の断面積を小さく、かつこの断面積を漸次低減させることにより、帯状導体の４６〜４９発熱による温度上昇の制約を充足しつつ、かつ巻線１０の横断面の面積を増加させることなく帯状導体２９の巻数を増大させている。この巻数の増大により、巻鉄心１３の小型化し、変成器全体としても小型化、軽量化、及びコスト低減を図ることができる。第２実施形態のその他の構成は第１参考例と同様であるので、同一の要素には同一の符号を付して説明を省略する
【００３６】
本発明は、上記実施形態に限定されず、種々の変形が可能である。
図１０（Ｄ）〜（Ｆ）に示すように、帯状導体１４９，１４９’，１４９’として、幅Ｗが一定である平行部１４９ａ，１４９ａ’，１４９ａ’’と、幅Ｗが段階的に縮小する部１４９ｂ，１４９ｂ’，１４９ｂ’’とを備えるものを使用してもよい。なお、帯状導体の厚みを、外側外周領域及び／又は内側外周領域と中心領域とで異ならせても良い。
【００３７】
【発明の効果】
以上の説明から明らかなように、本発明の変成器では、導体に生じるジュール熱に対する冷却効果が比較的高い領域である巻線の横断面における内側外周領域と外側外周領域のうちの少なくとも一方において、中心領域よりも導体の断面積を小さく設定している。従って、導体の発熱による温度上昇の制約を充足しつつ、かつ巻線の横断面の面積を増加させることなく導体の巻数を増大させ、それによって巻鉄心の小型化（鉄心有効断面積の低減）を図ることができる。巻鉄心は、変成器を構成する他の部品と比較し寸法も大きく、かつ重量も重いので巻鉄心の小型化により変成器全体として、小型化、軽量化を図ることができる。また、巻鉄心は変成器を構成する他の部品と比較して比較的高価である電磁鋼板からなるため、巻鉄心を小型化して電磁鋼板の使用量を低減することにより、変成器の製造コストを低減することができる。
【図面の簡単な説明】
【図１】 本発明の第１参考例の変成器を示す斜視図である。
【図２】 図１のII-II線での断面図である。
【図３】 本発明の第１参考例の変成器の回路図である。
【図４】 本発明の第２参考例の変成器を示す断面図である。
【図５】 本発明の第１実施形態の変成器を示す断面図である。
【図６】 本発明の第１実施形態の変成器の回路図である。
【図７】 第１実施形態の変成器が備えるコイルボビンを示す分解斜視図である。
【図８】 本発明の第２実施形態の変成器を示す断面図である。
【図９】 本発明の第２実施形態の変成器の回路図である。
【図１０】 （Ａ）、（Ｂ）、（Ｃ）、（Ｄ）、（Ｅ）、及び（Ｆ）は、帯状導体を示す平面図である。
【図１１】 従来の変成器を示す断面図である。
【図１２】 巻線の横断面における位置と導線に生じるジュール熱に起因する温度上昇との関係を示す線図である。
【符号の説明】
１０ 巻線
１０ａ 脚部
１０ｂ 連結部
１０ｃ 窓部
１１ 一次巻線
１１ａ，１１ｂ 導線
１２ 二次巻線
１２ａ，１２ｂ 導線
１３ 巻鉄心
１４ 絶縁テープ
１５ 絶縁スペーサ
２１，２２ 帯状導体
２１ｃ，２２ｃ 平行部
２１ｄ，２２ｄ テーパ部
２５ コイルボビン
２６ 外枠
２７ 内枠
２８ 導線
２９ 帯状導体
２９ｃ 平行部
２９ｄ テーパ部
４１ 一次巻線
４１ａ 導線
４２，４３，４４，４５ 二次巻線
４６，４７，４８，４９ 帯状導体
４６ａ，４７ａ，４８ａ，４９ａ 基端
４６ｂ，４７ｂ，４８ｂ，４９ｂ 末端
４６ｃ，４７ｃ，４８ｃ，４９ｃ 平行部
４６ｄ，４７ｄ，４８ｄ，４９ｄ テーパ部
Ａｒ１ 内側外周領域
Ａｒ２ 外側外周領域
Ａｒ３ 中心領域[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a transformer such as a transformer, and in particular, to reduce the size and weight of a transformer formed by winding a magnetic steel sheet such as a silicon steel sheet around a pair of legs provided in a winding to form a wound core. And manufacturing cost reduction.
[0002]
[Prior art]
  FIG. 11 shows a transformer already proposed by the present inventor (see Japanese Patent Laid-Open Nos. 5-226168 and 8-51034). The transformer includes a winding 1 and a pair of wound cores 4. The winding 1 is composed of a primary winding 2 and a secondary winding 3 in which the conducting wires 2a and 3a are wound a plurality of times. The winding 1 includes a pair of leg portions 1a facing each other with a gap, a pair of connecting portions 1b connecting both ends of the leg portions 1a, and a window portion surrounded by the leg portions 1a and the connecting portions 1b. 1c. The cross-sectional shape of the conducting wires 2a and 3a in the direction orthogonal to the winding direction is circular. On the other hand, the wound core 4 is formed by winding a strip of an electromagnetic steel plate such as a silicon steel plate around the leg 1 a of the winding 1. In FIG. 11, 5 is an insulating tape that covers the outer periphery of the winding 1, and 6 is an insulating spacer that insulates the primary winding 2 and the secondary winding 3.
[0003]
  Like the other various transformers, the relationship of the following formula (1) is established in the primary winding 2 and the secondary winding 3 of the transformer shown in FIG. In this formula (1), E is an electromotive force (V), k is a proportional constant, f is a frequency (Hz), N is the number of windings (number of windings) of the conductor, and A is an effective core area (m²), Bm is the magnetic flux density (T).
[0004]
[Expression 1]

[0005]
[Problems to be solved by the invention]
  In order to reduce the size and weight of the transformer, it is most effective to reduce the size of the wound iron core 4 which is large in size and heavy among the components constituting the transformer. Also, from electromagnetic steel sheets such as silicon steel sheetsWindingThe iron core 4 is relatively more expensive than other parts constituting the transformer, and the size of the wound iron core 4 is preferably as small as possible in order to reduce the manufacturing cost of the transformer.
[0006]
  As apparent from the above formula (1), in order to reduce the size of the wound core 4, that is, the effective core area A, while maintaining the same electromotive force E and without reducing the magnetic flux density Bm, What is necessary is just to increase N. Further, in order to increase the number of turns N of the conductors 2a and 3a without increasing the size of the wound core 4, that is, without increasing the size of the core window portion, the cutting in the direction perpendicular to the winding direction of the conductors 2a and 3a is required. It is necessary to reduce the area, that is, to reduce the diameter of the conducting wires 2a and 3a. On the other hand, when the cross-sectional areas of the conducting wires 2a and 3a are decreased, the current density is increased, so that the temperature rise due to Joule heat generated in the conducting wires 2a and 3a becomes remarkable. Therefore, conventionally, in consideration of the temperature rise in the entire winding 1 including both the primary winding 2 and the secondary winding 3, the conductors 2a, 2a, The diameter of 3a was set, and the diameters of the conductors 2a and 3a were constant for the primary winding 2 and the secondary winding 3, respectively.
[0007]
  However, when the present inventor conducted various experiments and researches, due to the Joule heat generated in the conductors 2a and 3a in the cross section (transverse cross section) in the direction orthogonal to the winding direction in the leg 1a of the winding 1 We found that there is a distribution in the temperature rise. Specifically, as shown in FIG. 12, an inner peripheral region Ar1 (region between position P4 and position P5 in FIG. 11), which is a region near the outer periphery on the window 1c side in the cross section of the winding 1, and the winding In the outer peripheral area Ar2 (the area at positions P1 and P2 in FIG. 11) that is the area near the outer periphery on the opposite side of the window 1c in the cross section of 1, the center that is the area near the center in the cross section of the winding 1 Compared with region Ar3 (region between positions P2 and P4 in FIG. 11), the degree of temperature rise due to Joule heat generated in conductors 2a and 3a is relatively low. In other words, the inner periphery area Ar1 and the inner periphery area Ar1.2Was found to have a higher winding cooling effect than the central region Ar3.
[0008]
  An object of the present invention is to reduce the size and weight of a transformer formed by forming a wound iron core between a pair of legs included in a winding, and to reduce the manufacturing cost based on such new knowledge.
[0009]
[Means for Solving the Problems]
  The present invention includes a pair of leg portions facing each other with a space therebetween, a pair of connection portions connecting both ends of the leg portions, and a window portion surrounded by the leg portions and the connection portion.GetA winding and a pair of wound iron cores each formed by winding a magnetic steel sheet on each of the pair of legs, and the winding has a substantially cross-sectional shape that is a cross section in a direction perpendicular to the winding direction of the conductor. A transformer that is circular,The winding is composed of a primary winding formed by winding a conductor having a circular cross section a plurality of times and a secondary winding formed by winding a single strip-shaped conductor a plurality of times,the aboveStrip of conductorThe cross-sectional area in the cross section orthogonal to the winding direction is the inner peripheral area, which is the outer peripheral area on the window side in the cross section of the winding, and the opposite side of the window in the cross section of the winding. A transformer is provided that is smaller in at least one of the outer peripheral areas, which are the outer peripheral areas, than the central area, which is an area in the vicinity of the center in the cross section of the winding.
[0010]
  In the transformer of the present invention,StripIn at least one of the inner peripheral area and the outer peripheral area in the cross section of the winding, which is a relatively high cooling effect on Joule heat generated in the conductor, than the central areaStripThe cross-sectional area of the conductor is set small. Therefore,StripSatisfying restrictions on temperature rise due to heat generated by conductors and without increasing the cross-sectional area of the windingStripThe number of windings of the conductor can be increased, thereby reducing the size of the wound core (reducing the effective core area). Since the wound core is larger in size and heavier than other components constituting the transformer, the entire transformer can be reduced in size and weight by downsizing the wound core. In addition, since the wound iron core is made of a magnetic steel sheet that is relatively expensive compared to other parts constituting the transformer, the manufacturing cost of the transformer can be reduced by reducing the volume of the magnetic steel sheet by reducing the size of the wound iron core. Can be reduced. Note that the “substantially circular” is not limited to a perfect circle but is a plane included in a substantially circular category as the shape of the cross section of the winding, such as an ellipse, an ellipse, a polygon, and a closed curve including a free curve. A figure.
[0011]
  For example,the aboveStrip conductorHas a constant thicknessAndCross sectionIn the form ofAhAnd aboveOuter peripheral areaAnd the width aboveWidth in the inner periphery areaAnd at least one ofBut,Smaller than the width in the central regionYes.
[0012]
  Specifically, the above-mentioned strip conductorThe width is aboveOuter peripheral areaAnd aboveInner peripheral areaAnd at least one ofAs the distance from the central region increases, the image shrinks continuously or stepwise. Note that the thickness of the strip-shaped conductor may be different between the outer peripheral region and / or the inner peripheral region and the central region.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
  Next, the present invention will be described in detail based on the embodiments of the present invention shown in the drawings.
[0014]
  (FirstReference example)
  1 to 3 show the first of the present invention.Reference exampleThe transformer which concerns on is shown.
  The transformer includes a single winding 10 including a primary winding 11 and a secondary winding 12, and a pair of wound iron cores 13. In the figure, reference numeral 14 denotes an insulating tape that covers the outer periphery of the winding 10, and 15 denotes an insulating spacer for insulating the primary winding 11 and the secondary winding 12.
[0015]
  The winding 10 includes a pair of leg portions 10a facing each other at an interval, a pair of connecting portions 10b connecting both ends of the leg portions 10a, and a window portion 10c surrounded by the leg portions 10a and the connecting portions 10b. And. Further, the winding 10 has a circular cross section (transverse cross section) in a direction orthogonal to a winding direction of conductive wires 11a to 12b described later. On the other hand, the wound iron core 13 is cylindrical and is formed by winding a magnetic steel sheet around a pair of leg portions 10a included in the winding 10. That is, the winding 10 is housed in an iron core window having a circular cross section of the wound iron core 13.
[0016]
  The primary winding 11 and the secondary winding 12 which comprise the coil | winding 10 are each comprised from the material which has electroconductivity, such as copper, and are comprised by winding conducting wire 11a-12b with a circular cross section many times. In the conventional transformer shown in FIG. 11, the conductors 2a and 2b of the primary winding 2 and the secondary winding 3 have a constant cross-sectional area.Reference exampleThen, the diameter of the conducting wire is changed in both the primary winding 11 and the secondary winding 12, thereby changing the cross-sectional area. In the figure, t1, t2, t3, and t4 indicate primary and secondary input / output terminals.
[0017]
  First, the primary winding 11 includes a primary-side inner conductor 11a and a primary-side outer conductor 11b. The primary-side inner conductor 11a has a smaller diameter than the primary-side outer conductor 11b, and thus has a smaller cross-sectional area. As shown schematically in FIG. 3, the primary inner conductor 11 a and the primary outer conductor 11 b are electrically connected at one end, and electrically constitute one conductor. Yes. The primary winding 11 is formed by winding the primary side inner conducting wire 11a and the primary side outer conducting wire 11b around a winding mold (not shown). At this time, the primary inner conductor 11a is wound around the winding mold, and the primary inner conductor 11a is disposed on the window 10c side. In FIG. 2, the arrow Y indicates the direction in which the conducting wires are stacked in the cross section of the winding 10.
[0018]
  Next, the secondary winding 12 includes a secondary-side inner conductor 12a and a primary-side outer conductor 11b. The secondary outer conductor 12b has a smaller diameter than the secondary inner conductor 12a, and therefore has a smaller cross-sectional area. As shown schematically in FIG. 3, the secondary-side inner conductor 12a and the secondary-side outer conductor 12b are electrically connected at one end to form a single conductor. is doing. The secondary winding 12 is formed by winding the secondary-side inner conductor 12a and the secondary-side outer conductor 12b with the insulating spacer 15 interposed between the primary winding 11 that has been wound around the winding mold. . At this time, the secondary inner conductor 12a is disposed on the primary winding 11 side by being wound from the primary inner conductor 11a. In addition, after forming the secondary winding 12, the insulating tape 14 is wound around the outer periphery of the winding 10.
[0019]
  As shown in FIG. 2, for the primary winding 11, the primary inner conductor having a small diameter (small cross-sectional area) in the inner outer peripheral area Ar <b> 1, which is an area near the outer periphery on the window portion 10 c side in the cross section of the winding 10. 11a is disposed, and a primary-side outer conductor 11b having a large diameter (large cross-sectional area) is disposed in a central region Ar3 that is a region near the center in the cross section of the winding 10. On the other hand, with respect to the secondary winding 12, a secondary-side inner conductor 12a having a large diameter (large cross-sectional area) is disposed in the central region Ar3, and in the vicinity of the outer periphery on the side opposite to the window portion 10c in the cross-section of the winding 10 The outer peripheral area Ar2 that is the area of the secondary outer conductor 12b having a small diameter (small cross-sectional area) is disposed. That is, the firstReference exampleThen, in the inner peripheral region Ar1 and the outer peripheral region Ar2, which are regions where the cooling effect against Joule heat generated in the conductive wires 11a-12b is relatively high, the areas of the conductive wires 11a-12b are set smaller than the central region Ar3 where the cooling effect is low. ing. Therefore, the number of turns of the conducting wires 11a to 12b is increased without satisfying the restriction of the temperature rise due to the heat generation of the conducting wires 11a to 12b and without increasing the area of the cross section of the winding 10, thereby reducing the size of the wound core 13. (Reduction of the effective core area) can be achieved. Since the wound core 13 is larger in size and heavier than other components constituting the transformer, the size of the transformer can be reduced as a whole by reducing the size of the wound core 13. In addition, since the wound core 13 is made of a magnetic steel sheet that is relatively expensive compared to other parts constituting the transformer, the volume of the transformer is reduced by reducing the volume of the magnetic steel sheet by reducing the size of the wound core 13. Manufacturing cost can be reduced.
[0020]
  (SecondReference example)
  FIG. 4 shows a second embodiment of the present invention.Reference exampleThe transformer which concerns on is shown.
  This secondReference exampleThen, the primary winding 11 and the secondary winding 12 of the winding 10 are formed by winding strip-like conductors 21 and 22 having a rectangular cross section made of a conductive material such as copper instead of a conducting wire. First, the strip-shaped conductors 21 and 22 have a constant plate thickness and a rectangular cross-sectional shape. Also,As shown in FIG.The strip-shaped conductors 21 and 22 are parallel portions 21c and 22c having a constant length L1 from the base ends 21a and 22a side and a constant width W. The widths W are gradually increased from the parallel portions 21c and 22c toward the distal ends 21b and 22b. Are provided with tapered portions 21d and 22d having a length L2. In the parallel portions 21c and 22c, the cross-sectional areas of the strip-shaped conductors 21 and 22 are constant, but in the tapered portions 21d and 22d, the cross-sectional areas of the strip-shaped conductors 21 and 22 gradually decrease toward the tip side.
[0021]
  The primary winding 11 is formed by winding a strip-shaped conductor 21 from a terminal 21b side around a winding mold (not shown), and a taper 21d is arranged on the window portion 10c side. Further, the secondary winding 12 is formed by winding the strip-shaped conductor 22 from the base end 22a side with the insulating spacer 15 interposed in the primary winding 11 wound around the winding mold, and the window portion 10c. The taper part 22d is arrange | positioned on the opposite side.
[0022]
  Figure4As shown in the figure, for the strip-shaped conductor 21 of the primary winding 11, a tapered portion 21d in which the width W gradually decreases and the cross-sectional area gradually decreases in the inner peripheral area Ar1, and the width W is constant in the center area Ar3. A parallel portion 21c is arranged. On the other hand, for the strip-shaped conductor 22 of the secondary winding 12, a parallel portion 22c having a constant width W and a large cross-sectional area is disposed in the central region Ar3, and the cross-sectional area is gradually reduced in the outer peripheral region Ar2. A tapered portion 22d that gradually decreases is disposed.
[0023]
  Inner peripheral area Ar1Then, although the size of the iron core window of the wound iron core 13 in the width direction of the band-shaped conductor 21 is small and the reduction rate is large, the taper portion 21d whose width W gradually decreases is disposed, so that the band-shaped conductor having a constant width is wound. The number of turns increases compared to the case of turning. On the other hand, the inner peripheral area Ar <b> 1 has a high cooling effect against Joule heat generated in the strip conductor 21. Similarly to the inner outer peripheral region Ar3, the outer peripheral region Ar2 has a small size of the core window of the wound core 13 in the width direction of the strip conductor 22 and a large reduction rate, but the tapered portion 22d whose width W gradually decreases. Therefore, the number of turns increases as compared with the case where a strip-shaped conductor having a constant width is wound. On the other hand, the outer peripheral area Ar <b> 2 also has a high cooling effect against Joule heat generated in the strip conductor 22. Like this secondReference exampleIn the inner outer peripheral region Ar1 and the outer outer peripheral region Ar2, which are regions where the cooling effect against Joule heat generated in the strip conductors 21 and 22 is relatively high, the cross-sectional areas of the strip conductors 21 and 22 are lower than the central region Ar3 where the cooling effect is low. By reducing the cross-sectional area gradually and reducing the cross-sectional area, the temperature of the belt-shaped conductors 21 and 22 can be reduced without increasing the cross-sectional area of the winding 10 while satisfying the restriction of the temperature rise due to the heat generation of the band-shaped conductors 21 and 22. The number of turns is increased. By increasing the number of turns, the wound iron core 13 can be reduced in size, and the transformer as a whole can be reduced in size, weight, and cost.
[0024]
  In addition, in FIG. 4, since the cross section of the wound iron core 10 is shown schematically, it seems that there is a gap in the iron core window of the wound iron core 13, but this gap is actually very small and substantially The cross section of the wound core 10 is circular. SecondReference exampleThe other structure and operation of the first isReference exampleTherefore, the same elements are denoted by the same reference numerals and description thereof is omitted.
[0025]
  (No.1Embodiment)
  Next, the present invention shown in FIGS.1Embodiments will be described.
  This first1In the embodiment, the winding is formed on the coil bobbin 25 shown in FIG. The coil bobbin 25 includes an outer frame 26 and an inner frame 27 both made of resin. The outer frame 26 includes a pair of core winding portions 26a that are wound around the wound core 13 and a pair of connecting portions 26b that connect the core winding portions 26a, and has a rectangular frame shape as a whole. Further, a groove 26c for accommodating the winding is formed on the outer periphery of the outer frame 26. Like the outer frame 26, the inner frame 27 has a rectangular frame shape including a pair of iron core winding portions 27a and a pair of connecting portions 27b, and a groove 27c is formed on the outer periphery thereof. An inner frame 27 is fitted into the outer frame 26 integrally.
[0026]
  As shown in FIG. 5, the cross section of the groove 26c of the outer frame 26 is rectangular, and the cross section of the groove 27c of the inner frame 27 is a shape obtained by dividing a regular hexagon into two. Accordingly, the cross-sectional shape of the grooves 26c and 27c, that is, the cross-sectional shape of the winding 10 is a shape that approximates a circle.
[0027]
  As shown in FIG. 5, the winding 10 includes a primary winding 11 and a secondary winding 12, and the primary winding 11 has a constant diameter (cross-sectional area) in the groove 27 c of the inner frame 27 of the coil bobbin 25. It is formed by winding a certain lead wire 28. Therefore, for the primary winding 11, the cross-sectional area of the conducting wire 28 is constant in the inner region Ar1 and the central region Ar3. On the other hand, the secondary winding 12 is configured by winding a strip-shaped conductor 29 around the groove 26 c of the outer frame 26 of the coil bobbin 25. The strip-shaped conductor 29 is the second conductor.Reference exampleThis is the same as the strip conductors 21 and 22 in FIG. That is, the strip-shaped conductor 29 has a constant plate thickness and includes a parallel portion 29c on the base end 29a side and a tapered portion 29d on the end 29b side. The strip-shaped conductor 29 is wound around the outer frame 26 of the coil bobbin 25 from the base end 29a side, a parallel portion 29c is disposed in the center region Ar3, and a tapered portion 29d is disposed in the outer peripheral portion Ar2. In the figure, t6, t7, t8, and t9 indicate primary and secondary input / output terminals.
[0028]
  In the outer peripheral region Ar2, the size of the core window of the wound core 13 in the width direction of the strip conductor 22 is small and the reduction rate is large, but since the tapered portion 29d in which the width W gradually decreases is disposed, the width is constant. The number of turns increases as compared with the case of winding the strip-shaped conductor. On the other hand, the outer peripheral area Ar <b> 2 has a high cooling effect against Joule heat generated in the strip conductor 22. Like this1In the embodiment, in the outer peripheral region Ar2 which is a region where the cooling effect on Joule heat generated in the strip conductor 29 is relatively high, the cross-sectional area of the strip conductor 29 is smaller than the central region Ar3 where the cooling effect is low, and this cross-sectional area is reduced. By gradually reducing the number of turns, the number of turns of the band-shaped conductor 29 is increased while satisfying the restriction of the temperature rise due to the heat generation of the band-shaped conductor 29 and without increasing the area of the cross section of the winding 10. Due to the increase in the number of turns, the wound core 13TheThe transformer can be downsized and the transformer as a whole can be reduced in size, weight, and cost. First1The other configuration of the embodiment is the firstReference exampleTherefore, the same elements are denoted by the same reference numerals and description thereof is omitted.
[0029]
  (No.2Embodiment)
  As shown in FIG. 8 and FIG.2The transformer winding 10 according to the embodiment includes one primary winding 41, two secondary windings 42 and 43 closer to the window portion 10c than the primary winding 41, and further a primary winding. Two secondary windings 44 and 45 are provided on the side opposite to the window portion 10 c with respect to the wire 41. The two secondary windings 42 and 443 on the window portion 10c side and the secondary windings 44 and 45 on the opposite side to the window portion 10c are electrically connected one by one. The transformer thus has one primary winding and two secondary windings.
[0030]
  The primary winding 41 is formed by winding a conductive wire 41 a having a constant diameter (a constant cross-sectional area), and is disposed near the center of the cross section of the winding 10.
  The two secondary windings 42 and 43 arranged closer to the window 10c than the primary winding 41 are insulated from the primary winding 41 by the insulating spacer 15A, and by the insulating spacer 15C. The secondary windings 42 and 43 are insulated from each other. Further, as shown in FIGS. 10B and 10C, the secondary windings 42 and 43 have a constant plate thickness and a rectangular cross section, and have a length L1 on the base end 46a and 47a side. , Parallel strips 46c and 47c and taper portions 46d and 47d having a length L2 on the end 46b and 46b side. These strip-like conductors 46 and 47 are straight lines with one side in the longitudinal direction not bent, and taper portions 46d and 47d are formed by extending the other side toward one side. The secondary windings 42 and 43 are formed by winding these strip-shaped conductors 46 and 47 from the ends 46b and 47b, and taper portions 46d and 47d of the strip-shaped conductors 46 and 47 are respectively formed in the inner peripheral area Ar1. The parallel portions 46c and 47c are arranged in the central region Ar3.
[0031]
  As shown in FIGS. 10B and 10C, the secondary windings 44 and 45 on the opposite side of the window portion 10c with respect to the primary winding 41 have a constant plate thickness and a rectangular cross section, It consists of strip-shaped conductors 48 and 49 having parallel portions 48c and 49c having a length L1 on the base ends 48a and 9a side and tapered portions 48d and 49d having a length L2. The secondary windings 44 and 45 are formed by winding these strip-shaped conductors 48 and 49 from the base end 48a and 49a side, respectively, and taper portions 48d and 49d of the strip-shaped conductors 48 and 49 in the outer peripheral area Ar2, respectively. Are arranged, and parallel portions 48c and 49c are arranged in the central region Ar3.
[0032]
  In the figure, t11 to t20 indicate terminals of the primary winding 41 and the secondary windings 42 to 45, respectively. Of these, terminals t11, t12, t13, t15, t18, and t20 indicate primary and secondary input / output terminals. On the other hand, terminals t14, t16, t17, and t19 are for interconnecting the secondary windings 42 to 45.
[0033]
  First, of the two secondary windings 42 and 43 on the side of the window portion 10c, the terminal t14 of one secondary winding 42 and the center of the secondary winding 42 and the cross section in the cross section of the winding 10 are shown. Are connected to a terminal t17 of the secondary winding 44 on the opposite side. Therefore, these secondary windings 42 and 44 constitute one winding.
[0034]
  Of the two secondary windings 42 and 43 on the side of the window 10c, the terminal t16 of the other secondary winding 43 and the center of the secondary winding 43 and the cross section in the cross section of the winding 10 are shown. Is connected to the terminal t19 of the secondary winding 45 on the opposite side of the window portion 10c arranged symmetrically with respect to the point. Therefore, these secondary windings 43 and 45 constitute one winding.
[0035]
  This first2In the embodiment, in the secondary windings 42 and 43 on the window portion 10c side, the taper portions 46d and 47d of the strip conductors 46 and 47 are disposed in the inner outer peripheral region Ar1, and the parallel portions 46c and 47c are disposed in the central region Ar3. Has been. Similarly, in the secondary windings 44 and 45 on the side opposite to the window portion 10c, the taper portions 48d and 49d of the strip conductors 48 and 49 are disposed in the outer peripheral region Ar2, and the parallel portions 48c and 49c are in the central region Ar3. Is arranged. Like this2In the embodiment, in the inner region Ar1 and the outer peripheral region Ar2 that are relatively high cooling effects against Joule heat generated in the strip conductors 46 to 49, the cross-sectional areas of the strip conductors 46 to 49 are lower than the central region Ar3 that has a low cooling effect. And by gradually reducing the cross-sectional area, the number of turns of the belt-like conductor 29 can be satisfied without increasing the cross-sectional area of the winding 10 while satisfying the restriction of the temperature rise due to heat generation of the belt-like conductors 46 to 49. Is increasing. By increasing the number of turns, the wound iron core 13 can be reduced in size, and the transformer as a whole can be reduced in size, weight, and cost. First2The other configuration of the embodiment is the firstReference exampleThe same elements are denoted by the same reference numerals and description thereof is omitted.
[0036]
  The present invention is not limited to the above embodiment, and various modifications can be made.
  As shown in FIGS. 10D to 10F, as the strip-shaped conductors 149, 149 ′, 149 ′, the parallel portions 149a, 149a ′, 149a ″ having the constant width W and the width W are gradually reduced. It is also possible to use one provided with parts 149b, 149b ′, 149b ″. Note that the thickness of the strip-shaped conductor may be different between the outer peripheral region and / or the inner peripheral region and the central region.
[0037]
【The invention's effect】
  As is clear from the above description, in the transformer of the present invention, in at least one of the inner peripheral region and the outer peripheral region in the cross section of the winding, which is a region where the cooling effect against Joule heat generated in the conductor is relatively high. The cross-sectional area of the conductor is set smaller than the central region. Therefore, while satisfying the restriction of temperature rise due to heat generation of the conductor and increasing the number of turns of the conductor without increasing the cross-sectional area of the winding, the winding core is reduced in size (reducing the effective core area) Can be achieved. Since the wound core is larger in size and heavier than other components constituting the transformer, the entire transformer can be reduced in size and weight by downsizing the wound core. In addition, since the wound iron core is made of a magnetic steel sheet that is relatively expensive compared to other parts constituting the transformer, the manufacturing cost of the transformer can be reduced by reducing the volume of the magnetic steel sheet by reducing the size of the wound iron core. Can be reduced.
[Brief description of the drawings]
FIG. 1 shows the first of the present invention.Reference exampleIt is a perspective view which shows this transformer.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 shows the first of the present invention.Reference exampleIt is a circuit diagram of a transformer.
FIG. 4 shows the second of the present invention.Reference exampleIt is sectional drawing which shows this transformer.
FIG. 5 shows the first of the present invention.1It is sectional drawing which shows the transformer of embodiment.
FIG. 6 shows the first of the present invention.1It is a circuit diagram of the transformer of an embodiment.
FIG. 71It is a disassembled perspective view which shows the coil bobbin with which the transformer of embodiment is provided.
FIG. 8 shows the first of the present invention.2It is sectional drawing which shows the transformer of embodiment.
FIG. 9 shows the first of the present invention.2It is a circuit diagram of the transformer of an embodiment.
10 (A), (B), (C), (D), (E), and (F) are plan views showing a strip-shaped conductor. FIG.
FIG. 11 is a cross-sectional view showing a conventional transformer.
FIG. 12 is a diagram showing a relationship between a position in a cross section of a winding and a temperature rise caused by Joule heat generated in a conducting wire.
[Explanation of symbols]
  10 windings
  10a Leg
  10b connecting part
  10c Window
  11 Primary winding
  11a, 11b conducting wire
  12 Secondary winding
  12a, 12b Conductor
  13 roll iron core
  14 Insulation tape
  15 Insulating spacer
  21, 22 Strip conductor
  21c, 22c Parallel part
  21d, 22d taper part
  25 Coil bobbin
  26 Outer frame
  27 Inner frame
  28 conductor
  29 Strip conductor
  29c Parallel part
  29d taper
  41 Primary winding
  41a Conductor
  42, 43, 44, 45 Secondary winding
  46, 47, 48, 49 Strip conductor
  46a, 47a, 48a, 49a
  46b, 47b, 48b, 49b
  46c, 47c, 48c, 49c Parallel part
  46d, 47d, 48d, 49d Tapered part
  Ar1 inner peripheral area
  Ar2 outer peripheral area
  Ar3 central region

Claims (3)

And a pair of leg portions facing each other at an interval, and a pair of connecting portions connecting both ends of these legs, and Bei obtain winding and a window portion surrounded by these legs and the connecting portion,
A pair of wound iron cores each including a magnetic steel sheet wound around the pair of legs,
The winding is a transformer having a substantially circular cross-sectional shape that is a cross section in a direction orthogonal to the winding direction of the conductor,
The winding is
A primary winding formed by winding a conducting wire having a circular cross section multiple times;
A secondary winding formed by winding a single strip-shaped conductor multiple times;
Composed of
The cross-sectional area of the strip-shaped conductor in the cross section orthogonal to the winding direction is the inner peripheral area, which is the vicinity of the outer periphery on the window section side in the cross section of the winding, and the window section in the cross section of the winding. A transformer that is smaller in at least one of the outer peripheral area that is the outer peripheral area on the opposite side to the center area that is an area in the vicinity of the center in the cross section of the winding. Said strip conductor is a thickness constant and Oh sectional rectangle Rutotomoni, the width of the upper Kisotogawa peripheral region, at least one of the width in the inner peripheral region is smaller than the width in the central region, wherein Item 5. The transformer according to Item 1. The width of the strip conductor, and the outer peripheral region, at least one of an the inner peripheral region, continuously or stepwise reduced in accordance with the away from the central region, metamorphic according to claim 2 vessel.

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