JP4103622B2

JP4103622B2 - Manufacturing method of stator of rotating electric machine

Info

Publication number: JP4103622B2
Application number: JP2003039516A
Authority: JP
Inventors: 隆鴇沢
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2003-02-18
Filing date: 2003-02-18
Publication date: 2008-06-18
Anticipated expiration: 2023-02-18
Also published as: JP2004254362A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車やトラックに搭載される車両用交流発電機等の回転電機の固定子の製造方法に関する。
【０００２】
【従来の技術】
従来から、回転電機の固定子巻線の接合には、電極と巻線溶接部との間でアーク放電させ、その熱を利用して巻線を溶融接合するアーク溶接が一般に採用されている。例えば、固定子鉄心に形成された複数のスロットに、Ｕ字状の電気導体を挿入した後に、その先端部側を周方向に傾斜させ、その後、隣接する先端部同士をアーク放電によって接合する回転電機の巻線接合方法が知られている（例えば、特許文献１参照。）。
【０００３】
図１６は、上述した接合方法の対象となる従来の固定子の構造を示す部分的な斜視図である。また、図１７は図１６に示した固定子巻線の接合部の配置を示す平面図である。図１８は、従来の接合装置の要部を示す図である。
図１６に示すように、固定子鉄心４００の各スロットから４本の電気導体４０４が突出している場合に、径方向に見るとその突出部分が交互に反対周方向に傾斜している。これらの電気導体４０４の先端が接合部４０６であり、図１７に示すように、径方向に並んだ４つの接合部４０６の２つずつが組になって接合作業が行われる。
【０００４】
具体的には、この接合作業は、図１８に示すように、内径側プラス電極４１０と外径側プラス電極４１２によって接合部４０６の内径側および外径側を拘束するとともに、周方向に隣接する各接合部４０６の間に棒状プラス電極４１４を配置した状態で行われる。このような状態において、接合部４０６に溶接電極としてのトーチ４２０を近づけることにより、接合部４０６の溶接による接合が行われる。
【０００５】
【特許文献１】
特許第３１０４７００号公報（第４−６頁、図１−５）
【０００６】
【発明が解決しようとする課題】
ところで、特許文献１に開示された従来の接合方法では、径方向に一列に並んだ接合部の間に隙間がある場合に、内径側プラス電極４１０および外径側プラス電極４１２によって内径側および外径側を拘束しようとしても、各接合部４０６がこの隙間部分に向かって移動してしまうため、接合部４０６の位置決めが容易でないという問題があった。また、接合部４０６が移動すると、各接合部４０６と内径側プラス電極４１０あるいは外径側プラス電極４１２との間の電気的な接触が不十分になり、接合不良が発生するおそれがあるという問題があった。
【０００７】
本発明は、このような点に鑑みて創作されたものであり、その目的は、接合部の位置決めを確実に行うことができ、接合不良の発生を防止することができる回転電機の固定子の製造方法を提供することにある。
【０００８】
【課題を解決するための手段】
上述した課題を解決するために、本発明の回転電機の固定子の製造方法は、周方向に複数のスロットが形成された固定子鉄心と、スロットのそれぞれに一部が収容され残りがスロットの外部に露出した電気導体を複数備えた固定子巻線とを備え、この電気導体は、露出部分がスロットから周方向の一方に傾斜して延びる第１の電気導体と、露出部分が第１の電気導体が収容されたスロットと周方向に異なる位置のスロットから周方向の他方に傾斜して延びるとともに、先端が第１の電気導体の先端と接合される第２の電気導体と、第１および第２の電気導体のそれぞれが収容されたスロットと異なるスロットから周方向の他方に傾斜して延びるとともに、第１および第２の電気導体同士の接合位置よりも固定子鉄心の端面に近い端面側交差部において第１の電気導体と交差する第３の電気導体とを有する回転電機の固定子の製造方法であって、第１および第２の電気導体同士の接合位置よりも固定子鉄心の端面に近い拘束部で第１の電気導体と第３の電気導体とを拘束し、第１の電気導体の先端と第２の電気導体の先端とを接合している。第１の電気導体と第２の電気導体の各先端の接合部を先端よりも固定子鉄心の端面に近い拘束部で拘束しているため、先端の接合部において拘束に必要なコイルエンド高さが不要になり、コイルエンド高さを低くすることができる。
【０００９】
また、上述した拘束部は端面側交差部であることが望ましい。これにより、端面側交差部において第１の電気導体と第３の電気導体の両方について一度に径方向および軸方向の位置決めが行われるため、接合対象となる第１の電気導体先端の接合部の径方向、周方向および軸方向の位置決めを確実に行うことができ、接合不良の発生を防止することが可能になる。
【００１０】
また、先端同士が接合される第１の電気導体と第２の電気導体からなる導体セットが径方向に複数組設けられて固定子巻線が形成されるとともに、径方向に並ぶ導体セットの間の空間に突出する突起が設けられた拘束部材が、第１の電気導体と第３の電気導体とを拘束することが望ましい。これにより、簡単な治具形状で、各接合部の位置決めを確実に行うことによる接合不良の発生防止と同時に、導体セット間のクリアランスを確保して隣接する接合部間の接触を防止することが可能になる。
【００１１】
また、上述した拘束部材は、突起に隣接配置された凹部を有しており、この凹部に第１の電気導体と第３の電気導体とを収容することによりこれらの電気導体を拘束することが望ましい。これにより、電気導体の拘束をより確実に行うことができる。
【００１２】
また、上述した凹部は、第１の電気導体と第３の電気導体が配置される側が幅広となる側面を有していることが望ましい。傾斜した側面に沿って電気導体を収容することになるため、拘束部材を取り付ける際に各電気導体を所定位置にガイドすることが可能になり、径方向および軸方向の位置ずれを生じることなく各電気導体を凹部の所定位置に収容することができる。
【００１３】
また、凹部の底面は、第１の電気導体および第３の電気導体の導体幅と同じ幅を有していることが望ましい。これにより、収容時における電気導体の位置ずれをなくすことができ、接合部の位置決め精度を向上させることができる。
また、本発明の回転電機の固定子の製造方法は、周方向に複数のスロットが形成された固定子鉄心と、スロットのそれぞれに一部が収容され残りがスロットの外部に露出した電気導体を複数備えた固定子巻線とを備え、この電気導体は、露出部分がスロットから周方向の一方に傾斜して延びる第１の電気導体と、露出部分が第１の電気導体が収容されたスロットと周方向に異なる位置のスロットから周方向の他方に傾斜して延びるとともに、先端が第１の電気導体の先端と接合される第２の電気導体と、第１および第２の電気導体のそれぞれが収容されたスロットと異なるスロットから周方向の他方に傾斜して延びるとともに、第１および第２の電気導体同士の接合位置よりも固定子鉄心の端面に近い端面側交差部において第１の電気導体と交差する第３の電気導体とを有する回転電機の固定子の製造方法であって、第１の電気導体と第３の電気導体とを径方向に拘束部材で拘束しつつ、第１の電気導体の先端と第２の電気導体の先端とを接合している。第１の電気導体と第３の電気導体を径方向に拘束部材で拘束しながら第１の電気導体と第２の電気導体の接合が行われるため、接合対象となる第１の電気導体先端の接合部の径方向の位置決めを確実に行うことができ、接合不良の発生を防止することが可能になる。
【００１４】
また、上述した第１の電気導体と、第２の電気導体および第３の電気導体は、それぞれスロットに径方向に複数並んで設けられ、拘束部材は、径方向に延び、複数の第１の電気導体と複数の第３の電気導体とを径方向に同時に拘束することが望ましい。これにより、径方向に並んだ複数の第１の電気導体と複数の第３の電気導体のそれぞれと同時に拘束することが可能になり、電気導体を拘束する工程を簡略化することができる。
【００１５】
また、上述した拘束部材は、第１および第２の電気導体同士の接合位置よりも固定子鉄心の端面に近い位置で、第１および第３の電気導体を拘束することが望ましい。第１の電気導体と第２の電気導体の接合位置よりも固定子鉄心の端面に近い位置で拘束しているため、先端の接合部において拘束に必要なコイルエンド高さが不要になり、コイルエンド高さを低くすることができる。
【００１６】
また、上述した拘束部材は、端面側交差部にて、第１および第３の電気導体を拘束することが望ましい。これにより、第１および第３の電気導体を同時に拘束することが可能になり、電気導体を拘束する工程をさらに簡略化することができる。
【００１７】
また、上述した拘束部材は一部に凹部が形成された串状であって、第１の電気導体と第３の電気導体との径方向拘束位置より軸方向にやや離れた位置に凹部が位置するように径方向に拘束部材を挿入する挿入工程と、軸方向に拘束部材を移動して凹部で第１の電気導体と第３の電気導体を拘束する拘束工程と、第１の電気導体と第２の電気導体を接合する接合工程と、軸方向に拘束部材を移動して径方向の拘束を解除する拘束解除工程と、拘束部材を径方向に移動して取り出す取り出し工程とを有することが望ましい。このように、接合前に拘束部材を径方向に挿入して各電気導体を拘束し、接合後にこの拘束部材による拘束を開示することにより、容易かつ確実に各電気導体の接合部の位置決めを行うことが可能になり、接合不良の発生を防止することができる。
【００１８】
【発明の実施の形態】
以下、本発明を適用した一実施形態の回転電機の固定子の製造方法について、図面を参照しながら詳細に説明する。
（第１の実施形態）
図１は第１の実施形態の回転電機としての車両用交流発電機の全体構成を示す断面図である。図１に示すように、本実施形態の車両用交流発電機１は、固定子２、回転子３、ハウジング４、整流器５等を含んで構成されている。
【００１９】
回転子３は、界磁として作用し、シャフト６と一体になって回転しており、ランデル型ポールコア７、界磁コイル８、スリップリング９、１０、送風装置としての斜流ファン１１および遠心ファン１２を備えている。シャフト６は、プーリ２０に連結されており、車両に搭載された走行用のエンジン（図示せず）により回転駆動される。
【００２０】
ランデル型ポールコア７は、一組のポールコアを組合わせて構成されている。このランデル型ポールコア７は、シャフト６に組付られたボス部７１と、ボス部７１の両端より径方向に延びるディスク部７２と、１２個の爪状磁極部７３により構成されている。
【００２１】
プーリ側の斜流ファン１１は、ポールコア７の端面に溶接などによって固着されたベース板１１１に対して鋭角の傾斜を持つブレードと直角のブレードとを有し、回転子３と一体になって回転する。反プーリ側の遠心ファン１２は、ポールコア７の端面に溶接などによって固着されたベース板１２１に対して直角のブレードのみを有する。
【００２２】
ハウジング４は、フロントハウジング４ａとリアハウジング４ｂからなっており、その軸方向端面には吸入孔４１が、外周両肩部には、固定子２の第１コイルエンド群３１ａと第２コイルエンド群３１ｂのそれぞれの径方向外側に対応して冷却風の排出孔４２が設けられている。
【００２３】
整流器５は、固定子２から出力される交流電圧を直流に変換する整流作用を行っており、車両用交流発電機１の反プーリ側の端部に設けられている。
次に、固定子２の詳細について説明する。図２は、固定子２の部分的な断面図である。図３は、固定子鉄心３２に装着されるセグメント３３の模式的形状を示す斜視図である。
【００２４】
固定子２は、電機子として作用し、固定子鉄心３２と、固定子鉄心３２に形成された複数のスロット３５内に配置された複数の電気導体としてのセグメント３３によって構成された固定子巻線３１と、固定子鉄心３２と固定子巻線３１との間を電気絶縁するインシュレータ３４とを備えている。
【００２５】
図２に示すように、固定子鉄心３２には、多相の固定子巻線３１を収容できるように、内径側に開口を有する複数のスロット３５が形成されている。固定子鉄心３２のスロット３５に装備された固定子巻線３１は、１本１本の電気導体として把握することができ、複数のスロット３５のそれぞれの中には、偶数本（本実施形態では８本）の電気導体が収容されている。また、一のスロット３５内の８本の電気導体は、固定子鉄心３２の径方向に関して内側から順に第１層から第８層まで一列に配列されている。これらの電気導体には、絶縁被膜３７として、ポリアミドイミド等の被膜材が塗布されている。
【００２６】
これらの電気導体が所定のパターンで接続されることにより、固定子巻線３１が形成される。なお、本実施形態では、スロット３５内の電気導体は、第１コイルエンド群３１ａ側においては、連続線を配置することにより一端が接続され、また、第２コイルエンド群３１ｂ側においては、他端を接合することにより接続される。また、本実施形態の固定子巻線３１では、第１層〜第４層の各電気導体相互の関係は、第５層〜第８層の各電気導体相互の関係と基本的に同じであるため、以下では、第１層〜第４層の電気導体について詳細に説明する。
【００２７】
各スロット３５内の１本の電気導体は、所定の磁極ピッチ離れた他のスロット３５内の１本の他の電気導体と対をなしている。特に、コイルエンド部における複数の電気導体間の隙間を確保し、整列して配置するために、一のスロット３５内の所定の層の電気導体は、所定の磁極ピッチ離れた他のスロット３５内の他の層の電気導体と対をなしている。
【００２８】
例えば、一のスロット内の第１層の電気導体３３１ａは、固定子鉄心３２の時計回り方向に向けて１磁極ピッチ離れた他のスロット内の第４層の電気導体３３１ｂと対をなしている。同様に、一のスロット内の第２層の電気導体３３２ａは固定子鉄心３２の時計回り方向に向けて１磁極ピッチ離れた他のスロット内の第３層の電気導体３３２ｂと対をなしている。そして、これらの対をなす電気導体は、固定子鉄心３２の軸方向の一方の端部において連続線を用いることにより、ターン部３３１ｃ、３３２ｃを経由することで接続される。したがって、固定子鉄心３２の一方の端部においては、第３層の電気導体と第２層の電気導体とを接続する連続線を、第４層の電気導体と第１層の電気導体とを接続する連続線が囲むこととなる。このように、固定子鉄心３２の一方の端部においては、対をなす電気導体の接続部が、同じスロット内に収容された他の対をなす電気導体の接続部により囲まれる。第３層の電気導体と第２層の電気導体との接続により中層コイルエンドが形成され、第４層の電気導体と第１層の電気導体との接続により端層コイルエンドが形成される。
【００２９】
一方、一のスロット３５内の第２層の電気導体３３２ａは、固定子鉄心３２の時計回り方向に向けて１磁極ピッチ離れた他のスロット３５内の第１層の電気導体３３１ａ’とも対をなしている。同様に、一のスロット３５内の第４層の電気導体３３１ｂ’は、固定子鉄心３２の時計回り方向に向けて１磁極ピッチ離れた他のスロット３５内の第３層の電気導体３３２ｂと対をなしている。そして、これらの電気導体は固定子鉄心３２の軸方向の他方の端部において接合により接続される。
【００３０】
したがって、固定子鉄心３２の他方の端部においては、第４層の電気導体と第３層の電気導体とを接続する接合部と、第１層の電気導体と第２層の電気導体とを接続する接合部とが、径方向に並んでいる。第４層の電気導体と第３層の電気導体との接続、および第１層の電気導体と第２層の電気導体との接続により隣接層コイルエンドが形成される。
【００３１】
さらに、複数の電気導体は、ほぼ矩形断面（平角断面）をもった一定の太さの電気導体を所定形状に成形したＵ字状のセグメントにより提供される。図３に示すように、第１層の電気導体と第４層の電気導体とが、一連の電気導体をほぼＵ字状に成形してなる大セグメント３３１により提供される。また、第２層の電気導体と第３層の電気導体とが一連の電気導体をほぼＵ字状に成形してなる小セグメント３３２により提供される。
【００３２】
大セグメント３３１と小セグメント３３２とは基本セグメント３３を形成する。そして、基本セグメント３３を規則的にスロット３５に配置して、固定子鉄心３２の周りを２周（第５層〜第８層の電気導体の分も含めると合計で４周）するコイルが形成される。
【００３３】
図４は、固定子巻線３１の部分的な側面図であり、径方向外側から見た図が示されている。また、図５は固定子巻線３１をセグメント３３の先端部側から見た図であり、径方向に並んだ一部のセグメント３３のみを抜き出して周方向に展開した図である。図４および図５に示すように、本実施形態のセグメント３３は、隣接する電気導体同士を０°よりも大きな角度をなした状態で交差させ、この交差部分において先端部の側面同士を互いに接触させた状態で溶接等を行って接合部を形成している。具体的には、図５に示すように、固定子鉄心３２から突出した第１層の電気導体３３１ａの先端部３３１ｄと第２層の電気導体３３２ａの先端部３３２ｄとが互いの側面を介して接触しており、この接触部分に対して溶接等が行われる。また、第３層の電気導体３３２ｂの先端部３３２ｅと第４層の電気導体３３１ｂの先端部３３１ｅとが互いの側面を介して接触しており、この接触部分に対して溶接等が行われる。第５層および第６層の各電気導体や第７層および第８層の各電気導体についても同様である。
【００３４】
次に、固定子巻線３１の製造工程を以下に説明する。
（挿入工程）基本セグメント３３は、Ｕ字状の小セグメント３３２のターン部３３２ｃをＵ字状の大セグメント３３１のターン部３３１ｃが囲むように揃えられ、固定子鉄心３２の軸方向側面の一方側から挿入される。その際、大セグメント３３１の一方の電気導体３３１ａは固定子鉄心３２の一のスロット３５の第１層に、小セグメント３３２の一方の電気導体３３２ａは一のスロット３５の第２層に、そして、大セグメント３３１の他方の電気導体３３１ｂは固定子鉄心３２の一のスロット３５から時計方向に１磁極ピッチ離れた他のスロット３５の第４層に、小セグメント３３２の他方の電気導体３３２ｂも他のスロット３５の第３層に挿入される。
【００３５】
その結果、図２に示すように一のスロット３５には第１層側から、上述した電気導体３３１ａ、３３２ａ、３３２ｂ’、３３１ｂ’が一列に配置される。ここで、電気導体３３２ｂ’、３３１ｂ’は、１磁極ピッチずれた他のスロット３５内の電気導体と対をなしている大小のセグメントの電気導体である。
【００３６】
第５層〜第８層の各電気導体についても同様であり、第１層〜第４層の各電気導体と同時にあるいはこれらの電気導体の挿入が終了した後に第５層〜第８層の各電気導体の挿入が行われる。
（折り曲げ工程）挿入後、第２コイルエンド群３１ｂにおいて、第１層と第４層の電気導体３３１ａ、３３１ｂは、大セグメント３３１が開く方向にその先端の接合部３３１ｄ、３３１ｅが捻られて折り曲げられる。そして、第２層および第３層の電気導体３３２ａ、３３２ｂは、小セグメント３３２が閉じる方向にその先端の３３２ｄ、３３２ｅが捻られて折り曲げられる。その結果、第２コイルエンド群３１ｂにおいては、径方向に隣接する電気導体は周方向の逆向きに傾斜している。以上の構成を、全てのスロット３５のセグメント３３について、および第５層〜第８層の電気導体からなるセグメント３３について繰り返す。これにより、接合部３３１ｄ、３３２ｄによって形成される一対の接合部と、接合部３３１ｅ、３３２ｅによって形成される一対の接合部が、それぞれ同心円上に４列に径方向に沿って配置される。
【００３７】
（接合工程）そして、第２コイルエンド群３１ｂにおいて、第１および第２層の電気導体の接合部同士、第３および第４層の電気導体の接合部同士、第５および第６層の電気導体の接合部同士、第７および第８層の電気導体の接合部同士がそれぞれ溶接、超音波溶着、アーク溶接、ろう付け等の手段によって電気的導通を得るように接合されて固定子２が得られる。
【００３８】
次に、接合工程の詳細について説明する。図６は、接合工程において用いられる本実施形態の巻線接合装置の外観および構成を示す図である。
図６に示す巻線接合装置１００は、溶接工具としての溶接電極を含むトーチ１０２と、トーチ１０２を移動させるロボットアーム１０４と、トーチ１０２に電力を供給する溶接電源１０６と、トーチ１０２に不活性ガスを供給するガス供給装置１０８と、接合対象としてのセグメント３３が装備された固定子２を固定する固定台１１０と、固定子２のセグメント３３を拘束する拘束装置１１２と、固定台１１０を回転させる回転駆動装置１１４と、ロボットアーム１０４、回転駆動装置１１４、溶接電源１０６およびガス供給装置１０８を制御する制御装置１１６とを含んで構成されている。
【００３９】
トーチ１０２は、タングステンによって形成されており、ロボットアーム１０４の先端に装備されている。トーチ１０２は、溶接電源１０６のマイナス側端子に接続されており、溶接工具としての溶接電極を含んでいる。また、トーチ１０２には、溶接時のアークの安定と溶接部の酸化防止のために、アルゴンやヘリウム等の不活性ガスがガス供給装置１０８から供給される。なお、このように、一方の電極にタングステンを用い、アルゴン等の不活性ガスを供給しながら溶接を行う構成は、ＴＩＧ（Tungsten Inert Gas arc welding）として一般に知られている。
【００４０】
ロボットアーム１０４は、制御装置１１６からの制御信号を受けて、トーチ１０２が設けられている先端を、溶接対象としてのセグメント先端の接合部に沿って接続部が並ぶ方向に沿って移動させる。
図７は、図６に示した拘束装置１１２に用いられる各種の拘束部材を示す平面図である。また、図８は図７に示した拘束部材の中の串状拘束部材の詳細を示す側面図である。図９は、図８に示した串状拘束部材をＡ方向から見た矢視図である。図１０は、図８に示した串状拘束部材をＢ方向から見た矢視図である。図１１は、串状拘束部材をセグメント３３に取り付けて各電気導体を拘束した状態を示す斜視図である。
【００４１】
拘束装置１１２は、円環状の内周側拘束部材１１２ａおよび外周側拘束部材１１２ｂと、各電気導体同士の接合位置よりも固定子鉄心３２の端面に近い端面側交差部に配置された串状拘束部材１１２ｃとを備えている。なお、図７および図８では、串状拘束部材１１２ｃは１本のみが図示されているが、実際には周方向に隣接する各接合部間に同じ形状の串状拘束部材１１２ｃがスロット３５の数と同じ数だけ備わっている。
【００４２】
内周側拘束部材１１２ａは、最内周（第１層）の電気導体の内周側に配置されており、この電気導体の内周側への移動を拘束する。外周側拘束部材１１２ｂは、最内周（第８層）の電気導体の外周側に配置されており、この電気導体の外周側での移動を拘束する。
【００４３】
串状拘束部材１１２ｃは、図８に示すように、断面が三角形形状であって、その一辺がスロット３５から周方向の一方に傾斜して延びた電気導体の上面（固定子鉄心３２の端面と反対側の面）に沿った角度を、他の一辺が他のスロット３５から周方向の他方に傾斜して延びた他の電気導体の上面に沿った角度を有している。
【００４４】
例えば、図７において、第１層の電気導体３３１ａ、第２層の電気導体３３２ａ、第３層の電気導体３３２ｂに着目する。第１層の電気導体３３１ａ（本発明における第２の電気導体）は、露出部分が固定子鉄心３２のスロット３５から周方向の一方に傾斜して延びている。第２層の電気導体３３２ａ（本発明における第１の電気導体）は、露出部分が第１層の電気導体３３１ａが収容されたスロット３５と周方向に異なる位置の別のスロット３５から周方向の他方に傾斜して延びるとともに、先端が第１層の電気導体３３１ａの先端の接合部３３１ｄと接合される。第３層の電気導体３３２ｂ（本発明における第３の電気導体）は、第１層および第２層の電気導体３３１ａ、３３２ａのそれぞれが収容されたいずれのスロット３５とも異なる別のスロット３５から周方向の他方に傾斜して延びるとともに、これら第１層および第２層の電気導体３３１ａ、３３２ａ同士の接合位置よりも固定子鉄心３２の端面に近い端面側交差部Ｃにおいて第２層の電気導体３３２ａと交差する。このような関係は、第１層〜第８層の各電気導体の中の隣接する各電気導体について成立する。
【００４５】
上述した串状拘束部材１１２ｃは、これらの各電気導体が相互に交差する端面側交差部Ｃに配置されている。
また、串状拘束部材１１２ｃは、セグメント３３の電気導体が当接する位置に凹部２１０が形成され、隣接する凹部２１０の間に突起２１２が形成されている。先端同士が接合される２本の電気導体からなる導体セットを考えると、凹部２１０は、各導体セットに対応する位置に形成されており、突起２１２は、径方向に隣接して並んだ２組の導体セットの間の空間に突出するように形成されている。
【００４６】
また、串状拘束部材１１２ｃに形成された凹部２１０は、テーパ状の傾斜した側面２１４を有している。この傾斜した側面２１４は、セグメント３３の電気導体を拘束するために串状拘束部材１１２ｃを取り付ける際に、凹部２１０に電気導体を収納するためのガイドの機能を有している。したがって、図１１に示すように、串状拘束部材１１２ｃを各セグメント３３の接合部側から取り付けることにより、径方向および軸方向の位置ずれを生じることなく各電気導体は凹部２１０の所定位置に収容される。
【００４７】
また、凹部２１０は、各セグメント３３の電気導体の導体幅と同じ幅を有している。これにより、電気導体を凹部２１０に収容した際の電気導体の位置ずれをなくすことができ、接合部の位置決め精度を向上させることができる。
なお、上述した内周側拘束部材１１２ａ、外周側拘束部材１１２ｂ、串状拘束部材１１２ｃは、アーク溶接時の一方の電極を兼ねている。
【００４８】
図１２および図１３は、拘束装置１１２に含まれる串状拘束部材１１２ｃの取付・解除機構に関する構成と動作手順を示す図である。また、図１４は串押し下げ部材１２６に串状拘束部材１１２ｃを挿入した状態を示す図である。
図１２および図１３に示す取付・解除機構１２０は、折り曲げ工程までが終了したセグメント３３が収容された固定子鉄心３２をセットした後に串状拘束部材１１２ｃを取り付けるためのものである。串状拘束部材１１２ｃが取り付けられ、端面側交差部Ｃにおいて各電気導体が拘束された状態において、図６に示した巻線接合装置１００によって接合工程が実施される。その後、接合工程が終了した各電気導体の拘束を解除すべく串状拘束部材１１２ｃが取り外される。
【００４９】
この取付・解除機構１２０は、固定子鉄心３２を内径側および外径側から押さえて固定する円柱状の押え治具１２２および円環状の押え治具１２４と、径方向外側から挿入された各串状拘束部材１１２ｃの上面を固定子鉄心３２の端面側に押圧して各セグメント３３の端面側交差部Ｃに向けて押し下げる串押し下げ部材１２６と、接合工程終了後に各串状拘束部材１１２ｃの下面を固定子鉄心３２の端面から遠ざかる向きに押圧して串状拘束部材１１２ｃの取付状態を解除する串解除部材１２８とを含んで構成されている。
【００５０】
上述した構造を有する取付・解除機構１２０による各セグメント３３の電気導体の拘束および解除動作は以下のようにして行われる。
（串状拘束部材の挿入工程）まず、折り曲げ工程までが終了したセグメント３３が収容された固定子鉄心３２が取付・解除機構１２０にセットされ、串状拘束部材１１２ｃが径方向外側から挿入される（図１２（Ａ）、（Ｂ））。なお、図１４に示すように、串状拘束部材１１２ｃは先端側が細くなっており、串押し下げ部材１２６と押え治具１２２との隙間に串状拘束部材１１２ｃを容易に挿入することができるようになっている。また、この状態では、各セグメント３３の電気導体が交差している端面側交差部Ｃよりも軸方向にやや離れた位置に凹部２１０が位置するように径方向に串状拘束部材１１２ｃが挿入されるため、串状拘束部材１１２ｃと各セグメント３３の電気導体が交差している端面側交差部Ｃとの間にも十分な隙間が形成されており、串状拘束部材１１２ｃの挿入作業には高い精度が要求されない。
【００５１】
（拘束工程）次に、串押し下げ部材１２６を固定子鉄心３２の端面側に降下させる（図１３（Ａ））。これにより、端面側交差部Ｃにおいて串状拘束部材１１２ｃが各電気導体を拘束する。
（接合工程）この状態において電気導体先端の各接合部に対してアーク溶接が実施される。
【００５２】
（拘束解除工程）その後、串解除部材１２８を上昇させることにより、串状拘束部材１１２ｃを各電気導体から分離して拘束状態が解除された後（図１３（Ｂ））、串状拘束部材１１２ｃが径方向外側に抜き取られる。
このように、セグメント３３の電気導体が互いに交差する端面側交差部Ｃにおいてこれらの電気導体が拘束されるため、接合対象となる２本の電気導体先端の接合部の径方向、周方向および軸方向の位置決めを確実に行うことができ、接合不良の発生を防止することが可能になる。また、接合部近傍ではなく、接合部よりも固定子鉄心３２の端面に近い位置で各電気導体を拘束して接合を行っているため、先端の接合部において拘束に必要なコイルエンド高さが不要になり、コイルエンドを低くすることができる。
【００５３】
また、電気導体に当接する位置に凹部２１０を、各電気導体の間に対応する位置に突起２１２を形成しただけの単純な形状を有する串状拘束部材１１２ｃを用いることにより、簡単な治具形状で各電気導体の接合部の位置決めを確実に行うことによる接合不良の発生防止と同時に、導体セット間のクリアランスを確保して隣接する接合部間の接触を防止することが可能になる。特に、隣接した突起２１２の間に形成される凹部２１０にセグメント３３の電気導体を収容することにより、電気導体の拘束をより確実に行うことができる。
【００５４】
また、径方向に並んだ複数の電気導体を、しかも、異なる方向に傾斜した２種類の電気導体を１本の串状拘束部材１１２ｃを用いて同時に拘束しているため、それぞれの電気導体を別々に拘束する場合に比べて、電気導体を拘束する工程の簡略化が可能になる。
【００５５】
（第２の実施形態）
ところで、上述した第１の実施形態では、傾斜方向が異なる２種類の電気導体を、断面が三角形状を有する１本の串状拘束部材１１２ｃをこれらの電気導体の端面側交差部Ｃに配置することにより拘束したが、断面が三角形形状以外の拘束部材を用いたり、傾斜方向が異なる２種類の電気導体をそれぞれ別々の後続部材を用いて拘束したり、端面側交差部Ｃ以外の拘束部において拘束したりしてもよい。
【００５６】
図１５は、断面形状や拘束位置等を変更した第２の実施形態の拘束部材を示す図である。
本実施形態の拘束部材１１２ｄは、図１５に示すように円形形状の断面を有しており、スロット３５から周方向の一方に傾斜して延びた電気導体を拘束するための凹部が、この電気導体に対応する位置に形成されている。拘束部材１１２ｄを図１５に示すＤ方向から見ると、図９に示した串状拘束部材１１２ｃの形状と同様に、セグメント３３の電気導体を収容する凹部が形成されている。また、この拘束部材１１２ｄは、傾斜方向が異なる２種類の電気導体が交差する端面側交差部Ｃよりも電気導体の先端側に近い拘束部において、凹部に収容された電気導体を拘束している。
【００５７】
同様に、拘束部材１１２ｅは、円形形状の断面を有しており、スロット３５から周方向の他方に傾斜して延びた電気導体を拘束するための凹部が、この電気導体に対応する位置に形成されている。この拘束部材１１２ｅは、端面側交差部Ｃよりも電気導体の先端側に近い拘束部において、凹部に収容された電気導体を拘束している。
【００５８】
このように、端面側交差部Ｃ以外の拘束部において、断面が任意形状（図１５では円形形状）を有する拘束部１１２ｄ、１１２ｅを用いて、傾斜方向が異なる２種類の電気導体を別々に拘束することによっても、これらの拘束部においてそれぞれの電気導体が拘束されるため、接合対象となる２本の電気導体先端の接合部の径方向、周方向および軸方向の位置決めを確実に行うことができ、接合不良の発生を防止することが可能になる。また、接合部近傍ではなく、接合部よりも固定子鉄心３２の端面に近い位置で各電気導体を拘束して接合を行っているため、先端の接合部において拘束に必要なコイルエンド高さが不要になり、コイルエンドを低くすることができる。
【００５９】
また、図１５に示した例では、端面側交差部Ｃよりも電気導体先端側に拘束部を設定し、拘束対象となる電気導体の上面（固定子鉄心３２の端面と反対側の面）に拘束部材１１２ｄ等を当接させたが、図１５に示す拘束部材１１２ｆや拘束部材１１２ｈのように電気導体の下面（固定子鉄心３２の端面に近い側の面）を当接させたり、拘束部材１１２ｇのように端面側交差部Ｃよりも固定子鉄心３２の端面に近い位置に拘束部を設定したりしてもよい。接合部との干渉の度合いや拘束対象以外の電気導体との干渉の度合い等、レイアウト上の各種の制約を考慮して各拘束部材の位置を決定すればよい。また、必ずしも傾斜が異なる２種類の電気導体を拘束部材で拘束する必要はなく、どちらか一方のみを拘束するようにしてもよい。
【００６０】
なお、本発明は上記実施形態に限定されるものではなく、本発明の要旨の範囲内において種々の変形実施が可能である。例えば、上述した実施形態のセグメント３３は、隣接する電気導体同士を０°よりも大きな角度をなした状態で交差させ、この交差部分において先端部の側面同士を互いに接触させた状態で溶接等を行って接合部を形成しているが、図１６に示したように、隣接する電気導体の先端を平行に配置して接合部を形成する場合にも本発明を適用することができる。
【００６１】
また、径方向に複数の電気導体が並んでいる場合に、複数の拘束部材を径方向に１列に並べてそれぞれの電気導体を拘束してもよい。
また、回転電機の固定子巻線を構成する電気導体の径方向の層数は８層に限定されず、４層や１２層あるいはその他の層数であってもよい。
【図面の簡単な説明】
【図１】第１の実施形態の回転電機としての車両用交流発電機の全体構成を示す断面図である。
【図２】固定子の部分的な断面図である。
【図３】固定子鉄心に装着されるセグメントの模式的形状を示す斜視図である。
【図４】固定子巻線の部分的な側面図である。
【図５】固定子巻線をセグメントの先端部側から見た図である。
【図６】接合工程において用いられる本実施形態の巻線接合装置の外観および構成を示す図である。
【図７】図６に示した拘束装置に用いられる各種の拘束部材を示す平面図である。
【図８】図７に示した拘束部材の中の串状拘束部材の詳細を示す側面図である。
【図９】図８に示した串状拘束部材をＡ方向から見た矢視図である。
【図１０】図８に示した串状拘束部材をＢ方向から見た矢視図である。
【図１１】串状拘束部材をセグメントに取り付けて各電気導体を拘束した状態を示す斜視図である。
【図１２】拘束装置に含まれる串状拘束部材の取付・解除機構に関する構成と動作手順を示す図である。
【図１３】拘束装置に含まれる串状拘束部材の取付・解除機構に関する構成と動作手順を示す図である。
【図１４】串押し下げ部材に串状拘束部材を挿入した状態を示す図である。
【図１５】断面形状や拘束位置等を変更した第２の実施形態の拘束部材を示す図である。
【図１６】従来の接合方法の対象となる固定子の構造を示す部分的な斜視図である。
【図１７】図１６に示した固定子巻線の接合部の配置を示す平面図である。
【図１８】従来の接合装置の要部を示す図である。
【符号の説明】
２固定子
３１固定子巻線
３２固定子鉄心
３３セグメント
１００巻線接合装置
１１２拘束装置
１１２ａ内周側拘束部材
１１２ｂ外周側拘束部材
１１２ｃ串状拘束部材
２１０凹部
２１２突起
２１４側面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a stator of a rotating electric machine such as a vehicle AC generator mounted on an automobile or a truck.
[0002]
[Prior art]
Conventionally, arc welding, in which arc discharge is performed between an electrode and a winding welding portion and the winding is melt-bonded using the heat, is generally used for joining the stator windings of the rotating electrical machine. For example, after inserting a U-shaped electrical conductor into a plurality of slots formed in the stator core, the tip side is inclined in the circumferential direction, and then the adjacent tip parts are joined together by arc discharge. An electric wire winding method is known (for example, see Patent Document 1).
[0003]
FIG. 16 is a partial perspective view showing a structure of a conventional stator that is an object of the joining method described above. FIG. 17 is a plan view showing the arrangement of the joints of the stator winding shown in FIG. FIG. 18 is a diagram showing a main part of a conventional joining apparatus.
As shown in FIG. 16, when the four electric conductors 404 protrude from each slot of the stator core 400, the protruding portions alternately incline in the opposite circumferential direction when viewed in the radial direction. The tips of these electric conductors 404 are the joints 406, and as shown in FIG. 17, two of the four joints 406 arranged in the radial direction are paired to perform a joining operation.
[0004]
Specifically, as shown in FIG. 18, this joining operation constrains the inner diameter side and the outer diameter side of the joint portion 406 by the inner diameter side plus electrode 410 and the outer diameter side plus electrode 412 and is adjacent in the circumferential direction. This is performed in a state in which the rod-like plus electrode 414 is disposed between the joint portions 406. In such a state, when the torch 420 as a welding electrode is brought close to the joint portion 406, the joint portion 406 is joined by welding.
[0005]
[Patent Document 1]
Japanese Patent No. 3104700 (page 4-6, FIG. 1-5)
[0006]
[Problems to be solved by the invention]
By the way, in the conventional joining method disclosed in Patent Document 1, when there is a gap between joints aligned in the radial direction, the inner diameter side plus electrode 410 and the outer diameter side plus electrode 412 allow the inner diameter side and the outer diameter side. Even if the radial side is constrained, each joint portion 406 moves toward the gap portion, so that there is a problem that positioning of the joint portion 406 is not easy. In addition, when the joints 406 move, the electrical contact between each joint 406 and the inner diameter side plus electrode 410 or the outer diameter side plus electrode 412 becomes insufficient, which may cause a joint failure. was there.
[0007]
The present invention was created in view of the above points, and an object of the present invention is to provide a stator for a rotating electrical machine that can reliably position a joint and prevent occurrence of joint failure. It is to provide a manufacturing method.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, a method of manufacturing a stator for a rotating electrical machine according to the present invention includes a stator core in which a plurality of slots are formed in the circumferential direction, a part of which is accommodated in each of the slots, and the remaining slots. A stator winding having a plurality of electrical conductors exposed to the outside, the electrical conductor having a first electrical conductor extending from the slot so as to incline in the circumferential direction; A second electrical conductor extending from the slot at a position different from the slot in which the electrical conductor is accommodated in the circumferential direction to the other in the circumferential direction and having a tip joined to the tip of the first electrical conductor; The end face side extending from the slot different from the slot in which each of the second electric conductors is accommodated to the other in the circumferential direction and closer to the end face of the stator core than the joining position of the first and second electric conductors Intersection A stator for a rotating electrical machine having a third electrical conductor intersecting with the first electrical conductor in the end face of the stator core rather than the joint position between the first and second electrical conductors. The first electric conductor and the third electric conductor are constrained by the near constraining portion, and the tip of the first electric conductor and the tip of the second electric conductor are joined. Since the joint portion at each tip of the first electric conductor and the second electric conductor is restrained by the restraint portion closer to the end face of the stator core than the tip, the coil end height necessary for restraint at the joint portion at the tip Becomes unnecessary, and the coil end height can be lowered.
[0009]
Moreover, it is desirable that the restraint part described above is an end face side crossing part. As a result, both the first electric conductor and the third electric conductor are positioned at the same time in the radial direction and the axial direction at the end face side crossing portion. Positioning in the radial direction, the circumferential direction, and the axial direction can be reliably performed, and it is possible to prevent the occurrence of poor bonding.
[0010]
In addition, a plurality of conductor sets each including a first electric conductor and a second electric conductor, whose ends are joined to each other, are provided in the radial direction to form a stator winding, and between the conductor sets arranged in the radial direction. It is desirable that a restraining member provided with a protrusion protruding in the space restrains the first electric conductor and the third electric conductor. As a result, it is possible to prevent the occurrence of poor bonding by reliably positioning each joint with a simple jig shape, and at the same time, ensure the clearance between conductor sets and prevent contact between adjacent joints. It becomes possible.
[0011]
Moreover, the restraining member mentioned above has the recessed part arrange | positioned adjacent to protrusion, and can accommodate these electrical conductors by accommodating the 1st electrical conductor and the 3rd electrical conductor in this recessed part. desirable. Thereby, an electric conductor can be restrained more reliably.
[0012]
Moreover, it is desirable that the above-mentioned recess has a side surface on which the side on which the first electric conductor and the third electric conductor are arranged is wide. Since the electric conductors are accommodated along the inclined side surfaces, it is possible to guide each electric conductor to a predetermined position when attaching the restraining member, and without causing any positional deviation in the radial direction and the axial direction. The electric conductor can be accommodated in a predetermined position of the recess.
[0013]
Moreover, it is desirable that the bottom surface of the recess has the same width as the conductor widths of the first electric conductor and the third electric conductor. Thereby, the position shift of the electric conductor at the time of accommodation can be eliminated, and the positioning accuracy of the joint portion can be improved.
The method of manufacturing a stator for a rotating electrical machine according to the present invention includes a stator iron core having a plurality of slots formed in the circumferential direction, and an electric conductor partially accommodated in each of the slots and the rest exposed outside the slots. A plurality of stator windings, the electrical conductor comprising: a first electrical conductor having an exposed portion extending in a circumferential direction from the slot; and a slot in which the exposed portion accommodates the first electrical conductor. A second electric conductor extending from the slot at a different position in the circumferential direction to the other in the circumferential direction and having a tip joined to the tip of the first electric conductor, and each of the first and second electric conductors Is extended from the slot different from the slot in which the first electric conductor is accommodated to the other in the circumferential direction, and at the end face side intersection nearer to the end face of the stator core than the joining position of the first and second electric conductors. With conductor A method for manufacturing a stator of a rotating electrical machine having a third electric conductor to be connected, wherein the first electric conductor and the third electric conductor are restrained in the radial direction by a restraining member, and the first electric conductor And the tip of the second electric conductor are joined. Since the first electric conductor and the second electric conductor are joined while the first electric conductor and the third electric conductor are restrained by the restraining member in the radial direction, the tip of the first electric conductor to be joined is joined. The joining portion can be reliably positioned in the radial direction, and it is possible to prevent the occurrence of joining failure.
[0014]
The first electric conductor, the second electric conductor, and the third electric conductor described above are provided in a plurality in the radial direction in each slot, and the restraining member extends in the radial direction, and includes a plurality of first electric conductors. It is desirable to constrain the electric conductor and the plurality of third electric conductors simultaneously in the radial direction. Thereby, it becomes possible to restrain simultaneously with each of the plurality of first electrical conductors and the plurality of third electrical conductors arranged in the radial direction, and the process of restraining the electrical conductors can be simplified.
[0015]
Moreover, it is desirable that the above-described restraining member restrains the first and third electric conductors at a position closer to the end face of the stator core than the joining position between the first and second electric conductors. Since it is restrained at a position closer to the end face of the stator core than the joining position of the first electric conductor and the second electric conductor, the coil end height necessary for restraining becomes unnecessary at the joint at the tip, and the coil The end height can be lowered.
[0016]
Moreover, as for the restraining member mentioned above, it is desirable to restrain the 1st and 3rd electrical conductor in an end surface side cross | intersection part. Thereby, it becomes possible to restrain the 1st and 3rd electric conductor simultaneously, and the process of restraining an electric conductor can be simplified further.
[0017]
In addition, the restraining member described above has a skewer shape in which a recess is formed in part, and the recess is located at a position slightly apart in the axial direction from the radial restraint position between the first electric conductor and the third electric conductor. An inserting step of inserting the restraining member in the radial direction, a restraining step of moving the restraining member in the axial direction and restraining the first electric conductor and the third electric conductor in the recess, and the first electric conductor, A joining step for joining the second electric conductor, a restraint releasing step for releasing the restraint in the radial direction by moving the restraining member in the axial direction, and a taking-out step for moving the restraining member in the radial direction and taking them out. desirable. In this way, by restraining each electrical conductor by inserting the restraining member in the radial direction before joining and disclosing restraint by this restraining member after joining, positioning of the joint portion of each electrical conductor is performed easily and reliably. Therefore, it is possible to prevent the occurrence of poor bonding.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for manufacturing a stator of a rotating electrical machine according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing the overall configuration of a vehicular AC generator as a rotating electrical machine of the first embodiment. As shown in FIG. 1, the vehicle alternator 1 of this embodiment includes a stator 2, a rotor 3, a housing 4, a rectifier 5, and the like.
[0019]
The rotor 3 acts as a field and rotates integrally with the shaft 6. The rotor 3 has a Landel pole core 7, a field coil 8, slip rings 9 and 10, a mixed flow fan 11 as a blower, and a centrifugal fan. 12 is provided. The shaft 6 is connected to a pulley 20 and is rotationally driven by a traveling engine (not shown) mounted on the vehicle.
[0020]
The Landel-type pole core 7 is configured by combining a pair of pole cores. The Landel-type pole core 7 includes a boss portion 71 assembled to the shaft 6, a disk portion 72 extending in the radial direction from both ends of the boss portion 71, and twelve claw-shaped magnetic pole portions 73.
[0021]
The pulley-side mixed flow fan 11 has a blade having an acute inclination with respect to the base plate 111 fixed to the end face of the pole core 7 by welding or the like and a right-angle blade, and rotates integrally with the rotor 3. To do. The centrifugal fan 12 on the side opposite to the pulley has only a blade perpendicular to the base plate 121 fixed to the end face of the pole core 7 by welding or the like.
[0022]
The housing 4 is composed of a front housing 4a and a rear housing 4b. A suction hole 41 is formed on the end surface in the axial direction, and a first coil end group 31a and a second coil end group of the stator 2 are formed on both outer peripheral shoulders. Cooling air discharge holes 42 are provided corresponding to the respective radial outer sides of 31b.
[0023]
The rectifier 5 performs a rectifying action for converting the alternating voltage output from the stator 2 into a direct current, and is provided at the end of the vehicle alternator 1 on the side opposite to the pulley.
Next, details of the stator 2 will be described. FIG. 2 is a partial cross-sectional view of the stator 2. FIG. 3 is a perspective view showing a schematic shape of the segment 33 attached to the stator core 32.
[0024]
The stator 2 acts as an armature, and is constituted by a stator core 32 and a stator winding constituted by a plurality of segments 33 as a plurality of electrical conductors arranged in a plurality of slots 35 formed in the stator core 32. 31, and an insulator 34 that electrically insulates between the stator core 32 and the stator winding 31.
[0025]
As shown in FIG. 2, a plurality of slots 35 having openings on the inner diameter side are formed in the stator core 32 so as to accommodate multiphase stator windings 31. The stator winding 31 provided in the slot 35 of the stator core 32 can be grasped as one electrical conductor, and each of the plurality of slots 35 has an even number (in this embodiment). 8) electrical conductors are accommodated. Further, the eight electric conductors in one slot 35 are arranged in a line from the first layer to the eighth layer in order from the inside in the radial direction of the stator core 32. These electric conductors are coated with a coating material such as polyamideimide as the insulating coating 37.
[0026]
The stator windings 31 are formed by connecting these electric conductors in a predetermined pattern. In the present embodiment, one end of the electrical conductor in the slot 35 is connected by arranging a continuous line on the first coil end group 31a side, and the other end is connected on the second coil end group 31b side. Connected by joining ends. Further, in the stator winding 31 of the present embodiment, the relationship between the electric conductors of the first layer to the fourth layer is basically the same as the relationship between the electric conductors of the fifth layer to the eighth layer. Therefore, hereinafter, the electric conductors of the first layer to the fourth layer will be described in detail.
[0027]
One electrical conductor in each slot 35 is paired with one other electrical conductor in another slot 35 that is separated by a predetermined magnetic pole pitch. In particular, in order to secure a gap between the plurality of electric conductors in the coil end portion and arrange them in an aligned manner, the electric conductors of a predetermined layer in one slot 35 are arranged in other slots 35 apart from a predetermined magnetic pole pitch. Pairs with other layers of electrical conductors.
[0028]
For example, the first-layer electric conductor 331a in one slot is paired with the fourth-layer electric conductor 331b in another slot that is one magnetic pole pitch away in the clockwise direction of the stator core 32. . Similarly, the second-layer electric conductor 332a in one slot is paired with the third-layer electric conductor 332b in another slot that is one magnetic pole pitch away in the clockwise direction of the stator core 32. . The paired electrical conductors are connected via the turn portions 331c and 332c by using a continuous line at one end of the stator core 32 in the axial direction. Therefore, at one end of the stator core 32, a continuous line connecting the third layer electric conductor and the second layer electric conductor is connected to the fourth layer electric conductor and the first layer electric conductor. A continuous line to be connected surrounds. As described above, at one end of the stator core 32, the connecting portion of the pair of electric conductors is surrounded by the connecting portion of the other pair of electric conductors accommodated in the same slot. The middle layer coil end is formed by the connection between the third layer electric conductor and the second layer electric conductor, and the end layer coil end is formed by the connection between the fourth layer electric conductor and the first layer electric conductor.
[0029]
On the other hand, the second-layer electric conductor 332a in one slot 35 is also paired with the first-layer electric conductor 331a 'in another slot 35 that is one magnetic pole pitch away in the clockwise direction of the stator core 32. There is no. Similarly, the fourth-layer electric conductor 331b ′ in one slot 35 is paired with the third-layer electric conductor 332b in another slot 35 that is one magnetic pole pitch away in the clockwise direction of the stator core 32. I am doing. These electric conductors are connected by joining at the other end in the axial direction of the stator core 32.
[0030]
Therefore, at the other end of the stator core 32, the joint portion connecting the fourth-layer electric conductor and the third-layer electric conductor, and the first-layer electric conductor and the second-layer electric conductor are connected to each other. The joints to be connected are aligned in the radial direction. The adjacent layer coil end is formed by the connection between the fourth-layer electric conductor and the third-layer electric conductor, and the connection between the first-layer electric conductor and the second-layer electric conductor.
[0031]
Further, the plurality of electric conductors are provided by U-shaped segments obtained by forming a predetermined thickness of an electric conductor having a substantially rectangular cross section (flat cross section) into a predetermined shape. As shown in FIG. 3, the first-layer electric conductor and the fourth-layer electric conductor are provided by a large segment 331 formed by forming a series of electric conductors in a substantially U shape. Further, the second-layer electric conductor and the third-layer electric conductor are provided by a small segment 332 formed by forming a series of electric conductors in a substantially U shape.
[0032]
The large segment 331 and the small segment 332 form a basic segment 33. The basic segments 33 are regularly arranged in the slots 35 to form a coil that makes two rounds around the stator core 32 (four rounds in total including the fifth to eighth layer electrical conductors). Is done.
[0033]
FIG. 4 is a partial side view of the stator winding 31 and shows a view from the outside in the radial direction. FIG. 5 is a view of the stator winding 31 as viewed from the tip end side of the segment 33, and is a view in which only a part of the segments 33 arranged in the radial direction is extracted and developed in the circumferential direction. As shown in FIGS. 4 and 5, the segment 33 of this embodiment intersects adjacent electrical conductors at an angle larger than 0 °, and the side surfaces of the tip end portions contact each other at this intersecting portion. In this state, welding or the like is performed to form a joint. Specifically, as shown in FIG. 5, the leading end portion 331d of the first-layer electric conductor 331a and the leading end portion 332d of the second-layer electric conductor 332a projecting from the stator core 32 are connected to each other through the side surfaces. They are in contact, and welding or the like is performed on the contact portion. Further, the tip 332e of the third-layer electric conductor 332b and the tip 331e of the fourth-layer electric conductor 331b are in contact with each other via the side surfaces, and welding or the like is performed on this contact portion. The same applies to the electric conductors of the fifth and sixth layers and the electric conductors of the seventh and eighth layers.
[0034]
Next, the manufacturing process of the stator winding 31 will be described below.
(Insertion step) The basic segment 33 is aligned so that the turn portion 332c of the U-shaped large segment 331 is surrounded by the turn portion 332c of the U-shaped small segment 332, and one side of the axial side surface of the stator core 32 Is inserted from. At that time, one electrical conductor 331a of the large segment 331 is in the first layer of one slot 35 of the stator core 32, one electrical conductor 332a of the small segment 332 is in the second layer of one slot 35, and The other electrical conductor 331b of the large segment 331 is in the fourth layer of the other slot 35 which is one pole pitch clockwise from the one slot 35 of the stator core 32, and the other electrical conductor 332b of the small segment 332 is another It is inserted into the third layer of the slot 35.
[0035]
As a result, as shown in FIG. 2, the above-described electric conductors 331a, 332a, 332b ′, and 331b ′ are arranged in a row in one slot 35 from the first layer side. Here, the electric conductors 332b 'and 331b' are electric conductors of large and small segments that are paired with electric conductors in other slots 35 that are shifted by one magnetic pole pitch.
[0036]
The same applies to the electric conductors of the fifth layer to the eighth layer. Each of the electric conductors of the fifth layer to the eighth layer is the same as the electric conductors of the first layer to the fourth layer or after the insertion of these electric conductors is completed. An electrical conductor is inserted.
(Bending process) After the insertion, in the second coil end group 31b, the electric conductors 331a and 331b of the first layer and the fourth layer are bent by twisting the joint portions 331d and 331e in the direction in which the large segment 331 opens. It is done. The electric conductors 332a and 332b of the second layer and the third layer are bent by twisting the ends 332d and 332e in the direction in which the small segment 332 is closed. As a result, in the second coil end group 31b, the electrical conductors adjacent in the radial direction are inclined in the opposite direction of the circumferential direction. The above configuration is repeated for the segments 33 of all the slots 35 and for the segments 33 made of the fifth to eighth layer electrical conductors. As a result, the pair of joint portions formed by the joint portions 331d and 332d and the pair of joint portions formed by the joint portions 331e and 332e are arranged along the radial direction in four rows on concentric circles, respectively.
[0037]
(Jointing Step) Then, in the second coil end group 31b, the joint portions of the first and second layer electrical conductors, the joint portions of the third and fourth layer electrical conductors, and the fifth and sixth layer electrical conductors. The stator 2 is formed by joining the conductor joints and the joints of the seventh and eighth layer electrical conductors so as to obtain electrical continuity by means of welding, ultrasonic welding, arc welding, brazing or the like. can get.
[0038]
Next, the detail of a joining process is demonstrated. FIG. 6 is a diagram showing an appearance and a configuration of the winding joining apparatus of the present embodiment used in the joining process.
A winding joining apparatus 100 shown in FIG. 6 includes a torch 102 including a welding electrode as a welding tool, a robot arm 104 that moves the torch 102, a welding power source 106 that supplies power to the torch 102, and an inertness to the torch 102. A gas supply device 108 for supplying gas, a fixing base 110 for fixing the stator 2 equipped with the segment 33 as a joining target, a restraining device 112 for restraining the segment 33 of the stator 2, and the fixing base 110 are rotated. And a control device 116 that controls the robot arm 104, the rotation drive device 114, the welding power source 106, and the gas supply device 108.
[0039]
The torch 102 is made of tungsten and is provided at the tip of the robot arm 104. The torch 102 is connected to the negative terminal of the welding power source 106 and includes a welding electrode as a welding tool. Further, an inert gas such as argon or helium is supplied from the gas supply device 108 to the torch 102 in order to stabilize the arc during welding and prevent oxidation of the welded portion. A configuration in which tungsten is used for one electrode and welding is performed while supplying an inert gas such as argon is generally known as TIG (Tungsten Inert Gas arc welding).
[0040]
The robot arm 104 receives a control signal from the control device 116 and moves the tip provided with the torch 102 along the direction in which the connecting portions are arranged along the joint portion of the segment tip as a welding target.
FIG. 7 is a plan view showing various restraining members used in the restraining device 112 shown in FIG. FIG. 8 is a side view showing details of the skewer-like restraining member in the restraining member shown in FIG. FIG. 9 is an arrow view of the skewer-like restraining member shown in FIG. 8 as viewed from the A direction. 10 is an arrow view of the skewer-like restraining member shown in FIG. 8 as viewed from the B direction. FIG. 11 is a perspective view showing a state in which each electric conductor is restrained by attaching a skewer-like restraining member to the segment 33.
[0041]
The restraint device 112 is a skewer-like restraint disposed at an end face side intersection nearer to the end face of the stator core 32 than the joining position between the annular inner circumference restraining member 112a and the outer circumference restraining member 112b and the electrical conductors. Member 112c. 7 and 8, only one skewer-like restraining member 112c is shown, but in actuality, the skewer-like restraining member 112c having the same shape is provided between the joint portions adjacent in the circumferential direction. There are as many as the number.
[0042]
The inner peripheral side restraining member 112a is disposed on the inner peripheral side of the innermost (first layer) electrical conductor, and restrains the movement of the electric conductor toward the inner peripheral side. The outer peripheral side restraining member 112b is disposed on the outer peripheral side of the innermost (eighth layer) electrical conductor, and restrains the movement of the electric conductor on the outer peripheral side.
[0043]
As shown in FIG. 8, the skewer-like restraining member 112 c has a triangular cross-section, and one side of the skew-restraining member 112 c extends from the slot 35 so as to incline toward the circumferential direction (the end face of the stator core 32 and the end face). The other side has an angle along the upper surface of the other electrical conductor extending from the other slot 35 to the other in the circumferential direction.
[0044]
For example, in FIG. 7, attention is paid to the first-layer electric conductor 331a, the second-layer electric conductor 332a, and the third-layer electric conductor 332b. The exposed portion of the first-layer electric conductor 331a (second electric conductor in the present invention) extends from the slot 35 of the stator core 32 so as to incline in one circumferential direction. The second-layer electric conductor 332a (the first electric conductor in the present invention) has an exposed portion in the circumferential direction from another slot 35 at a position different from the slot 35 in which the first-layer electric conductor 331a is accommodated in the circumferential direction. While extending to the other side, the tip is joined to the joint 331d at the tip of the first-layer electric conductor 331a. The third-layer electric conductor 332b (third electric conductor in the present invention) is surrounded by another slot 35 that is different from any slot 35 in which the first-layer and second-layer electric conductors 331a and 332a are accommodated. The second-layer electric conductor at the end surface side intersection C closer to the end surface of the stator core 32 than the joining position between the first-layer and second-layer electric conductors 331a and 332a. Crosses 332a. Such a relationship is established for the adjacent electrical conductors among the electrical conductors of the first to eighth layers.
[0045]
The skewer-like restraining member 112c described above is disposed at the end face side intersection C where these electric conductors intersect each other.
Further, the skewer-like restraining member 112c has a recess 210 formed at a position where the electrical conductor of the segment 33 abuts, and a protrusion 212 is formed between the adjacent recesses 210. Considering a conductor set composed of two electrical conductors whose tips are joined together, the recess 210 is formed at a position corresponding to each conductor set, and the projection 212 is arranged in two sets adjacent to each other in the radial direction. It is formed so as to protrude into the space between the conductor sets.
[0046]
The recess 210 formed in the skewer-like restraining member 112c has a tapered inclined side surface 214. The inclined side surface 214 has a function of a guide for housing the electric conductor in the recess 210 when the skewer-like restraining member 112c is attached to restrain the electric conductor of the segment 33. Therefore, as shown in FIG. 11, by attaching the skew-shaped restraining member 112 c from the joint portion side of each segment 33, each electric conductor is accommodated in a predetermined position of the recess 210 without causing a positional deviation in the radial direction and the axial direction. Is done.
[0047]
Further, the recess 210 has the same width as the conductor width of the electric conductor of each segment 33. Thereby, the position shift of the electric conductor at the time of accommodating an electric conductor in the recessed part 210 can be eliminated, and the positioning accuracy of a junction part can be improved.
The inner circumferential side restraining member 112a, the outer circumferential side restraining member 112b, and the skewered restraining member 112c described above also serve as one electrode during arc welding.
[0048]
FIG. 12 and FIG. 13 are diagrams showing a configuration and an operation procedure related to the attachment / release mechanism of the skew-like restraining member 112c included in the restraining device 112. FIG. FIG. 14 is a view showing a state in which the skewer-like restraining member 112 c is inserted into the skewer-pressing member 126.
The attachment / release mechanism 120 shown in FIGS. 12 and 13 is for attaching the skewer-like restraining member 112c after setting the stator core 32 in which the segment 33 that has been subjected to the bending process is accommodated. In a state where the skewer-like restraining member 112c is attached and the electric conductors are restrained at the end face side intersection C, the joining step is performed by the winding joining device 100 shown in FIG. Thereafter, the skewer-like restraining member 112c is removed in order to release the restraint of each electric conductor after the joining process.
[0049]
The attachment / release mechanism 120 includes a cylindrical holding jig 122 and an annular holding jig 124 that hold and fix the stator core 32 from the inner diameter side and the outer diameter side, and each skewer inserted from the radially outer side. The skewer pressing member 126 that presses the upper surface of the constraining member 112c toward the end surface side of the stator core 32 and presses it toward the end surface side intersection C of each segment 33, and the lower surface of each skewered constraining member 112c after the joining process is completed. It includes a skewer releasing member 128 that presses away from the end face of the stator core 32 and releases the attached state of the skewer-like restraining member 112c.
[0050]
The restraining and releasing operations of the electric conductors of the segments 33 by the attachment / release mechanism 120 having the above-described structure are performed as follows.
(Inserting process of skewer-like restraining member) First, the stator core 32 containing the segment 33 that has been subjected to the bending process is set in the mounting / releasing mechanism 120, and the skewering restraining member 112c is inserted from the outside in the radial direction. (FIGS. 12A and 12B). As shown in FIG. 14, the skewer-like restraining member 112 c has a narrow tip, so that the skewer-like restraining member 112 c can be easily inserted into the gap between the skewer pushing-down member 126 and the holding jig 122. It has become. Further, in this state, the skewer-like restraining member 112c is inserted in the radial direction so that the concave portion 210 is located at a position slightly separated in the axial direction from the end face side intersecting portion C where the electric conductors of the segments 33 intersect. Therefore, a sufficient gap is also formed between the skew-shaped restraining member 112c and the end face side intersecting portion C where the electric conductors of the segments 33 intersect, which is expensive for inserting the skewer-like restraining member 112c. Precision is not required.
[0051]
(Restraining step) Next, the skewer-lowering member 126 is lowered to the end face side of the stator core 32 (FIG. 13A). Thereby, the skew-like restraining member 112c restrains each electric conductor at the end face side intersecting portion C.
(Jointing step) In this state, arc welding is performed on each joint at the tip of the electric conductor.
[0052]
(Restraining Release Step) After that, the skewer release member 128 is lifted to separate the skewer restraint member 112c from each electrical conductor and the restraint state is released (FIG. 13B), and then the skewer restraint member 112c. Is extracted radially outward.
Thus, since these electric conductors are restrained at the end face side intersection C where the electric conductors of the segments 33 intersect with each other, the radial direction, the circumferential direction, and the axis of the joints at the tips of the two electric conductors to be joined Directional positioning can be performed reliably, and it is possible to prevent the occurrence of poor bonding. Moreover, since each electric conductor is restrained and joined not in the vicinity of the joint but in a position closer to the end face of the stator core 32 than the joint, the coil end height required for restraint is limited at the joint at the tip. It becomes unnecessary and the coil end can be lowered.
[0053]
Further, by using the skewer-like restraining member 112c having a simple shape in which the concave portion 210 is formed at a position where it abuts against the electric conductor and the protrusion 212 is formed at a position corresponding to each electric conductor, a simple jig shape can be obtained. Thus, it is possible to prevent the occurrence of poor bonding by reliably positioning the joint portions of the respective electrical conductors, and at the same time to secure the clearance between the conductor sets and prevent the contact between the adjacent joint portions. In particular, by accommodating the electric conductor of the segment 33 in the recess 210 formed between the adjacent protrusions 212, the electric conductor can be restrained more reliably.
[0054]
Further, since the plurality of electric conductors arranged in the radial direction and two kinds of electric conductors inclined in different directions are simultaneously restrained by using one skew-like restraining member 112c, the respective electric conductors are separately provided. Compared with the case where the electric conductor is restrained, the process of restraining the electric conductor can be simplified.
[0055]
(Second Embodiment)
By the way, in the above-described first embodiment, two types of electric conductors having different inclination directions are arranged at one end-side crossing portion C of the skewer-like restraining members 112c having a triangular cross section. In the restraint part other than the end face side intersection C, the restraint member having a cross section other than the triangular shape is used, or two types of electric conductors having different inclination directions are restrained using separate subsequent members. Or may be restrained.
[0056]
FIG. 15 is a diagram illustrating a restraining member according to the second embodiment in which the cross-sectional shape, the restraining position, and the like are changed.
The constraining member 112d of the present embodiment has a circular cross section as shown in FIG. 15, and a recess for constraining the electrical conductor extending incline from the slot 35 in the circumferential direction is an electric It is formed at a position corresponding to the conductor. When the restraining member 112d is viewed from the direction D shown in FIG. 15, a concave portion for accommodating the electric conductor of the segment 33 is formed similarly to the shape of the skew-like restraining member 112c shown in FIG. In addition, the restraining member 112d restrains the electrical conductor accommodated in the recess at the restraining portion closer to the front end side of the electrical conductor than the end face side intersection C where two types of electrical conductors having different inclination directions intersect. .
[0057]
Similarly, the restraining member 112e has a circular cross section, and a recess for restraining the electric conductor extending from the slot 35 to the other in the circumferential direction is formed at a position corresponding to the electric conductor. Has been. The restraining member 112e restrains the electric conductor accommodated in the recess in the restraining portion closer to the tip end side of the electric conductor than the end face side intersection C.
[0058]
As described above, in the restraining portions other than the end face side intersection C, the restraint portions 112d and 112e having an arbitrary cross section (circular shape in FIG. 15) are used to restrain two types of electric conductors having different inclination directions separately. By doing so, since the respective electric conductors are restrained in these restraining portions, the radial, circumferential and axial positioning of the joining portions of the two electrical conductor tips to be joined can be reliably performed. It is possible to prevent the occurrence of bonding failure. Moreover, since each electric conductor is restrained and joined not in the vicinity of the joint but in a position closer to the end face of the stator core 32 than the joint, the coil end height required for restraint is limited at the joint at the tip. It becomes unnecessary and the coil end can be lowered.
[0059]
Further, in the example shown in FIG. 15, a constraining portion is set on the front end side of the electric conductor with respect to the end surface side intersecting portion C, and the upper surface (surface opposite to the end surface of the stator core 32) of the electric conductor to be constrained. Although the restraining member 112d and the like are brought into contact with each other, the lower surface of the electric conductor (the surface near the end face of the stator core 32) is brought into contact with the restraining member 112f or the restraining member 112h shown in FIG. The restraint portion may be set at a position closer to the end face of the stator core 32 than the end face-side intersection C as in 112g. The position of each constraining member may be determined in consideration of various layout constraints such as the degree of interference with the joint and the degree of interference with electrical conductors other than the constrained object. Further, it is not always necessary to restrain two types of electric conductors having different inclinations with a restraining member, and only one of them may be restrained.
[0060]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, the segment 33 of the above-described embodiment intersects adjacent electrical conductors at an angle larger than 0 °, and performs welding or the like in a state where the side surfaces of the tip end portions are in contact with each other at the intersecting portion. However, as shown in FIG. 16, the present invention can also be applied to the case where the ends of adjacent electrical conductors are arranged in parallel to form a junction.
[0061]
Further, when a plurality of electrical conductors are arranged in the radial direction, a plurality of restraining members may be arranged in a row in the radial direction to restrain the respective electrical conductors.
The number of layers in the radial direction of the electric conductor constituting the stator winding of the rotating electrical machine is not limited to eight, and may be four, twelve, or other numbers.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall configuration of a vehicle AC generator as a rotating electrical machine according to a first embodiment.
FIG. 2 is a partial cross-sectional view of a stator.
FIG. 3 is a perspective view showing a schematic shape of a segment attached to a stator core.
FIG. 4 is a partial side view of a stator winding.
FIG. 5 is a view of a stator winding as viewed from the tip end side of a segment.
FIG. 6 is a view showing an appearance and a configuration of a winding joining apparatus of the present embodiment used in a joining process.
7 is a plan view showing various restraining members used in the restraining device shown in FIG. 6. FIG.
8 is a side view showing details of a skewer-like restraining member in the restraining member shown in FIG.
9 is an arrow view of the skewer-like restraining member shown in FIG. 8 as viewed from the direction A. FIG.
10 is an arrow view of the skewer-like restraining member shown in FIG. 8 as viewed from the B direction.
FIG. 11 is a perspective view showing a state in which each electric conductor is restrained by attaching a skewer-like restraining member to a segment.
FIG. 12 is a view showing a configuration and an operation procedure regarding a mechanism for attaching / releasing a skewer-like restraining member included in the restraining device.
FIG. 13 is a diagram showing a configuration and an operation procedure regarding a mechanism for attaching / releasing a skewer-like restraining member included in the restraining device.
FIG. 14 is a view showing a state in which a skewer-like restraining member is inserted into the skewer-lowering member.
FIG. 15 is a view showing a restraining member according to a second embodiment in which a cross-sectional shape, a restraining position, and the like are changed.
FIG. 16 is a partial perspective view showing a structure of a stator which is a target of a conventional joining method.
17 is a plan view showing the arrangement of the joint portions of the stator winding shown in FIG. 16. FIG.
FIG. 18 is a view showing a main part of a conventional joining apparatus.
[Explanation of symbols]
2 Stator
31 Stator winding
32 Stator core
33 segments
100 Winding joining device
112 Restraint device
112a Inner circumferential side restraint member
112b Outer peripheral side restraining member
112c Skewer-shaped restraining member
210 recess
212 protrusion
214 Side

Claims

A stator core having a plurality of slots formed in the circumferential direction;
A stator winding comprising a plurality of electrical conductors, each of which is housed in each of the slots and the rest exposed to the outside of the slot;
The electrical conductor has an exposed portion extending from the slot so as to incline in the circumferential direction, and an exposed portion of the electrical conductor at a position different from the slot in which the first electrical conductor is accommodated in the circumferential direction. A second electric conductor extending from the slot to the other circumferential direction and having a tip joined to the tip of the first electric conductor, and each of the first and second electric conductors accommodated therein The first electric circuit extends at an end in the circumferential direction from the slot different from the slot and extends closer to the other end in the circumferential direction and closer to the end surface of the stator core than the joining position of the first and second electric conductors. In a method for manufacturing a stator of a rotating electric machine having a third electric conductor intersecting with a conductor,
Restraining the said third electrical conductor and the first electrical conductor at the end surface side intersection, joining the tip of the tip of the first electric conductor and the second electrical conductors,
A plurality of conductor sets including the first electric conductor and the second electric conductor to which the tips are joined are provided in the radial direction to form the stator winding,
A restraining member provided with a protrusion protruding in a space between the conductor sets arranged in the radial direction restrains the first electric conductor and the third electric conductor;
The constraining member has a concave portion disposed adjacent to the protrusion, and the first electric conductor and the third electric conductor are accommodated in the concave portion to constrain these electric conductors. A method of manufacturing a stator of a rotating electric machine characterized by the above.

In claim 1,
The method of manufacturing a stator of a rotating electrical machine, wherein the recess has a side surface on which a side on which the first electric conductor and the third electric conductor are arranged is wide.

In claim 2,
The method for manufacturing a stator of a rotating electrical machine, wherein the bottom surface of the recess has the same width as the conductor width of the first electric conductor and the third electric conductor.

A stator core having a plurality of slots formed in the circumferential direction;
A stator winding comprising a plurality of electrical conductors, each of which is housed in each of the slots and the rest exposed to the outside of the slot;
The electrical conductor has an exposed portion extending from the slot so as to incline in the circumferential direction, and an exposed portion of the electrical conductor at a position different from the slot in which the first electrical conductor is accommodated in the circumferential direction. A second electric conductor extending from the slot to the other circumferential direction and having a tip joined to the tip of the first electric conductor, and each of the first and second electric conductors accommodated therein The first electric circuit extends at an end in the circumferential direction from the slot different from the slot and extends closer to the other end in the circumferential direction and closer to the end surface of the stator core than the joining position of the first and second electric conductors. In a method for manufacturing a stator of a rotating electric machine having a third electric conductor intersecting with a conductor,
Fixing the rotating electric machine for joining the distal end of the while restrained by the first electric conductor and the third restraining member and an electrical conductor in a radial direction, said first electrical conductor tip and the second electrical conductors A child manufacturing method,
The constraining member has a skewer shape in which a concavity is formed in part, and the concavity is located at a position slightly apart in the axial direction from the radial constraining position between the first electric conductor and the third electric conductor An insertion step of inserting the restraining member in the radial direction to
A restraining step of restraining the first electric conductor and the third electric conductor in the recess by moving the restraining member in the axial direction;
A joining step of joining the first electrical conductor and the second electrical conductor;
A restraint release step of moving the restraint member in the axial direction to release the restraint in the radial direction;
A step of taking out the restraining member by moving in the radial direction;
The manufacturing method of the stator of the rotary electric machine characterized by having .

In claim 4,
The first electric conductor, the second electric conductor, and the third electric conductor are each provided in the slot in a plurality in the radial direction,
The method of manufacturing a stator of a rotating electrical machine, wherein the restraining member extends in a radial direction and simultaneously restrains the plurality of first electric conductors and the plurality of third electric conductors in a radial direction.

In claim 4,
The rotating electric machine is characterized in that the restraining member restrains the first and third electric conductors at a position closer to an end face of the stator core than a joining position between the first and second electric conductors. Method of manufacturing the stator.

In claim 6,
The method of manufacturing a stator of a rotating electrical machine, wherein the restraining member restrains the first and third electric conductors at the end face side intersection.