JP3827345B2

JP3827345B2 - Transformer bushings

Info

Publication number: JP3827345B2
Application number: JP14079795A
Authority: JP
Inventors: 泰吉近藤; 恒雄井上; 彰芳佐藤; 良二河村; 実奥田; 設夫藤井
Original assignee: Daihen Corp; Chubu Electric Power Co Inc; Aichi Electric Co Ltd
Current assignee: Daihen Corp; Chubu Electric Power Co Inc; Aichi Electric Co Ltd
Priority date: 1995-06-07
Filing date: 1995-06-07
Publication date: 2006-09-27
Anticipated expiration: 2021-09-27
Also published as: JPH08335415A

Description

【０００１】
【産業上の利用分野】
本発明は、配電用変圧器に取り付ける変圧器用ブッシングに関するものである。
【０００２】
【従来の技術】
配電用変圧器においては、変圧器タンクに高圧ブッシング及び低圧ブッシングを取り付けて、高圧配電線につながる電線を高圧ブッシングに接続し、低圧ブッシングに需要家につながる低圧配電線を接続している。この場合に用いる高圧ブッシングは、絶縁碍子と、絶縁碍子内を貫通した状態で設けられて一端が該絶縁碍子の一端側に固定されるとともに他端が該絶縁碍子の他端から外部に導出された中心導体とを備えていて、該中心導体の他端に設けられた電線接続部に電線が接続される。
【０００３】
最近の柱上変圧器では、電灯負荷と動力負荷とに対して電源の共用化を図るために、２台の変圧器をＶ結線して運転することが多く行われている。図１８は、２台の単相変圧器Ｔa 及びＴb が設けられる場合の変圧器相互間及び変圧器と配電線との間の接続を示したもので、２台の変圧器Ｔa 及びＴb にはそれぞれ高圧ブッシング１a1，１a2及び１b1，１b2が設けられている。この例では、３相の高圧配電線Ｕ，Ｖ及びＷにそれぞれカットアウトスイッチＳu ，Ｓv 及びＳw を介して接続された高圧引き下げ線Ｌu ，Ｌv 及びＬw が、変圧器Ｔa のブッシング１a1，１a2及び変圧器Ｔb のブッシング１b2に接続されている。また変圧器Ｔa のブッシング１a2と変圧器Ｔb のブッシング１b1との間がＶ結線用リード線Ｌabを介して接続されて変圧器Ｔa ，Ｔb がＶ結線されている。変圧器Ｔa 及びＴb には図示しない低圧ブッシングが取り付けられていて、該低圧ブッシングに需要家につながる低圧配電線が接続されている。
【０００４】
近年コンピュータをはじめとする各種の高機能電気製品の普及に伴って、電力の安定供給の要請が強くなっており、配電線に対する工事を無停電で行うことが必要になっている。また社会の就業意識の変化により、高度な熟練技能を要し、危険を伴う現行の電気工事のありかたを見直すことが必要とされ、変圧器用ブッシングにおいても、電線の接続を安全かつ簡単に行い得るようにすることが要請されている。
【０００５】
上記のような変圧器が設けられている配電系統において、カットアウトスイッチＳu 〜Ｓw の取換え工事や、特定区間の高圧配電線Ｕ〜Ｗの張替え工事等を行う場合には、変圧器Ｔa 及びＴb の高圧ブッシング１a1，１a2及び１b2にそれぞれ健全区間の高圧配電線につながるバイパス線を接続して需要家への電力の供給を確保した後、高圧引き下げ線Ｌu 〜Ｌw を外して、無停電で工事を行うようにすることが望ましい。
【０００６】
ところが、従来広く用いられていた高圧ブッシングは、その中心導体に電線を接続する箇所を１つしか備えていなかったため、バイパス線を接続し、高圧引き下げ線を切り離す作業を無停電で行うことは困難であった。
【０００７】
そのため上記のような工事を行う場合には、工事現場に移動変圧器車を出動させて、該移動変圧器車に搭載された変圧器に、健全区間の高圧配電線に接続したバイパス線を引き込み、移動変圧器車の低圧ブッシングに接続した低圧バイパス線を需要家につながる配電線に接続することにより需要家への電力の供給を確保した後に高圧引き下げ線を切り離すようにしていた。
【０００８】
このように、従来の変圧器用ブッシングを用いた場合には、高圧配電線に対する工事を行う際に移動変圧器車を出動させる必要があり、それに伴って準備する必要がある資材及び人員が多くなるため、工事費が高くなるのを避けられなかった。
【０００９】
そこで、実開平３−１９２６１号に示されているように、高圧ブッシングの中心導体の端部に電線を接続した状態で更にバイパス線を接続し得るようにした変圧器用ブッシングが提案された。この既提案の変圧器用ブッシングでは、中心導体の端部に雄ネジ部を設けて、該雄ネジ部に高圧引き下げ線を接続するための電線接続具を取り付け得るようにするとともに、該雄ネジ部の近傍にバイパス線接続用のネジ穴を設けて、該ネジ穴にバイパス線接続具を取り付けるようにしている。バイパス線接続具は、バイパス線の端部に設けられた端子金具がボルト止めされたネジ付きの接触子と、該接触子を保持する絶縁操作棒とを備えたもので、絶縁操作棒を手で持って接触子のネジ部をブッシングの中心導体のネジ穴にねじ込むことにより、ブッシングの中心導体に取り付ける。
【００１０】
【発明が解決しようとする課題】
１台の変圧器のみが設置される場合、または２台の変圧器が共通のタンク内に収納されてＶ結線される場合に、実開平３−１９２６１号に示された変圧器用ブッシングを用いると、中心導体の電線接続部に高圧引き下げ線を接続した状態で、バイパス線接続具の接触子のネジ部を中心導体のバイパス線接続用のネジ穴にねじ込むことによりバイパス線を接続することができるため、無停電で高圧配電線に対する工事を行うことができる。
【００１１】
しかしながら、この従来の変圧器用ブッシングでは、中心導体の端部に設けられた雄ネジ部に取り付けられる電線接続具により複数の電線を接続することはできないため、タンクを異にする２台の変圧器をＶ結線する場合には対応することができないという問題があった。
【００１２】
なお上記の変圧器用ブッシングが取り付けられた２台の変圧器を敢えてＶ結線するために、バイパス線接続用のネジ穴に端子ボルトをねじ込んで、この端子ボルトによりＶ結線用リード線を中心導体に接続することも考えられる。しかしながら、このようにした場合には、活線状態でバイパス線の接続を行うことが困難であり、またバイパス線の接続を確実に行うことが困難である。
【００１３】
本発明の目的は、中心導体に２本の電線を容易に接続し得るようにして、中心導体への電線の接続の自由度を高めることができるようにした変圧器用ブッシングを提供することにある。
【００１４】
本発明の他の目的は、２台の変圧器がＶ結線される場合に、中心導体へのバイパス線の接続を容易に行うことができるようにした変圧器用ブッシングを提供することにある。
【００１５】
【課題を解決するための手段】
本発明は、絶縁碍子２と、絶縁碍子２内を貫通した状態で設けられて先端が該絶縁碍子の先端から外部に導出された中心導体３とを備えて、該中心導体の先端の外周に雄ネジ部３０５が設けられ、中心導体の先端の軸芯部には開口端部にテーパ孔部を有する端子挿入穴３０７が形成されている変圧器用ブッシングに係わるものである。
【００１６】
本発明においては、上記中心導体３の先端の雄ネジ部３０５の近傍に該中心導体の軸線方向と直交する方向に延びるネジ穴３０６が設けられている。また、後端にネジ部５０１を有し、先端の外周に中心導体３の先端の雄ネジ部３０５と同径同ピッチの雄ネジ部５０２を有するとともに、先端の軸芯部に中心導体３の先端の端子挿入穴３０７と同形状同寸法の端子挿入穴５０３を有する分岐導体５が設けられて、該分岐導体の後端のネジ部５０１が中心導体３のネジ穴３０６に螺合されている。
【００１７】
本発明ではまた、１対の電線接続具４，４´が設けられて、該１対の電線接続具の一方４及び他方４´がそれぞれ上記中心導体３の先端の雄ネジ部３０５及び分岐導体の先端の雄ネジ部５０２に取り付けられる。
【００１８】
各電線接続具は、ナット取付け孔４０３と該ナット取付け孔よりも小径に形成されて該ナット取付け孔と軸線を共有した電線挿通孔４０４とを内部に有して該ナット取付け孔及び電線挿通孔をそれぞれ一端側及び他端側に開口させたつまみ碍子４Ａ（図８参照）と、一端をつまみ碍子の一端側に開口させた状態で該ナット取付け孔内に固定された筒状ナット４Ｂ（図９参照）と、一端を筒状ナット４Ｂの開口部側に向けた状態で該筒状ナット内に配置されていて他端側に電線の芯線を接続する電線接続部４１４とつば部４１２とを有するとともに、端子挿入穴のテーパ孔部３０７または５０３に嵌合するテーパ部４１１を中間部に有する丸棒状の給電用端子４Ｃ（図１０参照）と、筒状ナット４Ｂ内で給電用端子４Ｃを取り囲むように形成されるとともに外周部にネジ部を有して該ネジ部が前記筒状ナットの内周の雌ネジに螺合された給電用端子止めリング４Ｄとからなっている。
【００１９】
上記１対の電線接続具４，４´の一方４及び他方４´の筒状ナット４Ｂがそれぞれ中心導体３の先端の雄ネジ部３０５及び分岐導体５の先端の雄ネジ部５０２に螺合され、該一方及び他方の電線接続具４及び４´の給電用端子４Ｃがそれぞれ中心導体３の端子挿入穴３０７及び分岐導体の端子挿入穴５０３内に挿入される。
【００２０】
各電線接続具の筒状ナット４Ｂの他端付近の内周に雌ネジを有しないネジ無し部４０６（図９参照）が形成されるとともに、該筒状ナットの他端に給電用端子の他端を貫通させる端子貫通孔４０７が形成されている。端子貫通孔４０７はネジ無し部４０６の内径よりも小径に形成されていて、該ネジ無し部４０６と端子貫通孔４０７との間に給電用端子４Ｃのつば部４１２に対向する端子締付用段部４０８が形成されている。
【００２１】
そして各電線接続具の筒状ナット４Ｂを各雄ネジ部に螺合させて締め付けた際に端子締付け用段部４０８が該電線接続具の給電用端子４Ｃのつば部４１２を押圧して該給電用端子を端子挿入穴側に付勢するように、各電線接続具の筒状ナットの軸線方向寸法が設定され、各電線接続具の筒状ナットを緩めた状態で該筒状ナットと給電用端子との間に相対的な回転が生じるのを許容するように給電用端子止めリング４Ｄと端子締付用段部４０８との間の間隔及びネジ無し部４０６の内径が設定されている。
【００２２】
中心導体３に接続される電線の芯線は、中心導体３の先端の雄ネジ部に取り付けられた電線接続具４及び（または）分岐導体５の雄ネジ部５０２に取り付けられた電線接続具４´のそれぞれの給電用端子の電線接続部に圧縮接続等により接続される。電線接続具を雄ネジ部に螺合させて締め付けた際に、各給電用端子が端子挿入穴内に押し込まれ、各給電用端子のテーパ部が端子挿入穴のテーパ孔部に嵌合した状態で締め付けられて、各電線が給電用端子を介して中心導体に電気的に接続される。
【００２３】
【作用】
上記のように、ブッシングの中心導体の先端に雄ネジ部を設けるとともに、該雄ネジ部の近傍に設けたネジ穴に取り付けた分岐導体の先端に、中心導体の先端の雄ネジ部と同径同ピッチの雄ネジ部を設けて、中心導体の先端の雄ネジ部及び分岐導体の先端の雄ネジ部にそれぞれ同様に構成された電線接続具を取り付けておくと、中心導体の先端部及び分岐導体のいずれにも同じように電線を接続することができるため、変圧器用ブッシングに対する電線の接続の自由度を高めることができ、変圧器の種々の設置状態に容易に対応することができる。
【００２４】
また上記のように中心導体に互換性がある２つの電線接続具を、それぞれの取付け方向を異ならせて取り付けるように構成しておくと、２台の変圧器をＶ結線する場合に、Ｖ結線用リード線及び高圧引き下げ線の双方を容易かつ確実に接続することができ、更に高圧配電線に対する工事を行う場合には、バイパス線を接続することもできる。この場合、各電線接続具はつまみ碍子を備えているため、バイパス線の接続は活線状態で行うことができ、無停電で配電線に対する工事を行わせることができる。
【００２５】
【実施例】
図１は本発明の実施例の変圧器用ブッシング１の全体的な構成を示した縦断面図であり、図２ないし図１３は図１の実施例の各部を構成する部品の詳細を示した部品図または組立図である。
【００２６】
本実施例のブッシング１は、絶縁碍子２と、絶縁碍子２内を貫通した状態で設けられて該絶縁碍子に対して固定されるとともに先端３ａが絶縁碍子の先端２ａから外部に導出された中心導体３と、中心導体３の先端に形成された第１の端子部Ｐに取り付けられた電線接続具４と、中心導体３の雄ネジ部３０５の近傍に取付けられた分岐導体５の先端に形成された第２の端子部Ｑに取り付けられた電線接続具４´とを備えている。以下各部の構成を詳細に説明する。
【００２７】
本実施例では、絶縁碍子２が、変圧器タンク６に固定される主碍子２Ａと、中心導体３に固定された補助碍子２Ｂとからなっている。
【００２８】
主碍子２Ａは、その後端側に位置する管状の首下部２０１と、中間部に設けられて首下部２０１よりも大径に形成された首部２０２と、該主碍子の先端側にあって首部２０２よりも更に大径に形成された筒状の頭部２０３とを一体に有している。
【００２９】
主碍子の頭部２０３は、中心導体３を同心的に取り囲む内周壁２０３ａと、内周壁２０３ａを同心的に取り囲む外周壁２０３ｂとを一体に有し、内周壁２０３ａの内側に形成された空間の底部には断面円形の凹部２０３ｃを有している。
【００３０】
主碍子２Ａの首部２０２内及び首下部２０１内には中空部２０４が形成され、該中空部と頭部２Ａの内側に形成された凹部２０３ｃとの境界部を貫通させて、連通穴２０５が形成されている。連通穴２０５は中空部２０４及び凹部２０３ｃの内径よりも小さく設定され、連通穴２０５の中空部２０４側の開口端周辺及び凹部２０３ｃ側の開口端周辺にそれぞれ位置決め用段部２０６及び２０７が形成されている。
【００３１】
首下部２０１と首部２０２との間には段部２０８が形成され、ブッシングを変圧器に取り付ける際には、首下部２０１が変圧器タンク６に設けられた取付け孔６ａを貫通した状態で配置されて、段部２０８がガスケット７を介して取付け孔６ａの周辺部に当接される。首下部２０１の外周に周設された溝に環状の取付けバネ８が嵌着され、首下部２０１に嵌合された取付け金具９の内周部が取付けバネ８に当接されている。取付け金具９に設けられた複数のネジ孔にそれぞれネジ１０が螺合されてそれぞれのネジ１０の先端が変圧器タンク６の内面に当接され、これらのネジの締め付けにより絶縁碍子２がタンク６に対して固定される。
【００３２】
中心導体３は、丸棒状に形成された主導体３Ａと、該主導体３Ａの後端部に中継導体３Ｂを介して連結された内部口出導体３Ｃとからなり、主導体３Ａと中継導体３Ｂ及び中継導体３Ｂと口出導体３Ｃとはそれぞれネジ結合により連結されている。中継導体３Ｂ及び口出導体３Ｃは主碍子の首部２０２及び首下部２０１の内部に形成された中空部２０４内に配置されて、中継導体３Ｂが段部２０６に当接されて軸線方向に位置決めされている。絶縁を強化するため、中空部２０４内にはエポキシ樹脂等の絶縁樹脂からなる充填材２０９が充填されている。
【００３３】
主導体３Ａは、図２（Ａ），（Ｂ）に示したように、主碍子の頭部の軸芯部に配置された棒状部３０１と、該棒状部の後端部に形成された小径部３０２と、棒状部３０１と小径部３０２との間の境界部に形成されたつば部３０３とを有し、小径部３０２の端部に形成されたネジ部３０２ａが主碍子の連通穴２０５を通して中継導体３Ｂのネジ穴に螺合されて、主導体３Ａと中継導体３Ｂとが連結されている。つば部３０３と段部２０７との間にはガスケット１１が挿入されている。
【００３４】
主導体３Ａの先端部（中心導体３の先端部）３ａの外周には、第１の端子部Ｐを構成する雄ネジ部３０５が設けられ、該雄ネジ部３０５の手前の位置には、中心導体３の軸線方向に対して直角な方向に延びるネジ穴３０６が形成されている。また中心導体３の先端の軸芯部には、該中心導体の先端の端面に開口した端子挿入穴３０７が形成され、該端子挿入穴３０７の開口端部は、該端子挿入穴の開口端部側に向って次第に径が大きくなる向きのテーパがつけられたテーパ孔部３０７ａとなっている。更に、主導体３Ａの中間部には軸線方向に延びるキー溝３０８とネジ部３０９（図２参照）とが形成されている。また端子挿入穴３０７内に侵入した空気及び水を抜くため、主導体３Ａの雄ネジ部３０５に隣接する位置に、主導体の軸線と直交する方向に延びる貫通孔３１０が形成され、該貫通孔３１０は端子挿入穴３０７の最深部に連通させられている。
【００３５】
補助碍子２Ｂは、中心導体３及び分岐導体５等の充電部を隠蔽して感電事故を防ぐとともに、主碍子２Ａの内周壁２０３ａと外周壁２０３ｂとの間に形成された深溝部Ｇ内に海水等が浸入してブッシングの漏れ電流を増大させるのを防ぐために設けられている。この補助碍子２Ｂは、図３（Ａ），（Ｂ）に示したように、中心導体３の主導体３Ａを同心的に取り囲むように形成されていて、きのこ状の突出部２１０ａを有する後端部２１０と先端が開口した周壁部２１１とを有し、周壁部２１１には電線接続具取付け用の横孔２１２が設けられている。
【００３６】
補助碍子２Ｂの後端部の内側には、図４（Ａ），（Ｂ）に示したようなガイド金具２１３がセメントまたは樹脂等の接着剤２１４により固定され、該ガイド金具が主導体３Ａの外周に嵌合されている。ガイド金具２１３にはキー２１５がはんだ付け等により固定され、該キー２１５が主導体３Ａに設けられたキー溝３０８に嵌合されて補助碍子２Ｂが軸線方向に位置決めされている。主導体３Ａに設けられたネジ部３０９には、図５（Ａ），（Ｂ）に示したようにリング状の部材の内周に雌ネジ２１６ａを形成した補助碍子固定ナット２１６が螺合され、該ナット２１６の締め付けにより補助碍子２Ｂが主導体３Ａに固定されている。図５（Ａ），（Ｂ）において、２１６ｂはナット２１６を緩めたり締め付けたりする工具を係入するための溝である。
【００３７】
補助碍子２Ｂは、その後端部２１０が主碍子の頭部２Ａの内周壁２０３ａの内側に挿入された状態になるように位置決めされており、突出部２１０ａが内周壁２０３ａ及び外周壁２０３ｂの開口端部に所定の間隙を介して対向させられている。
【００３８】
分岐導体５は、図６（Ａ）〜（Ｃ）に示したように、後端に小径のネジ部５０１を有し、先端の外周に中心導体３の先端のネジ部３０５と同径同ピッチの雄ネジ部５０２を有するとともに、先端の軸芯部に端子挿入穴５０３を有する丸棒状の部材からなっていて、図７に示すように、そのネジ部５０１がネジ穴３０６にねじ込まれて中心導体３に取り付けられている。分岐導体５を中心導体３のネジ穴にねじ込む際には、ネジ部５０１に接着剤を塗布して、該接着剤によりネジ部５０１をネジ穴３０６に強固に結合するようにするのが好ましい。分岐導体５の雄ネジ部５０２はネジ部５０１よりも大径に形成されているため、雄ネジ部５０２とネジ部５０１との間に形成された平坦な段部５０５が中心導体のネジ穴３０６の周辺部に直接またはワッシャを介して接触し、この接触により分岐導体５と中心導体３との電気的な導通が図られる。
【００３９】
分岐導体５の先端の端子挿入穴５０３は、中心導体の先端の端子挿入穴３０７と同形状同寸法に形成されていて、該端子挿入穴５０３の開口端部はテーパ孔部５０３ａとなっている。また端子挿入穴５０３内に浸入した空気及び水を抜くため、該端子挿入穴５０３の最深部に連通させて、分岐導体５の軸線方向と直交する方向に延びる貫通孔５０４が形成されている。この分岐導体５の先端の雄ネジ部５０２が第２の端子部Ｑを構成している。
【００４０】
中心導体３の先端に形成された第１の端子部Ｐ（雄ネジ部３０５）、及び分岐導体５の先端に形成された第２の端子部Ｑ（雄ネジ部５０２）には、互換性を有する電線接続具４及び４´が取り付けられる。これらの電線接続具の構成は全く同一であるので、以下第１の端子部Ｐに取り付けられる電線接続具４の構成を図８ないし図１２を参照して説明する。
【００４１】
電線接続具４は、図８に示すつまみ碍子４Ａと、図９に示す筒状ナット４Ｂと、図１０に示す給電用端子４Ｃと、図１１に示す端子止めナット４Ｄとにより構成されている。更に詳細に説明すると、つまみ碍子４Ａ（図８Ａ，Ｂ参照）は、図示しない間接活線作業用工具を係入するための溝部４０１ａを外周部に多数有する頭部４０１と、該頭部の一端側に形成された首部４０２とからなっていて、その内側には、ナット取付け孔４０３と、該ナット取付け孔よりも小径に形成されて該ナット取付け孔と軸線を共有した電線挿通孔４０４とが形成されている。ナット取付け孔４０３及び電線挿通孔４０４はそれぞれつまみ碍子の一端側及び他端側に開口するように設けられ、端子挿入穴４０３の内周面はセメントの接着性を強固にするために粗面にされている。
【００４２】
つまみ碍子４Ａのナット取付け孔４０３内には、図９に示す筒状ナット４Ｂが挿入されている。筒状ナット４Ｂは、その一端をつまみ碍子の一端側に開口させた状態で配置されていて、セメント１２によりつまみ碍子４Ａに固定されている（図１，図１２参照）。筒状ナット４Ｂの内周の大部分には雌ネジ４０５が形成されているが、該ナットの他端付近の内周には雌ネジを有しないネジ無し部４０６が形成されている。また筒状ナット４Ｂの他端には、後記する給電用端子４Ｃの他端を貫通させる端子貫通孔４０７が形成されている。端子貫通孔４０７はネジ無し部４０６の内径よりも小径に形成されて、該ネジ無し部と端子貫通孔４０７との間に給電用端子のつば部に対向する端子締付用段部４０８が形成されている。
【００４３】
給電用端子４Ｃは、図１０に示したように、一端側及び他端側にそれぞれ形成された小径部４０９及び大径部４１０と、小径部４０９と大径部４１０との間に形成されたテーパ部４１１と、大径部４１０の中間部に形成されたつば部４１２とを有する丸棒状の部材からなり、テーパ部４１１は、中心導体の端子挿入穴３０７のテーパ孔部３０７ａに隙間なく嵌合する形状に形成されている。
【００４４】
また給電用端子４Ｃの大径部には、該給電用端子の他端側に開口した電線挿入穴４１３が形成され、該電線挿入穴４１３を取り囲む周壁部が電線接続部４１４となっている。
【００４５】
給電用端子４Ｃは、図１２に示したように、その電線接続部４１４にワッシャ４１５を嵌合させた状態で、かつその一端を筒状ナット４Ｂの一端側（ナット取付け孔４０３の開口部側）に向けた状態で、筒状ナット４Ｂ内に挿入されている。そして図１１（Ａ），（Ｂ）に示したように、筒状ナット４Ｂ内で給電用端子４Ｃを取り囲むようにリング状に形成されて外周部に雄ネジ４１６が設けられた給電用端子止めリング４Ｄが設けられて、該給電用端子止めリング４Ｄのネジ部４１６が筒状ナット４Ｂの雌ネジ４０５に螺合され、この端子止めリング４Ｄにより、給電用端子４Ｃの筒状ナット４Ｂからの抜け止めが図られている。給電用端子止めリング４Ｄにも、工具を係入するための溝４１７が形成されている。
【００４６】
上記の電線接続具４は、給電用端子４Ｃを中心導体３の先端の端子挿入穴３０７内に挿入した状態で、その筒状ナット４Ｂを中心導体の先端の雄ネジ部３０５に螺合させることにより、中心導体の第１の端子部Ｐに取り付ける。
【００４７】
そして本実施例では、このように電線接続具４の筒状ナット４Ｂを雄ネジ部３０５に螺合させて締め付けた際に、端子締付け用段部４０８が給電用端子４Ｃのつば部４１２を押圧して該給電用端子を端子挿入穴３０７側に付勢するように、筒状ナット４Ｂの軸線方向寸法が設定されている。また電線接続具４の筒状ナット４Ｂを緩めた状態で該筒状ナットと給電用端子４Ｃとの間に相対的な回転が生じるのを許容するように、給電用端子止めリング４Ｄと端子締付用段部４０８との間の間隔及びネジ無し部４０６の内径が設定されている。このように、筒状ナット４Ｂと給電用端子４Ｃとの間に相対的な回転が生じるのを許容するようにしておくと、つまみ碍子４Ａを回転させた際に給電用端子４Ｃに接続された電線が捩じれることがないため、断線を生じさせることなく、電線接続具の取り付けを容易に行わせることができる。
【００４８】
分岐導体５に設けられた第２の端子部Ｑへの電線接続具４´の取り付けも上記と全く同様に行われる。即ち、電線接続具４´の給電用端子４Ｃを分岐導体５の端子挿入穴５０３内に挿入し、筒状ナット４Ｂを給電用端子４Ｃの先端の雄ネジ部５０２に螺合させることにより、電線接続具４´を第２の端子部Ｑに取り付ける。電線接続具４´を分岐導体５の雄ネジ部５０２に取り付けた状態では、該電線接続具４´のつまみ碍子４Ａの首部４０２が、補助碍子２Ｂの横孔２１２内に挿入された状態になる。
【００４９】
電線接続具４，４´に電線を接続する手順は、図１３（Ａ）ないし（Ｃ）に示す通りである。即ち、電線接続具４，４´に電線を接続する際には、まず図１３（Ａ）に示すように、給電用端子４Ｃを取り外した状態で、電線２０をつまみ碍子４Ａの電線挿通孔４０４内及び筒状ナット４Ｂ内を貫通させて、その先端を筒状ナット４Ｂの開口端から突出させる。次いで図１３（Ｂ）に示したように、電線２０の芯線２０ａを給電用端子４Ｃの電線接続部４１４の内側の穴に挿入し、電線接続部４１４を圧縮することにより該電線接続部４１４と芯線２０ａとを接続する。その後図１３（Ｃ）に矢印で示した方向に電線２０を引いて給電用端子４Ｃを筒状ナット４Ｂ内に挿入し、給電用端子止めリング４Ｄの外周のネジ部を筒状ナット４Ｂの内周の雌ネジに螺合させることにより、給電用端子４Ｃの抜け止めを図る。
【００５０】
２台の変圧器Ｔa ，Ｔb をＶ結線する際に用いるＶ結線用リード線Ｌabを構成する場合には、図１４に示したように、電線２０の両端に電線接続具４（または４´）を接続する。
【００５１】
なおブッシングに設けられた２つの電線接続具４，４´の内、電線が接続されない方の電線接続具の電線挿通孔４０４には、ゴム栓２１を挿入して、電線接続具の内部の充電部を隠蔽するようにしておく。図１に示した例では、第２の端子部Ｑに取り付けられた電線接続具４´に電線２０が接続され、第１の端子部Ｐに取り付けられた電線接続具４の電線挿通孔４０４内にゴム栓２１が挿入されている。
【００５２】
上記のように構成された変圧器用ブッシング１は、通常その軸線を斜め下方に向けた状態で、かつ第２の端子部Ｑを斜め上方に向けた状態で変圧器タンクの側壁に取り付けられ、各ブッシングの中心導体３の後端部（内部口出導体３Ｃ）が変圧器タンク内の変圧器本体の１次巻線に接続される。
【００５３】
今２台の変圧器Ｔa 及びＴb が装柱されているものとし、変圧器Ｔa に設けられる高圧ブッシング１a1，１a2、及び変圧器Ｔb に設けられる高圧ブッシング１b1及び１b2として、図１に示したブッシング１が用いられているものとする。２台の変圧器Ｔa 及びＴb が電柱に取り付けられたハンガーの上に並べて設置（ハンガー装柱）される場合には、２台の変圧器の間に比較的大きな間隔が確保され、図１５（Ａ）に示すように２台の変圧器Ｔa ，Ｔb の隣り合うブッシング１a2，１b1間の間隔に余裕があるため、各ブッシングを斜め下方に向けて取り付けておけば、各ブッシングの中心導体３の先端の第１の端子部Ｐ（雄ネジ部３０５）への電線接続具の着脱を容易に行うことができる。従って、例えば図１５（Ａ）に示すように、Ｖ結線用リード線Ｌabの一端及び他端をそれぞれ電線接続具４´及び４を介して変圧器Ｔa のブッシング１a2の第２の端子部Ｑ及び変圧器Ｔb のブッシング１b1の第１の端子部Ｐに接続することにより、変圧器Ｔa 及びＴb をＶ結線し、変圧器Ｔa のブッシング１a1の第２の端子部Ｑ、変圧器Ｔb のブッシング１b1の第２の端子部Ｑ、及び変圧器Ｔb のブッシング１b2の第２の端子部Ｑにそれぞれ、変圧器の上方に配置された高圧配電線につながる高圧引き下げ線Ｌu ，Ｌv 及びＬw の下端を電線接続具４´を介して接続することにより、各高圧引き下げ線の接続及びＶ結線用リード線の接続を容易に行うことができる。また高圧配電線の工事を行う場合には、斜め下方に向いているブッシング１a1，１a2及び１b2の先端の第１の端子部Ｐにそれぞれ電線接続具４を介してバイパス線を容易に接続することができる。
【００５４】
なお図１５（Ａ）の例において、Ｖ結線用リード線Ｌabをブッシング１a2の第１の端子部Ｐとブッシング１b1の第２の端子部Ｑとの間に接続し、ブッシング１a2の第２の端子部Ｑに中相の高圧引き下げ線Ｌv を接続するようにしてもよいのはもちろんである。
【００５５】
また２台の変圧器Ｔa 及びＴb が電柱に直接取り付けられる（直付け装柱される）場合には、２台の変圧器の間の間隔を広くとることができず、２台の変圧器の隣り合うブッシング１a2及び１b1の間の間隔に余裕がないため、ブッシング１a2及び１b1の中心導体の先端の第１の端子部Ｐへの電線接続具の着脱を容易に行うことはできない場合がある。このような場合に、中相のバイパス線（２台の変圧器の隣り合うブッシングに接続されるバイパス線）をブッシング１a2または１b1の第１の端子部に接続するようにしておくと、その接続が困難になる。そこでこの場合には、図１５（Ｂ）に示すように、２台の変圧器Ｔa 及びＴb の隣り合うブッシング１a2及び１b1の第１の端子部Ｐ，Ｐ間にＶ結線用リード線Ｌabを接続する。そして、高圧配電線の工事の際に、バイパス線ＢＬu 〜ＢＬw を接続する場合には、図１６に示したように、両端相のバイパス線ＢＬu 及びＢＬw をそれぞれ変圧器Ｔa のブッシング１a1の第１の端子Ｐ及び変圧器Ｔb のブッシング１b2の第１の端子Ｐに接続し、中相のバイパス線ＢＬv を変圧器Ｔa のブッシング１a2の第２の端子部Ｑに接続する。
【００５６】
高圧配電線に対する工事を行う際の手順は図１７（Ａ）ないし（Ｃ）に示す通りである。この例では、図１５（Ａ）に示した例と同様に、２台の変圧器Ｔa 及びＴb がハンガ装柱されて、ブッシング１a2の第２の端子部Ｑとブッシング１b1の第１の端子部Ｐとの間がＶ結線用リード線Ｌabにより接続されているものとし、ブッシング１a1，１b1及び１b2のそれぞれの第２の端子部Ｑに配電線Ｕ，Ｖ及びＷからそれぞれ引き下げられた高圧引き下げ線Ｌu ，Ｌv 及びＬw が電線接続具４´を介して接続されているものとする。配電線Ｕ〜Ｗの張り替え工事や、カットアウトスイッチＳu 〜Ｓw の取替え工事を行う際には、図１７（Ｂ）に示したように、ブッシング１a1，１a2及び１b2のそれぞれの第１の端子部Ｐに高圧配電線の健全区間に接続されたバイパス線ＢＬu ，ＢＬv 及びＢＬw を電線接続具４を介して接続する。次いで図１７（Ｃ）に示したように、高圧引き下げ線Ｌu 〜Ｌw を変圧器のブッシングから取り外し、高圧配電線Ｕ〜Ｗを停電させて工事を行う。
【００５７】
上記のように、変圧器用ブッシング１の中心導体３の先端に第１の端子部Ｐを構成する雄ネジ部３０５を設けるとともに、該雄ネジ部の近傍に設けたネジ穴に取り付けた分岐導体５の先端に、中心導体３の先端の雄ネジ部３０５と同径同ピッチの雄ネジ部５０２を設けて第２の端子部Ｑを構成し、中心導体の先端の雄ネジ部３０５及び分岐導体の先端の雄ネジ部５０２にそれぞれ同様に構成された電線接続具４を取り付けるように構成すると、中心導体の先端部の第１の端子部Ｐ及び分岐導体の先端の第２の端子部Ｑのいずれにも同じように電線を接続することができるため、変圧器ブッシングに対する電線の接続の自由度を高めることができ、変圧器の種々の設置状態に容易に対応することができる。
【００５８】
また電線接続具と電線との接続は現場で容易に行うことができるため、変圧器に対する配線を行う際には、変圧器の据付現場で、実際の変圧器の据付状況（変圧器相互間の間隔、変圧器のブッシングと配電線との間の距離等）に応じて、高圧引き下げ線やＶ結線用リード線の長さを最適な値に調整した後に電線接続具を取り付けることにより、電線の長さに過不足がない適確な配線を行うことができる。
【００５９】
また上記のように中心導体３に互換性がある２つの電線接続具４，４´を、それぞれの取付け方向を異ならせて取り付けるように構成すると、２台の変圧器をＶ結線する場合に、Ｖ結線用リード線及び高圧引き下げ線の双方を容易かつ確実に接続することができ、高圧配電線に対する工事を行う場合には、バイパス線を容易に接続することができる。バイパス線の接続は、つまみ碍子を間接活線作業用工具により把持して電線接続具を操作することにより、熟練を要すること無く、容易かつ安全に行うことができる。
【００６０】
更に上記のように構成すると、１種類の電線接続具を製作すればよいので、部品の種類を少なくすることができ、コストの低減を図ることができる。
【００６１】
上記の説明では、本発明に係わるブッシングを斜め下方に向けて取り付けるとしたが、その取付け方向は任意であり、水平方向に向けて取り付けたり、斜め上方に向けて取り付けたりすることもできる。
【００６２】
【発明の効果】
以上のように、本発明によれば、ブッシングの中心導体の先端部及び該中心導体に取り付けた分岐導体の先端部にそれぞれ同様の雄ネジ部と端子挿入穴とを設けて、両雄ネジ部及び端子挿入穴に互換性がある電線接続具を取り付けることができるようにしたので、ブッシングに対する電線の接続の自由度を高めることができ、変圧器の種々の設置態様に容易に対応することができる。
【００６３】
また本発明によれば、中心導体に互換性がある２つの電線接続具を、それぞれの取付け方向を異ならせて取り付けるように構成したので、２台の変圧器をＶ結線する場合に、Ｖ結線用リード線及び高圧引き下げ線の双方を容易かつ確実に接続することができ、更に高圧配電線に対する工事を行う場合には、バイパス線を容易に接続することができる。この場合、各電線接続具はつまみ碍子を備えているため、バイパス線の接続は活線状態で行うことができ、無停電で配電線に対する工事を行わせることができる。
【００６４】
更に本発明によれば、２つの電線接続具が互換性を有するので部品の種類を少なくして、コストの低減を図ることができる。
【図面の簡単な説明】
【図１】本発明の実施例の全体的な構成を示した縦断面図である。
【図２】（Ａ）及び（Ｂ）はそれぞれ同実施例で用いる主導体の正面図及び要部の縦断面図である。
【図３】（Ａ）及び（Ｂ）はそれぞれ同実施例で用いる補助碍子の正面図及び縦断面図である。
【図４】（Ａ）は同実施例で補助碍子を固定するために用いるガイド金具の正面図である。（Ｂ）は（Ａ）のＡ−Ａ線断面図である。
【図５】（Ａ）は同実施例で用いる補助碍子固定ナットの正面図である。（Ｂ）は（Ａ）のＢ−Ｂ線断面図である。
【図６】（Ａ）及び（Ｂ）はそれぞれは同実施例で用いる分岐導体の正面図及び上面図である。（Ｃ）は（Ａ）のＣ−Ｃ線断面図である。
【図７】主導体と分岐導体との結合構造を説明するための断面図である。
【図８】（Ａ）は本発明の実施例で用いるつまみ碍子の半部を断面して示した側面図である。（Ｂ）は同つまみ碍子の正面図である。
【図９】同実施例で用いる筒状ナットの半部を断面して示した正面図である。
【図１０】同実施例で用いる給電用端子の半部を断面して示した正面図である。
【図１１】（Ａ）は同実施例で用いる給電用端子止めリングの正面図である。（Ｂ）は（Ａ）のＤ−Ｄ線断面図である。
【図１２】本発明の実施例で用いる電線接続具の組立構造を説明するための断面図である。
【図１３】（Ａ），（Ｂ）及び（Ｃ）はそれぞれ電線接続具に電線を接続する際の手順を順に示した断面図である。
【図１４】２台の変圧器をＶ結線する際に用いるリード線の構造を示した断面図である。
【図１５】（Ａ）はハンガー装柱された２台の変圧器をＶ結線して各変圧器用ブッシングに高圧引き下げ線を接続した状態を示した説明図である。（Ｂ）は直付け装柱された２台の変圧器をＶ結線して各変圧器用ブッシングに高圧引き下げ線を接続した状態を示した説明図である。
【図１６】図１５（Ｂ）の例で各変圧器用ブッシングにバイパス線を接続した状態を示した説明図である。
【図１７】（Ａ），（Ｂ）及び（Ｃ）はそれぞれ、図１５（Ａ）の例において、変圧器用ブッシングにバイパス線を接続して高圧引き下げ線を切り離す際の手順を順に示した説明図である。
【図１８】２台の変圧器をＶ結線して各ブッシングに高圧引き下げ線を接続する場合の従来の接続の仕方を示した説明図である。
【符号の説明】
１変圧器用ブッシング
２絶縁碍子
２Ａ主碍子
２Ｂ補助碍子
３中心導体
３Ａ主導体
３Ｂ中継導体
３Ｃ内部口出導体
３０５雄ネジ部
３０６ネジ穴
３０７端子挿入穴
３０７ａテーパ孔部
４，４´ 電線接続具
４Ａつまみ碍子
４Ｂ筒状ナット
４Ｃ給電用端子
４Ｄ給電用端子止めリング
４０６ネジ無し部
４０７端子貫通孔
４０８端子締付用段部
５分岐導体
５０１ネジ部
５０２雄ネジ
５０３端子挿入穴
５０３ａテーパ孔部[0001]
[Industrial application fields]
The present invention relates to a bushing for a transformer attached to a distribution transformer.
[0002]
[Prior art]
In a distribution transformer, a high voltage bushing and a low voltage bushing are attached to a transformer tank, an electric wire connected to a high voltage distribution line is connected to the high voltage bushing, and a low voltage distribution line connected to a consumer is connected to the low voltage bushing. The high-pressure bushing used in this case is provided with an insulator and a state penetrating the insulator, and one end is fixed to one end of the insulator and the other end is led out from the other end of the insulator. A central conductor, and an electric wire is connected to an electric wire connecting portion provided at the other end of the central conductor.
[0003]
In recent pole transformers, in order to share a power source for a light load and a power load, two transformers are often operated by V-connection. FIG. 18 shows the connection between transformers and between the transformer and the distribution line when two single-phase transformers Ta and Tb are provided. The two transformers Ta and Tb include High pressure bushings 1a1, 1a2 and 1b1, 1b2 are provided, respectively. In this example, high-voltage pull-down lines Lu, Lv, and Lw connected to three-phase high-voltage distribution lines U, V, and W via cut-out switches Su, Sv, and Sw are bushings 1a1, 1a2, and 1a2 of transformer Ta. It is connected to the bushing 1b2 of the transformer Tb. Further, the bushing 1a2 of the transformer Ta and the bushing 1b1 of the transformer Tb are connected via a V-connection lead line Lab, and the transformers Ta and Tb are V-connected. A low voltage bushing (not shown) is attached to the transformers Ta and Tb, and a low voltage distribution line connected to a consumer is connected to the low voltage bushing.
[0004]
In recent years, with the spread of various high-performance electrical products such as computers, there has been a strong demand for stable power supply, and it is necessary to carry out work on distribution lines without interruption. In addition, due to changes in work consciousness in society, it is necessary to review the current state of electrical work that requires highly skilled skills and is dangerous, and it is safe and easy to connect wires even in bushings for transformers. It is requested to be able to do it.
[0005]
In the distribution system provided with the transformer as described above, when the replacement work of the cut-out switches Su to Sw or the replacement work of the high-voltage distribution lines U to W in a specific section is performed, the transformer Ta and After connecting the high-voltage bushings 1a1, 1a2 and 1b2 of Tb with bypass lines connected to the high-voltage distribution lines in the healthy section to secure the supply of power to consumers, the high-voltage pull-down lines Lu to Lw are disconnected and uninterrupted It is desirable to perform construction.
[0006]
However, the high-voltage bushing that has been widely used conventionally has only one location for connecting the electric wire to the center conductor, so it is difficult to connect the bypass line and disconnect the high-voltage pull-down line without an uninterruptible power supply. Met.
[0007]
Therefore, when performing the above-mentioned construction, move the mobile transformer car to the construction site and pull the bypass line connected to the high-voltage distribution line in the healthy section into the transformer mounted on the mobile transformer car. By connecting the low-voltage bypass line connected to the low-voltage bushing of the mobile transformer car to the distribution line connected to the consumer, the high-voltage pull-down line was disconnected after securing the supply of power to the consumer.
[0008]
As described above, when the conventional transformer bushing is used, it is necessary to move the mobile transformer car when performing the construction for the high-voltage distribution line, and the materials and personnel that need to be prepared increase accordingly. Therefore, the construction cost was unavoidable.
[0009]
Therefore, as shown in Japanese Utility Model Laid-Open No. 3-19261, a bushing for a transformer has been proposed in which a bypass line can be further connected in a state where an electric wire is connected to an end of a central conductor of a high voltage bushing. In this proposed bushing for a transformer, a male screw portion is provided at the end of the center conductor so that a wire connector for connecting a high voltage pull-down line can be attached to the male screw portion, and the male screw portion Is provided with a screw hole for connecting a bypass line, and a bypass line connector is attached to the screw hole. The bypass wire connector is provided with a contact with a screw to which a terminal fitting provided at an end of the bypass wire is bolted, and an insulating operation rod for holding the contact. Then, the screw part of the contactor is screwed into the screw hole of the central conductor of the bushing to attach it to the central conductor of the bushing.
[0010]
[Problems to be solved by the invention]
When only one transformer is installed, or when two transformers are housed in a common tank and V-connected, the transformer bushing shown in Japanese Utility Model Publication No. 3-19261 is used. The bypass wire can be connected by screwing the screw portion of the contact of the bypass wire connector into the screw hole for connecting the bypass wire of the center conductor with the high-voltage pull-down wire connected to the wire connection portion of the center conductor. Therefore, it is possible to work on the high-voltage distribution line without a power failure.
[0011]
However, in this conventional bushing for a transformer, a plurality of wires cannot be connected by a wire connector attached to the male screw portion provided at the end of the center conductor, so two transformers with different tanks There is a problem that it is impossible to cope with V-connection.
[0012]
In addition, in order to dare V-connect the two transformers with the above-mentioned transformer bushings, a terminal bolt is screwed into a screw hole for bypass wire connection, and the lead wire for V connection is used as a central conductor by this terminal bolt. It is possible to connect. However, in this case, it is difficult to connect the bypass line in a live line state, and it is difficult to reliably connect the bypass line.
[0013]
An object of the present invention is to provide a bushing for a transformer that can easily connect two electric wires to a central conductor and can increase the degree of freedom of connection of the electric wires to the central conductor. .
[0014]
Another object of the present invention is to provide a bushing for a transformer that can easily connect a bypass line to a central conductor when two transformers are V-connected.
[0015]
[Means for Solving the Problems]
The present invention includes an insulator 2 and a center conductor 3 provided in a state of penetrating the insulator 2 and having a tip led out to the outside from the tip of the insulator, and is provided on the outer periphery of the tip of the center conductor. The present invention relates to a bushing for a transformer in which a male screw portion 305 is provided and a terminal insertion hole 307 having a tapered hole portion at an opening end portion is formed in an axial core portion at the tip of a central conductor.
[0016]
In the present invention, a screw hole 306 extending in a direction orthogonal to the axial direction of the center conductor is provided in the vicinity of the male screw portion 305 at the tip of the center conductor 3. In addition, a screw portion 501 is provided at the rear end, a male screw portion 502 having the same diameter and the same pitch as the male screw portion 305 at the tip of the center conductor 3 is provided on the outer periphery of the tip, and the center conductor 3 is provided at the tip axial core portion. A branch conductor 5 having a terminal insertion hole 503 having the same shape and size as the terminal insertion hole 307 at the tip is provided, and a screw portion 501 at the rear end of the branch conductor is screwed into the screw hole 306 of the center conductor 3. .
[0017]
In the present invention, a pair of electric wire connectors 4 and 4 ′ are also provided, and one of the pair of electric wire connectors 4 and the other 4 ′ are the male screw portion 305 and the branch conductor at the tip of the center conductor 3, respectively. It is attached to the male screw portion 502 at the tip of the.
[0018]
Each wire connector has a nut attachment hole 403 and a wire insertion hole 404 formed in a smaller diameter than the nut attachment hole and sharing the axis with the nut attachment hole, and the nut attachment hole and the wire insertion hole. 4A (refer to FIG. 8) with each opening at one end and the other end, and a cylindrical nut 4B (FIG. 8) fixed in the nut mounting hole with one end opened at one end of the knob. 9), and a wire connecting portion 414 and a collar portion 412 that are arranged in the cylindrical nut with one end directed toward the opening side of the cylindrical nut 4B and connect the core wire of the electric wire to the other end side. 4C (see FIG. 10) having a taper part 411 fitted in the taper hole part 307 or 503 of the terminal insertion hole in the middle part, and the power supply terminal 4C in the cylindrical nut 4B. Formed to surround The threaded portion has a screw portion to Rutotomoni outer peripheral portion is composed of a screwed a feeding terminal stop ring 4D on the inner periphery of the female thread of the tubular nut.
[0019]
One and the other 4 ′ cylindrical nuts 4B of the pair of wire connectors 4 and 4 ′ are respectively screwed into the male screw portion 305 at the tip of the center conductor 3 and the male screw portion 502 at the tip of the branch conductor 5 respectively. The power supply terminals 4C of the one and other wire connectors 4 and 4 'are inserted into the terminal insertion hole 307 of the center conductor 3 and the terminal insertion hole 503 of the branch conductor, respectively.
[0020]
An unthreaded portion 406 (see FIG. 9) having no female screw is formed on the inner periphery near the other end of the cylindrical nut 4B of each wire connector, and other terminals for feeding are connected to the other end of the cylindrical nut. A terminal through hole 407 that penetrates the end is formed. The terminal through hole 407 is formed to have a diameter smaller than the inner diameter of the screwless portion 406, and the terminal tightening step facing the collar portion 412 of the power supply terminal 4 C between the screwless portion 406 and the terminal through hole 407. A portion 408 is formed.
[0021]
When the cylindrical nut 4B of each wire connector is screwed into each male screw portion and tightened, the terminal tightening step 408 presses the collar portion 412 of the power supply terminal 4C of the wire connector to supply the power. The axial direction dimension of the cylindrical nut of each wire connector is set so that the terminal is biased toward the terminal insertion hole side, and the cylindrical nut and the power supply are fed in the loosened state. The distance between the power supply terminal retaining ring 4D and the terminal tightening step 408 and the inner diameter of the screwless portion 406 are set so as to allow relative rotation between the terminal and the terminal.
[0022]
The core wire of the electric wire connected to the center conductor 3 is connected to the electric wire connector 4 attached to the male screw portion at the end of the central conductor 3 and / or the electric wire connector 4 ′ attached to the male screw portion 502 of the branch conductor 5. Are connected to the wire connecting portions of the respective power feeding terminals by compression connection or the like. When the wire connector is screwed into the male screw and tightened, each power supply terminal is pushed into the terminal insertion hole, and the taper portion of each power supply terminal is fitted in the taper hole of the terminal insertion hole. By being tightened, each electric wire is electrically connected to the central conductor via the power supply terminal.
[0023]
[Action]
As described above, a male screw part is provided at the tip of the center conductor of the bushing, and the same diameter as the male screw part at the tip of the center conductor is provided at the tip of the branch conductor attached to the screw hole provided in the vicinity of the male screw part. By providing a male screw part of the same pitch and attaching a wire connector having the same configuration to the male screw part at the tip of the center conductor and the male screw part at the tip of the branch conductor, the tip part of the center conductor and the branch Since an electric wire can be similarly connected to any of the conductors, the degree of freedom of connection of the electric wire to the transformer bushing can be increased, and it is possible to easily cope with various installation states of the transformer.
[0024]
In addition, if the two electric wire connectors having compatibility with the central conductor as described above are configured to be mounted with their mounting directions being different from each other, when connecting two transformers to the V connection, the V connection Both the lead wire for high voltage and the high-voltage pull-down wire can be connected easily and reliably, and further, when performing construction on the high-voltage distribution line, a bypass wire can also be connected. In this case, since each electric wire connector is provided with a knob lever, the bypass line can be connected in a live line state, and the construction for the distribution line can be performed without a power failure.
[0025]
【Example】
FIG. 1 is a longitudinal sectional view showing the overall structure of a transformer bushing 1 according to an embodiment of the present invention, and FIGS. 2 to 13 show the details of parts constituting each part of the embodiment of FIG. It is a figure or an assembly drawing.
[0026]
The bushing 1 of this embodiment is provided with an insulator 2 and a center that is provided in a state of penetrating the insulator 2 and is fixed to the insulator 2 and the tip 3a is led out from the tip 2a of the insulator to the outside. Formed at the tip of the conductor 3, the wire connector 4 attached to the first terminal portion P formed at the tip of the center conductor 3, and the branch conductor 5 attached in the vicinity of the male screw portion 305 of the center conductor 3. And a wire connector 4 ′ attached to the second terminal portion Q. The configuration of each part will be described in detail below.
[0027]
In the present embodiment, the insulator 2 includes a main insulator 2A fixed to the transformer tank 6 and an auxiliary insulator 2B fixed to the center conductor 3.
[0028]
The main insulator 2A includes a tubular neck lower portion 201 positioned on the rear end side, a neck portion 202 provided at an intermediate portion and having a diameter larger than that of the neck lower portion 201, and a neck portion 202 on the distal end side of the main insulator. In addition, it has a cylindrical head 203 formed with a larger diameter than that.
[0029]
The head portion 203 of the main insulator integrally includes an inner peripheral wall 203a that concentrically surrounds the central conductor 3 and an outer peripheral wall 203b that concentrically surrounds the inner peripheral wall 203a, and is a space formed inside the inner peripheral wall 203a. A recess 203c having a circular cross section is provided at the bottom.
[0030]
A hollow portion 204 is formed in the neck portion 202 and the neck lower portion 201 of the main insulator 2A, and a communication hole 205 is formed through a boundary portion between the hollow portion and the recess portion 203c formed inside the head portion 2A. Has been. The communication hole 205 is set to be smaller than the inner diameters of the hollow portion 204 and the recess 203c, and positioning step portions 206 and 207 are formed around the opening end of the communication hole 205 on the hollow portion 204 side and around the opening end on the recess 203c side, respectively. ing.
[0031]
A step portion 208 is formed between the neck lower portion 201 and the neck portion 202, and when the bushing is attached to the transformer, the neck lower portion 201 is disposed in a state of passing through the attachment hole 6a provided in the transformer tank 6. Thus, the step 208 is brought into contact with the peripheral portion of the mounting hole 6a through the gasket 7. An annular mounting spring 8 is fitted in a groove provided around the outer periphery of the neck lower portion 201, and an inner peripheral portion of the mounting bracket 9 fitted to the neck lower portion 201 is in contact with the mounting spring 8. Screws 10 are respectively screwed into a plurality of screw holes provided in the mounting bracket 9, and the tips of the screws 10 are brought into contact with the inner surface of the transformer tank 6, and the insulator 2 is connected to the tank 6 by tightening these screws. Fixed against.
[0032]
The center conductor 3 includes a main conductor 3A formed in a round bar shape, and an inner lead conductor 3C connected to a rear end portion of the main conductor 3A via a relay conductor 3B. The main conductor 3A and the relay conductor 3B The relay conductor 3B and the lead conductor 3C are connected by screw coupling. The relay conductor 3B and the lead conductor 3C are disposed in a hollow portion 204 formed in the neck portion 202 and the neck lower portion 201 of the main insulator, and the relay conductor 3B is in contact with the step portion 206 and positioned in the axial direction. ing. In order to reinforce insulation, the hollow portion 204 is filled with a filler 209 made of an insulating resin such as an epoxy resin.
[0033]
As shown in FIGS. 2 (A) and 2 (B), the main conductor 3A has a rod-shaped portion 301 disposed at the axial core portion of the main insulator head and a small diameter formed at the rear end portion of the rod-shaped portion. Part 302 and a collar part 303 formed at a boundary part between the rod-like part 301 and the small diameter part 302, and a screw part 302 a formed at the end of the small diameter part 302 passes through the communication hole 205 of the main insulator. The main conductor 3 A and the relay conductor 3 B are coupled by being screwed into the screw holes of the relay conductor 3 B. A gasket 11 is inserted between the collar portion 303 and the step portion 207.
[0034]
A male screw portion 305 constituting the first terminal portion P is provided on the outer periphery of the leading end portion (tip portion of the central conductor 3) 3a of the main conductor 3A. A screw hole 306 extending in a direction perpendicular to the axial direction of the conductor 3 is formed. Further, a terminal insertion hole 307 opened at the end face of the center conductor 3 is formed in the axial core portion at the end of the center conductor 3, and the opening end of the terminal insertion hole 307 is the opening end of the terminal insertion hole. A tapered hole portion 307a is provided with a taper in which the diameter gradually increases toward the side. Further, a key groove 308 and a screw portion 309 (see FIG. 2) extending in the axial direction are formed in the intermediate portion of the main conductor 3A. A through hole 310 extending in a direction orthogonal to the axis of the main conductor is formed at a position adjacent to the male screw portion 305 of the main conductor 3A in order to remove air and water that has entered the terminal insertion hole 307. 310 is communicated with the deepest part of the terminal insertion hole 307.
[0035]
The auxiliary insulator 2B conceals the charged parts such as the center conductor 3 and the branch conductor 5 to prevent an electric shock, and seawater is formed in the deep groove part G formed between the inner peripheral wall 203a and the outer peripheral wall 203b of the main insulator 2A. Is provided to prevent the leakage current of the bushing from increasing and the like. As shown in FIGS. 3A and 3B, the auxiliary insulator 2B is formed so as to concentrically surround the main conductor 3A of the center conductor 3, and has a rear end having a mushroom-like protruding portion 210a. The peripheral wall portion 211 has a portion 210 and a peripheral wall portion 211 having an open end, and the peripheral wall portion 211 is provided with a lateral hole 212 for attaching a wire connector.
[0036]
Inside the rear end portion of the auxiliary insulator 2B, a guide fitting 213 as shown in FIGS. 4A and 4B is fixed by an adhesive 214 such as cement or resin, and the guide fitting is attached to the main conductor 3A. It is fitted on the outer periphery. A key 215 is fixed to the guide metal fitting 213 by soldering or the like, and the key 215 is fitted into a key groove 308 provided in the main conductor 3A so that the auxiliary lever 2B is positioned in the axial direction. As shown in FIGS. 5A and 5B, an auxiliary insulator fixing nut 216 having a female screw 216a formed on the inner periphery of the ring-shaped member is screwed into the screw portion 309 provided on the main conductor 3A. The auxiliary insulator 2B is fixed to the main conductor 3A by tightening the nut 216. 5A and 5B, reference numeral 216b denotes a groove for engaging a tool for loosening or tightening the nut 216.
[0037]
The auxiliary insulator 2B is positioned so that the rear end portion 210 is inserted into the inner peripheral wall 203a of the main insulator head 2A, and the protruding portion 210a is the open end of the inner peripheral wall 203a and the outer peripheral wall 203b. It is made to oppose through a predetermined gap.
[0038]
As shown in FIGS. 6A to 6C, the branch conductor 5 has a small-diameter screw portion 501 at the rear end, and has the same diameter and pitch as the screw portion 305 at the tip of the center conductor 3 on the outer periphery of the tip. 7 and a round bar-like member having a terminal insertion hole 503 at the axial center portion of the tip, and the screw portion 501 is screwed into the screw hole 306 as shown in FIG. It is attached to the conductor 3. When the branch conductor 5 is screwed into the screw hole of the central conductor 3, it is preferable to apply an adhesive to the screw part 501 so that the screw part 501 is firmly bonded to the screw hole 306 by the adhesive. Since the male screw portion 502 of the branch conductor 5 is formed to have a larger diameter than the screw portion 501, a flat step portion 505 formed between the male screw portion 502 and the screw portion 501 is a screw hole 306 in the central conductor. The branch conductor 5 and the center conductor 3 are electrically connected to each other directly or via a washer.
[0039]
The terminal insertion hole 503 at the tip of the branch conductor 5 is formed in the same shape and size as the terminal insertion hole 307 at the tip of the center conductor, and the opening end of the terminal insertion hole 503 is a tapered hole 503a. . Further, in order to remove air and water that have entered the terminal insertion hole 503, a through hole 504 that communicates with the deepest portion of the terminal insertion hole 503 and extends in a direction perpendicular to the axial direction of the branch conductor 5 is formed. The male screw portion 502 at the tip of the branch conductor 5 constitutes the second terminal portion Q.
[0040]
The first terminal portion P (male screw portion 305) formed at the tip of the center conductor 3 and the second terminal portion Q (male screw portion 502) formed at the tip of the branch conductor 5 are compatible. The electric wire connector 4 and 4 'which have is attached. Since the configuration of these electric wire connectors is completely the same, the configuration of the electric wire connector 4 attached to the first terminal portion P will be described below with reference to FIGS.
[0041]
The wire connector 4 includes a knob lever 4A shown in FIG. 8, a cylindrical nut 4B shown in FIG. 9, a power supply terminal 4C shown in FIG. 10, and a terminal locking nut 4D shown in FIG. More specifically, the knob lever 4A (see FIGS. 8A and B) includes a head 401 having a large number of grooves 401a on the outer periphery for engaging an indirect hot wire working tool (not shown), and one end of the head. A nut mounting hole 403 and a wire insertion hole 404 formed in a smaller diameter than the nut mounting hole and sharing the axis with the nut mounting hole. Is formed. The nut mounting hole 403 and the wire insertion hole 404 are provided so as to open to one end side and the other end side of the knob insulator, respectively, and the inner peripheral surface of the terminal insertion hole 403 is roughened to strengthen the adhesiveness of cement. Has been.
[0042]
A cylindrical nut 4B shown in FIG. 9 is inserted into the nut mounting hole 403 of the knob lever 4A. The cylindrical nut 4B is arranged in a state where one end thereof is opened to one end side of the knob insulator, and is fixed to the knob insulator 4A by the cement 12 (see FIGS. 1 and 12). A female screw 405 is formed on most of the inner periphery of the cylindrical nut 4B, but an unthreaded portion 406 having no female screw is formed on the inner periphery near the other end of the nut. A terminal through hole 407 is formed at the other end of the cylindrical nut 4B so as to penetrate the other end of a power feeding terminal 4C described later. The terminal through hole 407 is formed to have a smaller diameter than the inner diameter of the screwless portion 406, and a terminal tightening step portion 408 is formed between the screwless portion and the terminal through hole 407 so as to face the flange portion of the power feeding terminal. Has been.
[0043]
As shown in FIG. 10, the power feeding terminal 4 C is formed between the small diameter portion 409 and the large diameter portion 410 formed on one end side and the other end side, and between the small diameter portion 409 and the large diameter portion 410. It consists of a round bar-like member having a taper portion 411 and a collar portion 412 formed in the middle portion of the large diameter portion 410, and the taper portion 411 fits into the taper hole portion 307a of the terminal insertion hole 307 of the center conductor without any gap. It is formed in a matching shape.
[0044]
Further, an electric wire insertion hole 413 opened on the other end side of the power supply terminal is formed in the large diameter portion of the power supply terminal 4C, and a peripheral wall portion surrounding the electric wire insertion hole 413 is an electric wire connection portion 414.
[0045]
As shown in FIG. 12, the power feeding terminal 4C is in a state in which a washer 415 is fitted to the electric wire connection portion 414, and one end thereof is connected to one end side of the cylindrical nut 4B (opening side of the nut mounting hole 403). ), And is inserted into the cylindrical nut 4B. Then, as shown in FIGS. 11 (A) and 11 (B), a power supply terminal stopper formed in a ring shape so as to surround the power supply terminal 4C in the cylindrical nut 4B and provided with a male screw 416 on the outer peripheral portion. A ring 4D is provided, and a screw portion 416 of the power supply terminal retaining ring 4D is screwed into a female screw 405 of the cylindrical nut 4B. By this terminal retaining ring 4D, the power supply terminal 4C is removed from the cylindrical nut 4B. The stopper is designed. A groove 417 for engaging the tool is also formed in the power supply terminal retaining ring 4D.
[0046]
The wire connector 4 has the cylindrical nut 4B screwed into the male screw portion 305 at the tip of the center conductor in a state where the power supply terminal 4C is inserted into the terminal insertion hole 307 at the tip of the center conductor 3. To attach to the first terminal portion P of the central conductor.
[0047]
In this embodiment, when the cylindrical nut 4B of the wire connector 4 is screwed into the male screw portion 305 and tightened in this way, the terminal tightening step portion 408 presses the collar portion 412 of the power feeding terminal 4C. Thus, the axial dimension of the cylindrical nut 4B is set so as to bias the power feeding terminal toward the terminal insertion hole 307. Also, the terminal clamp ring 4D for power supply and the terminal tightening so as to allow relative rotation between the cylindrical nut and the power supply terminal 4C in the loosened state of the cylindrical nut 4B of the wire connector 4. An interval between the attaching step 408 and an inner diameter of the screwless portion 406 are set. In this way, if relative rotation is allowed to occur between the cylindrical nut 4B and the power supply terminal 4C, it is connected to the power supply terminal 4C when the knob lever 4A is rotated. Since the electric wire is not twisted, it is possible to easily attach the electric wire connector without causing disconnection.
[0048]
Attachment of the wire connector 4 ′ to the second terminal portion Q provided on the branch conductor 5 is performed in exactly the same manner as described above. That is, the power supply terminal 4C of the wire connector 4 'is inserted into the terminal insertion hole 503 of the branch conductor 5, and the cylindrical nut 4B is screwed into the male screw portion 502 at the tip of the power supply terminal 4C, thereby The connection tool 4 ′ is attached to the second terminal portion Q. In a state where the electric wire connector 4 ′ is attached to the male screw portion 502 of the branch conductor 5, the neck portion 402 of the knob lever 4 A of the electric wire connector 4 ′ is inserted into the lateral hole 212 of the auxiliary lever 2 B. .
[0049]
The procedure for connecting the electric wires to the electric wire connectors 4, 4 ′ is as shown in FIGS. That is, when connecting the electric wires to the electric wire connectors 4 and 4 ', first, as shown in FIG. 13A, the electric wire 20 is grasped with the electric power supply terminal 4C removed, and the electric wire insertion hole 404 of the lever 4A. The inside and the inside of the cylindrical nut 4B are penetrated, and the front-end | tip protrudes from the opening end of the cylindrical nut 4B. Next, as shown in FIG. 13B, the core wire 20a of the electric wire 20 is inserted into the hole inside the electric wire connecting portion 414 of the power feeding terminal 4C, and the electric wire connecting portion 414 is compressed to The core wire 20a is connected. Thereafter, the electric wire 20 is pulled in the direction indicated by the arrow in FIG. 13C to insert the power supply terminal 4C into the cylindrical nut 4B, and the threaded portion on the outer periphery of the power supply terminal retaining ring 4D is inserted into the cylindrical nut 4B. The power supply terminal 4 C is prevented from coming off by being screwed into a peripheral female screw.
[0050]
In the case where the lead wire Lab for V connection used when the two transformers Ta and Tb are V-connected, the wire connector 4 (or 4 ') is connected to both ends of the wire 20, as shown in FIG. Connect.
[0051]
The rubber plug 21 is inserted into the electric wire insertion hole 404 of the electric wire connector to which the electric wire is not connected among the two electric wire connectors 4 and 4 ′ provided in the bushing, and charging inside the electric wire connector is performed. Keep the part hidden. In the example shown in FIG. 1, the electric wire 20 is connected to the electric wire connector 4 ′ attached to the second terminal portion Q, and the electric wire insertion hole 404 of the electric wire connector 4 attached to the first terminal portion P is inside. A rubber plug 21 is inserted in
[0052]
The transformer bushing 1 configured as described above is normally attached to the side wall of the transformer tank with its axis line obliquely downward and with the second terminal portion Q obliquely upward. The rear end portion (inner lead conductor 3C) of the central conductor 3 of the bushing is connected to the primary winding of the transformer body in the transformer tank.
[0053]
Assume that two transformers Ta and Tb are now installed, and the high-voltage bushings 1a1 and 1a2 provided in the transformer Ta and the high-voltage bushings 1b1 and 1b2 provided in the transformer Tb are shown in FIG. 1 is used. When two transformers Ta and Tb are installed side by side on a hanger attached to a power pole (hanger-mounted pole), a relatively large space is secured between the two transformers. As shown in A), there is a sufficient space between the adjacent bushings 1a2 and 1b1 of the two transformers Ta and Tb. If each bushing is attached obliquely downward, the central conductor 3 of each bushing The electric wire connector can be easily attached to and detached from the first terminal portion P (male screw portion 305) at the tip. Accordingly, for example, as shown in FIG. 15 (A), one end and the other end of the V-connection lead wire Lab are connected to the second terminal portion Q of the bushing 1a2 of the transformer Ta via the wire connectors 4 'and 4, respectively. By connecting to the first terminal P of the bushing 1b1 of the transformer Tb, the transformers Ta and Tb are V-connected, the second terminal Q of the bushing 1a1 of the transformer Ta, and the bushing 1b1 of the transformer Tb. The lower terminal of the high-voltage pull-down lines Lu, Lv and Lw connected to the high-voltage distribution line arranged above the transformer is connected to the second terminal part Q and the second terminal part Q of the bushing 1b2 of the transformer Tb, respectively. By connecting via the tool 4 ', it is possible to easily connect the high-voltage pull-down lines and the V-connection lead wires. When constructing a high-voltage distribution line, a bypass line should be easily connected to the first terminal portion P at the tip of the bushings 1a1, 1a2 and 1b2 facing diagonally downward via the wire connector 4, respectively. Can do.
[0054]
In the example of FIG. 15A, the V connection lead wire Lab is connected between the first terminal portion P of the bushing 1a2 and the second terminal portion Q of the bushing 1b1, and the second terminal of the bushing 1a2. Of course, the medium-phase high-voltage pull-down line Lv may be connected to the part Q.
[0055]
In addition, when the two transformers Ta and Tb are directly attached to the power pole (directly mounted), the distance between the two transformers cannot be widened. Since there is not enough space between the adjacent bushings 1a2 and 1b1, it may not be possible to easily attach and detach the wire connector to the first terminal portion P at the ends of the central conductors of the bushings 1a2 and 1b1. In such a case, if the intermediate phase bypass line (bypass line connected to the adjacent bushings of the two transformers) is connected to the first terminal portion of the bushing 1a2 or 1b1, the connection is established. Becomes difficult. Therefore, in this case, as shown in FIG. 15B, a lead wire Lab for V connection is connected between the first terminal portions P and P of the adjacent bushings 1a2 and 1b1 of the two transformers Ta and Tb. To do. When the bypass lines BLu to BLw are connected during the construction of the high-voltage distribution line, as shown in FIG. 16, the bypass lines BLu and BLw at both ends are respectively connected to the first bushing 1a1 of the transformer Ta. Are connected to the first terminal P of the bushing 1b2 of the transformer Tb, and the intermediate phase bypass line BLv is connected to the second terminal portion Q of the bushing 1a2 of the transformer Ta.
[0056]
The procedure for constructing the high-voltage distribution line is as shown in FIGS. 17 (A) to 17 (C). In this example, as in the example shown in FIG. 15 (A), two transformers Ta and Tb are provided with hangers, and the second terminal portion Q of the bushing 1a2 and the first terminal portion of the bushing 1b1 are provided. It is assumed that P is connected to P by a lead wire Lab for V connection, and high-voltage pull-down lines pulled down from the distribution lines U, V, and W to the second terminal portions Q of the bushings 1a1, 1b1, and 1b2, respectively. It is assumed that Lu, Lv, and Lw are connected via the wire connector 4 ′. When the replacement work of the distribution lines U to W and the replacement work of the cut-out switches Su to Sw are performed, the first terminal portions of the bushings 1a1, 1a2, and 1b2 as shown in FIG. The bypass lines BLu, BLv, and BLw connected to the healthy section of the high-voltage distribution line are connected to P through the wire connector 4. Next, as shown in FIG. 17 (C), the high voltage pull-down lines Lu to Lw are removed from the bushings of the transformer, and the high voltage distribution lines U to W are blacked out for construction.
[0057]
As described above, the male conductor 305 constituting the first terminal portion P is provided at the tip of the central conductor 3 of the transformer bushing 1, and the branch conductor 5 attached to the screw hole provided in the vicinity of the male screw portion. The second terminal portion Q is configured by providing a male screw portion 502 having the same diameter and the same pitch as the male screw portion 305 at the tip of the central conductor 3 at the tip of the central conductor 3, and the male screw portion 305 and the branch conductor of the central conductor. When the wire connector 4 having the same configuration is attached to the male screw portion 502 at the front end, either the first terminal portion P at the front end portion of the center conductor or the second terminal portion Q at the front end of the branch conductor is selected. In addition, since the electric wires can be connected in the same manner, the degree of freedom in connecting the electric wires to the transformer bushings can be increased, and various installation states of the transformer can be easily handled.
[0058]
In addition, since it is easy to connect the wire connector to the wire at the site, when wiring to the transformer, the actual transformer installation status (between the transformers) By adjusting the length of the high-voltage pull-down wire and the lead wire for V connection to the optimum value according to the distance, the distance between the bushing of the transformer and the distribution line, etc., Accurate wiring with no excess or shortness in length can be performed.
[0059]
In addition, when the two electric wire connectors 4 and 4 ′ that are compatible with the central conductor 3 as described above are configured to be mounted with different mounting directions, when two transformers are V-connected, Both the V-connection lead wire and the high-voltage pull-down wire can be connected easily and reliably, and when performing construction on the high-voltage distribution line, the bypass wire can be easily connected. The bypass line can be connected easily and safely without requiring skill by gripping the knob lever with the indirect hot wire working tool and operating the electric wire connector.
[0060]
Furthermore, if comprised as mentioned above, since what is necessary is just to manufacture one type of electric wire connector, the kind of components can be decreased and cost reduction can be aimed at.
[0061]
In the above description, the bushing according to the present invention is attached obliquely downward, but the attachment direction is arbitrary, and it can be attached horizontally or obliquely upward.
[0062]
【The invention's effect】
As described above, according to the present invention, the same male screw portion and the terminal insertion hole are provided at the tip portion of the central conductor of the bushing and the tip portion of the branch conductor attached to the center conductor, respectively, Since a compatible wire connector can be attached to the terminal insertion hole, the degree of freedom in connecting the wire to the bushing can be increased, and various installation modes of the transformer can be easily accommodated. .
[0063]
Further, according to the present invention, since the two electric wire connectors compatible with the central conductor are configured to be attached with their mounting directions being different from each other, when connecting two transformers to the V connection, the V connection Both the lead wire for high-voltage use and the high-voltage pull-down wire can be connected easily and reliably, and further, when performing construction on the high-voltage distribution line, the bypass wire can be easily connected. In this case, since each electric wire connector is provided with a knob lever, the bypass line can be connected in a live line state, and the construction for the distribution line can be performed without a power failure.
[0064]
Furthermore, according to the present invention, since the two electric wire connectors have compatibility, the number of parts can be reduced, and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an overall configuration of an embodiment of the present invention.
FIGS. 2A and 2B are a front view and a longitudinal sectional view of a main part of a main conductor used in the embodiment, respectively.
FIGS. 3A and 3B are a front view and a longitudinal sectional view of an auxiliary insulator used in the embodiment, respectively.
FIG. 4A is a front view of a guide fitting used for fixing the auxiliary insulator in the embodiment. (B) is the sectional view on the AA line of (A).
FIG. 5A is a front view of an auxiliary insulator fixing nut used in the embodiment. (B) is a BB line sectional view of (A).
6A and 6B are a front view and a top view, respectively, of a branch conductor used in the embodiment. (C) is CC sectional view taken on the line of (A).
FIG. 7 is a cross-sectional view for explaining a coupling structure between a main conductor and a branch conductor.
FIG. 8A is a side view showing a half part of a knob lever used in an embodiment of the present invention in cross section. (B) is a front view of the knob lever.
FIG. 9 is a front view showing a cross-section of a half of the cylindrical nut used in the embodiment.
FIG. 10 is a front view showing a cross section of a half portion of the power feeding terminal used in the embodiment.
FIG. 11A is a front view of a power feeding terminal retaining ring used in the embodiment. (B) is the DD sectional view taken on the line of (A).
FIG. 12 is a cross-sectional view for explaining the assembly structure of the wire connector used in the embodiment of the present invention.
FIGS. 13A, 13B, and 13C are cross-sectional views sequentially illustrating a procedure for connecting a wire to a wire connector.
FIG. 14 is a cross-sectional view showing the structure of a lead wire used when two transformers are V-connected.
FIG. 15A is an explanatory view showing a state in which two transformers mounted on a hanger are V-connected and a high-voltage pull-down line is connected to each transformer bushing. (B) is explanatory drawing which showed the state which connected the high voltage | pressure pull-down line | wire to each transformer bushing by V-connecting the two transformers mounted directly.
FIG. 16 is an explanatory diagram showing a state in which a bypass line is connected to each transformer bushing in the example of FIG. 15B.
17 (A), (B), and (C) are explanatory diagrams sequentially showing a procedure for disconnecting a high-voltage pull-down line by connecting a bypass line to a transformer bushing in the example of FIG. 15 (A). FIG.
FIG. 18 is an explanatory diagram showing a conventional connection method in the case where two transformers are V-connected and a high voltage pull-down line is connected to each bushing.
[Explanation of symbols]
1 Bushing for transformer
2 Insulator
2A main lion
2B Auxiliary insulator
3 Central conductor
3A Main conductor
3B Relay conductor
3C inner lead conductor
305 Male thread
306 Screw hole
307 Terminal insertion hole
307a Taper hole
4,4 'wire connector
4A Knob Eggplant
4B cylindrical nut
4C Power supply terminal
4D terminal ring for power supply
406 Screwless part
407 Terminal through hole
408 Terminal tightening step
5 Branch conductor
501 Screw part
502 Male thread
503 Terminal insertion hole
503a Taper hole

Claims

An insulator and a center conductor provided in a state of penetrating through the insulator and having a tip led out to the outside from the tip of the insulator, and a male screw portion is provided on the outer periphery of the tip of the center conductor In the bushing for a transformer in which a terminal insertion hole having a tapered hole portion is formed at the opening end portion in the axial core portion at the tip of the center conductor,
A screw hole extending in a direction orthogonal to the axial direction of the center conductor is provided in the vicinity of the male screw portion at the tip of the center conductor,
A screw portion at the rear end, a male screw portion having the same diameter and pitch as the male screw portion at the tip of the center conductor on the outer periphery of the tip, and a terminal insertion hole at the tip of the center conductor in the shaft core portion of the tip And a branch conductor having a terminal insertion hole of the same shape and the same size as that, and a screw portion of the rear end of the branch conductor is screwed into the screw hole of the center conductor
A nut mounting hole and a wire insertion hole formed in a smaller diameter than the nut mounting hole and sharing the axis with the nut mounting hole are provided inside, and the nut mounting hole and the wire insertion hole are respectively at one end side and the other end side. A nut that is open in the nut, a cylindrical nut that is fixed in the nut mounting hole with one end opened to one end of the knob, and a state in which one end faces the opening of the cylindrical nut And having a wire connecting portion and a collar portion for connecting the core wire of the electric wire on the other end side, and a tapered portion fitted in the tapered hole portion of the terminal insertion hole at the other end side. A round bar-shaped power supply terminal and a cylindrical nut are formed so as to surround the power supply terminal, and have a threaded portion on the outer peripheral portion, and the threaded portion is screwed to the female screw on the inner peripheral surface of the cylindrical nut. With the combined power supply terminal retaining ring A pair of wire connectors is provided, and one and the other cylindrical nuts of the pair of wire connectors are respectively screwed into the male screw portion at the tip of the center conductor and the male screw portion at the tip of the branch conductor. And the feeding terminals of the one and the other electric wire connectors are inserted into the terminal insertion hole of the central conductor and the terminal insertion hole of the branch conductor, respectively.
A terminal-less part that has no female screw formed on the inner periphery near the other end of the cylindrical nut of each wire connector, and passes through the other end of the power supply terminal to the other end of the cylindrical nut Holes are formed,
The terminal through hole is formed to have a smaller diameter than the inner diameter of the screwless portion, and a terminal tightening step portion is formed between the screwless portion and the terminal through hole so as to face the flange portion of the power feeding terminal.
When the cylindrical nut of each electric wire connector is screwed into the corresponding male screw portion and tightened, the terminal tightening step portion presses the collar portion of the electric power supply terminal of the electric wire connector to thereby press the electric power supply terminal. The axial dimension of the cylindrical nut of each wire connector is set so as to bias toward the terminal insertion hole side,
The power supply terminal retaining ring and the terminal tightening step so as to allow relative rotation to occur between the cylindrical nut and the power supply terminal in a state where the cylindrical nut of each wire connector is loosened. A bushing for a transformer, characterized in that the distance between the inner diameter and the inner diameter of the screwless portion is set.