JP4690559B2

JP4690559B2 - Insulated cylinder with expanded support cylinder

Info

Publication number: JP4690559B2
Application number: JP2001012620A
Authority: JP
Inventors: 大介武藤
Original assignee: THE FURUKAW ELECTRIC CO., LTD.
Current assignee: THE FURUKAW ELECTRIC CO., LTD.
Priority date: 2000-02-17
Filing date: 2001-01-22
Publication date: 2011-06-01
Anticipated expiration: 2021-01-22
Also published as: JP2001301030A

Description

【０００１】
【発明の属する技術分野】
本発明は電力ケーブルの接続に用いる拡径支持筒付絶縁筒体の改良に関するものである。
【０００２】
【従来の技術】
近年、電力ケーブルの中間接続等の施工性を向上させるために、図８に示すような拡径支持筒付絶縁筒体１が使用されつつある。この拡径支持筒付絶縁筒体１は、シリコーンゴムやＥＰゴム等の弾性体からなり、円筒体の両端をテーパ状に先細らせた常温収縮型の絶縁筒体（絶縁ゴムユニット）２を、ポリプロピレン等のプラスチック材料で作られた紐状体４をスパイラル円筒状に巻回して形成された拡径支持筒３で弾性的に拡径支持して構成されている。なお、拡径支持筒３の隣接する紐状体４同士は、図９に示すように、分離可能に周方向に沿って超音波または高周波等による加熱で、両側面相互が断続的にスポット溶着され、形状保持される。
【０００３】
このような構成の拡径支持筒付絶縁筒体１は下記のように使用する。即ち、図８に示すように、接続処理すべきケーブル心材Ａの外周の所定位置に拡径支持筒付絶縁筒体１を配置する。次に拡径支持筒付絶縁筒体１の拡径支持筒３を、その一方の端部３Ａから紐状体４を引き抜いて、拡径支持筒３の内側を通して他方の端部３Ｂ外方へ引き出すことにより、順次解体して撤去する。これに伴い、常温収縮型の絶縁筒体２を一方の端部２Ａ側から他方の端部２Ｂ側に向けて順次縮径させ、その自己収縮作用で前記ケーブル心材Ａに所定の面圧で密着固定して取り付ける。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記拡径支持筒付絶縁筒体１を６６ｋＶクラス以上の電力ケーブルの接続処理に使用する場合には、絶縁筒体２の絶縁厚が大きくなるため、絶縁筒体２を拡径支持する拡径支持筒３には絶縁筒体２の自己収縮作用に伴い、８０〜１２０ｋｇｆ／ｃｍ²という大きな円周応力が加わる。
【０００５】
このような場合、前記拡径支持筒付絶縁筒体１をケーブル心材Ａに挿入し、絶縁筒体２を縮径してケーブル心材Ａの外周面に密着固定する際、絶縁筒体２の縮径の最終段階において、長さの短くなった拡径支持筒３に応力が集中し、この部分が図１０に示すように一気に型くずれを起こし易い。
そうすると、絶縁筒体２の他方の端部２Ｂが急激に縮径し、拡径支持筒３から引き抜かれつつある紐状体４の残部がケーブル心材Ａと絶縁筒体２間に挟まれて、絶縁筒体２内に取り残され、ケーブル接続部の施工不良、電気的性能その他の品質低下の原因となる恐れがあった。
【０００６】
このような問題を解決するため、拡径支持筒３の厚さを増大して機械的強度を大きくすることも考えられる。
しかしながら、ケーブル接続部の補強絶縁体である絶縁筒体２の内径を大きく広げることになり（拡径率が上がり）、絶縁筒体２を構成するシリコーンゴム等の材料が永久伸びを起こす恐れがある。永久伸びが起こると、この絶縁筒体２をケーブル接続部で長期使用中に、所望の設計面圧を確保できなくなり、その電気的性能が低下するという問題があった。
【０００７】
また、拡径支持筒３の厚さを増大せず、該筒の長手方向全長にわたりその隣接する紐状体４同士を周方向に沿って連続して全周溶着することにより、機械的強度を大きくすることも考えられる。
しかしながら、全周溶着すると紐状体同士の溶着強度が強くなり過ぎて、拡径支持筒３を解体して撤去する際、紐状体の引き抜き作業が困難になる問題があった。更に、無理に紐状体同士を引き剥がすことになるので、引き剥がしの際、紐状体の屑（破材）が出やすい。しかも、この屑は拡径支持筒３の解体初期の段階から出る恐れがあるので、拡径支持筒３を解体して撤去を終了するまでの間に、該屑がケーブル接続作業時に内部に落下し、ケーブル心材Ａと絶縁筒体２間に閉じ込められて異物になり、接続部の絶縁性能を低下させる恐れがあった。
【０００８】
本発明は上記の課題を解決し、拡径支持筒付絶縁筒体における拡径支持筒の機械的強度を高めることにより、拡径支持筒付絶縁筒体をケーブル心材に挿入して絶縁筒体を縮径する際、拡径支持筒の絶縁筒体後端部を拡径支持する部分の型くずれを防止して、絶縁筒体のケーブル心材への取付けを容易にし、ケーブル接続部形成のための施工性と安定性を高めること、更に絶縁筒体の拡径率の上昇を抑え、絶縁筒体の永久伸びによる接触面圧の低下を防止し、その維持及び向上を図り、接続部の電気的性能を向上させることを可能にした拡径支持筒付絶縁筒体を提供するものである。
【０００９】
【課題を解決するための手段】
上記目的を達成するために、本発明の請求項１に記載された発明は、常温収縮型の絶縁筒体を拡径支持筒で拡径支持してなり、拡径支持筒は紐状体をスパイラル状に巻回して構成され、その一方の端部から紐状体を引き抜いて順次解体して撤去することにより、絶縁筒体が一方の端部から順次縮径される拡径支持筒付絶縁筒体において、前記拡径支持筒の他方の端部側であって、前記撤去の際に、筒形状のまま絶縁筒体の外方へスライド移動させて撤去する範囲を後部ゾーンとし、当該後部ゾーンの少なくとも前段部を、紐状体同士が容易に分離しないように強溶着したことを特徴とするものである。
【００１０】
このような構成によると、拡径支持筒付絶縁筒体をケーブル心材に挿入し、絶縁筒体を縮径してケーブル心材の外周面に密着固定する際、絶縁筒体の縮径の最終段階において、長さの短くなった拡径支持筒に応力が集中しても、その部分の拡径支持筒は隣接する紐状体同士が容易に分離しないように強溶着され、機械的に補強されているので、この部分が一気に型崩れを起こすことがない。このため、拡径支持筒から引き抜かれつつある紐状体の残部がケーブル心材と絶縁筒体間に挟まれて絶縁筒体内に取り残されることがなくなり、ケーブル接続部の施工が容易かつ確実となり、施工不良に起因する電気絶縁特性その他の品質低下を防止することができる。
【００１１】
また、拡径支持筒の厚さを増大する必要がないので、絶縁筒体の内径を広げる必要がなく、従って、絶縁筒体を構成する材料が永久伸びを起こすこともなく、ケーブル接続部で長期間使用しても、設計面圧を確保でき、電気的性能の低下を防止することができる。
【００１２】
さらに、拡径支持筒の大きさを変えることなく、拡径支持筒を機械的強度が大きくなるように補強するゾーンは、絶縁筒体の縮径が最終的に終了する後端部を拡径支持する後部ゾーンのみであるから、紐状体の引き抜き作業は従来の作業と殆ど同じで容易なほか、その作業時に紐状体の屑（破材）が出ることもないので、該屑が接続部内に異物として侵入することもなく、接続部の絶縁性能の低下を抑えることができる。
【００１３】
次に本発明の請求項２に記載された発明は、請求項１に記載された発明において、強溶着は、一方の短部から紐状体を引き抜いて拡径支持筒を解体するときに後部ゾーンの前段部で解体が停止するように、後部ゾーンの少なくとも前段部の紐状体同士を、該後部ゾーンを除く前、中間部のゾーンにおける紐状体同士の溶着状態に比較して、機械的強度が大きくなるように溶着した状態であることを特徴とするものである。
【００１４】
このような構成によると、絶縁筒体の後端部を拡径支持する拡径支持筒の後部ゾーンにおいて、実際に最も応力が集中する前段部が大きく補強されることになる。そして、紐状体を引き抜いて拡径支持筒の解体が進み、絶縁筒体の後端部を拡径支持する後部ゾーンの前段部に至って、長さの短くなった拡径支持筒に応力が集中する事態になっても、前記後部ゾーンの前段部で紐状体の引抜きが中断され、拡径支持筒の解体が停止するので、拡径支持筒が一気に型崩れを起こすことがなくなる。このような状態で、長さの短くなった拡径支持筒の後部ゾーンを、筒形状を保持したまま、絶縁筒体内を他方の端部側へスライド移動して撤去させる。
【００１５】
次に本発明の請求項３に記載された発明は、請求項１に記載された発明において、後部ゾーンの紐状体同士が周方向に沿って連続して全周溶着され、該後部ゾーンを除く前、中間部ゾーンにおける紐状体同士が周方向に沿って断続的にスポット溶着されていることを特徴とするものである。請求項３に記載された発明も請求項２に記載された発明と同等の効果を有する。更に、拡径支持筒の表面形状が強溶着しないものと殆ど変わらず平滑状態に保たれるので、絶縁筒体の内面を傷付ける恐れもなく、ケーブル接続部の電気特性を向上させるのにより有効である。
【００１６】
次に本発明の請求項４に記載された発明は、請求項１に記載された発明において、拡径支持筒の後部ゾーンの前段部が、後部ゾーンにおける紐状体の巻回が開始される始端部位又は紐状体が始端部位から１巻回するまでの任意周長分の範囲であることを特徴とするものである。このような箇所で、紐状体同士を強溶着することにより、請求項１に記載された発明の効果をより一層確実に得ることができ、好ましい。
【００１７】
【発明の実施の形態】
次に本発明の実施の形態を図１、２により詳細に説明する。本発明の拡径支持筒付絶縁筒体１０は、シリコーンゴムや、ＥＰゴム等の弾性体からなり、円筒体の両端をテーパ状に先細らせた常温収縮型の絶縁筒体１２を拡径支持筒１４で拡径支持して構成される。
拡径支持筒１４は、両側面に互いに逆向きのかぎ部（フック部）（図示せず）を有する長方形等の断面形状を有し、ポリプロピレン等のプラスチック材料で作られた紐状体１６をスパイラル円筒状に巻回しながら、隣接する紐状体１６の両側面に設けたかぎ部を互いに噛み合わせることにより形成される。
また、拡径支持筒１４の隣接する紐状体１６同士は分離可能に主に両側面近傍が周方向に沿って溶着されて形状保持されている。
そして、拡径支持筒１４を、その一方の端部１４Ａから紐状体１６を引き抜いて順次解体して撤去することにより、絶縁筒体１２が一方の端部１２Ａから順次縮径されるように構成されている。
【００１８】
次に、拡径支持筒１４を構成する紐状体１６の溶着方法について更に詳細に説明する。拡径支持筒１４が絶縁筒体１２を拡径支持するゾーンＸのうち、絶縁筒体１２の縮径が最終的に終了する後端部１２Ｂを拡径支持する後部ゾーンＹにおける紐状体１６同士がアイロン等で加熱され、周方向に沿って連続して全周溶着され、機械的強度が大きくなるよう補強される（図２（イ）参照）。
また、その後部ゾーンＹを除くゾーン、即ち、前、中間部ゾーンＺにおける紐状体１６同士が超音波または高周波等により加熱され、周方向に沿って断続的にスポット溶着される（図２（ロ）参照）。このゾーンＺにおける溶着方法は従来の溶着方法と同じであり、機械的な強度を大きくする補強が施されない。
【００１９】
前記拡径支持筒１４において、絶縁筒体１２を拡径支持しない先端ゾーンＰ及び末端ゾーンＱは、通常は周方向に沿って断続的にスポット溶着が施される。なお、末端ゾーンＱは溶着の施工性を考慮し、後部ゾーンＹに引き続いて全周溶着を施してもよい。更に、後部ゾーンＹは、最初から全周溶着するのではなく、施工性を考慮し、最初は断続的にスポット溶着を施しておき、その後、そのスポット溶着部分の上にアイロン、半田ごて等により、全周溶着を施すようにしてもよい。
【００２０】
このような構成の拡径支持筒付絶縁筒体１０は下記のように使用する。即ち、図３に示すように、接続処理すべきケーブル心材Ａの外周の所定位置にこの拡径支持筒付絶縁筒体１０を配置する。次に拡径支持筒付絶縁筒体１０の拡径支持筒１４を、その一方の端部１４Ａから紐状体１６を引き抜いて、拡径支持筒１４の内側を通して他方の端部１４Ｂ外方へ引き出すことにより、順次解体して撤去する。これに伴い、常温収縮型の絶縁筒体１２を一方の端部１２Ａ側から後端部（他方の端部）１２Ｂ側に向けて順次縮径させ、その自己収縮作用で前記ケーブル心材Ａに所定の面圧で密着固定して取り付けていく。
【００２１】
そして、拡径支持筒１４の解体が進み、前、中間部ゾーンＺを過ぎて、絶縁筒体１２の縮径の最終段階に相当する後部ゾーンＹまで解体されてくると、長さの短くなった拡径支持筒１４に応力が集中するが、その後部ゾーンＹは、拡径支持筒１４を構成する紐状体１６同士が全周溶着されて機械的強度が大きくなるように補強されているので、図４に示すように、この部分で拡径支持筒１４が一気に型崩れを起こすことがない。このため、拡径支持筒１４から引き抜かれつつある紐状体１６の残部がケーブル心材Ａと絶縁筒体１２間に挟まれて絶縁筒体内に取り残されることがなくなり、ケーブル接続部の施工が容易かつ確実となり、施工不良に起因する電気絶縁特性その他の品質低下を防止することができる。
【００２２】
次に、６６ｋＶ級電力ケーブル接続部に使用する拡径支持筒付絶縁筒体１０において、拡径支持筒１４の紐状体１６が全周溶着される後部ゾーンＹの距離Ｌと拡径支持筒１４の型崩れ（崩壊）有無の関係についての検討を行った。なお、前記距離Ｌは２０ｍｍ、３０ｍｍ、５０ｍｍの３種類、全周溶着の加熱手段は半田ごてとアイロンの２種類である。また、この拡径支持筒付絶縁筒体１０は、絶縁筒体１２を拡径支持筒１４で拡径支持した後、１週間放置し、その後、拡径支持筒１４を解体し、絶縁筒体１２を縮径することにより、後部ゾーンＹにおける拡径支持筒１４の型崩れ（崩壊）等の有無を調査したものである。
なお、該表で測定された距離長さは最も短い部分の長さを指し、該表の備考に記載された「抜けた」及び「抜けず」は、拡径支持筒１４が絶縁筒体１２の収縮力による縮径作用で、絶縁筒体１２から人の手を借りず自発的に「抜けてくる」及び「抜けてこない」ことを意味する。その結果は表１に示す通りである。
【００２３】
【表１】

【００２４】
この結果、後部ゾーンＹの距離Ｌが３０ｍｍ及び５０ｍｍの場合、拡径支持筒１４の型崩れは生じないが、補強し過ぎて、引き抜き力が大きくなり、屑発生の恐れがあること、加えて、拡径支持筒の解体が十分終了しないうちに、拡径支持筒が早期に絶縁筒体から抜けてしまい、ケーブル心材Ａと絶縁筒体１２間に紐状体１６や空気が閉じ込められ、絶縁特性を低下させる問題がある。そこで、６６ｋＶ級電力ケーブル接続部に使用する拡径支持筒の場合、前記距離Ｌの一例として、２０±５ｍｍ程度に設定するのが適切と考えられる。
更に、１１０ｋＶ級電力ケーブル接続部に使用する拡径支持筒についても同様の検討を行った結果、前記距離Ｌの一例として、５０±１０ｍｍ程度に設定するのが適切であると考えられる。
なお、後部ゾーンＹの表面上にオイルを塗布しておくとより施工が容易になる。
【００２５】
図５、６に示すものは、前記拡径支持筒１４とは構成の異なる拡径支持筒２０を用いた拡径支持筒付絶縁筒体１８の実施形態の例である。この絶縁筒体１８に用いる拡径支持筒２０は、両側面に互いに逆向きのかぎ部（フック部）（図示せず）を有する長方形等の断面形状を有し、ポリプロピレン等のプラスチック材料で作られた紐状体１６をスパイラル円筒状に巻回しながら、隣接する紐状体１６の両側面に設けたかぎ部を互いに噛み合わせることにより形成され、隣接する紐状体１６同士は主に両側面近傍が周方向に沿って溶着されて形状保持されている。そして、拡径支持筒２０を、その一方の端部２０Ａから紐状体１６を引き抜いて、拡径支持筒２０の内側を通して他方の端部２０Ｂ外方へ引き出し、順次撤去することにより、絶縁筒体１２が一方の端部１２Ａから他方の端部１２Ｂに向けて順次縮径されるように構成されている。
【００２６】
また、拡径支持筒２０では、拡径支持筒２０が絶縁筒体１２を拡径支持するゾーンＸのうち、絶縁筒体１２の縮径が最終的に終了する後端部１２Ｂを拡径支持する後部ゾーンＹの前段部２２における紐状体１６同士が、容易に分離しないように周方向に沿って超音波等により強く加熱され、強溶着される。図６（イ）では、その前段部２２が後部ゾーンＹにおける紐状体１６の巻回が開始される始端部位（１箇所）において、紐状体１６同士が容易に分離しないように強溶着される場合を示す。また、図６（ロ）では、その前段部２２が後部ゾーンＹにおける紐状体１６が始端部位から１巻回した１周長分の範囲において、紐状体１６同士が線状に、且つ、容易に分離しないように、例えば、超音波強溶着される場合を示す。なお、その前段部２２は、図示しないが、紐状体１６が始端部位から１巻回するまでの任意周長分の範囲、例えば、１／４周長分の範囲で、紐状体１６同士が線状に強溶着されるようにしてもよい。更に、後部ゾーンＹの前記前段部２２を除く部分（図６（イ）（ロ）参照）及び前、中間部ゾーンＺ（図６（ハ）参照）における紐状体１６同士が分離可能に周方向に沿って、超音波等により弱く加熱され、断続的にスポット溶着されるか、或いは弱溶着される。なお、前記拡径支持筒２０において、絶縁筒体１２を拡径支持しない先端ゾーンＰ及び末端ゾーンＱは、紐状体１６同士が分離可能に周方向に沿って断続的にスポット溶着され、或いは弱溶着される。
【００２７】
このような拡径支持筒付絶縁筒体１８を使用すると、紐状体１６の引抜きによる拡径支持筒２０の解体が進み、絶縁筒体１２が一方の端部１２Ａ側から順次縮径してケーブル心材Ａに密着固定されて行くが、図７に示すように、絶縁筒体１２の後端部１２Ｂを拡径支持する後部ゾーンＹの前段部２２に至って、長さの短くなった拡径支持筒２０に応力が集中する事態になっても、前記後部ゾーンＹの前段部２２で紐状体１６の引抜きが中断され、拡径支持筒２０の解体が停止するので、拡径支持筒２０が一気に型崩れを起こすことがなくなる。このような状態で、長さの短くなった拡径支持筒２０の後部ゾーンＹを、筒形状を保持したまま、絶縁筒体１２内を他方の端部１２Ｂ側へスライド移動し、絶縁筒体１２の外方へ撤去させる。
【００２８】
拡径支持筒２０を使用すると、前記拡径支持筒１４の場合と同様に、拡径支持筒２０から引き抜かれる紐状体１６の残部がケーブル心材Ａと絶縁筒体１２間に挟まれて絶縁筒体１２内に取り残されることがなくなり、ケーブル接続部の施工が容易かつ確実となり、施工不良に起因する電気絶縁特性その他の品質低下を防止することができる。更に、拡径支持筒２０の後部ゾーンＹの前段部２２だけを強溶着すればよいので、強溶着する箇所が短くて済み、補強作業が簡単になり、拡径支持筒付絶縁筒体１８の製造コストを低減させることができる。また、強溶着箇所が短くなるため、溶着強度のばらつきが減少して安定かつ向上し、拡径支持筒付絶縁筒体１８の品質管理が容易になる等の効果を奏するので有効である。
【００２９】
紐状体１６の引抜きによる拡径支持筒２０の解体が進み、絶縁筒体１２の後端部１２Ｂを拡径支持する後部ゾーンＹの前段部２２に至って、紐状体１６の引抜きが中断され、拡径支持筒２０の解体が停止した後、拡径支持筒２０の後部ゾーンＹを、筒形状が保持したまま、絶縁筒体１２内を他方の端部１２Ｂ側へスライド移動させ、絶縁筒体１２の外方へ撤去させるが、この際、後部ゾーンＹの距離Ｌが長過ぎると、拡径支持筒２０をスライド移動させるのに支障を来たす恐れがある。そこで、この拡径支持筒付絶縁筒体１８を接続部に用いる電力ケーブルの電圧階級（ｋＶ）毎に、拡径支持筒２０の距離Ｌ（ｍｍ）の限界長の一例を実験により求めた。その結果を表２に示す。
【００３０】
【表２】

【００３１】
拡径支持筒２０をスライド移動させ得る距離Ｌの限界長は、上記表２から分かるように、拡径電力ケーブルの電圧階級によって異なる。更に、該距離Ｌは導体サイズや拡径率によっても異なるので、使用電圧階級、導体サイズ及び拡径率に適応した拡径支持筒２０の付いた拡径支持筒付絶縁筒体１８を用いることが望ましい。また、拡径支持筒２０の後部ゾーンＹの表面又は絶縁筒体１２の内面に予めオイルを塗布しておくと、その後部ゾーンＹを、筒形状を保持したままスライド移動させて撤去させることが容易になり、施工性を高めるのに有効である。
【００３２】
【発明の効果】
以上のように、本発明の請求項１に記載された発明によると、常温収縮型の絶縁筒体を拡径支持筒で拡径支持してなり、拡径支持筒は紐状体をスパイラル状に巻回して構成され、その一方の端部から紐状体を引き抜いて順次解体して撤去することにより、絶縁筒体が一方の端部から順次縮径される拡径支持筒付絶縁筒体において、前記拡径支持筒の他方の端部側であって、前記撤去の際に、筒形状のまま絶縁筒体の外方へスライド移動させて撤去する範囲を後部ゾーンとし、当該後部ゾーンの少なくとも前段部を、紐状体同士が容易に分離しないように強溶着しているので、絶縁筒体の縮径が最終段階を至っても、拡径支持筒の後部ゾーンが一気に型崩れを起こすことがない。
このため、拡径支持筒から引き抜かれつつある紐状体の残部がケーブル心材と絶縁筒体間に挟まれて絶縁筒体内に取り残されることがなくなり、ケーブル接続部の施工が容易かつ確実となり、施工不良に起因する電気絶縁特性その他の品質低下を防止することができる。
【００３３】
また、拡径支持筒の厚さを増大する必要がないので、絶縁筒体の内径を広げる必要がなく、従って、絶縁筒体を構成する材料が永久伸びを起こすこともなく、ケーブル接続部で長期間使用しても、設計面圧を確保でき、電気的性能の低下を防止することができる。
【００３４】
さらに、拡径支持筒の大きさを変えることなく、拡径支持筒を機械的に補強するゾーンは、絶縁筒体の縮径が最終的に終了する後端部を拡径支持する後部ゾーンのみであるから、紐状体の引き抜き作業は従来の作業と殆ど同じで容易なほか、その作業時に紐状体の屑（破材）が出ることもないので、該屑が接続部内に異物として侵入することもなく、接続部の絶縁性能の低下を抑えることができる。
【００３５】
次に本発明の請求項２に記載された発明によると、常温収縮型の絶縁筒体を拡径支持筒で拡径支持してなり、拡径支持筒は紐状体をスパイラル状に巻回して構成され、その一方の端部から紐状体を引き抜いて順次撤去することにより、絶縁筒体が一方の端部から順次縮径される拡径支持筒付絶縁筒体において、強溶着は、一方の短部から紐状体を引き抜いて拡径支持筒を解体するときに後部ゾーンの前段部で解体が停止するように、後部ゾーンの少なくとも前段部の紐状体同士を、該後部ゾーンを除く前、中間部のゾーンにおける紐状体同士の溶着状態に比較して、機械的強度が大きくなるように溶着した状態であるので、請求項１に記載された発明と同等の効果を得ることができるほか、補強作業が簡単になり、拡径支持筒付絶縁筒体の製造コストを低減させることができる。
【００３６】
次に本発明の請求項３に記載された発明は、請求項１に記載された発明において、後部ゾーンの紐状体同士が周方向に沿って連続して全周溶着され、該後部ゾーンを除く前、中間部ゾーンにおける紐状体同士が周方向に沿って断続的にスポット溶着されているので、請求項１に記載された発明と同等の効果を得ることができるほか、拡径支持筒の表面形状が強溶着しないものと殆ど変わらず平滑状態に保たれるので、絶縁筒体の内面を傷付ける恐れもなく、ケーブル接続部の電気特性を向上させるのにより有効である。
【００３７】
次に本発明の請求項４に記載された発明によると、請求項１に記載された発明において、拡径支持筒の後部ゾーンの前段部が、後部ゾーンにおける紐状体の巻回が開始される始端部位又は紐状体が始端部位から１巻回するまでの任意周長分の範囲であるので、紐状体同士を強溶着する個所が短くて済み、請求項１に記載された発明の効果をより一層確実に得ることができる。
【図面の簡単な説明】
【図１】本発明の拡径支持筒付絶縁筒体を示す概要図である。
【図２】上記拡径支持筒付絶縁筒体において、拡径支持筒を構成する紐状体同士の溶着状態を示す説明図で、（イ）は後部ゾーンの溶着状態の図、（ロ）は前、中間部ゾーンの溶着状態の図である。
【図３】上記拡径支持筒付絶縁筒体をケーブル接続に適用する場合を示す概要図である。
【図４】上記拡径支持筒付絶縁筒体において、絶縁筒体の縮径の最終段階における拡径支持筒の解体状態を示す説明図である。
【図５】本発明の他の実施形態を示す概要図である。
【図６】図５の拡径支持筒付絶縁筒体において、拡径支持筒を構成する紐状体同士の溶着状態を示す説明図で、（イ）（ロ）は後部ゾーンの前段部の異なる２例の溶着状態の図、（ハ）は前、中間部ゾーンの溶着状態の図である。
【図７】図５の拡径支持筒付絶縁筒体において、拡径支持筒の解体がその後部ゾーンの前段部に至った場合の状態を示す説明図である。
【図８】従来の拡径支持筒付絶縁筒体をケーブル接続に適用する状態を示す概要図である。
【図９】従来の拡径支持筒付絶縁筒体において、拡径支持筒を構成する紐状体同士の溶着状態を示す説明図である。
【図１０】従来の拡径支持筒付絶縁筒体において、絶縁筒体の縮径の最終段階における拡径支持筒の解体状態を示す説明図である。
【符号の説明】
１０、１８拡径支持筒付絶縁筒体
１２絶縁筒体
１２Ａ一方の端部
１２Ｂ後端部
１４、２０拡径支持筒
１４Ａ、２０Ａ一方の端部
１４Ｂ、２０Ｂ他方の端部
１６紐状体
２２前段部
Ａケーブル心材
Ｘゾーン
Ｙ後部ゾーン
Ｚ前、中間部ゾーン
Ｐ先端ゾーン
Ｑ末端ゾーン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of an insulating cylinder with an enlarged diameter support cylinder used for connecting a power cable.
[0002]
[Prior art]
In recent years, in order to improve workability such as intermediate connection of power cables, an insulating cylinder 1 with a diameter-enlarged support cylinder as shown in FIG. 8 is being used. This insulating cylinder 1 with an expanded support cylinder is made of an elastic body such as silicone rubber or EP rubber, and includes a normal temperature shrinkable insulating cylinder (insulating rubber unit) 2 in which both ends of the cylindrical body are tapered. The string-like body 4 made of a plastic material such as polypropylene is elastically expanded and supported by a diameter-enlarged support cylinder 3 formed by winding the string-like body 4 into a spiral cylinder. In addition, as shown in FIG. 9, the adjacent string-like bodies 4 of the diameter-enlarged support cylinder 3 are spot welded to each other intermittently by heating with ultrasonic waves or high-frequency waves along the circumferential direction so as to be separable. And the shape is maintained.
[0003]
The insulating cylinder 1 with a diameter-enlarged support cylinder having such a configuration is used as follows. That is, as shown in FIG. 8, the insulating cylinder 1 with a diameter-enlarged support cylinder is disposed at a predetermined position on the outer periphery of the cable core A to be connected. Next, the diameter-enlarged support cylinder 3 of the insulating cylinder 1 with the diameter-enlarged support cylinder is pulled out from one end 3A of the diameter-enlarged support cylinder 3, and the outside of the other end 3B is passed through the inside of the diameter-enlarged support cylinder 3. By pulling it out, it is dismantled and removed. Along with this, the normal temperature shrinkable insulating cylinder 2 is gradually reduced in diameter from one end 2A side to the other end 2B side, and the self-shrinking action causes the cable core material A to adhere to the cable core A with a predetermined surface pressure. Secure and attach.
[0004]
[Problems to be solved by the invention]
However, when the insulating cylinder 1 with an expanded support cylinder is used for connecting a power cable of 66 kV class or higher, the insulation thickness of the insulating cylinder 2 is increased, so that the insulating cylinder 2 is expanded and supported. A large circumferential stress of 80 to 120 kgf / cm ² is applied to the diameter-enlarged support cylinder 3 along with the self-contraction action of the insulating cylinder 2.
[0005]
In such a case, when the insulating cylinder 1 with the expanded support cylinder is inserted into the cable core A, the diameter of the insulating cylinder 2 is reduced, and the insulation cylinder 2 is contracted and fixed to the outer peripheral surface of the cable core A. At the final stage of the diameter, stress concentrates on the diameter-expanded support cylinder 3 whose length is shortened, and this portion is likely to be deformed at once as shown in FIG.
Then, the other end 2B of the insulating cylindrical body 2 is suddenly reduced in diameter, and the remaining portion of the string-like body 4 being pulled out from the expanded diameter supporting cylinder 3 is sandwiched between the cable core material A and the insulating cylindrical body 2, There was a risk that it would be left behind in the insulating cylinder 2 and cause poor construction of the cable connection part, electrical performance and other quality deterioration.
[0006]
In order to solve such a problem, it is conceivable to increase the thickness of the diameter-enlarged support cylinder 3 to increase the mechanical strength.
However, the inner diameter of the insulating cylinder 2 that is the reinforcing insulator of the cable connection portion is greatly expanded (the diameter expansion rate is increased), and there is a possibility that the material such as silicone rubber constituting the insulating cylinder 2 may cause permanent elongation. is there. When permanent elongation occurs, there is a problem in that the desired design surface pressure cannot be secured during long-term use of the insulating cylinder 2 at the cable connection portion, and its electrical performance is lowered.
[0007]
Further, the mechanical strength is increased by continuously welding the adjacent string-like bodies 4 along the circumferential direction over the entire length in the longitudinal direction without increasing the thickness of the diameter-enlarged support cylinder 3. It is possible to enlarge it.
However, if the entire circumference is welded, the welding strength between the string-like bodies becomes too strong, and there is a problem that when the diameter-enlarged support tube 3 is disassembled and removed, the drawing work of the string-like bodies becomes difficult. Furthermore, since the string-like bodies are forcibly separated from each other, scraps (broken material) of the string-like bodies are likely to be generated at the time of peeling. In addition, since there is a risk that this scrap will come out from the initial stage of disassembly of the diameter-enlarged support cylinder 3, the scrap falls to the inside during cable connection work until the diameter-enlarged support cylinder 3 is disassembled and removal is completed. However, it is trapped between the cable core A and the insulating cylinder 2 and becomes a foreign substance, which may deteriorate the insulation performance of the connection portion.
[0008]
The present invention solves the above-described problems and increases the mechanical strength of the diameter-enlarged support cylinder in the insulated cylinder with the diameter-enlarged support cylinder, thereby inserting the insulated cylinder with the diameter-enlarged support cylinder into the cable core material and insulating cylinder When reducing the diameter, the rear end portion of the insulating cylinder body of the diameter-enlarging support cylinder is prevented from being deformed to facilitate the mounting of the insulating cylinder body to the cable core material, and to form the cable connection part. Improve the workability and stability, further suppress the increase in the expansion ratio of the insulating cylinder, prevent the contact surface pressure from decreasing due to the permanent elongation of the insulating cylinder, and maintain and improve it. It is an object of the present invention to provide an insulating cylinder with a diameter-enlarged support cylinder that can improve the performance.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention described in claim 1 of the present invention comprises a room-temperature-shrinkable insulating cylinder that is expanded and supported by an expanded-diameter support cylinder, and the expanded-diameter support cylinder has a string-like body. Insulated with a diameter-enhanced support cylinder that is constructed by winding in a spiral shape, and pulling out the string-like body from one end, sequentially disassembling and removing it, so that the insulating cylinder is sequentially reduced in diameter from one end In the cylindrical body, on the other end side of the diameter-enlarged support cylinder, a range in which the cylindrical body is slid to the outside of the insulating cylindrical body and removed during the removal is a rear zone, and the rear part It is characterized in that at least the front part of the zone is strongly welded so that the string-like bodies are not easily separated from each other .
[0010]
According to such a configuration, when the insulating cylinder with the diameter-enlarged support cylinder is inserted into the cable core, the diameter of the insulating cylinder is reduced, and the final stage of the diameter reduction of the insulating cylinder is fixed to the outer peripheral surface of the cable core. In this case, even if stress is concentrated on the diameter-expanded support cylinder whose length is shortened, the diameter-expanded support cylinder in that portion is strongly welded and mechanically reinforced so that adjacent string-like bodies are not easily separated from each other. So, this part will not lose shape at once. For this reason, the remaining part of the string-like body that is being pulled out from the diameter-enhanced support cylinder is not sandwiched between the cable core material and the insulating cylinder, and is not left in the insulating cylinder, making the construction of the cable connection portion easy and reliable, It is possible to prevent electrical insulation characteristics and other quality deterioration due to poor construction.
[0011]
In addition, since it is not necessary to increase the thickness of the expanded diameter support cylinder, there is no need to increase the inner diameter of the insulating cylinder, and therefore, the material constituting the insulating cylinder does not cause permanent elongation. Even if it is used for a long period of time, the design surface pressure can be secured, and the deterioration of the electrical performance can be prevented.
[0012]
Furthermore, the zone that reinforces the expanded support cylinder so as to increase the mechanical strength without changing the size of the expanded support cylinder expands the rear end where the diameter reduction of the insulating cylinder finally ends. Since there is only the rear zone to support, the pulling out of the string-like body is almost the same as the conventional work, and it is easy to connect. The deterioration of the insulation performance of the connecting portion can be suppressed without entering the portion as a foreign substance.
[0013]
Next, in the invention described in claim 2 of the present invention, in the invention described in claim 1, the strong welding is performed by pulling the string-like body from one short part and disassembling the diameter-enlarged support cylinder. Compare the string-like bodies in at least the front stage of the rear zone to the welded state of the string-like bodies in the middle zone before removing the rear zone so that disassembly stops at the front stage of the zone. is to shall and wherein the strength is in a state of being welded to be larger.
[0014]
According to such a configuration, in the rear zone of the diameter expansion support cylinder that expands and supports the rear end portion of the insulating cylinder, the front stage portion where the stress is actually concentrated is greatly reinforced. Then, the string-shaped body is pulled out and the dismantling of the diameter-enhanced support cylinder proceeds, reaching the front stage part of the rear zone that supports the diameter-expanding of the rear end of the insulating cylinder, and stress is applied to the diameter-expanded support cylinder shortened. Even if the situation becomes concentrated, the drawing of the string-like body is interrupted at the front part of the rear zone, and the disassembly of the diameter-enlarged support cylinder stops, so that the diameter-enlarged support cylinder does not lose its shape at once. In such a state, the rear zone of the diameter-expanded support cylinder whose length is shortened is slid to the other end side while being retained in the cylindrical shape, and removed.
[0015]
Next, the invention described in claim 3 of the present invention is the invention described in claim 1, wherein the string-like bodies in the rear zone are continuously welded along the circumferential direction, and the rear zone is Before removal, the string-like bodies in the intermediate zone are intermittently spot-welded along the circumferential direction. The invention described in claim 3 has the same effect as the invention described in claim 2 . Further, since the surface shape of the enlarged diameter support tube is kept almost unchanged smooth state shall not be strongly welded, without risk of damaging the inner surface of the insulating cylinder, effective in improving the electrical characteristics of the cable connection It is.
[0016]
Next, in the invention described in claim 4 of the present invention, in the invention described in claim 1 , winding of the string-like body in the rear zone starts at the front stage of the rear zone of the diameter-enlarged support cylinder. The starting end portion or the string-like body is in a range corresponding to an arbitrary circumferential length until one turn from the starting end portion. By strongly welding the string-like bodies at such locations, the effect of the invention described in claim 1 can be obtained more reliably, which is preferable.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described in detail with reference to FIGS. An insulating cylinder 10 with an expanded support cylinder of the present invention is made of an elastic body such as silicone rubber or EP rubber, and expands the diameter of a cold-shrinkable insulating cylinder 12 having both ends of the cylindrical body tapered. The support cylinder 14 is configured to be expanded in diameter.
The expanded diameter support cylinder 14 has a cross-sectional shape such as a rectangle having hook portions (not shown) opposite to each other on both side surfaces, and a string-like body 16 made of a plastic material such as polypropylene. It is formed by engaging the hook portions provided on both side surfaces of the adjacent string-like body 16 while winding in a spiral cylindrical shape.
Further, adjacent string-like bodies 16 of the diameter-enlarged support cylinder 14 are separable mainly in the vicinity of both side surfaces and are held in shape along the circumferential direction.
Then, by pulling out the string-like body 16 from one end portion 14A and sequentially disassembling and removing the diameter-enlarged support tube 14, the insulating cylinder body 12 is successively reduced in diameter from the one end portion 12A. It is configured.
[0018]
Next, the welding method of the string-like body 16 constituting the diameter expansion support cylinder 14 will be described in more detail. Of the zone X in which the diameter expansion support cylinder 14 supports the insulation cylinder body 12 to expand the diameter, the string-like body 16 in the rear zone Y that supports the diameter expansion of the rear end portion 12B where the diameter reduction of the insulation cylinder body 12 finally ends. They are heated with an iron or the like, continuously welded along the circumferential direction, and reinforced so as to increase the mechanical strength (see FIG. 2 (A)).
Further, the cords 16 in the zones excluding the rear zone Y, that is, the front and intermediate zones Z, are heated by ultrasonic waves or high-frequency waves and are intermittently spot-welded along the circumferential direction (FIG. 2 ( (See b)). The welding method in the zone Z is the same as the conventional welding method, and no reinforcement is given to increase the mechanical strength.
[0019]
In the diameter-expanded support cylinder 14, the front end zone P and the end zone Q that do not support the diameter expansion of the insulating cylinder 12 are usually spot-welded intermittently along the circumferential direction. The end zone Q may be welded all around the rear zone Y in consideration of welding workability. In addition, the rear zone Y is not welded all around from the beginning, but in consideration of workability, first, spot welding is performed intermittently, and then the iron, soldering iron, etc. on the spot welding part. Thus, all-around welding may be performed.
[0020]
The insulating cylinder 10 with the enlarged diameter support cylinder having such a configuration is used as follows. That is, as shown in FIG. 3, the insulating cylinder 10 with the expanded diameter support cylinder is disposed at a predetermined position on the outer periphery of the cable core A to be connected. Next, the string-like body 16 is pulled out from one end 14A of the diameter-enlarged support cylinder 14 of the insulating cylinder 10 with the diameter-enlarged support cylinder, and the other end 14B outwards through the inside of the diameter-enlarged support cylinder 14. By pulling it out, it is dismantled and removed. Accordingly, the normal temperature shrinkable insulating cylindrical body 12 is sequentially reduced in diameter from the one end portion 12A side toward the rear end portion (the other end portion) 12B side, and the cable core material A is predetermined by the self-shrinking action. It is fixed with close contact pressure.
[0021]
Then, when the dismantling of the diameter-enlarging support cylinder 14 progresses and the dismantling is performed to the rear zone Y corresponding to the final stage of the diameter reduction of the insulating cylinder 12 past the front and intermediate zones Z, the length is shortened. Although the stress concentrates on the expanded diameter support cylinder 14, the rear zone Y is reinforced so that the string-like bodies 16 constituting the expanded diameter support cylinder 14 are welded all around to increase the mechanical strength. Therefore, as shown in FIG. 4, the diameter-enlarged support cylinder 14 does not collapse at a stretch in this portion. For this reason, the remaining part of the string-like body 16 being pulled out from the diameter-enlarged support cylinder 14 is not sandwiched between the cable core A and the insulation cylinder 12 and left in the insulation cylinder, and the cable connection part can be easily constructed. And it becomes reliable and it can prevent the electrical insulation characteristic and other quality degradation resulting from the construction defect.
[0022]
Next, in the insulating cylinder 10 with a diameter expansion support cylinder used for the 66 kV class power cable connecting portion, the distance L of the rear zone Y where the string-like body 16 of the diameter expansion support cylinder 14 is welded all around and the diameter expansion support cylinder. The relationship between the presence or absence of 14 types of collapse (collapse) was examined. The distance L includes three types of 20 mm, 30 mm, and 50 mm, and there are two types of heating means for all-around welding: a soldering iron and an iron. Further, the insulating cylinder 10 with the expanded diameter support cylinder is supported by the expanded diameter support cylinder 14 to expand the diameter of the insulating cylinder 12, and is left for one week, after which the expanded diameter support cylinder 14 is disassembled and the insulated cylinder body. The diameter of the expanded support cylinder 14 in the rear zone Y is examined for the presence or absence of deformation (collapse).
Note that the distance length measured in the table indicates the length of the shortest portion, and “disengaged” and “not detached” described in the remarks of the table indicate that the diameter expansion support cylinder 14 is the insulating cylinder 12. This means that the diameter is reduced by the contraction force, and it means that the insulation cylinder 12 “gets out” and “does not come out” spontaneously without the help of a person. The results are as shown in Table 1.
[0023]
[Table 1]

[0024]
As a result, when the distance L of the rear zone Y is 30 mm and 50 mm, the diameter-enlarged support cylinder 14 is not deformed, but it is reinforced too much, and the pulling force becomes large, and there is a risk of generating waste. Before the dismantling of the diameter-enlarged support cylinder is sufficiently completed, the diameter-enlarged support cylinder is quickly removed from the insulating cylinder, and the cable-like material 16 and air are trapped between the cable core material A and the insulating cylinder 12 to insulate. There is a problem of deteriorating characteristics. Therefore, in the case of the diameter expansion support cylinder used for the 66 kV class power cable connection portion, it is considered appropriate to set the distance L as an example of about 20 ± 5 mm.
Furthermore, as a result of conducting the same investigation on the diameter-enlarged support cylinder used for the 110 kV class power cable connection portion, it is considered appropriate to set the diameter L as about 50 ± 10 mm as an example of the distance L.
If oil is applied on the surface of the rear zone Y, the construction becomes easier.
[0025]
5 and 6 are examples of an embodiment of an insulating cylinder 18 with a diameter-enlarged support cylinder using a diameter-enlarged support cylinder 20 having a configuration different from that of the diameter-enlarged support cylinder 14. The diameter-enlarged support cylinder 20 used for the insulating cylinder 18 has a cross-sectional shape such as a rectangle having hook parts (not shown) opposite to each other on both side surfaces, and is made of a plastic material such as polypropylene. It is formed by engaging the hooks provided on both side surfaces of adjacent string-like bodies 16 while winding the formed string-like bodies 16 in a spiral cylindrical shape, and the adjacent string-like bodies 16 are mainly near both side surfaces. Are welded along the circumferential direction to maintain the shape. Then, by pulling out the string-like body 16 from one end portion 20A of the diameter-enlarged support cylinder 20, pulling it out of the other end section 20B through the inside of the diameter-enlarged support cylinder 20, and sequentially removing it, the insulating cylinder The body 12 is configured such that its diameter is sequentially reduced from one end 12A to the other end 12B.
[0026]
Further, in the diameter-enlarged support cylinder 20, in the zone X in which the diameter-enlarged support cylinder 20 expands and supports the insulating cylinder 12, the rear end portion 12 </ b> B where the diameter reduction of the insulating cylinder 12 finally ends is expanded-supported. The string-like bodies 16 in the front stage portion 22 of the rear zone Y to be heated are strongly heated by ultrasonic waves or the like along the circumferential direction so as not to be easily separated and strongly welded. In FIG. 6 (a), the front stage portion 22 is strongly welded so that the string-like bodies 16 are not easily separated from each other at the start end portion (one place) where the winding of the string-like body 16 in the rear zone Y is started. Shows the case. Moreover, in FIG. 6 (b), the string-like bodies 16 are linear in the range of one circumference in which the front-stage portion 22 of the string-like body 16 in the rear zone Y is wound once from the start end portion, and In order not to easily separate, for example, a case where ultrasonic welding is performed is shown. In addition, although the front stage part 22 is not illustrated, the string-like bodies 16 are in a range for an arbitrary circumferential length until the string-like body 16 is wound once from the starting end portion, for example, a quarter circumference length. May be strongly welded linearly. Further, the portion of the rear zone Y excluding the front stage portion 22 (see FIGS. 6 (A) and 6 (B)) and the front and intermediate zone Z (see FIG. 6C) can be separated from each other so as to be separable. Along the direction, it is weakly heated by ultrasonic waves or the like, and intermittently spot welded or weakly welded. In the diameter expansion support cylinder 20, the tip zone P and the end zone Q that do not support the diameter expansion of the insulating cylinder 12 are intermittently spot welded along the circumferential direction so that the string-like bodies 16 can be separated from each other, or Welded weakly.
[0027]
When such an insulating cylindrical body 18 with an enlarged diameter supporting cylinder is used, the diameter-enlarging supporting cylinder 20 is disassembled by pulling out the string-like body 16, and the insulating cylindrical body 12 is gradually reduced in diameter from the one end 12A side. As shown in FIG. 7, the cable core material A is tightly fixed, and reaches the front stage portion 22 of the rear zone Y that supports the rear end portion 12 </ b> B of the insulating cylinder 12 to expand the diameter, and the diameter is increased. Even when stress is concentrated on the support cylinder 20, the drawing of the string-like body 16 is interrupted at the front stage 22 of the rear zone Y, and the disassembly of the diameter expansion support cylinder 20 is stopped. No longer loses its shape. In such a state, the rear zone Y of the diameter-expanded support cylinder 20 whose length is shortened is slid and moved in the insulating cylinder 12 toward the other end 12B while maintaining the cylindrical shape, and the insulating cylinder Remove to the outside of twelve.
[0028]
When the diameter-enlarged support cylinder 20 is used, the remainder of the string-like body 16 pulled out from the diameter-enlarged support cylinder 20 is sandwiched between the cable core A and the insulation cylinder 12 in the same manner as in the case of the diameter-enlarged support cylinder 14. It is no longer left in the cylinder 12, and the construction of the cable connecting portion is easy and reliable, and the electrical insulation characteristics and other quality deterioration due to the construction failure can be prevented. Furthermore, since only the front stage portion 22 of the rear zone Y of the diameter-enlarged support cylinder 20 needs to be strongly welded, the portion to be strongly welded can be shortened, and the reinforcement work can be simplified. Manufacturing cost can be reduced. Further, since the strong welding location is shortened, the variation in the welding strength is reduced and stable and improved, and the quality control of the insulating cylindrical body 18 with the expanded support cylinder is facilitated, which is effective.
[0029]
The dismantling of the diameter-enhanced support cylinder 20 proceeds by pulling out the string-like body 16, reaches the front stage portion 22 of the rear zone Y that supports the rear end portion 12 </ b> B of the insulating cylinder 12 in an enlarged diameter, and the withdrawal of the string-like body 16 is interrupted. After the disassembly of the diameter-enlarged support cylinder 20 is stopped, the rear zone Y of the diameter-enlarged support cylinder 20 is slid and moved in the insulating cylinder 12 toward the other end 12B while the cylinder shape is maintained. The body 12 is removed to the outside. At this time, if the distance L of the rear zone Y is too long, there is a risk of hindering the sliding movement of the enlarged diameter support cylinder 20. Therefore, an example of the limit length of the distance L (mm) of the diameter-enlarged support cylinder 20 was obtained by experiments for each voltage class (kV) of the power cable using the insulating cylinder 18 with the diameter-enlarged support cylinder as a connection portion. The results are shown in Table 2.
[0030]
[Table 2]

[0031]
As can be seen from Table 2 above, the limit length of the distance L at which the diameter expansion support cylinder 20 can be slid and moved varies depending on the voltage class of the diameter expansion power cable. Further, since the distance L varies depending on the conductor size and the diameter expansion ratio, the insulating cylinder 18 with the diameter expansion support cylinder with the diameter expansion support cylinder 20 adapted to the working voltage class, the conductor size and the diameter expansion ratio should be used. Is desirable. In addition, when oil is applied in advance to the surface of the rear zone Y of the diameter-enlarged support cylinder 20 or the inner surface of the insulating cylinder 12, the rear zone Y can be slid and removed while maintaining the cylindrical shape. It becomes easy and is effective in improving workability.
[0032]
【The invention's effect】
As described above, according to the invention described in claim 1 of the present invention, the cold-shrinkable insulating cylinder is supported by the diameter-enlarging support cylinder to expand, and the diameter-enlarging support cylinder spirals the string-like body. An insulating cylinder with a diameter-enlarging support cylinder that is configured to be wound around the one end, and the insulating cylinder is sequentially reduced in diameter from one end by pulling out the string-like body from one end and sequentially disassembling and removing it. In this case, the range of the other end side of the diameter-enlarged support cylinder, which is slid and moved to the outside of the insulating cylinder while being removed in the removal state, is defined as a rear zone. Since at least the front part is strongly welded so that the string-like bodies do not easily separate from each other , even if the diameter of the insulating cylinder reaches the final stage, the rear zone of the diameter-enhanced support cylinder will suddenly collapse. There is no.
For this reason, the remaining part of the string-like body that is being pulled out from the diameter-enhanced support cylinder is not sandwiched between the cable core material and the insulating cylinder, and is not left in the insulating cylinder, making the construction of the cable connection portion easy and reliable, It is possible to prevent electrical insulation characteristics and other quality deterioration due to poor construction.
[0033]
In addition, since it is not necessary to increase the thickness of the expanded diameter support cylinder, there is no need to increase the inner diameter of the insulating cylinder, and therefore, the material constituting the insulating cylinder does not cause permanent elongation. Even if it is used for a long period of time, the design surface pressure can be secured, and the deterioration of the electrical performance can be prevented.
[0034]
Furthermore, the zone that mechanically reinforces the diameter expansion support cylinder without changing the size of the diameter expansion support cylinder is the only rear zone that supports the diameter expansion of the rear end where the diameter reduction of the insulating cylinder finally ends. Therefore, the string-like body pull-out work is almost the same as the conventional work and easy, and since the string-like waste (broken material) does not come out during the work, the waste enters the connection part as a foreign object. Therefore, it is possible to suppress a decrease in the insulation performance of the connection portion.
[0035]
Next, according to the invention described in claim 2 of the present invention, the cold-shrinkable insulating cylinder is supported by the diameter-expanding support cylinder to expand the diameter, and the diameter-expanding support cylinder winds the string-like body in a spiral shape. In the insulating cylinder with a diameter-expanding support cylinder in which the diameter of the insulating cylinder is sequentially reduced from one end by pulling out the string-like body from one end and sequentially removing it, strong welding is Pull out the string-like body from one short part and disassemble the diameter-enlarged support cylinder so that the disassembly stops at the front-stage part of the rear zone. except before, compared to the welding state between the string-like body in the zone of the intermediate portion, to obtain high mechanical strength so as welded condition der Runode, the same effect as the invention described in claim 1 in addition to that it is possible, it is simple reinforcement work, manufacturing of the enlarged diameter support tube with the insulating cylinder It is possible to reduce the cost.
[0036]
Next, the invention described in claim 3 of the present invention is the invention described in claim 1, wherein the string-like bodies in the rear zone are continuously welded along the circumferential direction, and the rear zone is Before removal, since the string-like bodies in the intermediate zone are intermittently spot welded along the circumferential direction, the same effect as that of the invention described in claim 1 can be obtained, and the diameter-expanded support cylinder Since the surface shape is kept in a smooth state almost the same as that of the case where it is not strongly welded, it is more effective to improve the electrical characteristics of the cable connecting portion without damaging the inner surface of the insulating cylinder.
[0037]
Next, according to the invention described in claim 4 of the present invention, in the invention described in claim 1 , winding of the string-like body in the rear zone is started in the front stage portion of the rear zone of the expanded diameter support cylinder. Since the start end portion or the string-like body is in a range of an arbitrary circumferential length until one turn from the start end portion, the portion where the string-like bodies are strongly welded can be short, and the invention described in claim 1 The effect can be obtained more reliably.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an insulating cylinder with a diameter-enlarged support cylinder of the present invention.
FIG. 2 is an explanatory view showing the welding state of the string-like bodies constituting the diameter-enlarged support cylinder in the insulating cylinder with the diameter-enlarged support cylinder, wherein (a) is a diagram of the welded state of the rear zone; These are the figures of the welding state of a front and an intermediate | middle part zone.
FIG. 3 is a schematic view showing a case where the insulating cylinder with an expanded support cylinder is applied to cable connection.
FIG. 4 is an explanatory view showing a disassembled state of the diameter-enlarged support cylinder in the final stage of the diameter reduction of the insulating cylinder in the above-described insulated cylinder with the diameter-enlarged support cylinder.
FIG. 5 is a schematic view showing another embodiment of the present invention.
6 is an explanatory view showing a welded state of string-like bodies constituting the diameter-enlarged support cylinder in the insulating cylinder with diameter-enlarged support cylinder of FIG. 5, wherein (a) and (b) are the front part of the rear zone; The figure of the welding state of two different examples, (c) is a figure of the welding state of a front and an intermediate | middle part zone.
7 is an explanatory view showing a state in the case where the disassembly of the enlarged diameter support cylinder reaches the front stage portion of the rear zone in the insulating cylinder with the enlarged diameter support cylinder of FIG. 5;
FIG. 8 is a schematic view showing a state in which a conventional insulating cylinder with a diameter-enlarged support cylinder is applied to cable connection.
FIG. 9 is an explanatory view showing a welded state of string-like bodies constituting a diameter-enlarged support cylinder in a conventional insulating cylinder with a diameter-enlarged support cylinder.
FIG. 10 is an explanatory view showing a disassembled state of the diameter-enlarged support cylinder in the final stage of the diameter reduction of the insulating cylinder in the conventional insulated cylinder with diameter-enlarged support cylinder.
[Explanation of symbols]
10, 18 Insulating cylinder 12 with expanded support cylinder Insulated cylinder 12A One end

12B Rear end

14, 20

Expanded support cylinder

14A, 20A One end 14B, 20B The other end 16 String-like body 22 Front part A Cable core X Zone Y Rear zone Z Front, middle zone P End zone Q End zone

Claims

A room temperature shrinkable insulation cylinder is supported by a diameter expansion support cylinder, and the diameter expansion support cylinder is formed by winding a string-like body in a spiral shape, and the string-like body is pulled out from one end thereof. In an insulating cylinder with a diameter-increasing support cylinder in which the diameter of the insulating cylinder is sequentially reduced from one end by dismantling and removing sequentially , the other end side of the diameter-increasing support cylinder, the removal In this case, the area to be removed by sliding outside the insulating cylinder while keeping the cylindrical shape is defined as the rear zone, and at least the front stage of the rear zone is strongly welded so that the string-like bodies are not easily separated from each other. An insulating cylinder with an expanded diameter support cylinder.

In the strong welding, the string-like bodies at least at the front stage in the rear zone are stopped so that the disassembly stops at the front-stage part of the rear zone when the string-like body is pulled out from one short part and the diameter-enlarged support cylinder is disassembled. 2. The diameter-expanded diameter according to claim 1, wherein, before the rear zone is excluded, the welded state is such that the mechanical strength is increased as compared with the welded state of the string-like bodies in the intermediate zone. Insulating cylinder with support cylinder.

The string members in the rear zone are continuously welded along the circumferential direction, and the string members in the intermediate zone are intermittently spot welded along the circumferential direction before the rear zone is removed. The insulating cylinder with a diameter-enlarged support cylinder according to claim 1, wherein

2. The front stage of the rear zone is a starting end portion where the winding of the string-like body in the rear zone is started or a range corresponding to an arbitrary circumferential length until the string-like body is wound once from the starting end portion. Insulating cylinder with expanded diameter support cylinder.