JP3993911B2

JP3993911B2 - Connection structure between corrosion-resistant pipe and corrosion-resistant pipe joint

Info

Publication number: JP3993911B2
Application number: JP05036797A
Authority: JP
Inventors: 錠治大脇; 克己大森; 富司加藤; 元清伊藤; 義郎岡崎
Original assignee: Nippon Steel Corp; JFE Pipe Fitting Mfg Co Ltd
Current assignee: Nippon Steel Corp; JFE Pipe Fitting Mfg Co Ltd
Priority date: 1997-03-05
Filing date: 1997-03-05
Publication date: 2007-10-17
Anticipated expiration: 2017-03-05
Also published as: JPH10246390A

Description

【０００１】
【発明の属する技術分野】
本発明は、防蝕管と防蝕管継手との接続構造に関する。
【０００２】
【従来の技術】
地中に埋設される通信ケーブル保護管の接続に用いられる管継手は、施工時の作業面から接続作業性のよい差込み継手であることが望ましい。また、通信ケーブル保護管と管継手との接続構造には、水分が管路に浸入することを防ぐことのできるシール性や伸縮性、さらには引抜き阻止力を持つことが要求されるほか、防錆性が要求される。そこで、従来は、金属製の管本体の先端側の所定の長さ領域だけに金属面が露出した金属面露出領域を形成しその他の部分を防蝕被覆層で覆った防蝕管を通信ケーブル保護管として用い、そのような防蝕管を、筒状の継手本体の外周面と外端面とが防蝕面になっている防蝕管継手に差し込んで接続するようにしていた。
【０００３】
このような従来の防蝕管と防蝕管継手との接続構造において、水分が管路に浸入することを阻止するシール性は、防蝕管継手と防蝕管の防蝕被覆層によって覆われていない金属面露出領域の外周面との間の隙間を、防蝕管継手側に保持させたシール材によって塞ぐことにより確保していた。また、引抜き阻止力は、防蝕管継手側に保持させた抜止めリングを、防蝕管が引抜き方向に移動したときにその防蝕管の上記金属面露出領域の所定箇所に喰い込ませて係合させることなどによって確保していた。さらに、防蝕管と防蝕管継手との接続部分の防錆性は、防蝕管継手の防蝕面や防蝕管の防蝕被覆層によって確保していた。
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の防蝕管と防蝕管継手との接続構造では、上記したシール性を確保するために採用されているシール材が、防蝕管の金属面露出領域の外周面に密着することによって確保されていたので、そのシール材の配備箇所よりも外側では、上記金属面露出領域の外周面に外部（地中など）の水分が接触し、そのような水分の接触箇所を起点として腐食が進行していくおそれがあった。そして、シール材の配備箇所よりも外側に位置する上記金属面露出領域の外周面の面積は、抜止めリングによって防蝕管が抜け止めされたときのように、当初の差込み位置よりも防蝕管が引抜き方向に移動されているときにより広くなっているので、そのような状況下では腐食がより発生しやすい状況になっているといえる。
【０００５】
本発明は以上の状況に鑑みてなされたものであり、地中に埋設される通信ケーブル保護管に用いられる上記したような防蝕管とその接続に用いられる上記したような防蝕管と防蝕管継手との接続構造において、水分が管路に浸入することを防ぐことのできるシール性、接続部分の伸縮性、防蝕管に対する引抜き阻止力を良好に発揮させることができるものでありながら、上記シール性を確保するためのシール材の配備箇所の外側に、防蝕管の金属面が露出するといった事態が生じることのないものを提供することを目的とする。
【０００６】
また、本発明は、防蝕管だけでなく、防蝕管継手の内面の金属面についても、上記シール材の配備箇所の外側で露出しないようにすることのできる防蝕管と防蝕管継手との接続構造を提供することを目的とする。
【０００７】
【課題を解決するための手段】
請求項１に係る発明の防蝕管と防蝕管継手との接続構造は、筒状の継手本体の内周部に、抜止め部材と、この抜止め部材の配備箇所よりも外側箇所に配備されたシール材とが設けられ、上記継手本体の外周面および外端面が防蝕面となされた防蝕管継手と、金属製の管本体に、その先端部に形成されてその外周の金属面が露出された先端領域とこの先端領域を除く部分を覆いかつ端縁が上記先端領域の内端部に位置された防蝕被覆層と上記先端領域に形成されて上記抜止め部材が係合可能な係合部とが設けられた防蝕管と、を有し、上記防蝕管継手とその防蝕管継手に差し込まれた上記防蝕管の上記防蝕被覆層との間の隙間が上記シール材によって塞がれ、上記防蝕管の上記先端領域の金属面でなる外周面に対応して上記抜止め部材が位置していると共に、その抜止め部材の位置よりも上記防蝕管の先端側に上記係合部が位置され、上記シール材の配備箇所から上記防蝕被覆層の端縁までの長さが、上記防蝕管が引抜き方向に移動することにより上記抜止め部材が上記係合部に係合してその防蝕管を抜け止めするときのその防蝕管の移動距離よりも長くなっている、というものである。
【０００８】
この発明において、防蝕管継手の外周面や外端面は、それら自体が防蝕面になっているので腐食することがない。同様に、防蝕管の先端領域を除く部分の腐食はその部分を覆っている防蝕被覆層により防止される。また、防蝕管継手の継手本体の内周部に配備されたシール材は、防蝕管継手とその防蝕管継手に差し込まれた防蝕管の防蝕被覆層との間の隙間を塞いでいるので、そのシール材の外側に防蝕管の先端領域の外周面が露出していない。そのため、防蝕管の先端領域の外周面を形成している金属面が外部の水分（地中や空気中の水分、雨水など）に接触することがなくなり、そのことが腐食の防止に役立つ。
【０００９】
この接続構造において、防蝕管が引抜き方向に移動した場合、その防蝕管の最大移動距離は、防蝕管継手の継手本体の内周部に配備されている抜止め部材が防蝕管の先端領域に形成されている係合部に係合してその防蝕管を抜け止めするときのその防蝕管の移動距離に一致し、しかもその抜止め時の防蝕管の移動距離は、上記シール材の配備箇所から上記防蝕被覆層の端縁までの長さよりも短くなっている。そのため、防蝕管が引抜き方向に移動したとしても、その最大移動距離範囲内の移動であれば、防蝕管の先端領域の外周面を形成している金属面がシール材の配備箇所の外側に露出することがなく、そのことが、防蝕管の腐食の防止に役立つ。抜け止めされている防蝕管が差し込み方向に移動された場合にも同様の作用が発揮される。
【００１０】
なお、この接続構造において、水分が管路に浸入することを防ぐことのできるシール性は、シール材が防蝕管継手とその防蝕管継手に差し込まれた防蝕管の防蝕被覆層との間の隙間を塞ぐことによって確保され、引抜き阻止力は、抜止め部材が防蝕管の先端領域の係合部に係合することによって確保され、伸縮性は、シール材と防蝕管継手の防蝕被覆層とが摺動することによって確保される。
【００１１】
請求項２に係る発明の防蝕管と防蝕管継手との接続構造は、請求項１に記載したものにおいて、上記継手本体の内周部に、上記引抜き方向に向かって漸次径小となるテーパ状の作用面を壁面として備えた凹入部が形成され、この凹入部に、上記防蝕管の先端領域の外周面に摺動可能に保持されかつ内周側に突部を具備する縮径可能なリングでなる上記抜止め部材が軸方向移動可能に嵌合状に配備され、上記防蝕管の上記先端領域の上記係合部がその先端領域の外周面に具備されかつ上記リングの上記突部が嵌合状に係合可能な環状凹部でなる、というものである。
【００１２】
この発明によれば、防蝕管が引抜き方向に移動されると、その防蝕管の先端領域に保持されて抜止め部材を形成しているリングも同じ方向に追従して継手本体の凹入部内で移動する。そして、そのリングが上記凹入部の壁面であるテーパ状の作用面に当たると、その作用面の作用でリングが縮径される。したがって、さらに防蝕管が引抜き方向に移動され、その防蝕管の先端領域の外周面がリングと摺動してその先端領域に形成されている係合部が上記リングの突部に対応する位置まで移動すると、その突部が係合部に係合して引抜き阻止力が発揮され、防蝕管が抜け止めされる。
【００１３】
請求項３に係る発明の防蝕管と防蝕管継手との接続構造は、請求項１または請求項２に記載したものにおいて、上記継手本体の内周部に、上記抜止め部材の配備箇所よりも内側箇所に配備されて防蝕管の差込み代を規制するストッパが設けられ、金属製の管本体に、上記ストッパに当たって上記防蝕管継手に対する上記防蝕管の差込み代を規制する当り部が設けられている、というものである。
【００１４】
この発明によれば、防蝕管の管本体の当り部が継手本体のストッパに当たるまでその防蝕管を防蝕管継手に差し込むことによって防蝕管の差込み代が一定寸法になり、そのことが、シール材や抜止め部材の位置関係を適正に保つことに役立つ。
【００１５】
請求項４に係る発明の防蝕管と防蝕管継手との接続構造は、請求項１、請求項２、請求項３のいずれかに記載したものにおいて、上記継手本体が、その内周部に上記抜止め部材の配備箇所と上記シール材の配備箇所とを有する金属製の筒状体と、この筒状体の外周面および外端面を被覆する合成樹脂被覆層とでなり、この合成樹脂被覆層の外表面が上記防蝕面となされている、というものである。
【００１６】
この発明によっても、請求項１、請求項２、請求項３に係る各発明について説明した上記作用が奏される。
【００１７】
請求項５に係る発明の防蝕管と防蝕管継手との接続構造は、請求項４に記載したものにおいて、上記筒状体における上記シール材の配備箇所とその筒状体の外端面を被覆している防蝕面の端縁との間の部分で露出している当該筒状体の金属面が液状防蝕剤で被覆されている、というものである。
【００１８】
この発明によると、防蝕管継手の継手本体を形成している筒状体の内面を形成している金属面のうち、シール材の配備箇所の外側に位置している金属面の全体が液状防蝕剤で被覆されてその腐食が防止される。
【００１９】
請求項６に係る発明の防蝕管と防蝕管継手との接続構造は、請求項１、請求項２、請求項３のいずれかに記載したものにおいて、上記継手本体が、その内周部に上記抜止め部材の配備箇所を有する金属製の筒状体と、この筒状体の外周面を被覆する合成樹脂層と、この合成樹脂層から延び出しかつ内周部に上記シール材の配備箇所を有する合成樹脂製の筒部とでなり、上記合成樹脂層の外表面と上記筒部の外表面とが上記防蝕面となされている、というものである。
【００２０】
この発明によっても、請求項１、請求項２、請求項３に係る各発明について説明した上記作用が奏される。
【００２１】
請求項７に係る発明の防蝕管と防蝕管継手との接続構造は、請求項１または請求項３に記載したものにおいて、上記継手本体が、金属製の筒状体と、この筒状体の外周面を被覆する合成樹脂層と、この合成樹脂層から延び出しかつ内周部に上記シール材の配備箇所を有する合成樹脂製の筒部とでなり、上記合成樹脂層の外表面と上記筒部の外表面とが上記防蝕面となっていると共に、上記筒状体の内周部に環状の凹所が形成され、上記引抜き方向に向かって漸次径小となるテーパ状の作用面を壁面として有する凹入部を内周側に備えた合成樹脂製のリング体が上記凹所に嵌入状に保持され、このリング体の上記凹入部に、内周側に突部を具備する縮径可能なリングでなる上記抜止め部材が軸方向移動可能に嵌合状に配備され、上記防蝕管の上記先端領域の上記係合部がその先端領域の外周面に具備されかつ上記リングの突部が嵌合状に係合可能な環状凹部でなる、というものである。
【００２２】
この発明によれば、請求項２に係る発明について説明した抜止め作用が、合成樹脂製のリング体と、そのリング体のテーパ状の作用面に当たる抜止め部材としてのリングと、防蝕管側の係合部としての環状凹部とによって奏される。
【００２３】
【発明の実施の形態】
図１および図２は請求項１、請求項２、請求項３および請求項４に係る発明の実施形態を示しており、図１は初期状態の接続構造を示した部分縦断側面図、図２は防蝕管８が抜け止めされている状態の接続構造を示した部分縦断側面図である。
【００２４】
この実施形態において、防蝕管継手１の継手本体２は、金属製の筒状体３と、この筒状体３の外周面３１および外端面３２を被覆している合成樹脂被覆層４とでなり、合成樹脂被覆層４の表面が防蝕面１２となされている。合成樹脂被覆層４には、ポリエチレン、ポリ塩化ビニル、ナイロンなどの合成樹脂ライニング層が採用されている。
【００２５】
継手本体２の内周部、具体的には筒状体３の内周部に、径小に絞られた形状のストッパ３３が形成されていると共に、このストッパ３３と外端部３４との間の箇所に凹入部３５が環状に設けられ、この凹入部３５よりも外側で上記外端部３４の近傍の内周部に環状の溝部３６が設けられている。上記凹入部３５の壁面は、当該防蝕管継手１に差し込まれた防蝕管８（後述する）の引抜き方向（矢符ａで示してある）に向かって漸次径小となるテーパ状の作用面３７を有している。この凹入部３５には、抜止め部材の一例である縮径可能な金属製のリング５１と、弾力性を備えた合成樹脂でなるリング状の弾性体５３とが軸方向に並んで収容保持されている。抜止め部材として用いられている上記リング５１は、たとえば周方向の１箇所を欠除することにより縮径可能となされており、そのリング５１が、上記弾性体５３と上記作用面３７との間の空間にそれほど大きながたつきを持たない状態で保持されている。なお、弾性体５３には合成ゴムが好適に用いられる。また、リング体５１は、その内周部にアール形状の突部５２を有している。このリング体５１の配備箇所よりも外側箇所、具体的には、上記溝部３６に、シール材３８が配備されている。
【００２６】
防蝕管８は、金属製の管本体８１に防蝕被覆層８２を形成したものである。この防蝕管８において、その先端部には、防蝕被覆層８２で覆われていない領域すなわち管本体８１の外周の金属面が露出された先端領域８３が形成されており、この先端領域８３を除く部分が上記防蝕被覆層８２で覆われていると共に、防蝕被覆層８２の端縁８２ａが先端領域８３の内端部に位置している。また、先端領域８３の外周面８５の所定箇所に環状凹部でなる係合部８４が形成されている。さらに、防蝕管８の管本体８１の先端部外周が上記ストッパ３３に対する当り部８６となされている。
【００２７】
図１のように、防蝕管継手１に防蝕管８を差し込んだ状態において、その防蝕管８側の当り部８６が防蝕管継手１側のストッパ３３に当たっているときが初期状態であり、この初期状態のときに防蝕管８の差込み代が最大になっている。したがって、ストッパ３３に当り部８６が当たることによって防蝕管８の差込み代が規制される。
【００２８】
初期状態において、リング５１は、防蝕管８の先端領域８３の外周面８５に摺動可能に保持されている。したがって、図１の初期状態から矢符ａのように防蝕管８が引抜き方向に移動されると、その防蝕管８の先端領域８３に保持されているリング５１も同じ方向に追従して凹入部３５内で移動する。そして、そのリング５１が凹入部３５の壁面であるテーパ状の作用面３７に当たると、その作用面３７の作用でリング５１が縮径される。したがって、防蝕管８の引抜き方向ａへの移動によって先端領域８３の外周面がリング５１と摺動して係合部８４がリング５１の突部５２に対応する位置まで移動すると、図２のように、その突部５２が係合部８４に係合して引抜き阻止力が発揮され、防蝕管８がその位置で抜け止めされる。
【００２９】
図１の初期状態において、シール材３８の配備箇所から防蝕管８の防蝕被覆層８２の端縁８２ａまでの長さＬ１が、防蝕管８が引抜き方向ａに移動することによりリング５１が係合部８４に係合してその防蝕管８を抜け止めするときのその防蝕管８の移動距離Ｌ２よりも長くなっている。
【００３０】
したがって、図１に示した初期状態と図２に示した抜止め状態との間で防蝕管８が引抜き方向ａや差込み方向ｂに移動したとしても、シール材３８は、防蝕管継手１とその防蝕管継手１に差し込まれた防蝕管８の防蝕被覆層８２との間に圧縮状態で介在されたままになり、上記溝部３６の壁面と上記防蝕被覆層８２の外表面とに密着してこの部分の隙間を塞いでいる。そのため、防蝕管８が引抜き方向ａや差込み方向ｂに移動しても、防蝕管８の先端領域８３の外周面８５を形成している金属面がシール材３８の配備箇所の外側に露出することがない。したがって、防蝕管８や防蝕管継手１が地中に埋設されている場合には、地中の水分が防蝕管８の先端領域８３の外周面に付着して発錆させるといった事態が起こらない。防蝕管８や防蝕管継手１が屋外に配管されている場合には、外気中の水分や雨水が防蝕管８の先端領域８３の外周面に付着して発錆させるといった事態が起こらない。
【００３１】
図１や図２で説明した接続構造において、防蝕管継手１の外周面や外端面は、それら自体が防蝕面１２になっているので腐食することがない。同様に、防蝕管８の先端領域８３を除く部分の腐食はその部分を覆っている防蝕被覆層８２により防止される。また、水分が管路に浸入することを防ぐことのできるシール性は、シール材３８によって確保される。伸縮性は、シール材３８と防蝕管継手１の防蝕被覆層８２とが摺動することによって確保される。
【００３２】
上記した接続構造においては、継手本体２のシール材３８の配備箇所よりも外側の内面、すなわち金属製の筒状体３の外端部側の内面３９を形成している金属面は、その内面３９と防蝕管８の防蝕被覆層８２との間の隙間を通じて外部に露出していることになる。そのため、防蝕管８や防蝕管継手１が地中に埋設されている場合には地中の水分が上記内面３９に付着し、防蝕管８や防蝕管継手１が屋外に配管されている場合には、外気中の水分や雨水が上記内面３９に付着して、その内面を発錆させるおそれがある。
【００３３】
そこで、そのようなそれを無くするために、図５に示したように、筒状体３におけるシール材３８の配備箇所とその筒状体３の外端面３２を被覆している合成樹脂被覆層４の外表面すなわち防蝕面１２の端縁との間の部分で露出している当該筒状体３の内面（金属面）３９を、液状防蝕材６で被覆しておくことが有効である。この内面３９を液状防蝕材６で被覆させるためには、液状防蝕材６を内面３９と防蝕被覆層８２との間の隙間に充填すればよい。こうしておけば、内面３９が発錆するおそれがなくなる。
【００３４】
図４および図５は請求項６に係る発明の実施形態を示している。図４は初期状態の接続構造を示した部分縦断側面図、図５は防蝕管８が抜け止めされている状態の接続構造を示した部分縦断側面図である。
【００３５】
この実施形態においては、防蝕管継手１を形成している継手本体２の構成が図１および図２で説明した実施形態と異なっている。この実施形態の継手本体２は、金属製の筒状体７１と、この筒状体７１の外周面を被覆する合成樹脂層７２と、この合成樹脂層７２から延び出た合成樹脂製の筒部７３とでなる。上記筒状体７１は、金属のパイプ材の端部を膨出形状に形成してその膨出部７４の内側に環状の凹入部７５を形成してあり、この凹入部３５の壁面を、当該防蝕管継手１に差し込まれた防蝕管８の引抜き方向ａに向かって漸次径小となるテーパ状の作用面７６としてある。上記凹入部７５に、図１および図２で説明したものと同様な抜止め部材の一例である縮径可能な金属製のリング５１と、弾力性を備えた合成樹脂でなるリング状の弾性体５３とが軸方向に並んで収容保持されている。筒部７３の外端部の内周部に、環状の溝部７７が形成されており、この溝部７７にシール材７８が配備されている。また、上記合成樹脂層７２の外表面と筒部７３の外表面とが防蝕面１２となされている。そして、防蝕管継手１には、図１および図２で説明ものと同様の防蝕管８が差し込まれている。
【００３６】
この接続構造において、その他の構成は図１および図２で説明したものと同様であるので、同一部分に同一符号を付して詳細な構成説明を省略する。
【００３７】
図４のように、防蝕管継手１に防蝕管８を差し込んだ状態において、その防蝕管８側の当り部８６が防蝕管継手１側のストッパ３３に当たっているときが初期状態であり、このようにストッパ３３に当り部８６が当たることによって防蝕管８の差込み代が規制されている。
【００３８】
図４の初期状態から矢符ａのように防蝕管８が引抜き方向に移動されると、その防蝕管８の先端領域８３に保持されているリング５１も同じ方向に追従して凹入部７５内で移動する。そして、そのリング５１が凹入部７５のテーパ状の作用面７６に当たると、その作用面７６の作用でリング５１が縮径される。したがって、防蝕管８の引抜き方向ａへの移動によって先端領域８３の係合部８４がリング５１の突部５２に対応する位置まで移動すると、図５のように、その突部５２が係合部８４に係合して引抜き阻止力が発揮され、防蝕管８がその位置で抜け止めされる。
【００３９】
図４の初期状態において、シール材７８の配備箇所から防蝕管８の防蝕被覆層８２の端縁８２ａまでの長さＬ１が、防蝕管８が引抜き方向ａに移動することによりリング５１が係合部８４に係合してその防蝕管８を抜け止めするときのその防蝕管８の移動距離Ｌ２よりも長くなっているので、図４に示した初期状態と図５に示した抜止め状態との間で防蝕管８が引抜き方向ａや差込み方向ｂに移動したとしても、シール材７８は、防蝕管継手１とその防蝕管継手１に差し込まれた防蝕管８の防蝕被覆層８２との間に圧縮状態で介在されたままになり、その部分の隙間を塞いでいる。そのため、防蝕管８が引抜き方向ａや差込み方向ｂに移動しても、防蝕管８の先端領域８３の外周面８５を形成している金属面がシール材７８の配備箇所の外側に露出することがない。したがって、水分が防蝕管８の先端領域８３の外周面に付着して発錆させるといった事態が起こらない。
【００４０】
その他の作用は、図１および図２で説明したところと同様であるので説明を簡略にするため、ここでは作用説明を省略する。
【００４１】
図６および図７は請求項７に係る発明の実施形態を示している。図６は初期状態の接続構造を示した部分縦断側面図、図７は防蝕管８が抜け止めされている状態の接続構造を示した部分縦断側面図である。
【００４２】
この実施形態においては、図４および図５で説明したものと異なる点は、金属製の筒状体７１の内周部に環状の凹所７９が形成されている点、この凹所７９に、合成樹脂製のリング体９が嵌入状に保持されている点、このリング体９が、防蝕管継手１に差し込まれた防蝕管８の引抜き方向ａに向かって漸次径小となるテーパ状の作用面９１を壁面として有する凹入部９２を内周側に備えている点、その凹入部９２に、内周側に突部５２を具備する縮径可能なリング５１でなる抜止め部材が軸方向移動可能に嵌合状に配備されている点である。
【００４３】
この接続構造において、その他の構成は図１および図２で説明したものと同様であるので、同一部分に同一符号を付して詳細な構成説明を省略する。
【００４４】
図６のように、防蝕管継手１に防蝕管８を差し込んだ状態において、その防蝕管８側の当り部８６が防蝕管継手１側のストッパ３３に当たっているときが初期状態であり、このようにストッパ３３に当り部８６が当たることによって防蝕管８の差込み代が規制されている。
【００４５】
図６の初期状態から矢符ａのように防蝕管８が引抜き方向に移動されると、その防蝕管８の先端領域８３に保持されているリング５１も同じ方向に追従してリング体９の凹入部９２内で移動する。そして、そのリング５１が凹入部９２のテーパ状の作用面９１に当たると、その作用面９１の作用でリング５１が縮径される。したがって、防蝕管８の引抜き方向ａへの移動によって先端領域８３の係合部８４がリング５１の突部５２に対応する位置まで移動すると、図７のように、その突部５２が係合部８４に係合して引抜き阻止力が発揮され、防蝕管８がその位置で抜け止めされる。
【００４６】
図６の初期状態において、シール材７８の配備箇所から防蝕管８の防蝕被覆層８２の端縁８２ａまでの長さＬ１が、防蝕管８が引抜き方向ａに移動することによりリング５１が係合部８４に係合してその防蝕管８を抜け止めするときのその防蝕管８の移動距離Ｌ２よりも長くなっているので、図６に示した初期状態と図７に示した抜止め状態との間で防蝕管８が引抜き方向ａや差込み方向ｂに移動したとしても、シール材７８は、防蝕管継手１とその防蝕管継手１に差し込まれた防蝕管８の防蝕被覆層８２との間に圧縮状態で介在されたままになり、その部分の隙間を塞いでいる。そのため、防蝕管８が引抜き方向ａや差込み方向ｂに移動しても、防蝕管８の先端領域８３の外周面８５を形成している金属面がシール材７８の配備箇所の外側に露出することがない。したがって、水分が防蝕管８の先端領域８３の外周面に付着して発錆させるといった事態が起こらない。
【００４７】
その他の作用は、図１および図２、または、図４および図５で説明したところと同様であるので説明を簡略にするため、ここでは作用説明を省略する。
【００４８】
【発明の効果】
本発明によれば、防蝕管と防蝕管継手との接続構造において、水分が管路に浸入することを防ぐことのできるシール性、接続部分の伸縮性、防蝕管に対する引抜き阻止力を良好に発揮させることができるものでありながら、上記シール性を確保するためのシール材の配備箇所の外側に防蝕管の先端領域の金属面が露出して発錆するという事態を防ぐことが可能になるという効果がある。
【００４９】
特に、防蝕管が引抜き方向に移動されて抜止め部材により抜け止めされているときにも、シール材の配備箇所の外側に防蝕管の金属面が露出することがないので、外部の水分との接触に伴う防蝕管の先端領域の金属面の発錆やその金属面からの腐食の進行を確実に防止することが可能である。
【００５０】
また、本発明は、防蝕管だけでなく、防蝕管継手の内面の金属面についても、上記シール材の配備箇所の外側で露出しないようにすることのできる防蝕管と防蝕管継手との接続構造を提供することが可能になる。
【図面の簡単な説明】
【図１】請求項１〜４に係る発明の実施形態において、初期状態の接続構造を示した部分縦断側面図である。
【図２】請求項１〜４に係る発明の実施形態において、防蝕管が抜け止めされている状態の接続構造を示した部分縦断側面図である。
【図３】請求項５に係る発明の実施形態において、その要部を示した部分縦断側面図である。
【図４】請求項６に係る発明の実施形態において、初期状態の接続構造を示した部分縦断側面図である。
【図５】請求項６に係る発明の実施形態において、防蝕管が抜け止めされている状態の接続構造を示した部分縦断側面図である。
【図６】請求項７に係る発明の実施形態において、初期状態の接続構造を示した部分縦断側面図である。
【図７】請求項７に係る発明の実施形態において、防蝕管が抜け止めされている状態の接続構造を示した部分縦断側面図である。
【符号の説明】
１防蝕管継手
２継手本体
３筒状体
４合成樹脂被覆層
６液状防蝕剤
８防蝕管
９リング体
１２防蝕面
３３ストッパ
３５凹入部
３７作用面
３８シール材
３９内面（金属面）
５１リング（抜止め部材）
７１筒状体
７２合成樹脂層
７３筒部
７９凹所
８１管本体
８２防蝕被覆層
８２ａ防蝕被覆層の端縁
８３先端領域
８４係合部
８６当り部
９１作用面
９２凹入部
Ｌ１シール材の配備箇所から防蝕被覆層の端縁までの長さ
Ｌ２防蝕管の移動距離
ａ引抜き方向[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection structure between a corrosion-resistant pipe and a corrosion-resistant pipe joint.
[0002]
[Prior art]
It is desirable that the pipe joint used for connection of the communication cable protection pipe buried in the ground is an insertion joint with good connection workability from the work surface at the time of construction. In addition, the connection structure between the communication cable protection pipe and the pipe joint is required to have sealability and stretchability that can prevent moisture from entering the pipe line, and to have a pull-out prevention force. Rust is required. Therefore, conventionally, a corrosion protection tube having a metal surface exposed region where a metal surface is exposed only in a predetermined length region on the distal end side of a metal tube body and the other portion covered with a corrosion protection coating layer is a communication cable protection tube. Such a corrosion-resistant pipe is inserted into and connected to a corrosion-resistant pipe joint in which the outer peripheral surface and the outer end surface of the cylindrical joint body are corrosion-resistant surfaces.
[0003]
In such a conventional connection structure between a corrosion-resistant pipe and a corrosion-resistant pipe joint, the sealing property that prevents moisture from entering the pipe line is exposed to the metal surface that is not covered by the corrosion-resistant coating layer of the corrosion-resistant pipe joint and the corrosion-resistant pipe. A gap between the outer peripheral surface of the region was secured by closing with a sealing material held on the corrosion-resistant pipe joint side. Further, the pull-out preventing force is such that the retaining ring held on the corrosion-resistant pipe joint side is engaged with the corrosion-resistant pipe by biting into the predetermined portion of the exposed area of the metal surface when the corrosion-resistant pipe moves in the drawing direction. It was secured by things. Furthermore, the rust prevention property of the connection part of a corrosion-resistant pipe and a corrosion-resistant pipe joint has been ensured by the corrosion-resistant surface of the corrosion-resistant pipe joint and the corrosion-resistant coating layer of the corrosion-resistant pipe.
[0004]
[Problems to be solved by the invention]
However, in the conventional connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint, the sealing material employed to ensure the sealing performance described above is secured by closely contacting the outer peripheral surface of the metal surface exposed area of the corrosion-resistant pipe. Therefore, outside of the location where the seal material is provided, external (such as underground) moisture comes into contact with the outer peripheral surface of the exposed surface of the metal surface, and corrosion proceeds from such moisture contact location as a starting point. There was a risk of going. And the area of the outer peripheral surface of the metal surface exposed region located outside the location where the seal material is disposed is such that the corrosion-resistant tube is located more than the original insertion position, as when the corrosion-resistant tube is retained by the retaining ring. Since it becomes wider when it is moved in the drawing direction, it can be said that corrosion is more likely to occur under such circumstances.
[0005]
The present invention has been made in view of the above situation, and the above-described corrosion-resistant pipe used for a communication cable protective pipe buried in the ground and the above-described corrosion-resistant pipe and corrosion-resistant pipe joint used for the connection thereof. In the connection structure, the sealing property that can prevent moisture from entering the pipe line, the stretchability of the connection part, and the pulling-out preventing force against the corrosion-resistant pipe can be satisfactorily exhibited. An object of the present invention is to provide a material that does not cause a situation in which the metal surface of the corrosion-resistant pipe is exposed outside the location where the sealing material is provided to ensure the resistance.
[0006]
Further, the present invention provides a connection structure between a corrosion-resistant pipe and a corrosion-resistant pipe joint that can prevent not only the corrosion-resistant pipe but also the metal surface of the inner face of the corrosion-resistant pipe joint from being exposed outside the location where the sealing material is provided. The purpose is to provide.
[0007]
[Means for Solving the Problems]
The connection structure between the anticorrosion pipe and the anticorrosion pipe joint according to the first aspect of the present invention is provided on the inner peripheral portion of the tubular joint main body at a position outside the position where the retaining member and the retaining member are disposed. A seal material is provided, and the outer peripheral surface and the outer end surface of the joint body are formed as a corrosion-resistant surface, and the metal pipe body is formed at the tip thereof and the outer peripheral metal surface is exposed. An anticorrosion coating layer covering the tip region and a portion excluding the tip region and having an edge positioned at the inner end of the tip region; and an engaging portion formed on the tip region and engageable with the retaining member A gap between the anticorrosion pipe joint and the anticorrosion coating layer of the anticorrosion pipe inserted into the anticorrosion pipe joint is closed by the sealing material, and the anticorrosion pipe The retaining member is positioned corresponding to the outer peripheral surface made of the metal surface of the tip region. In addition, the engagement portion is positioned on the distal end side of the corrosion-resistant tube from the position of the retaining member, and the length from the location where the seal material is provided to the edge of the corrosion-resistant coating layer is the length of the corrosion-resistant tube. By moving in the pulling direction, the retaining member is longer than the moving distance of the anticorrosion tube when the anticorrosion tube engages with the engaging portion to prevent the anticorrosion tube from coming off.
[0008]
In the present invention, the outer peripheral surface and the outer end surface of the corrosion-resistant pipe joint are not corroded because they are themselves corrosion-resistant surfaces. Similarly, corrosion of the portion other than the tip region of the corrosion resistant tube is prevented by the corrosion resistant coating layer covering the portion. In addition, the seal material provided on the inner periphery of the joint body of the corrosion-resistant pipe joint closes the gap between the corrosion-resistant pipe joint and the corrosion-resistant coating layer of the corrosion-resistant pipe inserted into the corrosion-resistant pipe joint. The outer peripheral surface of the tip region of the corrosion resistant tube is not exposed outside the sealing material. For this reason, the metal surface forming the outer peripheral surface of the tip region of the corrosion-resistant tube does not come into contact with external moisture (such as underground or atmospheric moisture, rainwater, etc.), which helps to prevent corrosion.
[0009]
In this connection structure, when the corrosion-resistant pipe moves in the drawing direction, the maximum movement distance of the corrosion-resistant pipe is formed by the retaining member provided in the inner periphery of the joint body of the corrosion-resistant pipe joint in the tip region of the corrosion-resistant pipe. The distance of movement of the anticorrosion pipe when the anticorrosion pipe is prevented from coming off by engaging with the engaging portion, and the distance of movement of the anticorrosion pipe at the time of removal is determined from the location where the sealing material is provided. It is shorter than the length to the edge of the said corrosion-proof coating layer. Therefore, even if the corrosion-resistant tube moves in the drawing direction, the metal surface forming the outer peripheral surface of the tip region of the corrosion-resistant tube is exposed to the outside of the location where the sealing material is provided as long as it moves within the maximum movement distance range. This helps to prevent corrosion of the corrosion protection tube. The same effect is exhibited when the corrosion-resistant tube that has been prevented from coming off is moved in the insertion direction.
[0010]
In this connection structure, the sealing property that can prevent moisture from entering the pipeline is the gap between the corrosion-resistant pipe joint and the corrosion-resistant coating layer of the corrosion-resistant pipe inserted into the corrosion-resistant pipe joint. The pull-out preventing force is ensured by engaging the retaining member with the engaging portion of the tip region of the corrosion-resistant pipe, and the stretchability is provided by the sealing material and the corrosion-resistant coating layer of the corrosion-resistant pipe joint. Secured by sliding.
[0011]
According to a second aspect of the present invention, there is provided a connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint according to the first aspect, wherein the inner peripheral portion of the joint body has a tapered shape that gradually decreases in diameter toward the drawing direction. A recessed portion having a working surface as a wall surface is formed, and in this recessed portion, the diameter-reducible ring is slidably held on the outer peripheral surface of the tip region of the corrosion-resistant tube and has a protrusion on the inner peripheral side. The retaining member is arranged in a fitting manner so as to be movable in the axial direction, the engaging portion of the tip region of the corrosion-proof pipe is provided on the outer peripheral surface of the tip region, and the protrusion of the ring is fitted It consists of an annular recess that can be engaged together.
[0012]
According to the present invention, when the corrosion-resistant pipe is moved in the drawing direction, the ring that is held in the tip region of the corrosion-resistant pipe and forms the retaining member also follows the same direction in the recessed portion of the joint body. Moving. When the ring hits the tapered working surface that is the wall surface of the recessed portion, the diameter of the ring is reduced by the action of the working surface. Therefore, the anticorrosion tube is further moved in the drawing direction, and the outer peripheral surface of the tip region of the anticorrosion tube slides with the ring until the engaging portion formed in the tip region corresponds to the protrusion of the ring. When it moves, the protrusion engages with the engaging portion to exert a pull-out preventing force, and the corrosion-resistant tube is prevented from coming off.
[0013]
The connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint of the invention according to claim 3 is the one described in claim 1 or claim 2, in which the inner peripheral portion of the joint body is located more than the location where the retaining member is provided. A stopper that is provided at an inner portion and restricts the insertion allowance of the corrosion resistant pipe is provided, and a metal pipe main body is provided with a contact portion that contacts the stopper and restricts the insertion allowance of the corrosion resistant pipe to the corrosion resistant pipe joint. That's it.
[0014]
According to this invention, until the contact portion of the pipe body of the corrosion resistant tube hits the stopper of the joint main body, the insertion allowance of the corrosion resistant pipe becomes a constant size by inserting the corrosion resistant pipe into the corrosion resistant pipe joint. It helps to keep the positional relationship of the retaining member appropriate.
[0015]
According to a fourth aspect of the present invention, there is provided the connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint according to any one of the first, second, and third aspects. A metal cylindrical body having a location where the retaining member is provided and a location where the sealing material is provided, and a synthetic resin coating layer covering the outer peripheral surface and the outer end surface of the cylindrical body, and this synthetic resin coating layer The outer surface is made the above-mentioned corrosion-proof surface.
[0016]
Also according to the present invention, the above-described operation described for each of the inventions according to claim 1, claim 2, and claim 3 is achieved.
[0017]
According to a fifth aspect of the present invention, there is provided the connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint according to the fourth aspect, wherein the location where the sealing material is provided in the cylindrical body and the outer end surface of the cylindrical body are covered. The metal surface of the cylindrical body exposed at the portion between the edges of the corrosion-resistant surface is covered with a liquid corrosion-resistant agent.
[0018]
According to the present invention, among the metal surfaces forming the inner surface of the cylindrical body forming the joint body of the corrosion-resistant pipe joint, the entire metal surface located outside the location where the sealing material is provided is liquid corrosion-resistant. It is coated with an agent to prevent its corrosion.
[0019]
The connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint of the invention according to claim 6 is the structure according to any one of claim 1, claim 2, and claim 3, wherein the joint main body is connected to the inner peripheral portion thereof. A metal cylindrical body having a location where the retaining member is provided, a synthetic resin layer covering the outer peripheral surface of the cylindrical body, and a location where the sealing material is provided on the inner peripheral portion extending from the synthetic resin layer The outer surface of the synthetic resin layer and the outer surface of the cylindrical portion are the anticorrosive surface.
[0020]
Also according to the present invention, the above-described operation described for each of the inventions according to claim 1, claim 2, and claim 3 is achieved.
[0021]
According to a seventh aspect of the present invention, there is provided a connection structure between a corrosion-resistant pipe and a corrosion-resistant pipe joint according to the first or third aspect, wherein the joint body is made of a metal cylindrical body and the cylindrical body. A synthetic resin layer covering the outer peripheral surface, and a synthetic resin cylindrical portion extending from the synthetic resin layer and having an installation portion of the sealing material on the inner peripheral portion, and the outer surface of the synthetic resin layer and the cylinder The outer surface of the portion is the anticorrosive surface, and an annular recess is formed in the inner peripheral portion of the cylindrical body, and the tapered working surface whose diameter gradually decreases toward the drawing direction is a wall surface. A ring body made of synthetic resin having a recessed portion on the inner peripheral side is held in the recess so as to be fitted, and the concave portion of the ring body has a protrusion on the inner peripheral side and can be reduced in diameter. The retaining member made of a ring is arranged in a fitting shape so as to be movable in the axial direction, and The engaging portion of the tip region is in engageable annular recess protrusion fitting shape is and the ring provided on the outer peripheral surface of the distal region, is that.
[0022]
According to this invention, the retaining action described for the invention according to claim 2 is made of a synthetic resin ring body, a ring as a retaining member that contacts the tapered working surface of the ring body, and the corrosion prevention pipe side. It is played by the annular recessed part as an engaging part.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show an embodiment of the invention according to claim 1, claim 2, claim 3 and claim 4, and FIG. 1 is a partially longitudinal side view showing a connection structure in an initial state, FIG. FIG. 3 is a partially longitudinal side view showing a connection structure in a state in which a corrosion-resistant tube 8 is prevented from being detached.
[0024]
In this embodiment, the joint body 2 of the corrosion-resistant pipe joint 1 includes a metal tubular body 3 and a synthetic resin coating layer 4 covering the outer peripheral surface 31 and the outer end surface 32 of the tubular body 3. The surface of the synthetic resin coating layer 4 is a corrosion-resistant surface 12. The synthetic resin coating layer 4 employs a synthetic resin lining layer such as polyethylene, polyvinyl chloride, and nylon.
[0025]
A stopper 33 having a narrowed diameter is formed on the inner peripheral portion of the joint body 2, specifically, on the inner peripheral portion of the cylindrical body 3, and between the stopper 33 and the outer end portion 34. A recessed portion 35 is provided in an annular shape at this location, and an annular groove portion 36 is provided on the inner peripheral portion in the vicinity of the outer end portion 34 outside the recessed portion 35. The wall surface of the recessed portion 35 is a tapered working surface 37 that gradually decreases in diameter in the drawing direction (shown by an arrow a) of the corrosion-resistant pipe 8 (described later) inserted into the corrosion-resistant pipe joint 1. have. In the recessed portion 35, a metal ring 51 capable of reducing the diameter, which is an example of a retaining member, and a ring-shaped elastic body 53 made of a synthetic resin having elasticity are accommodated and held side by side in the axial direction. ing. The ring 51 used as a retaining member can be reduced in diameter by, for example, removing one place in the circumferential direction, and the ring 51 is provided between the elastic body 53 and the working surface 37. It is held in a state where there is not so much rattling in the space. Note that synthetic rubber is preferably used for the elastic body 53. Further, the ring body 51 has a round-shaped protrusion 52 on its inner peripheral portion. A seal material 38 is provided in a place outside the place where the ring body 51 is provided, specifically, in the groove 36.
[0026]
The corrosion-resistant tube 8 is obtained by forming a corrosion-resistant coating layer 82 on a metal tube body 81. In the corrosion-resistant tube 8, a tip region 83 where a region not covered with the corrosion-resistant coating layer 82, that is, a metal surface on the outer periphery of the tube main body 81 is exposed is formed at the tip portion. The portion is covered with the corrosion-resistant coating layer 82, and the edge 82 a of the corrosion-resistant coating layer 82 is located at the inner end of the tip region 83. Further, an engagement portion 84 formed of an annular recess is formed at a predetermined location on the outer peripheral surface 85 of the tip region 83. Further, the outer periphery of the distal end portion of the tube main body 81 of the corrosion-resistant tube 8 is a contact portion 86 against the stopper 33.
[0027]
As shown in FIG. 1, in the state where the corrosion prevention pipe 8 is inserted into the corrosion prevention pipe joint 1, the initial state is when the contact portion 86 on the corrosion prevention pipe 8 side contacts the stopper 33 on the corrosion prevention pipe joint 1 side. At this time, the insertion allowance of the corrosion-resistant tube 8 is maximized. Therefore, the insertion allowance of the anticorrosion pipe 8 is regulated by the contact portion 86 hitting the stopper 33.
[0028]
In the initial state, the ring 51 is slidably held on the outer peripheral surface 85 of the tip region 83 of the corrosion-resistant tube 8. Accordingly, when the corrosion-resistant tube 8 is moved in the drawing direction as indicated by an arrow a from the initial state of FIG. 1, the ring 51 held in the tip region 83 of the corrosion-resistant tube 8 follows the same direction and is recessed. Move within 35. When the ring 51 hits the tapered action surface 37 that is the wall surface of the recessed portion 35, the diameter of the ring 51 is reduced by the action of the action surface 37. Therefore, when the outer peripheral surface of the distal end region 83 slides with the ring 51 and the engaging portion 84 moves to a position corresponding to the protrusion 52 of the ring 51 by the movement of the corrosion-resistant tube 8 in the drawing direction a, as shown in FIG. In addition, the protrusion 52 engages with the engaging portion 84 to exert a pull-out preventing force, and the corrosion-resistant tube 8 is prevented from coming off at that position.
[0029]
In the initial state of FIG. 1, the length L1 from the location where the sealing material 38 is provided to the end edge 82a of the corrosion-resistant coating layer 82 of the corrosion-resistant tube 8 is engaged with the ring 51 by the movement of the corrosion-resistant tube 8 in the drawing direction a. It is longer than the moving distance L2 of the anticorrosion tube 8 when it is engaged with the portion 84 to prevent the anticorrosion tube 8 from coming off.
[0030]
Therefore, even if the corrosion-resistant pipe 8 moves in the drawing direction a or the insertion direction b between the initial state shown in FIG. 1 and the retaining state shown in FIG. It remains interposed in a compressed state between the anticorrosion pipe 8 inserted into the anticorrosion pipe joint 1 and the anticorrosion coating layer 82, and adheres closely to the wall surface of the groove 36 and the outer surface of the anticorrosion coating layer 82. The gap between the parts is blocked. Therefore, even if the corrosion-resistant tube 8 moves in the drawing direction a or the insertion direction b, the metal surface forming the outer peripheral surface 85 of the distal end region 83 of the corrosion-resistant tube 8 is exposed outside the location where the sealing material 38 is provided. There is no. Therefore, when the corrosion-resistant pipe 8 and the corrosion-resistant pipe joint 1 are buried in the ground, a situation in which underground moisture adheres to the outer peripheral surface of the tip region 83 of the corrosion-resistant pipe 8 and rusts does not occur. When the corrosion-resistant pipe 8 and the corrosion-resistant pipe joint 1 are piped outdoors, there is no situation where moisture or rainwater in the outside air adheres to the outer peripheral surface of the tip region 83 of the corrosion-resistant pipe 8 and rusts.
[0031]
In the connection structure described with reference to FIGS. 1 and 2, the outer peripheral surface and the outer end surface of the corrosion-resistant pipe joint 1 are not corroded because they themselves are the corrosion-resistant surface 12. Similarly, corrosion of the portion other than the tip region 83 of the corrosion-resistant tube 8 is prevented by the corrosion-resistant coating layer 82 covering the portion. Further, the sealing material 38 ensures sealing performance that can prevent moisture from entering the pipe line. The stretchability is ensured by the sliding of the sealing material 38 and the anticorrosion coating layer 82 of the anticorrosion pipe joint 1.
[0032]
In the connection structure described above, the inner surface on the outer side of the place where the sealing member 38 of the joint body 2 is disposed, that is, the metal surface forming the inner surface 39 on the outer end side of the metallic cylindrical body 3 is the inner surface. That is, it is exposed to the outside through a gap between 39 and the anticorrosion coating layer 82 of the anticorrosion tube 8. Therefore, when the corrosion-resistant pipe 8 or the corrosion-resistant pipe joint 1 is buried in the ground, underground water adheres to the inner surface 39, and the corrosion-resistant pipe 8 or the corrosion-resistant pipe joint 1 is piped outdoors. May cause moisture or rainwater in the outside air to adhere to the inner surface 39 and rust the inner surface.
[0033]
Therefore, in order to eliminate such a problem, as shown in FIG. 5, as shown in FIG. 5, the synthetic resin coating layer covering the location where the sealing material 38 is provided in the cylindrical body 3 and the outer end surface 32 of the cylindrical body 3. It is effective to coat the inner surface (metal surface) 39 of the tubular body 3 exposed at the portion between the outer surface of 4, that is, the edge of the corrosion-resistant surface 12, with the liquid corrosion-resistant material 6. In order to coat the inner surface 39 with the liquid corrosion-resistant material 6, the liquid corrosion-resistant material 6 may be filled in the gap between the inner surface 39 and the corrosion-resistant coating layer 82. In this way, there is no possibility that the inner surface 39 rusts.
[0034]
4 and 5 show an embodiment of the invention according to claim 6. FIG. 4 is a partially longitudinal side view showing the connection structure in the initial state, and FIG. 5 is a partially longitudinal side view showing the connection structure in a state where the corrosion protection tube 8 is prevented from coming off.
[0035]
In this embodiment, the structure of the joint body 2 forming the corrosion-resistant pipe joint 1 is different from the embodiment described with reference to FIGS. 1 and 2. The joint body 2 of this embodiment includes a metal cylindrical body 71, a synthetic resin layer 72 covering the outer peripheral surface of the cylindrical body 71, and a synthetic resin cylindrical section extending from the synthetic resin layer 72. 73. The cylindrical body 71 is formed with an end portion of a metal pipe member in a bulging shape, and an annular recessed portion 75 is formed inside the bulged portion 74. The wall surface of the recessed portion 35 is A taper-shaped working surface 76 that gradually decreases in diameter in the drawing direction a of the corrosion-resistant pipe 8 inserted into the corrosion-resistant pipe joint 1. A metal ring 51 capable of reducing the diameter, which is an example of a retaining member similar to that described with reference to FIGS. 1 and 2, and a ring-shaped elastic body made of a synthetic resin having elasticity. 53 are accommodated and held side by side in the axial direction. An annular groove 77 is formed in the inner peripheral portion of the outer end of the cylindrical portion 73, and a sealing material 78 is provided in the groove 77. In addition, the outer surface of the synthetic resin layer 72 and the outer surface of the cylindrical portion 73 form the corrosion-resistant surface 12. And the corrosion-resistant pipe | tube 8 similar to what was demonstrated in FIG. 1 and FIG.
[0036]
In this connection structure, the other configurations are the same as those described with reference to FIGS. 1 and 2, and thus the same components are denoted by the same reference numerals and detailed description of the configurations is omitted.
[0037]
As shown in FIG. 4, in the state where the corrosion prevention pipe 8 is inserted into the corrosion prevention pipe joint 1, the contact portion 86 on the corrosion prevention pipe 8 side is in contact with the stopper 33 on the corrosion prevention pipe joint 1 is the initial state. By inserting the contact portion 86 against the stopper 33, the insertion allowance of the anticorrosion tube 8 is restricted.
[0038]
When the anticorrosion tube 8 is moved in the extraction direction as indicated by an arrow a from the initial state of FIG. 4, the ring 51 held in the tip region 83 of the anticorrosion tube 8 follows the same direction and enters the recess 75. Move with. When the ring 51 hits the tapered working surface 76 of the recessed portion 75, the diameter of the ring 51 is reduced by the action of the working surface 76. Therefore, when the engagement portion 84 of the tip region 83 is moved to a position corresponding to the protrusion 52 of the ring 51 by the movement of the corrosion prevention tube 8 in the drawing direction a, as shown in FIG. The pull-out preventing force is exerted by engaging with 84, and the corrosion-resistant tube 8 is prevented from coming off at that position.
[0039]
In the initial state of FIG. 4, the length L1 from the location where the sealing material 78 is provided to the edge 82a of the corrosion-resistant coating layer 82 of the corrosion-resistant tube 8 is engaged with the ring 51 by the movement of the corrosion-resistant tube 8 in the drawing direction a. 4 is longer than the moving distance L2 of the anticorrosion tube 8 when the anticorrosion tube 8 is prevented from coming off by engaging with the portion 84, so that the initial state shown in FIG. 4 and the prevention state shown in FIG. Even if the corrosion-resistant pipe 8 moves in the drawing direction a or the insertion direction b, the sealing material 78 is between the corrosion-resistant pipe joint 1 and the corrosion-resistant coating layer 82 of the corrosion-resistant pipe 8 inserted into the corrosion-resistant pipe joint 1. It remains interposed in a compressed state and closes the gap in that portion. Therefore, even if the corrosion-resistant tube 8 moves in the drawing direction a or the insertion direction b, the metal surface forming the outer peripheral surface 85 of the tip region 83 of the corrosion-resistant tube 8 is exposed outside the location where the sealing material 78 is provided. There is no. Therefore, a situation in which moisture adheres to the outer peripheral surface of the tip region 83 of the corrosion-resistant tube 8 and causes rusting does not occur.
[0040]
Since other operations are the same as those described with reference to FIGS. 1 and 2, the description of the operations is omitted here in order to simplify the description.
[0041]
6 and 7 show an embodiment of the invention according to claim 7. FIG. 6 is a partially longitudinal side view showing the connection structure in the initial state, and FIG. 7 is a partially longitudinal side view showing the connection structure in a state where the corrosion protection tube 8 is prevented from coming off.
[0042]
In this embodiment, a different point from what was demonstrated in FIG. 4 and FIG. 5 is that the annular recess 79 is formed in the inner peripheral part of the metal cylindrical body 71, The ring body 9 made of a synthetic resin is held in a fitting manner, and the ring body 9 has a taper-like action in which the diameter gradually decreases in the drawing direction a of the corrosion-resistant pipe 8 inserted into the corrosion-resistant pipe joint 1. A recess 92 having a surface 91 as a wall surface is provided on the inner peripheral side, and a retaining member composed of a ring 51 having a reduced diameter having a protrusion 52 on the inner peripheral side is moved in the axial direction. It is the point which is arranged in the fitting form possible.
[0043]
In this connection structure, the other configurations are the same as those described with reference to FIGS. 1 and 2, and thus the same components are denoted by the same reference numerals and detailed description of the configurations is omitted.
[0044]
As shown in FIG. 6, in the state where the corrosion prevention pipe 8 is inserted into the corrosion prevention pipe joint 1, the contact portion 86 on the corrosion prevention pipe 8 side is in contact with the stopper 33 on the corrosion prevention pipe joint 1 is the initial state. By inserting the contact portion 86 against the stopper 33, the insertion allowance of the anticorrosion tube 8 is restricted.
[0045]
When the anticorrosion tube 8 is moved in the drawing direction as indicated by an arrow a from the initial state of FIG. 6, the ring 51 held in the tip region 83 of the anticorrosion tube 8 follows the same direction and It moves in the recess 92. When the ring 51 hits the tapered working surface 91 of the recessed portion 92, the diameter of the ring 51 is reduced by the action of the working surface 91. Therefore, when the engagement portion 84 of the tip region 83 is moved to a position corresponding to the protrusion 52 of the ring 51 by the movement of the corrosion-resistant tube 8 in the drawing direction a, the protrusion 52 is engaged with the engagement portion as shown in FIG. The pull-out preventing force is exerted by engaging with 84, and the corrosion-resistant tube 8 is prevented from coming off at that position.
[0046]
In the initial state of FIG. 6, the length L1 from the location where the sealing material 78 is provided to the edge 82a of the corrosion-resistant coating layer 82 of the corrosion-resistant tube 8 is engaged with the ring 51 by the movement of the corrosion-resistant tube 8 in the drawing direction a. 6 is longer than the moving distance L2 of the anticorrosion tube 8 when the anticorrosion tube 8 is prevented from coming off by engaging with the portion 84, so that the initial state shown in FIG. 6 and the prevention state shown in FIG. Even if the corrosion-resistant pipe 8 moves in the drawing direction a or the insertion direction b, the sealing material 78 is between the corrosion-resistant pipe joint 1 and the corrosion-resistant coating layer 82 of the corrosion-resistant pipe 8 inserted into the corrosion-resistant pipe joint 1. It remains interposed in a compressed state and closes the gap in that portion. Therefore, even if the corrosion-resistant tube 8 moves in the drawing direction a or the insertion direction b, the metal surface forming the outer peripheral surface 85 of the tip region 83 of the corrosion-resistant tube 8 is exposed outside the location where the sealing material 78 is provided. There is no. Therefore, a situation in which moisture adheres to the outer peripheral surface of the tip region 83 of the corrosion-resistant tube 8 and causes rusting does not occur.
[0047]
Since other operations are the same as those described with reference to FIGS. 1 and 2 or FIGS. 4 and 5, the description of the operations is omitted here for the sake of brevity.
[0048]
【The invention's effect】
According to the present invention, in the connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint, the sealing performance capable of preventing moisture from entering the pipeline, the stretchability of the connection portion, and the pull-out preventing force against the corrosion-resistant pipe are satisfactorily exhibited. Although it can be made, it is possible to prevent the situation where the metal surface of the tip region of the corrosion-resistant tube is exposed and rusted outside the location where the sealing material is provided to ensure the sealing performance. effective.
[0049]
In particular, even when the corrosion-resistant tube is moved in the drawing direction and is prevented from being removed by the retaining member, the metal surface of the corrosion-resistant tube is not exposed outside the location where the sealing material is provided. It is possible to reliably prevent the rusting of the metal surface at the tip region of the corrosion-resistant tube due to the contact and the progress of corrosion from the metal surface.
[0050]
Further, the present invention provides a connection structure between a corrosion-resistant pipe and a corrosion-resistant pipe joint that can prevent not only the corrosion-resistant pipe but also the metal surface of the inner face of the corrosion-resistant pipe joint from being exposed outside the location where the sealing material is provided. It becomes possible to provide.
[Brief description of the drawings]
FIG. 1 is a partially longitudinal side view showing a connection structure in an initial state in an embodiment of the invention according to claims 1 to 4;
FIG. 2 is a partially longitudinal side view showing a connection structure in a state in which a corrosion-resistant tube is prevented from coming off in an embodiment of the invention according to claims 1 to 4;
FIG. 3 is a partial longitudinal sectional side view showing an essential part of an embodiment of the invention according to claim 5;
FIG. 4 is a partial longitudinal side view showing a connection structure in an initial state in an embodiment of the invention according to claim 6;
FIG. 5 is a partially longitudinal side view showing a connection structure in a state where a corrosion-resistant tube is prevented from being detached in an embodiment of the invention according to claim 6;
6 is a partially longitudinal side view showing a connection structure in an initial state in an embodiment of the invention according to claim 7. FIG.
7 is a partially longitudinal side view showing a connection structure in a state in which a corrosion-resistant tube is prevented from coming off in an embodiment of the invention according to claim 7. FIG.
[Explanation of symbols]
1 Corrosion-proof fittings
2 Joint body
3 Tubular body
4 Synthetic resin coating layer
6 Liquid corrosion inhibitor
8 Corrosion-proof pipe
9 Ring body
12 Corrosion-proof surface
33 Stopper
35 Recessed part
37 working surface
38 Sealing material
39 Inner surface (metal surface)
51 Ring (prevention member)
71 Cylindrical body
72 Synthetic resin layer
73 Tube
79 recess
81 Tube body
82 Corrosion-resistant coating layer
82a Edge of corrosion protection coating layer
83 Tip area
84 engaging part
86 per unit
91 Working surface
92 Recessed part
L1 Length from the location of the seal material to the edge of the anticorrosion coating layer
L2 Travel distance of corrosion resistant tube
a Pulling direction

Claims

The inner periphery of the tubular joint body is provided with a retaining member and a seal material disposed at a location outside the location where the retaining member is disposed, and the outer peripheral surface and the outer end surface of the joint body are corrosion-resistant surfaces. Corrosion-proof pipe joints,
Corrosion-proof covering a metal tube body covering the tip region formed on the tip of the metal tube body and exposing the outer peripheral metal surface and the portion excluding the tip region, and having an edge positioned at the inner end of the tip region A corrosion-resistant tube provided with a coating layer and an engagement portion formed in the tip region and engageable with the retaining member;
Have
A gap between the corrosion-resistant pipe joint and the corrosion-resistant coating layer of the corrosion-resistant pipe inserted into the corrosion-resistant pipe joint is closed by the sealing material, and an outer peripheral surface formed by a metal surface of the tip region of the corrosion-resistant pipe. Correspondingly, the retaining member is located, and the engagement portion is located on the distal end side of the corrosion-resistant tube from the position of the retaining member,
The length from the location where the sealing material is disposed to the edge of the anticorrosion coating layer is such that the anticorrosion tube moves in the pulling direction so that the retaining member engages with the engaging portion and comes out of the anticorrosion tube. A connection structure between a corrosion-resistant pipe and a corrosion-resistant pipe joint, characterized in that it is longer than the distance traveled by the corrosion-resistant pipe when it is stopped.

A concave portion provided with a wall having a tapered working surface whose diameter gradually decreases in the drawing direction is formed in the inner peripheral portion of the joint body, and the outer peripheral surface of the tip region of the corrosion-resistant pipe is formed in the concave portion. The retaining member, which is a slidable ring that is slidably held on the inner peripheral side and has a projecting portion on the inner peripheral side, is disposed in a fitting manner so as to be axially movable, and The connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint according to claim 1, wherein the engagement portion is provided on an outer peripheral surface of the tip region, and the protrusion of the ring is an annular recess that can be engaged in a fitting manner.

A stopper is provided on the inner peripheral part of the joint body, which is disposed at an inner side of the position where the retaining member is disposed and restricts the insertion allowance of the corrosion prevention pipe. The connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint according to claim 1 or 2, wherein a contact portion for restricting the insertion allowance of the corrosion-resistant pipe to the joint is provided.

The joint main body has a metallic cylindrical body having an installation location of the retaining member and an installation location of the sealing material on an inner peripheral portion thereof, and a synthetic resin that covers an outer peripheral surface and an outer end surface of the cylindrical body. The connection structure between the corrosion-resistant pipe and the corrosion-resistant pipe joint according to any one of claims 1, 2, and 3, wherein the outer surface of the synthetic resin coating layer is the corrosion-resistant surface.

The metal surface of the cylindrical body exposed at a portion between the location where the sealing material is disposed in the cylindrical body and the edge of the corrosion-proof surface covering the outer end surface of the cylindrical body is a liquid corrosion inhibitor. The connection structure of the corrosion-resistant pipe and the corrosion-resistant pipe joint according to claim 4, wherein the corrosion-resistant pipe is coated with

The joint main body has a metallic cylindrical body having a location where the retaining member is disposed on an inner peripheral portion thereof, a synthetic resin layer covering the outer peripheral surface of the cylindrical body, and extends from the synthetic resin layer; The synthetic resin cylinder part which has the deployment location of the said sealing material in an inner peripheral part, The outer surface of the said synthetic resin layer and the outer surface of the said cylinder part are the said corrosion-proof surface, Claim 1 The connection structure of the corrosion-resistant pipe and the corrosion-resistant pipe joint according to claim 2.

The joint body includes a metal cylindrical body, a synthetic resin layer that covers the outer peripheral surface of the cylindrical body, and a synthetic resin that extends from the synthetic resin layer and has a location where the sealing material is provided on the inner peripheral portion. And the outer surface of the synthetic resin layer and the outer surface of the cylindrical portion are the anticorrosive surface,
An annular recess is formed in the inner peripheral part of the cylindrical body, and a synthetic resin made of a synthetic resin provided with a recessed part on the inner peripheral side having a tapered working surface whose wall surface gradually decreases in the drawing direction. The ring body is fitted in the recess, and the retaining member made of a ring that can be reduced in diameter and has a protrusion on the inner peripheral side is fitted in the recess of the ring body so as to be movable in the axial direction. 2. The ring-shaped concave portion, wherein the engagement portion of the tip region of the anticorrosion tube is provided on the outer peripheral surface of the tip region and the protrusion of the ring is engageable in a fitting manner. A connection structure between the corrosion-resistant pipe according to claim 3 and the corrosion-resistant pipe joint.