JP3926683B2

JP3926683B2 - Flexible pressure-resistant synthetic resin tube

Info

Publication number: JP3926683B2
Application number: JP2002172188A
Authority: JP
Inventors: 昭夫永吉; 清治永吉
Original assignee: ユーシー産業株式会社
Priority date: 2002-06-13
Filing date: 2002-06-13
Publication date: 2007-06-06
Anticipated expiration: 2022-06-13
Also published as: JP2004019701A

Description

【０００１】
【発明の属する技術分野】
本発明は可撓性と耐圧強度を要求される排水管等の流体供給用管や地中埋設管、或いは、電線保護管などの耐圧合成樹脂管に関するものである。
【０００２】
【従来の技術】
従来から、可撓性を有する合成樹脂管としては軟質合成樹脂製管があり、耐圧性を有する合成樹脂管としては硬質合成樹脂製管が知られているが、軟質合成樹脂製管の場合には耐圧強度が弱くて土圧等の外圧を受ける場所には使用することができない一方、硬質合成樹脂製管の場合には可撓性が殆ど有していないために、施工性や取扱性に困難をきたすという問題点がある。
【０００３】
このため、例えば、特開平10−110869号公報に記載されているように、軟質合成樹脂製ホースの外周面に硬質合成樹脂材料よりなる螺旋補強体を一定のピッチでもって螺旋巻きし、軟質合成樹脂製ホースによる可撓性と共に該螺旋補強体による耐圧強度を発揮させるように構成した可撓性を有する耐圧合成樹脂管が開発されている。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記耐圧合成樹脂管によれば、軟質合成樹脂製ホースの外周面に螺旋巻きしている螺旋補強体は、軟質合成樹脂製ホースの外周面に融着している小幅の底辺部の一端から立ち上がり部を介して底辺部と反対方向に延設された庇状の突設部とからなり、隣接する螺旋補強体における庇状突設部間に隙間を設けた構造としているために、この隙間を通じて土砂等が軟質合成樹脂製ホースの外周面と庇状突設部の内周面間の空間部に侵入、充満して軟質合成樹脂製ホースを損傷させる虞れがあると共に土砂その他の不純物が付着、堆積して屈曲性を損なう虞があり、その上、取扱中や施工中において庇状突設部の先端に他物が引っ掛かった場合には、該庇状突設部を有する螺旋補強体が破損する虞れがあって取り扱いに注意を要するという問題点がある。
【０００５】
さらに、この耐圧合成樹脂管を円弧状に屈曲させた場合、凸円弧状に湾曲した周壁部側においては、隣接する螺旋補強体における庇状突設部間が長さ方向の引張力によってさらに離間してその離間部から隣接する螺旋補強体における底辺部間の軟質合成樹脂製ホース部分の外周面が外部に露呈し、その露呈部が他物により直接、損傷を受ける虞れが生じると共に、凹円弧状に湾曲した反対側の周壁部側においては、圧縮力によって隣接する螺旋補強体における一方の庇状突設部の先端が他方の庇状突設部の背面に当接してそれ以上の変形が阻止され、従って、耐圧合成樹脂管の屈曲度が制限されると共に、それ以上屈曲させると耐圧合成樹脂管が偏平状に座屈、変形して排水機能等が低下する上に損傷するという問題点があった。
【０００６】
本発明は上記のような問題点に鑑みてなされたもので、その目的とするところは、優れた耐圧強度及び耐磨耗性を有していると共に良好な可撓性を発揮し、且つ損傷などが生じ難い上に排水管として採用した場合には円滑な排水を可能にし得る可撓性を有する耐圧合成樹脂管を提供するにある。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、本発明の可撓性を有する耐圧合成樹脂管は、請求項１に記載したように、軟質合成樹脂製管の外周面を硬質合成樹脂製外殻によって被覆してなる耐圧合成樹脂管であって、軟質合成樹脂製管の外周面に硬質合成樹脂製紐状材を一定のピッチでもって螺旋状に巻回、融着し、この硬質合成樹脂製紐状材に該硬質合成樹脂製紐状材間のピッチよりも広幅に形成されている硬質合成樹脂製帯状材の一端部内周面を融着、一体化させると共に、先に巻回した硬質合成樹脂製帯状材部上に次に巻回した硬質合成樹脂製帯状材部の少なくとも一部を重ね合わせた状態で螺旋巻きして上記硬質合成樹脂製外殻を形成していることを特徴とする。
【０００８】
さらに、請求項２に係る発明は、上記硬質合成樹脂製帯状材の幅方向の両端部が外面側に向かって凸円弧状に湾曲した湾曲部に形成されてあり、軟質合成樹脂製管の外周面に螺旋巻きしている硬質合成樹脂製紐状材にその一端側の湾曲部を一体に融着している共に、先に巻回した硬質合成樹脂製帯状材部における該湾曲部上に、次に巻回した硬質合成樹脂製帯状材部の他端部側の湾曲部を重ね合わせて硬質合成樹脂製外殻を形成した構造としている。
【０００９】
【作用】
軟質合成樹脂製管の外周面は、硬質合成樹脂製帯状材を一定幅だけ管軸方向にずらして重ね合わせながら螺旋状に巻回してなる硬質合成樹脂製外殻によって被覆された構造となっているので、この硬質合成樹脂製外殻によって軟質合成樹脂製管が全面的に被覆されて全長に亘り均一な耐圧強度を発揮する合成樹脂管を形成することができ、その上、隣接する硬質合成樹脂製帯状材部が隙間なく断面鱗状に重ね合わされているから、土砂等が軟質合成樹脂製管の外周面側に侵入、付着する虞れもなく、軟質合成樹脂製管を全面的に保護して長期の使用に供する耐圧合成樹脂管を提供することができる。
【００１０】
さらに、硬質合成樹脂製帯状材の一端部内周面のみを上記軟質合成樹脂製管の外周面に一定のピッチでもって螺旋状に固着すると共に、隣接する硬質合成樹脂製帯状材部を一体に融着することなく断面鱗状に重ね合わせているので、この耐圧合成樹脂管を屈曲させた時に、断面鱗状に重ね合わせている硬質合成樹脂製帯状材部が互いに管軸方向に摺動しながら円滑に屈曲すると共に、大きく屈曲させた場合においても隣接する硬質合成樹脂製帯状材部が互いに重なり合った状態を保持して軟質合成樹脂製管が保護され、所定の耐圧強度を維持することができる。また、軟質合成樹脂製管の内周面は、全長に亘って略平坦な面に形成されているから排水等の流通が円滑に行われる。
【００１１】
軟質合成樹脂製管の外周面を全面的に被覆している硬質合成樹脂製外殻は、軟質合成樹脂製管の外周面に硬質合成樹脂製紐状材を螺旋状に巻回、融着してこの螺旋巻きした紐状材上に硬質合成樹脂製帯状材を、その一端部内周面を一体に融着させながら螺旋巻きした合成樹脂管の構造としている。この合成樹脂管によれば、軟質合成樹脂製管の外周面に螺旋巻きしてなる硬質合成樹脂製紐状材によって合成樹脂管の圧潰変形が生じがたく、耐圧強度が一層増大する。
【００１２】
また、請求項２に記載したように、上記硬質合成樹脂製帯状材の幅方向の両端部を外面側に向かって凸円弧状に湾曲した湾曲部に形成しておき、上記軟質合成樹脂製管の外周面に螺旋巻きしている硬質合成樹脂製紐状材にその一端側の湾曲部を一体に融着している共に、先に巻回した硬質合成樹脂製帯状材部における該湾曲部上に、次に巻回した硬質合成樹脂製帯状材部の他端部側の湾曲部を重ね合わせて硬質合成樹脂製外殻を形成した構造としておくことによって、あたかも腹蛇管のような体裁のよい外観を呈するばかりでなく、この合成樹脂管を屈曲させた場合においては、硬質合成樹脂製外殻を形成している隣接する硬質合成樹脂製帯状材同士が、互いに凸円弧状の湾曲部によって常に隙間なく重なり合った状態を維持しながらこの湾曲部に沿って屈曲し、円滑にして正確な屈曲が可能となるものである。
【００１３】
【発明の実施の形態】
次に、本発明の具体的な実施の形態を図面について説明すると、図１は可撓性を有する耐圧合成樹脂管Ａの一部を断面した簡略側面図であって、この耐圧合成樹脂管Ａは軟質塩化ビニルからなる軟質合成樹脂製管１の外周面に硬質塩化ビニルからなる屈曲変形が可能な硬質合成樹脂製外殻２を一体に被覆した構造を有している。なお、軟質合成樹脂製管１や硬質合成樹脂製外殻２は、それぞれ軟質、硬質の塩化ビニル樹脂から形成しているが、その他の接着性が良好な同質材料で且つ硬度の異なって合成樹脂材、例えば、硬質ポリエチレン樹脂と軟質ポリエチレン樹脂等から形成しておいてもよい。
【００１４】
上記硬質合成樹脂製外殻２は、軟質合成樹脂製管１の外周面に一定のピッチでもって全長に亘って螺旋巻きし且つその内面を軟質合成樹脂製管１の外周面に融着している断面横長矩形状又は楕円形状の硬質合成樹脂製紐状材2Bと、この硬質合成樹脂製紐状材2Bにその一方の長辺側の一端部内周面を融着により一体に固着し且つ硬質合成樹脂製紐状材2Bと同一ピッチでもって螺旋巻きしてなる硬質合成樹脂製帯状材2Aとから構成されている。
【００１５】
さらに、この硬質合成樹脂製帯状材2Aにおける管軸方向の幅、即ち、両側長辺端縁間の幅Ｗは、上記硬質合成樹脂製紐状材2BのピッチＰよりも大きい幅に形成されてあり、従って、硬質合成樹脂製帯状材2Aを、その一端部内周面を硬質合成樹脂製紐状材2Bに融着させながら該紐状材2Bと同一ピッチでもって軟質合成樹脂製管１上に螺旋巻きして硬質合成樹脂製外殻２を形成した形態においては、先に巻回した硬質合成樹脂製帯状材部2a上に次に巻回した硬質合成樹脂製帯状材部2aが管軸方向に巻きピッチＰだけずれた状態で断面鱗状に重ね合わされた構造となっている。
【００１６】
即ち、図１においては、硬質合成樹脂製帯状材2Aの幅Ｗは巻きピッチＰの略２倍に形成されてあり、従って、先に巻回した硬質合成樹脂製帯状材部2aの一端部側（基端部側）の１／２幅部分上に次に巻回した硬質合成樹脂製帯状材部2aの他端部側（先端部側）の１／２幅部分が重なった状態となっている。さらに、この重なり合った部分は融着されておらず、互いにその対向面を摺動可能に密接した状態となっている。
【００１７】
なお、巻きピッチＰに対する硬質合成樹脂製帯状材2Aの幅を余り大きくすると、硬質合成樹脂製外殻２の屈曲性（可撓性）が低下すると共に、屈曲させた場合に、凸円弧状に屈曲した周壁部側においては先に巻回した硬質合成樹脂製帯状材部2a、即ち、内側の硬質合成樹脂製帯状材部2aの外周面と次に巻回した硬質合成樹脂製帯状材部2a、即ち、外側の硬質合成樹脂製帯状材部2aの先端との間に比較的大きな隙間が生じるので、硬質合成樹脂製帯状材2Aの幅を巻きピッチＰの1.5 〜3.0 の幅として内側の硬質合成樹脂製帯状材部2aに外側の硬質合成樹脂製帯状材部2aの少なくとも先端部が重ね合わせた構造となるようにしておくことが望ましい。勿論、上記のような隙間が生じても、内側の硬質合成樹脂製帯状材部2aの一端部上に外側の硬質合成樹脂製帯状材部2aの対向内面が密接した状態を保持しているから、内部に向かって土砂等が浸入する虞れはない。
【００１８】
このように構成した合成樹脂管Ａは、硬質合成樹脂製外殻２によって全長に亘り均一な耐圧強度を発揮すると共に、この硬質合成樹脂製外殻２を形成している硬質合成樹脂製帯状材2Aは、先に巻回した帯状材部2aに次に巻回した帯状材部2aが巻きピッチＰの幅だけ管軸方向にずれた状態で順次重なり合って軟質合成樹脂製管１の外周面を被覆した構造となっているので、硬質合成樹脂製外殻２は恰も軟質合成樹脂製管１を内管とした通常の螺旋巻き管の外管形状を呈し、外周面が管軸方向に連続した形状を有して取扱性、施工性が向上するものである。
【００１９】
さらに、図２に示すように、この合成樹脂管Ａを円弧状に屈曲（湾曲）させると、軟質合成樹脂製管１は容易に屈曲すると共にこの軟質合成樹脂製管１と共に硬質合成樹脂製外殻２も一体に屈曲することになる。この硬質合成樹脂製外殻２の屈曲形態は、凸円弧状に屈曲した外側周壁部A1においては、管軸方向に引張力が発生して硬質合成樹脂製紐状材2Bの隣接する紐状材2b、2b上に一体に融着している硬質合成樹脂製帯状材部2a、2a間の軟質合成樹脂製管部が緊張すると共に、その管部分が凸円弧状に湾曲してこの湾曲によって内側の帯状材部2a上に重なっている外側の帯状材部2aの先端が内側の帯状材部2aの外面に対して外方に離間して僅かな隙間（開口）が生じるが、外側の帯状材部2aの管軸方向の少なくとも一部が常に内側帯状材部2aの外面の少なくとも一部に周方向に全面的に密接した状態を維持しているものである。
【００２０】
一方、凹円弧状に屈曲した内側周壁部A2においては、管軸方向に圧縮力が発生してその圧縮力により硬質合成樹脂製紐状材2Bの隣接する紐状材2b、2b上に一体に融着している硬質合成樹脂製帯状材部2a、2a間の軟質合成樹脂製管部分が円弧長方向に収縮すると共にその収縮によって内側の帯状材部2a上に外側の帯状材部2aが一層、強固に圧着した状態となるものである。
【００２１】
従って、例えば、この合成樹脂管Ａを排水管として床下や地中に敷設する場合には、自由に屈曲させながら計画通りに配管することができると共に、土砂等の異物が硬質合成樹脂製外殻２の内面側に侵入するのを確実に防止して長期間に亘る使用を可能にし、その上、硬質合成樹脂製外殻２によって全面的に被覆されている軟質合成樹脂製管１の内周面は長さ方向に比較的平坦な面に形成されているから、円滑な流通が可能となるものである。また、この合成樹脂管Ａは、図３に示すように、電線Ｃの保護管として地中に埋設して使用することもできる。
【００２２】
次に、このように構成した耐圧合成樹脂管Ａの製造方法を図４に基づいて簡単に説明すると、一定幅と厚みを有する半溶融状態の軟質塩化ビニル樹脂よりなる軟質合成樹脂製帯状材11を第１成形ノズル21から押し出しながら周知のように成形回転軸20の基端部上に、先行する帯状材部11a の一側部上に後続する帯状材部11a の他側部を重ね合わせて一体に溶着させながら一定のピッチでもって螺旋状に巻回することによって軟質合成樹脂製管１を形成していくと共に、この軟質合成樹脂製管１上に、第２成形ノズル22から断面が偏平な矩形状又は楕円形状の半溶融状態の硬質塩化ビニル樹脂よりなる紐状材2Bを押し出しながら、一定のピッチでもって螺旋状に巻回し、軟質合成樹脂製管１の外周面に融着させる。
【００２３】
さらに、この硬質合成樹脂製紐状材2Bを軟質合成樹脂製管１上に一定のピッチでもって螺旋巻きする工程に引き続いて、第３成形ノズル23から硬質合成樹脂製紐状材2Bと同一材料よりなり且つ幅が紐状材2Bの巻きピッチの略２倍の幅を有する半溶融状態の硬質合成樹脂製帯状材2Aを押し出してその一方の長辺縁部側の一端部内面のみを紐状材2Bに一体に融着させながら、軟質合成樹脂製管１の外周面上に、先に巻回した帯状材部2aの幅方向の一半部上に次に巻回した帯状材部2aの幅方向の他半部を順次断面鱗状に重ね合わせるようにして紐状材2Bと同一ピッチでもって螺旋状に巻装することにより硬質合成樹脂製外殻２を形成するものである。
【００２４】
この際、半溶融状の硬質合成樹脂製帯状材2Aを軟質合成樹脂製管１上に螺旋巻きする前に、第３成形ノズル23から押し出した該半溶融状の硬質合成樹脂製帯状材2Aを冷風の吹き付け等による冷却装置24を通過させて軟質合成樹脂製管１上で帯状材部2a、2a同士を重ね合わせた時に互いに融着することなく螺旋状に巻回させると共に、その一端部内周面のみを加熱装置25によって加熱、溶融させて硬質合成樹脂製紐状材2Bに一体に融着させるものである。
【００２５】
こうして、軟質合成樹脂製管１の外周面に硬質合成樹脂製外殻２を設けてなる可撓性を有する耐圧合成樹脂管Ａを成形回転軸20上で連続的に製造し、所望長さ毎に切断して所定長の合成樹脂管Ａを得るものである。
【００２６】
図５は本発明可撓性を有する耐圧合成樹脂管の別な実施の形態を示すもので、上記実施の形態においては、硬質合成樹脂製外殻２を形成している硬質合成樹脂製帯状材2Aを内外面とも全幅に亘って略平坦な面に形成しているが、この実施の形態においては、硬質合成樹脂製帯状材2A' の管軸方向の幅を硬質合成樹脂製紐状材2Bの巻きピッチＰよりもこの紐状材2Bの幅だけ広い幅に形成していると共に該硬質合成樹脂製帯状材2A' の幅方向の両端部を外面側に向かって凸円弧状に湾曲している湾曲部2b、2cに形成し、先に巻回した帯状材部2a' における硬質合成樹脂製紐状材2Bに一体に融着した一端側の湾曲部2b上に、次に巻回した帯状材部2a' の他端部側の湾曲部2cを係止状態に重ね合わせて硬質合成樹脂製外殻2'を形成しているものである。
【００２７】
即ち、軟質合成樹脂製管１上に硬質合成樹脂製紐状材2Bを一定のピッチＰでもって螺旋巻きしてその内面を軟質合成樹脂製管１に一体に融着してあり、この軟質合成樹脂製管１上に硬質合成樹脂製帯状材2A' の一端側の湾曲部2bを融着させながら硬質合成樹脂製紐状材2Bと同一ピッチでもって螺旋巻きして先に巻回した硬質合成樹脂製帯状材部2a' の上記一端側湾曲部2b上に、次に巻回した硬質合成樹脂製帯状材部2a' の他端部側の湾曲部2cを融着させることなく重ね合わせた構造としている。
【００２８】
このように構成した合成樹脂管A'は、上記実施の形態で示した合成樹脂管Ａと同様に、硬質合成樹脂製外殻2'によって全長に亘り均一な耐圧強度を発揮するのは勿論、この硬質合成樹脂製外殻2'を形成している硬質合成樹脂製帯状材2A' は、先に巻回した帯状材部2a' の一端側湾曲部2bを硬質合成樹脂製紐状材2Bに一体に融着させ、この湾曲部2b上に次に巻回した帯状材2a' の他端側湾曲部2cを重ね合わせることにより上記硬質合成樹脂製外殻2'を形成しているので、この硬質合成樹脂製外殻2'は恰も軟質合成樹脂製管１を内管とした腹蛇管のような体裁のよい外観を呈する。
【００２９】
さらに、この合成樹脂管A'を屈曲させた場合においては、図６に示すように、硬質合成樹脂製外殻2'を形成している隣接する硬質合成樹脂製帯状材部2a' 、2a' が硬質合成樹脂製紐状材2B上に融着している一方の硬質合成樹脂製帯状材2a' の凸円弧状湾曲部2b上に他方の硬質合成樹脂製帯状材2a' の先端側の凸円弧状湾曲部2cが常に隙間なく係止した状態で該凸円弧面の円弧方向に摺動しながら円滑且つ正確に屈曲するものである。
【００３０】
なお、上記いずれの可撓性を有する耐圧合成樹脂管Ａ、A'においても、長さ方向の所定部分を外力によって円弧状に屈曲させたのち、その外力を解くと、元の直管形状に復元するものである。
【００３１】
【発明の効果】
以上のように本発明の可撓部を有する耐圧合成樹脂管は、請求項１に記載したように、軟質合成樹脂製管の外周面を硬質合成樹脂製外殻によって被覆してなる耐圧合成樹脂管であって、上記硬質合成樹脂製外殻は、一定幅を有する硬質合成樹脂製帯状材を上記軟質合成樹脂製管の外周面に一定のピッチでもって螺旋状に巻回しながらその一端部内周面のみを軟質合成樹脂製管の内管の外周面に一体に固着し且つ先に巻回した帯状材部上に次に巻回した帯状材部を管軸方向に一定幅だけずらした状態で重ね合わせた構造としているので、硬質合成樹脂製外殻により軟質合成樹脂製管を全面的に被覆、保護することができると共に、全長に亘って均一な耐圧強度を発揮することができ、その上、硬質合成樹脂製外殻を形成している隣接する硬質合成樹脂製帯状材部同士が隙間なく断面鱗状に重ね合わされているから、土砂等の異物が内部に侵入する虞れもなく、軟質合成樹脂製管を全面的に保護して長期の使用に耐えることができる耐圧合成樹脂管を提供し得るものである。
【００３２】
さらに、硬質合成樹脂製帯状材の一端部内周面のみを上記軟質合成樹脂製管の外周面に一定のピッチでもって螺旋状に固着すると共に、隣接する硬質合成樹脂製帯状材部を一体に融着することなく断面鱗状に重ね合わせているので、この耐圧合成樹脂管を屈曲させた時に、断面鱗状に重ね合わせている硬質合成樹脂製帯状材部が互いに管軸方向に摺動しながら円滑に屈曲すると共に、大きく屈曲させた場合においても隣接する硬質合成樹脂製帯状材部が互いに重なり合った状態を保持して全面的に耐圧強度を発揮することができ、また、軟質合成樹脂製管の内周面は、全長に亘って略平坦な面に形成されているから排水管等に使用した場合には排水の流通が良好となるものである。
【００３３】
さらに、上記軟質合成樹脂製管の外周面に硬質合成樹脂製紐状材を一定のピッチでもって螺旋状に巻回、融着し、この硬質合成樹脂製紐状材に該硬質合成樹脂製紐状材間のピッチよりも広幅に形成されている硬質合成樹脂製帯状材の一端部内周面を融着、一体化させ、且つ、先に巻回した硬質合成樹脂製帯状材部上に次に巻回した硬質合成樹脂製帯状材部の少なくとも一部を重ね合わせた状態で螺旋巻きして硬質合成樹脂製外殻を形成しているので、製造が容易で多量生産に適する合成樹脂管の構造を提供することができると共に、軟質合成樹脂製管の外周面に螺旋巻きしている硬質合成樹脂製紐状材によって耐圧強度が一層増大し、圧潰変形が生じ難い合成樹脂管を構成することができる。
【００３４】
また、請求項２に係る発明によれば、上記硬質合成樹脂製帯状材の幅方向の両端部を外面側に向かって凸円弧状に湾曲した湾曲部に形成し、上記軟質合成樹脂製管の外周面に螺旋巻きしている硬質合成樹脂製紐状材にその一端側の湾曲部を一体に融着している共に、先に巻回した硬質合成樹脂製帯状材部における該湾曲部上に、次に巻回した硬質合成樹脂製帯状材部の他端部側の湾曲部を重ね合わせて硬質合成樹脂製外殻を形成した構造としているので、あたかも腹蛇管のような体裁のよい外観を呈するばかりでなく、この合成樹脂管を屈曲させた場合においては、硬質合成樹脂製外殻を形成している隣接する硬質合成樹脂製帯状材同士が、互いに凸円弧状の湾曲部によって常に隙間なく重なり合った状態を維持しながらこの湾曲部に沿って屈曲し、円滑にして正確な屈曲が可能となると共に、軟質合成樹脂製管側への異物の侵入を確実に防止して長期の使用に耐えることができるものである。
【図面の簡単な説明】
【図１】可撓性を有する耐圧合成樹脂管の一部分の一部を断面した簡略側面図、
【図２】屈曲させた状態の一部を断面した簡略側面図、
【図３】使用状態の一例を示す簡略縦断側面図、
【図４】製造方法を説明するための簡略側面図、
【図５】本発明の別な実施の形態を示す一部を断面した簡略側面図、
【図６】屈曲させた状態の一部を断面した簡略側面図。
【符号の説明】
Ａ可撓性を有する耐圧合成樹脂管
１軟質合成樹脂製管
２硬質合成樹脂製外殻
2A 硬質合成樹脂製帯状材
2B 硬質合成樹脂製紐状材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid supply pipe such as a drain pipe and a underground pipe, or a pressure resistant synthetic resin pipe such as a wire protection pipe, which are required to have flexibility and pressure resistance.
[0002]
[Prior art]
Conventionally, as a synthetic resin tube having flexibility, there is a soft synthetic resin tube, and as a synthetic resin tube having pressure resistance, a hard synthetic resin tube is known, but in the case of a soft synthetic resin tube, Can not be used in places subject to external pressure such as earth pressure because of its weak pressure resistance, but in the case of hard synthetic resin pipes it has little flexibility, so it is easy to work and handle There is a problem of causing difficulty.
[0003]
For this reason, for example, as described in Japanese Patent Application Laid-Open No. 10-110869, a helical reinforcement body made of a hard synthetic resin material is spirally wound at a constant pitch on the outer peripheral surface of a soft synthetic resin hose, A flexible pressure-resistant synthetic resin pipe has been developed that is configured to exhibit the pressure-resistant strength of the helical reinforcing body as well as the flexibility of a resin hose.
[0004]
[Problems to be solved by the invention]
However, according to the pressure-resistant synthetic resin tube, the spiral reinforcing body spirally wound around the outer peripheral surface of the soft synthetic resin hose is one end of the narrow bottom portion fused to the outer peripheral surface of the soft synthetic resin hose. Since it has a structure in which a gap is provided between the hook-shaped projecting portions of the adjacent spiral reinforcing bodies, the projecting portion extends from the base portion in the opposite direction to the bottom side portion. Sediment and other impurities may enter the space between the outer peripheral surface of the soft synthetic resin hose and the inner peripheral surface of the bowl-shaped projecting portion through the gap and fill the space to damage the soft synthetic resin hose. In addition, there is a risk that adhesion and deposition may impair the flexibility, and in addition, when other objects are caught on the tip of the hook-shaped protruding portion during handling or construction, the spiral reinforcement having the hook-shaped protruding portion Handle with care as there is a risk of body damage There is a problem to say.
[0005]
Further, when this pressure-resistant synthetic resin tube is bent in an arc shape, on the side of the peripheral wall portion curved in a convex arc shape, the hook-like projecting portions in the adjacent spiral reinforcing bodies are further separated by a tensile force in the length direction. Then, the outer peripheral surface of the soft synthetic resin hose portion between the bottom portions of the adjacent spiral reinforcement body from the separated portion is exposed to the outside, and the exposed portion may be directly damaged by other objects, and the concave portion may be recessed. On the opposite peripheral wall side that is curved in an arc shape, the tip of one hook-shaped protruding portion of the adjacent spiral reinforcement body abuts against the back surface of the other hook-shaped protruding portion by compressive force, and further deformation occurs. Therefore, the degree of bending of the pressure-resistant synthetic resin tube is limited, and if the pressure-resistant synthetic resin tube is bent further, the pressure-resistant synthetic resin tube is buckled and deformed in a flat shape and the drainage function etc. is deteriorated and damaged. There was a point.
[0006]
The present invention has been made in view of the above-mentioned problems, and its object is to have excellent pressure resistance and wear resistance, and to exhibit good flexibility and damage. In addition, there is a need to provide a pressure-resistant synthetic resin pipe having flexibility that can enable smooth drainage when it is employed as a drain pipe.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a flexible pressure-resistant synthetic resin pipe according to the present invention comprises a soft synthetic resin outer shell coated with a hard synthetic resin outer shell as described in claim 1. This is a pressure-resistant synthetic resin pipe, and a hard synthetic resin string-like material is spirally wound and fused at a constant pitch on the outer peripheral surface of a soft synthetic resin pipe. The hard synthetic resin belt-like material wound first is fused and integrated with the inner peripheral surface of one end of the hard synthetic resin belt-like material formed wider than the pitch between the hard synthetic resin string-like materials. The hard synthetic resin outer shell is formed by spirally winding at least a part of the hard synthetic resin belt-shaped material portion wound next on the portion.
[0008]
Furthermore, in the invention according to claim 2 , both end portions in the width direction of the hard synthetic resin strip-like material are formed in curved portions that are curved in a convex arc shape toward the outer surface, and the outer periphery of the soft synthetic resin pipe On the curved portion of the hard synthetic resin belt-shaped material portion wound first, the curved portion on one end side is integrally fused to the hard synthetic resin string-shaped material spirally wound on the surface, Next, the hard synthetic resin outer shell is formed by superimposing the curved portion on the other end side of the wound hard synthetic resin belt-shaped material portion.
[0009]
[Action]
The outer peripheral surface of the soft synthetic resin pipe is covered with a hard synthetic resin outer shell formed by winding a hard synthetic resin belt-like material in a spiral shape while shifting it in the pipe axis direction by a certain width. Therefore, a soft synthetic resin pipe is entirely covered with this hard synthetic resin outer shell, so that a synthetic resin pipe that exhibits uniform compressive strength over the entire length can be formed. Since the resin strips are overlapped in a cross-sectional scale without any gaps, there is no risk of earth and sand entering and attaching to the outer peripheral surface of the soft synthetic resin pipe, protecting the soft synthetic resin pipe entirely. In addition, it is possible to provide a pressure-resistant synthetic resin tube for long-term use.
[0010]
Furthermore, only the inner peripheral surface of one end portion of the hard synthetic resin strip is fixed to the outer peripheral surface of the soft synthetic resin tube in a spiral manner at a constant pitch, and the adjacent hard synthetic resin strip member is fused together. Since they are superposed in a scale shape without being worn, when this pressure-resistant synthetic resin tube is bent, the rigid synthetic resin belt-like material parts superposed in a cross-sectional scale shape slide smoothly in the direction of the tube axis. Even when bent, it is possible to maintain the predetermined pressure strength by maintaining the state in which the adjacent hard synthetic resin strips are overlapped with each other even when they are bent greatly. Moreover, since the inner peripheral surface of the soft synthetic resin pipe is formed in a substantially flat surface over the entire length, the flow of drainage and the like is smoothly performed.
[0011]
The outer wall of the hard synthetic resin that covers the entire outer surface of the soft synthetic resin pipe is wound around the outer surface of the soft synthetic resin pipe in a spiral manner and fused. A synthetic synthetic resin pipe is formed by spirally winding a rigid synthetic resin strip on a helically wound string-like material while fusing the inner peripheral surface of one end thereof integrally . According to this synthetic resin pipe, the synthetic resin pipe is hardly crushed and deformed by the hard synthetic resin string-like material spirally wound around the outer peripheral surface of the soft synthetic resin pipe, and the pressure strength is further increased.
[0012]
According to a second aspect of the present invention, both ends in the width direction of the hard synthetic resin strip are formed into curved portions that are curved in a convex arc shape toward the outer surface, and the soft synthetic resin pipe is formed. The curved portion at one end is integrally fused to the hard synthetic resin cord-like material spirally wound on the outer peripheral surface of the belt, and the curved portion of the hard synthetic resin-made belt-like material portion wound earlier is In addition, the curved portion on the other end side of the wound hard synthetic resin belt-shaped material portion is overlapped to form a hard synthetic resin outer shell, so that it looks like a belly snake tube. When the synthetic resin pipe is bent, not only the appearance but also the adjacent hard synthetic resin strips forming the hard synthetic resin outer shell are always bent by the convex arcuate curved portions. This bay is maintained without any gaps Parts bent along the one in which smoothly to correct bending is possible.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a simplified side view of a part of a flexible pressure-resistant synthetic resin tube A. Has a structure in which the outer surface of a soft synthetic resin tube 1 made of soft vinyl chloride is integrally covered with a hard synthetic resin outer shell 2 made of hard vinyl chloride that can be bent and deformed. The soft synthetic resin pipe 1 and the hard synthetic resin outer shell 2 are made of soft and hard vinyl chloride resin, respectively. You may form from materials, for example, a hard polyethylene resin, a soft polyethylene resin, etc.
[0014]
The hard synthetic resin outer shell 2 is spirally wound over the outer peripheral surface of the soft synthetic resin pipe 1 over the entire length with a constant pitch, and its inner surface is fused to the outer peripheral surface of the soft synthetic resin pipe 1. A rigid synthetic resin string-like material 2B having a horizontally long rectangular or elliptical cross section, and an inner peripheral surface of one end portion on one long side thereof are firmly fixed to the rigid synthetic resin string-like material 2B by fusion and rigid. It is composed of a synthetic resin cord-like material 2B and a hard synthetic resin-made belt-like material 2A that is spirally wound at the same pitch.
[0015]
Furthermore, the width in the tube axis direction of the hard synthetic resin strip-like material 2A, that is, the width W between the long side edges of both sides is formed to be larger than the pitch P of the hard synthetic resin cord-like material 2B. Therefore, the hard synthetic resin belt-like material 2A is fused onto the soft synthetic resin pipe 1 at the same pitch as the cord-like material 2B while the inner peripheral surface of one end thereof is fused to the hard synthetic resin cord-like material 2B. In the form in which the hard synthetic resin outer shell 2 is formed by spiral winding, the hard synthetic resin strip 2a wound next on the previously wound hard synthetic resin strip 2a is in the tube axis direction. In the state where the winding pitch P is shifted, the cross-sectional scale is superimposed.
[0016]
That is, in FIG. 1, the width W of the hard synthetic resin strip 2A is formed to be approximately twice the winding pitch P. Therefore, one end side of the previously wound hard synthetic resin strip 2a. Next, the 1/2 width portion on the other end side (tip end side) of the hard synthetic resin belt-like material portion 2a wound next on the 1/2 width portion on the (base end side) is overlapped. Yes. Further, the overlapping portions are not fused and are in close contact with each other so that the opposing surfaces can slide.
[0017]
Note that if the width of the hard synthetic resin strip 2A with respect to the winding pitch P is too large, the flexibility (flexibility) of the hard synthetic resin outer shell 2 is lowered, and when it is bent, it becomes a convex arc shape. On the bent peripheral wall portion side, the hard synthetic resin strip member 2a wound earlier, that is, the outer peripheral surface of the inner hard synthetic resin strip member 2a and the hard synthetic resin strip member 2a wound next. That is, since a relatively large gap is generated between the end of the outer hard synthetic resin strip 2a, the width of the hard synthetic resin strip 2A is set to 1.5 to 3.0 of the winding pitch P, and the inner hard It is desirable to have a structure in which at least the distal end portion of the outer hard synthetic resin strip member 2a is superimposed on the synthetic resin strip member 2a. Of course, even if such a gap occurs, the opposing inner surface of the outer hard synthetic resin strip 2a is kept in close contact with one end of the inner hard synthetic resin strip 2a. There is no risk of dirt or the like entering the interior.
[0018]
The synthetic resin pipe A configured as described above exhibits a uniform compressive strength over the entire length by the hard synthetic resin outer shell 2, and a hard synthetic resin belt-shaped material forming the hard synthetic resin outer shell 2 In 2A, the outer circumferential surface of the soft synthetic resin pipe 1 is overlapped with the previously wound belt-like material portion 2a in a state where the next wound belt-like material portion 2a is sequentially displaced in the tube axis direction by the width of the winding pitch P. Since it has a covered structure, the outer shell 2 made of a hard synthetic resin has an outer tube shape of a normal spirally wound tube with an inner tube made of a tube 1 made of a soft synthetic resin, and the outer peripheral surface is continuous in the tube axis direction. It has a shape that improves handling and construction.
[0019]
Further, as shown in FIG. 2, when the synthetic resin pipe A is bent (curved) in an arc shape, the soft synthetic resin pipe 1 is easily bent and the soft synthetic resin pipe 1 and the soft synthetic resin pipe 1 are bent. The shell 2 is also bent together. The outer shell 2 made of a hard synthetic resin is bent into a convex arcuate shape, and the outer peripheral wall A1 is bent in the direction of the tube axis. 2b, 2b, the soft synthetic resin pipe part between the hard synthetic resin strips 2a, 2a, which are fused together, is tensioned, and the pipe part is curved into a convex arc shape. The outer band-shaped material part 2a, which overlaps the other band-shaped material part 2a, is spaced outwardly from the outer surface of the inner band-shaped material part 2a to form a slight gap (opening). At least a part of the portion 2a in the tube axis direction always maintains a state in which it is in close contact with at least a part of the outer surface of the inner strip member 2a in the circumferential direction.
[0020]
On the other hand, in the inner peripheral wall portion A2 bent into a concave arc shape, a compressive force is generated in the tube axis direction, and the compressive force integrally forms the adjacent cord-like materials 2b and 2b of the hard synthetic resin-made cord-like material 2B. The soft synthetic resin pipe portion between the fused synthetic resin strip portions 2a, 2a shrinks in the arc length direction, and the outer strip portion 2a is further layered on the inner strip portion 2a due to the shrinkage. It is in a state where it is firmly crimped.
[0021]
Therefore, for example, when this synthetic resin pipe A is laid under the floor or in the ground as a drain pipe, it can be piped as planned while being bent freely, and foreign substances such as earth and sand are hard synthetic resin outer shells. The inner circumference of the soft synthetic resin pipe 1 which is reliably prevented from entering the inner surface side of the pipe 2 and can be used for a long period of time, and which is entirely covered with the outer shell 2 made of hard synthetic resin Since the surface is formed as a relatively flat surface in the length direction, smooth distribution is possible. Further, as shown in FIG. 3, the synthetic resin pipe A can be used as a protective pipe for the electric wire C by being buried in the ground.
[0022]
Next, a method of manufacturing the pressure-resistant synthetic resin tube A configured as described above will be briefly described with reference to FIG. 4. A soft synthetic resin strip 11 made of a soft vinyl chloride resin in a semi-molten state having a certain width and thickness. As is well known, the other side portion of the succeeding strip-like material portion 11a is superimposed on one side portion of the preceding strip-like material portion 11a on the base end portion of the molding rotating shaft 20 as is well known while being extruded from the first molding nozzle 21 The soft synthetic resin pipe 1 is formed by spirally winding at a constant pitch while being welded together, and the cross section is flattened from the second molding nozzle 22 on the soft synthetic resin pipe 1. A string-like material 2B made of a rigid or rectangular semi-molten hard vinyl chloride resin is extruded while being spirally wound at a constant pitch and fused to the outer peripheral surface of the soft synthetic resin tube 1.
[0023]
Further, following the step of spirally winding the hard synthetic resin string-like material 2B on the soft synthetic resin pipe 1 at a constant pitch, the same material as the hard synthetic resin string-like material 2B is obtained from the third molding nozzle 23. The semi-molten hard synthetic resin strip 2A having a width approximately twice as wide as the winding pitch of the strap 2B is extruded, and only the inner surface of one end on one long side is stringed. The width of the belt-like material portion 2a wound next on the half of the width direction of the belt-like material portion 2a wound on the outer peripheral surface of the soft synthetic resin pipe 1 while being fused integrally with the material 2B. A hard synthetic resin outer shell 2 is formed by winding the other half of the direction in a spiral shape with the same pitch as that of the cord-like material 2B so that the other half portions are sequentially overlapped in a scale shape.
[0024]
At this time, before the semi-molten hard synthetic resin strip 2A is spirally wound on the soft synthetic resin tube 1, the semi-molten hard synthetic resin strip 2A extruded from the third molding nozzle 23 is removed. When the belt-like material portions 2a and 2a are superposed on the soft synthetic resin pipe 1 by passing through a cooling device 24 by blowing cold air or the like, they are wound in a spiral shape without being fused to each other, and the inner circumference of one end portion thereof Only the surface is heated and melted by the heating device 25 to be integrally fused to the hard synthetic resin string-like material 2B.
[0025]
In this way, a flexible pressure-resistant synthetic resin tube A having a hard synthetic resin outer shell 2 provided on the outer peripheral surface of the soft synthetic resin tube 1 is continuously manufactured on the molding rotary shaft 20, and is made for each desired length. To obtain a synthetic resin tube A having a predetermined length.
[0026]
FIG. 5 shows another embodiment of the flexible pressure-resistant synthetic resin pipe according to the present invention. In the above-described embodiment, a hard synthetic resin strip-like material forming a hard synthetic resin outer shell 2 is shown. 2A is formed on a substantially flat surface across the entire width of the inner and outer surfaces, but in this embodiment, the width in the tube axis direction of the hard synthetic resin strip 2A 'is set to the hard synthetic resin string 2B. Are formed wider than the winding pitch P by the width of the string-like material 2B, and both ends in the width direction of the hard synthetic resin-made belt-like material 2A ′ are curved in a convex arc shape toward the outer surface side. Next, on the curved portion 2b formed on the curved portion 2b, 2c and fused to the rigid synthetic resin string-like material 2B in the previously wound belt-like material portion 2a ' The curved portion 2c on the other end side of the material portion 2a ′ is overlapped in the locked state to form a hard synthetic resin outer shell 2 ′.
[0027]
That is, a hard synthetic resin string-like material 2B is spirally wound with a constant pitch P on a soft synthetic resin pipe 1 and its inner surface is integrally fused to the soft synthetic resin pipe 1. A hard synthetic material that is wound first on the resin pipe 1 while spirally wound at the same pitch as the hard synthetic resin string-like material 2B while fusing the curved portion 2b of one end of the hard synthetic resin-like belt-like material 2A 'onto the resin pipe 1. A structure in which the curved portion 2c on the other end side of the hard synthetic resin strip-shaped material portion 2a 'wound next is superimposed on the one-end curved portion 2b of the resin-shaped belt-shaped material portion 2a' without being fused. It is said.
[0028]
The synthetic resin pipe A ′ configured in this manner, like the synthetic resin pipe A shown in the above embodiment, exhibits a uniform pressure strength over the entire length by the hard synthetic resin outer shell 2 ′. The hard synthetic resin strip 2A 'forming the hard synthetic resin outer shell 2' has one end-side curved portion 2b of the previously wound strip 2a 'as a hard synthetic resin cord 2B. The hard synthetic resin outer shell 2 ′ is formed by superimposing the other end-side curved portion 2c of the band-like material 2a ′ wound next on the curved portion 2b. The outer shell 2 'made of hard synthetic resin has a good appearance like an abdominal snake tube having a soft synthetic resin tube 1 as an inner tube.
[0029]
Further, when this synthetic resin pipe A ′ is bent, as shown in FIG. 6, adjacent hard synthetic resin strip members 2a ′, 2a ′ forming the hard synthetic resin outer shell 2 ′. On the convex arcuate curved portion 2b of one hard synthetic resin strip 2a 'fused to the hard synthetic resin cord 2B. The arcuate curved portion 2c is smoothly and accurately bent while sliding in the arc direction of the convex arcuate surface with the arcuate curved portion 2c always locked without a gap.
[0030]
In any of the flexible pressure-resistant synthetic resin pipes A and A ′ described above , after bending a predetermined portion in the length direction into an arc shape by an external force and then releasing the external force, the original straight pipe shape is obtained. It is something to restore.
[0031]
【The invention's effect】
As described above, the pressure-resistant synthetic resin pipe having the flexible portion according to the present invention is the pressure-resistant synthetic resin obtained by coating the outer peripheral surface of the soft synthetic resin pipe with the hard synthetic resin outer shell as described in claim 1. The outer wall of the hard synthetic resin is formed by winding a hard synthetic resin strip having a certain width around the outer peripheral surface of the soft synthetic resin tube in a spiral manner at a constant pitch. In a state where only the surface is integrally fixed to the outer peripheral surface of the inner tube of the soft synthetic resin pipe, and the next wound belt-shaped material portion is shifted by a certain width in the tube axis direction on the previously wound belt-shaped material portion. Since it has a superposed structure, it can cover and protect the entire surface of the soft synthetic resin pipe with the hard synthetic resin outer shell, and can also exhibit uniform pressure resistance over the entire length. Adjacent hard joints forming a hard synthetic resin shell Since the resin strips are overlapped in a cross-sectional shape with no gaps, foreign materials such as earth and sand are not likely to enter the inside, and the soft synthetic resin pipe is fully protected to withstand long-term use. It is possible to provide a pressure-resistant synthetic resin tube that can be used.
[0032]
Furthermore, only the inner peripheral surface of one end portion of the hard synthetic resin strip is fixed to the outer peripheral surface of the soft synthetic resin tube in a spiral manner at a constant pitch, and the adjacent hard synthetic resin strip member is fused together. Since they are superposed in a scale shape without being worn, when this pressure-resistant synthetic resin tube is bent, the rigid synthetic resin belt-like material parts superposed in a cross-sectional scale shape slide smoothly in the direction of the tube axis. Even when it is bent, it can exhibit the pressure resistance on the entire surface while maintaining the state in which the adjacent hard synthetic resin strips overlap each other. Since the peripheral surface is formed in a substantially flat surface over the entire length, when used in a drain pipe or the like, the circulation of the waste water becomes good.
[0033]
Further, a hard synthetic resin string-like material is spirally wound and fixed at a constant pitch on the outer peripheral surface of the soft synthetic resin pipe, and the hard synthetic resin string is attached to the hard synthetic resin string-like material. Next, the inner peripheral surface of one end of the hard synthetic resin strip formed wider than the pitch between the strips is fused, integrated, and then wound on the previously wound hard synthetic resin strip. The structure of a synthetic resin tube that is easy to manufacture and suitable for mass production is formed by spirally winding at least a part of the wound rigid synthetic resin strip material part to form a hard synthetic resin outer shell. A hard synthetic resin string-like material spirally wound on the outer peripheral surface of the soft synthetic resin pipe, and the pressure resistance strength is further increased, thereby forming a synthetic resin pipe that does not easily cause crushing deformation. it can.
[0034]
Moreover, according to the invention which concerns on Claim 2 , the both ends of the width direction of the said hard synthetic resin strip | belt-shaped material are formed in the curved part curved in the convex arc shape toward the outer surface side, The said soft synthetic resin pipe | tube of The curved portion on one end side is integrally fused to the hard synthetic resin string-like material spirally wound on the outer peripheral surface, and the rigid synthetic resin-made belt-shaped material portion wound on the curved portion is wound on the curved portion. Next, it is structured to form a hard synthetic resin outer shell by superimposing the curved part on the other end side of the wound hard synthetic resin belt-like material part, so that it looks like a belly snake tube In addition to presenting, when this synthetic resin tube is bent, the adjacent hard synthetic resin strips forming the hard synthetic resin outer shell are always free from gaps by the convex arcuate curved portions. Along this curved part while maintaining the overlapping state And song smoothly to it becomes possible to accurately bend, it is capable of withstanding prolonged use in reliably prevent foreign material from entering the soft synthetic resin-made pipe side.
[Brief description of the drawings]
FIG. 1 is a simplified side view of a part of a flexible pressure-resistant synthetic resin pipe,
FIG. 2 is a simplified side view showing a section of a bent state,
FIG. 3 is a simplified vertical side view showing an example of the usage state;
FIG. 4 is a simplified side view for explaining a manufacturing method;
FIG. 5 is a simplified side view, partly in section, showing another embodiment of the present invention;
FIG. 6 is a simplified side view showing a part of a bent state.
[Explanation of symbols]
A Flexible pressure-resistant synthetic resin tube 1 Soft synthetic resin tube 2 Hard synthetic resin outer shell
2A Hard synthetic resin strip
2B Hard synthetic resin string

Claims

A pressure-resistant synthetic resin tube in which the outer peripheral surface of a soft synthetic resin tube is covered with a hard synthetic resin outer shell, and a hard synthetic resin string-like material is placed on the outer peripheral surface of the soft synthetic resin tube at a constant pitch. One end inner circumference of a hard synthetic resin belt-like material that is wound and fused in a spiral shape and is formed on the hard synthetic resin string material wider than the pitch between the hard synthetic resin string materials The surfaces are fused, integrated, and spirally wound with at least a portion of the next wound synthetic synthetic resin strip on the rigid synthetic resin strip wound. A flexible pressure-resistant synthetic resin tube characterized by forming the hard synthetic resin outer shell .

Both ends in the width direction of the band made of hard synthetic resin are formed in a curved portion curved in a convex arc shape toward the outer surface, and are made of hard synthetic resin spirally wound around the outer peripheral surface of the soft synthetic resin pipe The curved portion at one end thereof is integrally fused to the string-shaped material, and the hard synthetic resin-shaped strip wound next on the curved portion of the previously-cured rigid synthetic resin-shaped strip-shaped material portion. 2. The flexible pressure-resistant synthetic resin pipe according to claim 1 , wherein a curved portion on the other end side of the portion is overlapped to form a hard synthetic resin outer shell.