JP4001470B2

JP4001470B2 - Rib main joint

Info

Publication number: JP4001470B2
Application number: JP2001231183A
Authority: JP
Inventors: 宏文平岡; 親徳福井
Original assignee: Kubota CI Co Ltd
Current assignee: Kubota CI Co Ltd
Priority date: 2001-07-31
Filing date: 2001-07-31
Publication date: 2007-10-31
Anticipated expiration: 2021-07-31
Also published as: JP2003042364A

Description

【０００１】
【産業上の利用分野】
この発明はリブ付本管自在継手に関し、特にたとえば下水道配管等に用いられてリブ付管どうしを所定の角度を有して接続する、リブ付本管自在継手に関する。
【０００２】
【従来の技術】
従来、所定の角度で傾斜した接合端面を介して受口側部材と差口側部材とが回動自在に組み合わされたリブなしの本管自在継手はよく知られている。このリブなしの本管自在継手は、たとえばリブのないプレーン管どうしを接続するためのものであり、したがって、受口側部材の受口および差口側部材の差口はそれぞれプレーン管の差口および受口と接続可能に形成されており、リブ付管とは接続不可能である。
【０００３】
そこで、リブ付管と接続可能にされたリブ付本管自在継手が公表されている（たとえば意匠登録第１１０４５６０号公報等）。このリブ付本管自在継手１では、図９に示すように、受口側部材２の受口３にリブ付受口管４が接合され、差口側部材５の差口６にリブ付差口管７が接合される。
【０００４】
【発明が解決しようとする課題】
しかし、従来のリブ付本管自在継手１では、接合部分８等の受口側部材２および差口側部材５の外面にリブが形成されていないため、砕石による埋め戻しができず、リブなし部分は砂等で埋め戻す必要があった。このように、埋め戻し材をリブ付部分とリブなし部分とで区別する必要があり、施工性が悪かった。
【０００５】
また、射出成形により外面全体にリブが一体形成されたリブ付本管自在継手も一定の呼び径（φ２００）までは製品化されているが、射出成形用金型の開発には莫大な費用がかかるため、さまざまなサイズで品揃えしようとすると、コスト高となってしまう。
【０００６】
それゆえに、この発明の主たる目的は、リブ付管と接続でき、かつ、砕石埋め戻しできる、リブ付本管自在継手を提供することである。
【０００７】
この発明の他の目的は、安価に製造できる、リブ付本管自在継手を提供することである。
【０００８】
【課題を解決するための手段】
この発明は、所定角度で傾斜した接合端面を介して受口側部材と差口側部材とが回動自在に組み合わされたリブなし本管自在継手、リブなし本管自在継手の受口側部材に接合されたリブ付受口管、リブなし本管自在継手の差口側部材に接合されたリブ付差口管、リブ付受口管の下流側に装着されて受口側部材を覆う第１リブ付管、およびリブ付差口管の上流側に装着されて差口側部材を覆う第２リブ付管を備える、リブ付本管自在継手である。
【０００９】
また、リブ付受口管は受口側部材内面に挿入されたリブなし短管の上流側に接合されてもよい。
【００１０】
【作用】
受口側部材にはリブ付受口管が接合され、差口側部材にはリブ付差口管が接合される。たとえば、リブ付受口管にはリブ付管の差口を受容する拡径受口が形成され、リブ付差口管にはリブ付管の拡径受口に差し込まれる差口が形成されている。したがって、リブ付管と接続することができる。そして、リブのない受口側部材および差口側部材は、第１リブ付管および第２リブ付管によってそれぞれ覆われており、リブなし部分は外部に露出しない。したがって、砕石により埋め戻しできる。また、リブ付本管自在継手を構成するリブなし本管自在継手，リブ付受口管，リブ付差口管，第１リブ付管および第２リブ付管等には、既存のリブなし本管自在継手およびリブ付管等に簡単な二次加工を施したものを用いることができる。
【００１１】
【発明の効果】
この発明によれば、リブ付管と接続することができ、しかも、第１リブ付管および第２リブ付管によって、リブのない受口側部材および差口側部材が覆われるので、すべて砕石により埋め戻しをすることができる。したがって、埋め戻し材をリブ付部分とリブなし部分とで区別する必要がなく、施工性を向上できる。
【００１２】
また、既存のリブなし本管自在継手およびリブ付管等を用いて製造できるので、新たな射出成形用金型の開発は不要であり、安価に製造できる。
【００１３】
この発明の上述の目的，その他の目的，特徴および利点は、図面を参照して行う以下の実施例の詳細な説明から一層明らかとなろう。
【００１４】
【実施例】
図１に示すこの実施例のリブ付本管自在継手１０は、たとえば、下水道配管等に用いられて、図５に示すように２つのリブ付管５６および７０を所定の角度を有して接続するためのものであり、リブなし本管自在継手１２，リブ付受口管１４，リブ付差口管１６，第１リブ付管１８および第２リブ付管２０を含む。
【００１５】
リブなし本管自在継手１２は、受口側部材２２および差口側部材２４を含む。受口側部材２２と差口側部材２４とは、各々の軸線に対して所定角度θで傾斜する接合端面Ｓで突き合わせられ、接合端面Ｓ内で回動自在に組み合わされる。そして、両者が互いに回動されることによって接続角度が０から２θの範囲で変更される。図１では、接続角度０度の場合が示されている。
【００１６】
なお、原則として、受口側部材２２は上流側（流入側）に配置され、差口側部材２４は下流側（流出側）に配置されるので、受口側部材２２の配置される一方側を上流側、差口側部材２４の配置される他方側を下流側とも言うものとする。
【００１７】
受口側部材２２は、たとえば塩化ビニル等の合成樹脂からなり、略筒状に形成される。受口側部材２２は、リブ付管５６および７０と同じ内径を有し、その一方側（上流側）端部には拡径受口２６が形成され、他方側（下流側）端部には差口２８が形成される。拡径受口２６は、たとえばゴム輪受口の先端部を切除することにより形成されたものである。差口２８の端部外面には、端面Ｓ側からゴム輪装着溝３０，係止フランジ３２およびがたつき防止フランジ３４が形成される。ゴム輪装着溝３０には受口側部材２２と差口側部材２４との接合部をシールするゴム輪３６が装着される。また、受口側部材２２の外面の所定位置（この実施例では拡径受口２６の外面）には、２つの取っ手３８が周方向に１８０度間隔を隔てて設けられる。取っ手３８は、接続角度を変更する際に把持されるまたは治具が取り付けられる等して用いられる。
【００１８】
差口側部材２４は、たとえば塩化ビニル等の合成樹脂からなり、略筒状に形成される。差口側部材２４は、受口側部材２２と同じ内径を有し、その一方側端部には受口４０が形成され、他方側端部には差口４２が形成される。受口４０の内面には、ゴム輪３６が当接される止水面４４が形成され、受口４０の端部内面には、係止フランジ３２の外周縁に係合される係止溝４６が形成される。また、差口側部材２４の外面の所定位置（この実施例では受口４０の基端部）には、２つの取っ手４８が周方向に１８０度間隔を隔てて設けられる。この取っ手４８も取っ手３８と同様に接続角度の変更の際に用いられ得る。
【００１９】
このリブなし本管自在継手１２では、受口側部材２２の差口２８が差口側部材２４の受口４０に差し込まれ、差口２８に形成された係止フランジ３２と受口４０に形成された係止溝４６とが嵌合される。そして、拡径受口２６および差口４２には、リブ付管と接続可能なようにそれぞれリブ付受口管１４およびリブ付差口管１６が設けられる。
【００２０】
リブ付受口管１４は、たとえば塩化ビニル等の合成樹脂からなり、リブ付受口管１４の外面には、軸方向に間隔を隔てて複数の周方向リブ５０が形成されている。リブ付受口管１４は、受口側部材２２とほぼ同じ内径を有する直管部５２を含み、直管部５２の上流側端部には、使用時にリブ付管５６（図５）の差口５８を受容する拡径受口５４が形成される。また、リブ付受口管１４は、この実施例ではリブなし短管６０を介して受口側部材２２に接続されるため、直管部５２の下流側端部は、リブなし短管６０の外径とほぼ同じ内径に拡径されて、リブなし短管６０の一方端部を受容する受口５２ａが形成される。
【００２１】
リブなし短管６０は、たとえば塩化ビニル等の合成樹脂からなり、受口側部材２２および直管部５２の内径とほぼ同じ内径を有する。リブなし短管６０の下流側端部は、受口側部材２２の拡径受口２６の内面に適合するように、拡径受口２６の内径とほぼ同じ外径に拡径される。そして、リブなし短管６０の上流側端部は、リブ付受口管１４の下流側端部の受口５２ａ内に差し込まれて接着接合され、リブなし短管６０の下流側端部は、受口側部材２２の拡径受口２６内に差し込まれて接着接合される。このようなリブなし短管６０を介在させることによって、受口側部材２２とリブ付受口管１４とが内面ほぼ平滑に接続される。
【００２２】
リブ付差口管１６は、たとえば塩化ビニル等の合成樹脂からなり、リブ付差口管１６の外面には、軸方向に間隔を隔てて複数の周方向リブ６２が形成されている。リブ付差口管１６は、差口側部材２４とほぼ同じ内径を有する直管部６４を含み、直管部６４の上流側端部は、差口側部材２４の外径とほぼ同じ内径に拡径されて、差口側部材２４の差口４２を受容する受口６４ａが形成される。そして、差口側部材２４の差口４２がリブ付差口管１６の受口６４ａに差し込まれて接着接合される。また、直管部６４の下流側端部は差口６６とされ、差口６６の外面の所定のリブ６２間には、ゴム輪６８が装着される。リブ付差口管１６の差口６６は、使用時にはリブ付管７０（図５）の一方端部に形成された拡径受口７２に差し込まれて接続される。
【００２３】
第１リブ付管１８は、第２リブ付管２０と共にリブなし本管自在継手１２を保護するためのものである。第１リブ付管１８は、たとえば塩化ビニル等の合成樹脂からなり、第１リブ付管１８の外面には、軸方向に間隔を隔てて複数の周方向リブ７４が形成されている。第１リブ付管１８の内径は、リブ付受口管１４の下流側端部のリブ外径よりもやや大きく設定される。第１リブ付管１８は、リブ付受口管１４の下流側端部から受口側部材２２の差口２８にわたって装着され、この第１リブ付管１８によって、受口側部材２２のリブのない外面が覆われる。この実施例では、第１リブ付管１８の下流側の端面は、接合端面Ｓとほぼ同じ角度に傾斜して形成され、がたつき防止フランジ３４の側面に近接される。第１リブ付管１８には、受口側部材２２の２つの取っ手３８に対応して２つの貫通孔７６が形成されており、この貫通孔７６を通して取っ手３８が外部に突き出される。また、下流側端部のリブ７４の一部は、角度変更時に第２リブ付管２０の内面に当たらないように除去されている。
【００２４】
第２リブ付管２０は、第１リブ付管１８と共にリブなし本管自在継手１２を保護するためのものである。第２リブ付管２０は、塩化ビニル等の合成樹脂からなり、第２リブ付管２０の外面には、軸方向に間隔を隔てて複数の周方向リブ７８が形成されている。第２リブ付管２０は、差口側部材２４の上流側端部のリブ外径よりもやや大きい内径を有する直管部８０を含み、直管部８０の上流側端部には拡径受口８２が形成される。また、直管部８０の内径は第１リブ付管１８の内径とほぼ同じに設定されており、拡径受口８２の内径は、第１リブ付管１８を受容し得るように、第１リブ付管１８のリブ外径よりもやや大きく設定される。第２リブ付管２０は、リブ付差口管１６の上流側端部から少なくとも差口側部材２４の受口４０にわたって装着され、この第２リブ付管２０によって差口側部材２４のリブのない外面が覆われる。この実施例では、第１リブ付管１８の下流側端部も第２リブ付管２０の拡径受口８２内に差し込まれて、この拡径受口８２によって覆われている。また、第２リブ付管２０には、差口側部材２４の２つの取っ手４８に対応して２つの貫通孔８４が形成されており、この貫通孔８４を通して取っ手４８が外部に突き出される。
【００２５】
このリブ付本管自在継手１０を製造する際には、まず、リブなし本管自在継手１２，リブなし短管６０，リブ付受口管１４，リブ付差口管１６，第１リブ付管１８および第２リブ付管２０等をそれぞれ準備する。
【００２６】
たとえば、リブなし本管自在継手１２を形成する際には、既製品のリブなし本管自在継手を準備する。既製のリブなし本管自在継手の受口側部材２２の一方端部は、図２に示すように、一般的にゴム輪受口８６として形成されているので、ゴム輪受容部８６ａから先端部分を切断除去することによって拡径受口２６を形成する。
【００２７】
リブなし短管６０を形成する際には、リブなし本管自在継手１２と同じ内径を有する適宜な長さのプレーンな短管を準備し、たとえばブロー成形等によって他方端部の外径を拡径受口２６の内径とほぼ同じに拡径させる。
【００２８】
リブ付受口管１４を形成する際には、リブなし本管自在継手１２と同じ内径を有するかつ一端に拡径受口５４が形成された適宜な長さのリブ付管を準備する。そして、他方端部の差口を二次加工することによって、すなわち、たとえば他方端部を加熱軟化させて適宜な金型を差し込み、冷却養生することによって、他方端部内径をリブなし短管６０の外径とほぼ同じに拡径させ、受口５２ａを形成する。
【００２９】
リブ付差口管１６を形成する際には、リブなし本管自在継手１２と同じ内径を有するかつ両端が差口形状とされた適宜な長さのリブ付管を準備する。そして、一方端部の差口を、リブ付受口管１４の受口５２ａの場合と同様にして二次加工することによって、一方端部内径を差口側部材２４の差口４２の外径とほぼ同じに拡径させ、受口６４ａを形成する。また、他端の差口６６の所定のリブ６２間にゴム輪６８を装着する。
【００３０】
第１リブ付管１８を形成する際には、リブ付受口管１４およびリブ付差口管１６の素材となったリブ付管のリブ外径よりも大きい内径を有するかつ両端が差口形状とされたリブ付管を準備する。このようなリブ付管としては、たとえばリブ付受口管１４およびリブ付差口管１６よりも一回り大きいサイズ（呼び径）のリブ付管が適用され得る。そして、他方端面を斜めに切断して所定角度に傾斜させ、他方端部側のリブ７４の一部を切除する。また、受口側部材２２の取っ手３８に対応する位置に貫通孔７６を形成する。
【００３１】
第２リブ付管２０を形成する際には、第１リブ付管１８の素材となったリブ付管と同じサイズを有するかつ一端に拡径受口８２が形成されたリブ付管を準備し、他端側を切断除去して適宜な長さにする。また、差口側部材２４の取っ手４８に対応する位置に貫通孔８４を形成する。
【００３２】
次に、リブ付受口管１４の他方端部受口５２ａにリブなし短管６０の一方端部を差し込んで接着接合するとともに、リブなし本管自在継手１２の受口側部材２２の拡径受口２６にリブなし短管６０の他方端部を差し込んで接着接合する。他方、リブなし本管自在継手１２の差口側部材２４の差口４２をリブ付差口管１６の一方端部受口６４ａに差し込んで接着接合する。
【００３３】
続いて、第１リブ付管１８を受口側部材２２およびリブ付受口管１４の外面に装着する。第１リブ付管１８を装着する際には、図３の破線で示すように、予め管壁の一部を軸方向に切断しておき、この切断端から押し広げて受口側部材２２の取っ手３８を貫通孔７６に挿通させて、第１リブ付管１８を所定位置に被せる。そして、切断端をたとえば塩ビ溶接等によって一体化する。このようにして、第１リブ付管１８は、リブ付受口管１４および受口側部材２２に固着されず、貫通孔７６に挿通された取っ手３８によって保持される。
【００３４】
そして、第２リブ付管２０を差口側部材２４およびリブ付差口管１６の外面に装着する。第２リブ付管２０を装着する際には、第１リブ付管１８の場合と同様にして、予め管壁を軸方向に切断しておき、この切断端から押し広げて差口側部材２４の取っ手４８を貫通孔８４に挿通させて、第２リブ付管２０を所定位置に被せる。そして、切断端をたとえば塩ビ溶接によって一体化する。第２リブ付管２０も、第１リブ付管１８と同様に、リブ付差口管１６および差口側部材２４に固着されず、貫通孔８４に挿通された取っ手４８によって保持される。
【００３５】
なお、このリブ付本管自在継手１０の製造方法は上述のものに限定されず適宜変更され得る。
【００３６】
このリブ付本管自在継手１０において接続角度を変更する際には、たとえば受口側部材２２の取っ手３８を用いて、受口側部材２２を差口側部材２４に対して回動させる。すると、第１リブ付管１８は受口側部材２２と共に第２リブ付管２０の拡径受口８２内で回動され、接続角度は０から２θ度の範囲で変更することができる。このとき、リブなし部分は常に第１リブ付管１８および第２リブ付管２０によって覆われており、外部に露出することはない。たとえば図４には、接続角度２θに変更された場合が示されている。なお、差口側部材２４の取っ手４８を用いて差口側部材２４を受口側部材２２に対して回動させてもよい。
【００３７】
リブ付本管自在継手１０を用いて管路を敷設する際には、このリブ付本管自在継手１０を所望の接続角度に設定しておき、たとえば図５に示すように、下流側のリブ付管７０の拡径受口７２にリブ付差口管１６の差口６６を差し込んで接続する。一方、上流側のリブ付管５６のゴム輪８８が装着された差口５８を、リブ付受口管１４の拡径受口５４に差し込んで接続する。なお、図５では、接続角度０度の場合が示されている。
【００３８】
この実施例によれば、受口側部材２２にリブ付受口管１４が設けられ、かつ、差口側部材２４にリブ付差口管１６が設けられているので、リブ付管５６および７０と接続することができる。しかも、第１リブ付管１８および第２リブ付管２０によって、リブのないリブなし本管自在継手１２（受口側部材２２および差口側部材２４）が覆われるので、すべて砕石によって埋め戻しをすることができる。したがって、埋め戻し材をリブ付部分とリブなし部分とで区別する必要がなく、施工性を向上できる。
【００３９】
また、既存のリブなし本管自在継手やリブ付管等を用いて、これらに簡単な二次加工を施すことによって製造できるので、新たな射出成形用金型の開発は不要であり、安価に製造できる。たとえば、内径がφ２５０のリブ付本管自在継手１０を製造する場合には、リブなし本管自在継手１２としては呼び径φ２５０の既製のリブなし本管自在継手を適用し、リブ付受口管１４およびリブ付差口管１６としては呼び径φ２５０の既製のリブ付管を適用し、リブなし短管６０としては呼び径φ２５０の既製のプレーンな管を適用し、第１リブ付管１８および第２リブ付管２０としては一回り大きい呼び径φ３００の既製のリブ付管を適用すればよい。
【００４０】
なお、上述の実施例では、リブ付管５６および７０と接続するようにしているが、接続される管路構造物は適宜変更され得るのは言うまでもなく、たとえばリブ付の管継手およびリブ付の接続口を有するマンホール等であってもよい。
【００４１】
また、リブなし本管自在継手１２は、上述の各実施例（図１実施例等）で示したような形状および嵌合構造等のものに限定されず、任意の形状等のものが適用され得るのは言うまでもない。たとえば、上述の各実施例では、受口側部材２２のゴム輪受口８６（図２）のゴム輪受容部８６ａから先端部分を切断除去することによって拡径受口２６を形成するようにしているが、切断除去せずにゴム輪受口８６をそのまま用いるようにしてもよい。また、受口側部材２２とリブ付受口管１４とをリブなし短管６０を介在させて接合するようにしているが、受口側部材２２の一方端部が差口とされている場合等には、リブ付受口管１４の他方端部の内径を受口側部材２２の外径とほぼ同じに拡径させて、リブなし短管６０を介在させずに直接に接着接合するようにしてもよい。
【００４２】
また、上述の各実施例では、第２リブ付管２０としてその一方端部に拡径受口８２が形成されたものを適用し、この拡径受口８２で第１リブ付管１８の他方端部（差口）を覆うようにしているが、これら第１リブ付管１８と第２リブ付管２０の被覆関係は逆であってもよい。つまり、たとえば図６に示すように、第１リブ付管１８としてその他方端部に拡径受口８２が形成されたものを適用するとともに、この拡径受口８２で第２リブ付管２０の一方端部（差口）を覆うようにしてもよい。具体的には、図６実施例では、第２リブ付管２０の一方端面は傾斜して形成され、この第２リブ付管２０によって差口側部材２４の受口４０の一部まで覆われる。他方、第１リブ付管１８の拡径受口８２によって差口側部材２４の受口４０の基端部付近まで覆われる。また、拡径受口８２の先端面はたとえば接合端面Ｓとほぼ同じ角度で斜めに形成され、回動時に差口側部材２４の取っ手４８と当たらないようにされる。
【００４３】
また、上述の各実施例では、第１リブ付管１８および第２リブ付管２０のうち一方のリブ付管に拡径受口８２が形成されたものを適用して、拡径受口８２によって他方のリブ付管の端部（差口）を覆うようにしているが、一方のリブ付管として、他方のリブ付管のリブ外径よりも大きい内径を有するものを適用することによって、他方のリブ付管の端部を覆うようにしてもよい。たとえば図７には、図１実施例の拡径受口８２を有する第２リブ付管２０に代えて、第２リブ付管２０として、第１リブ付管１８のリブ外径よりもやや大きい内径を有するかつ両端が差口形状とされたリブ付管が適用された場合の一例が示されている。この第２リブ付管２０としては、たとえば第１リブ付管１８より一回り大きいサイズ（呼び径）のリブ付管が用いられ得る。
【００４４】
また、上述の各実施例では、第１リブ付管１８および第２リブ付管２０のうち一方のリブ付管で他方のリブ付管の端部（差口）を覆うようにしているが、たとえば図８に示すように、両者は傾斜された端面で突き合わせられるようにされてもよい。具体的には、図８実施例では、第１リブ付管１８および第２リブ付管２０には、それぞれ拡径受口９０および９２を有するリブ付管が適用され、拡径受口９０および９２の端面は、たとえばリブなし本管自在継手１２の接合端面Ｓとほぼ同じ角度に傾斜して形成されるとともに、互いに突き合わせられる。この場合には、接続角度変更時にも、第１リブ付管１８と第２リブ付管２０とは傾斜端面で互いに突き合わせられたままで回動される。
【００４５】
また、上述の各実施例では、リブ付受口管１４の一方端部には拡径受口５４が形成されているが、場合によってはリブ付受口管１４の一方端部は差口とされてもよい。また、リブ付差口管１６の他方端部は差口６６とされているが、場合によってはリブ付差口管１６の他方端部には拡径受口が形成されてもよい。
【図面の簡単な説明】
【図１】この発明の一実施例を示す図解図である。
【図２】図１実施例のリブなし本管自在継手の形成方法を示す図解図である。
【図３】図１実施例の第１リブ付管の装着前の状態を示す図解図である。
【図４】図１実施例の接続角度を変更した状態を示す図解図である。
【図５】図１実施例の使用状態を示す図解図である。
【図６】この発明の他の実施例を示す図解図である。
【図７】この発明の他の実施例を示す図解図である。
【図８】この発明の他の実施例を示す図解図である。
【図９】従来技術の一例を示す図解図である。
【符号の説明】
１０ …リブ付本管自在継手
１２ …リブなし本管自在継手
１４ …リブ付受口管
１６ …リブ付差口管
１８ …第１リブ付管
２０ …第２リブ付管
２２ …受口側部材
２４ …差口側部材[0001]
[Industrial application fields]
The present invention relates to a ribbed main pipe universal joint, and more particularly to a ribbed main pipe universal joint that is used in, for example, sewer piping and connects ribbed pipes with a predetermined angle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a ribless main pipe universal joint in which a receiving end member and a differential opening side member are rotatably combined via a joint end face inclined at a predetermined angle is well known. This rib-free main pipe universal joint is for connecting plain pipes having no ribs, for example. Therefore, the receiving port of the receiving side member and the connecting port of the connecting port side member are respectively connected to the outlets of the plain tube. In addition, it is formed so as to be connectable to the receiving port, and cannot be connected to the ribbed tube.
[0003]
Accordingly, a ribbed main pipe universal joint that can be connected to a ribbed pipe has been announced (for example, Design Registration No. 1104560). In this ribbed main pipe universal joint 1, as shown in FIG. 9, the ribbed receiving pipe 4 is joined to the receiving port 3 of the receiving side member 2, and the ribbed differential pipe 6 is connected to the differential opening 6 of the inserting side member 5. The mouth tube 7 is joined.
[0004]
[Problems to be solved by the invention]
However, in the conventional ribbed main joint 1 with ribs, no ribs are formed on the outer surfaces of the receiving-side member 2 and the connecting-side member 5 such as the joint portion 8, so that it cannot be backfilled with crushed stone, and there is no rib The part had to be backfilled with sand. Thus, it was necessary to distinguish the backfill material between the ribbed portion and the ribless portion, and the workability was poor.
[0005]
In addition, ribbed main joints with ribs integrally formed on the entire outer surface by injection molding have been commercialized up to a certain nominal diameter (φ200), but the development of injection molds is enormous. For this reason, if an attempt is made to assort the products in various sizes, the cost becomes high.
[0006]
Therefore, a main object of the present invention is to provide a ribbed main pipe universal joint that can be connected to a ribbed pipe and can be backfilled with crushed stone.
[0007]
Another object of the present invention is to provide a ribbed main joint that can be manufactured at low cost.
[0008]
[Means for Solving the Problems]
The present invention relates to a ribless main pipe universal joint in which a receiving end member and a differential opening side member are rotatably combined via a joint end face inclined at a predetermined angle, and a receiving side member of a ribless main pipe universal joint The ribbed receptacle tube joined to the rib, the ribbed receptacle tube joined to the rib-side main joint of the ribless main pipe universal joint, and attached to the downstream side of the ribbed receptacle tube to cover the receptacle-side member A rib-equipped main pipe universal joint including a rib-attached pipe and a second rib-attached pipe that is mounted on the upstream side of the rib-attached outlet pipe and covers the outlet-side member.
[0009]
In addition, the ribbed receiving tube may be joined to the upstream side of the short tube without ribs inserted into the inner surface of the receiving member.
[0010]
[Action]
A ribbed receptacle tube is joined to the receptacle side member, and a ribbed receptacle tube is joined to the receptacle side member. For example, the ribbed receptacle tube is formed with an enlarged diameter receiving port for receiving the ribbed tube receptacle, and the ribbed receptacle tube is formed with the receptacle inserted into the ribbed tube enlarged receptacle. Yes. Therefore, it can be connected to the ribbed tube. The receiving side member and the opening side member without ribs are respectively covered with the first ribbed tube and the second ribbed tube, and the rib-free portion is not exposed to the outside. Therefore, it can be backfilled with crushed stone. In addition, existing ribless main pipes are included in the ribless main pipe universal joints, ribbed receiving pipes, ribbed differential pipes, first ribbed pipes, and second ribbed pipes that constitute the ribbed main pipe universal joints. It is possible to use a pipe universal joint and a ribbed pipe that have been subjected to simple secondary processing.
[0011]
【The invention's effect】
According to this invention, since it can connect with a ribbed pipe, and the 1st ribbed pipe and the 2nd ribbed pipe cover the receiving side member and the opening side member without a rib, all crushed stones Can be backfilled. Therefore, it is not necessary to distinguish the backfill material between the ribbed portion and the ribless portion, and the workability can be improved.
[0012]
In addition, since it can be manufactured using an existing ribless main pipe universal joint and a ribbed pipe, it is not necessary to develop a new injection mold and can be manufactured at low cost.
[0013]
The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.
[0014]
【Example】
A ribbed main pipe universal joint 10 of this embodiment shown in FIG. 1 is used, for example, in a sewer pipe or the like, and connects two ribbed pipes 56 and 70 with a predetermined angle as shown in FIG. And includes a ribless main pipe universal joint 12, a ribbed receiving pipe 14, a ribbed differential pipe 16, a first ribbed pipe 18, and a second ribbed pipe 20.
[0015]
The ribless main pipe universal joint 12 includes a receiving port side member 22 and a differential port side member 24. The receiving side member 22 and the opening side member 24 are abutted at the joining end surface S inclined at a predetermined angle θ with respect to the respective axes, and are combined so as to be rotatable within the joining end surface S. Then, the connection angle is changed in the range of 0 to 2θ by rotating both of them. FIG. 1 shows a case where the connection angle is 0 degree.
[0016]
In principle, the receiving port side member 22 is disposed on the upstream side (inflow side), and the insertion port side member 24 is disposed on the downstream side (outflow side). Is the upstream side, and the other side where the outlet side member 24 is arranged is also called the downstream side.
[0017]
The receiving side member 22 is made of a synthetic resin such as vinyl chloride, and is formed in a substantially cylindrical shape. The receiving side member 22 has the same inner diameter as the ribbed tubes 56 and 70, and has an enlarged diameter receiving port 26 formed at one end (upstream side) thereof, and at the other end (downstream side) end thereof. A slot 28 is formed. The enlarged diameter receiving port 26 is formed, for example, by cutting off the tip of the rubber ring receiving port. A rubber ring mounting groove 30, a locking flange 32, and an anti-rattle flange 34 are formed on the outer surface of the end portion of the difference port 28 from the end surface S side. A rubber ring 36 for sealing the joint between the receiving side member 22 and the insertion side member 24 is mounted in the rubber ring mounting groove 30. Further, two handles 38 are provided at a predetermined position on the outer surface of the receiving-side member 22 (in this embodiment, the outer surface of the diameter-enlarged receiving port 26) with an interval of 180 degrees in the circumferential direction. The handle 38 is used when it is gripped or a jig is attached when the connection angle is changed.
[0018]
The outlet side member 24 is made of a synthetic resin such as vinyl chloride, and is formed in a substantially cylindrical shape. The insertion port side member 24 has the same inner diameter as the reception port side member 22, and the reception port 40 is formed at one end portion thereof, and the insertion port 42 is formed at the other end portion thereof. A water stop surface 44 with which the rubber ring 36 is abutted is formed on the inner surface of the receiving port 40, and a locking groove 46 that is engaged with the outer peripheral edge of the locking flange 32 is formed on the inner surface of the end of the receiving port 40. It is formed. In addition, two handles 48 are provided at a predetermined position on the outer surface of the outlet side member 24 (the base end portion of the receiving port 40 in this embodiment) with an interval of 180 degrees in the circumferential direction. Similarly to the handle 38, the handle 48 can be used for changing the connection angle.
[0019]
In the ribless main pipe universal joint 12, the insertion port 28 of the receiving port side member 22 is inserted into the receiving port 40 of the loading port side member 24, and is formed in the locking flange 32 and the receiving port 40 formed in the insertion port 28. The engaged locking groove 46 is fitted. The enlarged diameter receiving port 26 and the insertion port 42 are provided with a receiving tube 14 with a rib and an insertion tube 16 with a rib, respectively, so as to be connectable to the ribbed tube.
[0020]
The ribbed receiving pipe 14 is made of, for example, a synthetic resin such as vinyl chloride, and a plurality of circumferential ribs 50 are formed on the outer surface of the ribbed receiving pipe 14 at intervals in the axial direction. The ribbed receptacle tube 14 includes a straight pipe portion 52 having substantially the same inner diameter as the receptacle-side member 22, and the upstream end portion of the straight pipe portion 52 is different from the ribbed pipe 56 (FIG. 5) in use. An enlarged diameter receiving port 54 that receives the port 58 is formed. In addition, the receiving pipe 14 with ribs is connected to the receiving side member 22 through the short pipe 60 without ribs in this embodiment, so that the downstream end of the straight pipe section 52 is connected to the short pipe 60 without ribs. A receiving port 52a is formed which is expanded to an inner diameter substantially the same as the outer diameter and receives one end of the short pipe 60 without ribs.
[0021]
The ribless short tube 60 is made of a synthetic resin such as vinyl chloride, for example, and has an inner diameter that is substantially the same as the inner diameter of the receiving side member 22 and the straight pipe portion 52. The downstream end of the short pipe 60 without ribs is expanded to have an outer diameter that is substantially the same as the inner diameter of the enlarged diameter receiving port 26 so as to match the inner surface of the enlarged diameter receiving port 26 of the receiving side member 22. The upstream end of the short pipe 60 without ribs is inserted into the receiving port 52a at the downstream end of the receiving pipe 14 with ribs and bonded and bonded, and the downstream end of the short pipe 60 without ribs is It is inserted into the enlarged diameter receiving port 26 of the receiving side member 22 and bonded. By interposing such a short pipe 60 without ribs, the receiving side member 22 and the receiving pipe 14 with ribs are connected almost smoothly to the inner surface.
[0022]
The rib-attached pipe 16 is made of a synthetic resin such as vinyl chloride, and a plurality of circumferential ribs 62 are formed on the outer surface of the rib-attached pipe 16 at intervals in the axial direction. The ribbed differential pipe 16 includes a straight pipe portion 64 having substantially the same inner diameter as the differential port side member 24, and the upstream end of the straight pipe portion 64 has an inner diameter substantially the same as the outer diameter of the differential port side member 24. The receiving port 64a for receiving the insertion port 42 of the insertion port side member 24 is formed by expanding the diameter. The insertion port 42 of the insertion port side member 24 is inserted into the receiving port 64a of the rib-attached insertion tube 16 to be bonded. In addition, the downstream end of the straight pipe portion 64 is a gap 66, and a rubber ring 68 is mounted between predetermined ribs 62 on the outer surface of the gap 66. The rib 66 of the rib-attached pipe 16 is inserted into and connected to an enlarged diameter receiving port 72 formed at one end of the ribbed pipe 70 (FIG. 5).
[0023]
The first ribbed tube 18 is for protecting the ribless main pipe universal joint 12 together with the second ribbed tube 20. The first ribbed tube 18 is made of, for example, a synthetic resin such as vinyl chloride, and a plurality of circumferential ribs 74 are formed on the outer surface of the first ribbed tube 18 at intervals in the axial direction. The inner diameter of the first ribbed tube 18 is set to be slightly larger than the rib outer diameter at the downstream end of the ribbed receiving tube 14. The first ribbed pipe 18 is mounted from the downstream end of the ribbed receiving pipe 14 to the outlet 28 of the receiving side member 22, and the rib of the receiving side member 22 is formed by the first ribbed pipe 18. Not the outer surface is covered. In this embodiment, the downstream end surface of the first ribbed tube 18 is inclined at substantially the same angle as the joining end surface S, and is close to the side surface of the rattling prevention flange 34. In the first ribbed tube 18, two through holes 76 are formed corresponding to the two handles 38 of the receiving side member 22, and the handle 38 protrudes to the outside through the through holes 76. A part of the rib 74 at the downstream end is removed so as not to hit the inner surface of the second ribbed tube 20 when the angle is changed.
[0024]
The second ribbed tube 20 is for protecting the ribless main pipe universal joint 12 together with the first ribbed tube 18. The second ribbed tube 20 is made of a synthetic resin such as vinyl chloride, and a plurality of circumferential ribs 78 are formed on the outer surface of the second ribbed tube 20 at intervals in the axial direction. The second ribbed tube 20 includes a straight pipe portion 80 having an inner diameter slightly larger than the rib outer diameter of the upstream end portion of the outlet side member 24, and the diameter of the upstream end portion of the straight pipe portion 80 is increased. A mouth 82 is formed. Further, the inner diameter of the straight pipe portion 80 is set to be substantially the same as the inner diameter of the first ribbed pipe 18, and the inner diameter of the enlarged diameter receiving port 82 is such that the first ribbed pipe 18 can be received. It is set slightly larger than the rib outer diameter of the ribbed tube 18. The second ribbed tube 20 is mounted from the upstream end of the ribbed differential port tube 16 to at least the receiving port 40 of the differential port side member 24, and the rib of the differential port side member 24 is formed by the second ribbed tube 20. Not the outer surface is covered. In this embodiment, the downstream end portion of the first ribbed tube 18 is also inserted into the diameter-enlarged receiving port 82 of the second ribbed tube 20 and is covered by the diameter-enlarged receiving port 82. Further, the second ribbed tube 20 is formed with two through holes 84 corresponding to the two handles 48 of the outlet side member 24, and the handle 48 protrudes to the outside through the through holes 84.
[0025]
When manufacturing the ribbed main pipe universal joint 10, first, the ribless main pipe universal joint 12, the ribless short pipe 60, the ribbed receiving pipe 14, the ribbed differential pipe 16, and the first ribbed pipe 10 are used. 18 and the second ribbed tube 20 are prepared.
[0026]
For example, when the ribless main pipe universal joint 12 is formed, a ready-made ribless main pipe universal joint is prepared. As shown in FIG. 2, one end portion of the receiving-side member 22 of the ready-made rib-free main pipe universal joint is generally formed as a rubber ring receiving port 86, so that the tip end portion extends from the rubber ring receiving portion 86 a. Is cut and removed to form the enlarged diameter receiving port 26.
[0027]
When forming the ribless short pipe 60, a plain short pipe having an appropriate length having the same inner diameter as the ribless main pipe universal joint 12 is prepared, and the outer diameter of the other end is increased by, for example, blow molding. The diameter is increased to be substantially the same as the inner diameter of the diameter receiving port 26.
[0028]
When forming the ribbed receiving pipe 14, a ribbed pipe having an appropriate length having the same inner diameter as the ribless main pipe universal joint 12 and having an enlarged diameter receiving port 54 at one end is prepared. Then, by subjecting the other end portion to the secondary opening, that is, for example, by heating and softening the other end portion and inserting an appropriate mold and cooling and curing, the inner diameter of the other end portion is reduced to the short tube 60 without ribs. The receiving port 52a is formed by expanding the diameter to be substantially the same as the outer diameter.
[0029]
When the rib-attached differential pipe 16 is formed, an appropriate length of the rib-attached pipe having the same inner diameter as that of the main pipe-free joint 12 without ribs and having both ends made into a differential shape is prepared. Then, by subjecting the one end portion of the opening to secondary processing in the same manner as in the case of the receiving port 52a of the rib-attached receiving tube 14, the one end portion of the inner diameter is changed to the outer diameter of the difference port 42 of the opening side member 24. The diameter is increased to approximately the same as that of the receiving port 64a. Further, a rubber ring 68 is mounted between the predetermined ribs 62 of the other end 66.
[0030]
When the first ribbed tube 18 is formed, the ribbed tube 14 and the ribbed tube 16 used as the material of the ribbed tube 14 have a larger inner diameter than the rib outer diameter, and both ends have a port shape. Prepare the pipe with ribs. As such a ribbed tube, for example, a ribbed tube having a size (nominal diameter) that is slightly larger than the ribbed receptacle tube 14 and the ribbed differential tube 16 can be applied. Then, the other end face is cut obliquely and inclined at a predetermined angle, and a part of the rib 74 on the other end side is cut off. Further, a through hole 76 is formed at a position corresponding to the handle 38 of the receiving side member 22.
[0031]
When the second ribbed tube 20 is formed, a ribbed tube having the same size as the ribbed tube used as the material of the first ribbed tube 18 and having an enlarged diameter receiving opening 82 at one end is prepared. Then, the other end side is cut and removed to an appropriate length. Further, a through hole 84 is formed at a position corresponding to the handle 48 of the differential port side member 24.
[0032]
Next, one end of the ribless short tube 60 is inserted into the other end receiving port 52a of the ribbed receiving tube 14 and bonded, and the diameter of the receiving side member 22 of the ribless main pipe universal joint 12 is increased. The other end of the short pipe 60 without ribs is inserted into the receiving port 26 and bonded. On the other hand, the inlet 42 of the outlet side member 24 of the ribless main pipe universal joint 12 is inserted into the one end receiving port 64a of the ribbed outlet pipe 16 and adhesively bonded.
[0033]
Subsequently, the first ribbed tube 18 is attached to the outer surfaces of the receiving side member 22 and the ribbed receiving tube 14. When the first ribbed tube 18 is mounted, as shown by the broken line in FIG. 3, a part of the tube wall is cut in advance in the axial direction, and is pushed out from the cut end so that the receiving side member 22 The handle 38 is inserted into the through hole 76 and the first ribbed tube 18 is put in place. Then, the cut ends are integrated by, for example, vinyl chloride welding. In this way, the first ribbed tube 18 is held by the handle 38 inserted through the through hole 76 without being fixed to the ribbed receiving tube 14 and the receiving side member 22.
[0034]
Then, the second ribbed tube 20 is attached to the outer surfaces of the port-side member 24 and the ribbed port tube 16. When the second ribbed tube 20 is mounted, the tube wall is cut in advance in the axial direction in the same manner as in the case of the first ribbed tube 18, and is pushed out from the cut end so as to be widened. The handle 48 is inserted into the through hole 84, and the second ribbed tube 20 is put in place. Then, the cut ends are integrated by, for example, vinyl chloride welding. Similarly to the first ribbed tube 18, the second ribbed tube 20 is not fixed to the ribbed differential port 16 and the differential port side member 24 but is held by a handle 48 inserted through the through hole 84.
[0035]
In addition, the manufacturing method of this ribbed main pipe universal joint 10 is not limited to the above-mentioned thing, It can change suitably.
[0036]
When changing the connection angle in the ribbed main pipe universal joint 10, for example, the receiving side member 22 is rotated with respect to the opening side member 24 using the handle 38 of the receiving side member 22. Then, the first ribbed tube 18 is rotated together with the receiving side member 22 in the diameter expansion receiving port 82 of the second ribbed tube 20, and the connection angle can be changed in the range of 0 to 2θ degrees. At this time, the ribless portion is always covered with the first ribbed tube 18 and the second ribbed tube 20 and is not exposed to the outside. For example, FIG. 4 shows a case where the connection angle is changed to 2θ. In addition, you may rotate the opening side member 24 with respect to the receiving side member 22 using the handle 48 of the opening side member 24.
[0037]
When laying a pipe line using the ribbed main pipe universal joint 10, the ribbed main pipe universal joint 10 is set to a desired connection angle. For example, as shown in FIG. The insertion port 66 of the rib-attached insertion tube 16 is inserted into and connected to the diameter expansion receiving port 72 of the attachment tube 70. On the other hand, the differential port 58 to which the rubber ring 88 of the ribbed tube 56 on the upstream side is mounted is inserted and connected to the enlarged diameter receiving port 54 of the ribbed tube 14. FIG. 5 shows a case where the connection angle is 0 degree.
[0038]
According to this embodiment, since the rib-side receiving pipe 14 is provided in the receiving-side member 22 and the rib-attached pipe 16 is provided in the differential-side member 24, the ribbed pipes 56 and 70 are provided. Can be connected with. Moreover, since the ribless main pipe universal joint 12 (the receiving side member 22 and the outlet side member 24) is covered by the first ribbed pipe 18 and the second ribbed pipe 20, they are all backfilled with crushed stone. Can do. Therefore, it is not necessary to distinguish the backfill material between the ribbed portion and the ribless portion, and the workability can be improved.
[0039]
In addition, it can be manufactured by using existing ribless main pipe universal joints and ribbed pipes by performing a simple secondary process on them, so there is no need to develop a new injection mold and it is inexpensive. Can be manufactured. For example, when manufacturing a ribbed main pipe universal joint 10 having an inner diameter of φ250, a ready-made ribless main pipe universal joint having a nominal diameter of φ250 is applied as the ribless main pipe universal joint 12, and a ribbed receiving pipe is used. 14 and the rib-attached differential pipe 16 are made of ready-made ribbed pipes having a nominal diameter of φ250, and the ribless short pipe 60 is made of a ready-made plain pipe having a nominal diameter of φ250, and the first ribbed pipe 18 and As the second ribbed tube 20, a ready-made ribbed tube having a larger nominal diameter φ300 may be applied.
[0040]
In the above-described embodiment, the ribbed pipes 56 and 70 are connected. However, it is needless to say that the pipe structure to be connected can be changed as appropriate, for example, a pipe joint with ribs and a ribbed pipe joint. It may be a manhole having a connection port.
[0041]
Further, the ribless main pipe universal joint 12 is not limited to the shape and fitting structure as shown in each of the above-described embodiments (FIG. 1 embodiment, etc.), and may be any shape. Needless to say you get. For example, in each of the above-described embodiments, the enlarged diameter receiving port 26 is formed by cutting and removing the tip portion from the rubber ring receiving portion 86a of the rubber ring receiving port 86 (FIG. 2) of the receiving side member 22. However, the rubber ring receiving port 86 may be used as it is without being cut and removed. Moreover, although the receiving side member 22 and the receiving pipe 14 with a rib are joined through the short pipe 60 without a rib, when the one end part of the receiving side member 22 is made into a slot For example, the inner diameter of the other end of the ribbed receiving tube 14 is increased to be approximately the same as the outer diameter of the receiving member 22 so that the ribless short tube 60 is not directly interposed and bonded. It may be.
[0042]
Further, in each of the above-described embodiments, the second ribbed tube 20 is applied with a diameter-enlarged receiving port 82 formed at one end thereof. The end portion (differential port) is covered, but the covering relationship between the first ribbed tube 18 and the second ribbed tube 20 may be reversed. That is, for example, as shown in FIG. 6, as the first ribbed tube 18, a tube having a diameter-enlarged receiving port 82 formed at the other end is applied. You may make it cover the one edge part (opening). Specifically, in the embodiment of FIG. 6, one end surface of the second ribbed tube 20 is formed to be inclined, and the second ribbed tube 20 covers a part of the receiving port 40 of the outlet side member 24. . On the other hand, the enlarged diameter receiving port 82 of the first ribbed tube 18 covers the vicinity of the proximal end portion of the receiving port 40 of the differential port side member 24. Further, the distal end surface of the diameter-enlarged receiving port 82 is formed obliquely at substantially the same angle as the joining end surface S, for example, so that it does not come into contact with the handle 48 of the outlet side member 24 during rotation.
[0043]
Further, in each of the above-described embodiments, the one having the diameter-expanded opening 82 formed on one of the first ribbed pipe 18 and the second ribbed pipe 20 is applied, and the diameter-expanded opening 82 is applied. By covering the end of the other ribbed tube (differential), by applying one ribbed tube having an inner diameter larger than the rib outer diameter of the other ribbed tube, You may make it cover the edge part of the other ribbed pipe | tube. For example, in FIG. 7, the second ribbed tube 20 is slightly larger than the rib outer diameter of the first ribbed tube 18 in place of the second ribbed tube 20 having the diameter expansion receiving port 82 of FIG. 1 embodiment. An example is shown in the case where a ribbed tube having an inner diameter and having both ends shaped as a gap is applied. As the second ribbed tube 20, for example, a ribbed tube having a size (nominal diameter) slightly larger than the first ribbed tube 18 can be used.
[0044]
Further, in each of the above-described embodiments, the end portion (differential port) of the other ribbed tube is covered with one ribbed tube of the first ribbed tube 18 and the second ribbed tube 20, For example, as shown in FIG. 8, both may be made to abut at an inclined end face. Specifically, in the embodiment shown in FIG. 8, ribbed tubes having enlarged diameter receiving ports 90 and 92 are applied to the first ribbed tube 18 and the second ribbed tube 20, respectively. The end surfaces of 92 are formed to be inclined at substantially the same angle as the joining end surface S of the main joint 12 without ribs, for example, and are abutted against each other. In this case, even when the connection angle is changed, the first ribbed tube 18 and the second ribbed tube 20 are rotated while being abutted against each other at the inclined end surfaces.
[0045]
Further, in each of the above-described embodiments, the enlarged diameter receiving port 54 is formed at one end portion of the ribbed receiving tube 14. May be. Moreover, although the other end part of the rib-attached differential pipe 16 is made into the differential slot 66, an enlarged diameter receiving port may be formed in the other end part of the rib-attached differential pipe 16 depending on circumstances.
[Brief description of the drawings]
FIG. 1 is an illustrative view showing one embodiment of the present invention;
FIG. 2 is an illustrative view showing a method of forming the main joint with no ribs of the embodiment in FIG. 1;
3 is an illustrative view showing a state before mounting of the first ribbed tube of FIG. 1 embodiment; FIG.
FIG. 4 is an illustrative view showing a state in which the connection angle of the embodiment in FIG. 1 is changed;
FIG. 5 is an illustrative view showing a use state of the embodiment in FIG. 1;
FIG. 6 is an illustrative view showing another embodiment of the present invention.
FIG. 7 is an illustrative view showing another embodiment of the present invention.
FIG. 8 is an illustrative view showing another embodiment of the present invention.
FIG. 9 is an illustrative view showing one example of a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Rib main pipe universal joint 12 ... Rib-free main pipe universal joint 14 ... Rib receiving port pipe 16 ... Rib-attached pipe 18 ... 1st rib-equipped pipe 20 ... 2nd rib-equipped pipe 22 ... Reception side member 24 .. opening side member

Claims

A ribless main pipe universal joint in which a receiving side member and a differential side member are rotatably combined through a joint end face inclined at a predetermined angle;
A ribbed receiving pipe joined to a receiving side member of the ribless main pipe universal joint,
A ribbed outlet pipe joined to the outlet side member of the ribless main pipe universal joint,
A first ribbed tube that is mounted on the downstream side of the ribbed receptacle tube and covers the receptacle side member, and a second rib that is mounted on the upstream side of the ribbed receptacle tube and covers the differential portside member A ribbed main joint with a tube.

A ribless short tube inserted into the inner surface of the receiving side member;
The ribbed main pipe universal joint according to claim 1, wherein the ribbed receiving pipe is joined to the upstream side of the ribless short pipe.