JP2004116101A

JP2004116101A - Pipe joint seal packing of drain pipe

Info

Publication number: JP2004116101A
Application number: JP2002279996A
Authority: JP
Inventors: Tetsuji Yamazaki; 山崎　哲司
Original assignee: Maezawa Kasei Kogyo KK
Current assignee: Maezawa Kasei Kogyo KK
Priority date: 2002-09-25
Filing date: 2002-09-25
Publication date: 2004-04-15

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal packing capable of increasing water-tightness to either positive pressure or negative pressure. <P>SOLUTION: A first sealing section 46 is provided to a circular packing body 45 molded by a member having elasticity to press-contact to a fitting groove in a state of water-tightness. A first curved section 53 is extended to an upstream side of waste-water from the first sealing section 46 to curve to a downstream side by return. A second curved section 54 is extended to the downstream side of waste-water from the first curved section 53 to curve to the upstream side by return. A second sealing section 55 is extended to the second curved section 54 to press-contact to the inner circumferential surface of a first diameter widening section. The first curved section 53 and the second curved section 54 are respectively curved to the upstream side and the downstream side of the waste-water to form bending sections 57 and 58. A radial elasticity of the packing body 45 is increased to surely come into press-contact with the first sealing section 46 and the second sealing section 55. Water-tightness can be increased to either the positive pressure or the negative pressure. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、一方の筒状体およびこの筒状体に接続される他方の筒状体を備えた管継手に取り付けられる排水管の管継手用シールパッキンに関する。
【０００２】
【従来の技術】
従来、この種の排水管の管継手用シールパッキンとしては、例えば特許文献１に示す構成が知られている。より具体的には、この種のシールパッキンは、図６および図７に示すように、環状のパッキン本体１を断面視で略く字状に形成してパッキン本体１の軸方向の一端側に凹状の屈曲部２を設け、この屈曲部２の両側部であるパッキン本体１の外周部および内周部にシール部３，４を形成している。
【０００３】
そして、第１の継手体５の内周面に設けた嵌合溝６にシール部４を当接させてパッキン本体１を嵌合した状態で第１の継手体５に第２の継手体７を挿入し、シール部３，４をそれぞれ嵌合溝６の底面部およびこの第２の継手体７の外周面に圧接させて液密性を確保する。
【０００４】
【特許文献１】
特開平７−２９３７５９号公報（第３頁、図１）
【０００５】
【発明が解決しようとする課題】
しかしながら、上述のシールパッキンでは、パッキン本体１の軸方向の一端側にのみ屈曲部２が形成されていることにより、正圧および負圧のいずれか一方に対する液密性は確保できるものの、正圧および負圧のいずれか他方に対する液密性を確保することが容易でないという問題点を有している。
【０００６】
本発明はこのような点に鑑みなされたもので、正圧および負圧のいずれに対しても液密性を向上できる排水管の管継手用シールパッキン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記載の排水管の管継手用シールパッキンは、一方の筒状体およびこの筒状体に接続される他方の筒状体を備えた管継手に取り付けられるシールパッキンであって、弾性を有する部材にて成形され、一方の筒状体および他方の筒状体のいずれか一方の接続部の周囲に設けられた環状の嵌合溝に嵌合される環状のパッキン本体を具備し、このパッキン本体は、嵌合溝に液密に圧接される第１のシール部と、この第１のシール部から排水の上流側および下流側のいずれか一方に延設されて折り返し彎曲された第１の彎曲部と、この第１の彎曲部から排水の上流側および下流側のいずれか他方に延設されて前記第１の彎曲部と反対方向に折り返し彎曲された第２の彎曲部と、この第２の彎曲部から延設され、一方の筒状体および他方の筒状体のいずれか他方の接続部の周囲に液密に圧接される第２のシール部とを備えたものである。
【０００８】
そして、弾性を有する部材にて成形した環状のパッキン本体に、管継手の一方の筒状体およびこの筒状体に接続される他方の筒状体のいずれか一方の接続部の周囲に設けられた環状の嵌合溝に液密に圧接される第１のシール部を設け、この第１のシール部から排水の上流側および下流側のいずれか一方に延設して折り返し彎曲された第１の彎曲部を設け、この第１の彎曲部から排水の上流側および下流側のいずれか他方に延設して第１の彎曲部と反対方向に折り返し彎曲した第２の彎曲部を延設するとともに、この第２の彎曲部に、一方の筒状体および他方の筒状体のいずれか他方の接続部の周囲に液密に圧接される第２のシール部を延設する。この結果、第１の彎曲部および第２の彎曲部が排水の上流側および下流側にそれぞれ彎曲し、かつこれら第１の彎曲部および第２の彎曲部によりパッキン本体の径方向の弾性が向上して第１のシール部および第２のシール部が確実に圧接されるため、正圧および負圧のいずれに対しても液密性が向上する。
【０００９】
請求項２記載の排水管の管継手用シールパッキンは、被接続管に接続される管継手の継手本体に取り付けられるシールパッキンであって、弾性を有する部材にて成形され、前記継手本体の接続部の内周に設けられた環状の嵌合溝に嵌合される環状のパッキン本体を具備し、このパッキン本体は、嵌合溝に液密に圧接される第１のシール部と、この第１のシール部から排水の上流側および下流側のいずれか一方に延設されて折り返し彎曲された第１の彎曲部と、この第１の彎曲部から排水の上流側および下流側のいずれか他方に延設されて前記第１の彎曲部と反対方向に折り返し彎曲された第２の彎曲部と、この第２の彎曲部から延設され、前記被接続管の接続部の外周に液密に圧接される第２のシール部とを備えたものである。
【００１０】
そして、弾性を有する部材にて成形した環状のパッキン本体に、継手本体の接続部の内周に設けられた環状の嵌合溝に液密に圧接される第１のシール部を設け、この第１のシール部から排水の上流側および下流側のいずれか一方に延設して折り返し彎曲された第１の彎曲部を設け、この第１の彎曲部から排水の上流側および下流側のいずれか他方に延設して第１の彎曲部と反対方向に折り返し彎曲した第２の彎曲部を延設するとともに、この第２の彎曲部に、被接続管の接続部の外周に液密に圧接される第２のシール部を延設する。この結果、第１の彎曲部および第２の彎曲部が排水の上流側および下流側にそれぞれ彎曲し、かつこれら第１の彎曲部および第２の彎曲部によりパッキン本体の径方向の弾性が向上して第１のシール部および第２のシール部が確実に圧接されるため、正圧および負圧のいずれに対しても液密性が向上する。
【００１１】
請求項３記載の排水管の管継手用シールパッキンは、請求項１または２記載のシールパッキンにおいて、第１のシール部は、この第１のシール部に切り欠き形成された第１の切欠部を有し、第２のシール部は、この第２のシール部に切り欠き形成された第２の切欠部を有したものである。
【００１２】
そして、第１のシール部に第１の切欠部を切り欠き形成し、第２のシール部に第２の切欠部を切り欠き形成することにより、第１のシール部および第２のシール部の当接面積が減少するため、これら第１のシール部および第２のシール部にパッキン本体の弾性力がより確実に加わり、第１のシール部および第２のシール部をより強く圧接することなく液密性がより向上する。
【００１３】
【発明の実施の形態】
以下、本発明の排水管の管継手用シールパッキンの第１の実施の形態の構成を図１ないし図４を参照して説明する。
【００１４】
図３および図４において、１１は排水菅の管継手としての自在管継手を示し、この自在管継手１１は、例えば地中に埋設されている図示しない下水本管を点検、あるいは清掃するための図示しない小型マンホールの受口側に接続させる継手体であり、例えばＰＶＣ（Ｐｏｌｙ　Ｖｉｎｙｌ　Ｃｈｌｏｒｉｄｅ）、すなわち塩化ビニル樹脂などの合成樹脂にて略円筒状に成形されている。
【００１５】
また、自在管継手１１は、一方の筒状体としての略円筒状の第１の継手体１２および他方の筒状体としての略円筒状の第２の継手体１３にて構成されている。ここで、第１の継手体１２は、軸方向の一端側である流入側、すなわち上流側が下水本管としての被接続管に接続され、この第１の継手体１２の軸方向の他端側である流出側、すなわち下流側の端面には、第２の継手体１３の軸方向の一端側である流入側、すなわち上流側の端面が挿入されて接続され、互いの端面の周方向に摺動可能に接合されている。一方、第２の継手体１３の軸方向の他端側である流出側、すなわち下流側は、小型マンホールの受口側に接続される。
【００１６】
さらに、第１の継手体１２の上流側は、流出側の開口方向に向けて突出する流入口１４となっており、この流入口１４は、被接続管に挿入されて連通される。そして、流入口１４の開口内縁には、第１の継手体１２の周方向の全周に亘って凹溝状の取付凹部１５が設けられている。
【００１７】
この取付凹部１５には、例えばＳＢＲ（Ｓｔｙｒｅｎｅ　Ｂｕｔａｄｉｅｎｅ　Ｒｕｂｂｅｒ）、すなわちスチレンブタジエンゴムなどの弾性を有する部材で円環状に成形された流入側パッキン２１が嵌合されている。
【００１８】
この流入側パッキン２１の外周面全体は、取付凹部１５に圧接される溝シール部としての外側シール部２２となっており、この外側シール部２２には、内方に向けて断面視で鋭角三角形状に突出された内側当接部としての内側シール部２３が一体に設けられている。すなわち、流入側パッキン２１は、第１の継手体１２の下流側に流入側屈曲部２４が設けられた断面視で略く字状に形成されている。
【００１９】
そして、内側シール部２３は、流入側パッキン２１を取付凹部１５に嵌合した状態で第１の継手体１２の内周に先端側が突出しており、被接続管の外周面に圧接されることにより液密性を確保する。
【００２０】
また、第１の継手体１２の軸方向の略中心域の内周面には、流入口１４から挿入された被接続管が位置決めされる位置決め段部２５が全周に亘って形成されている。さらに、第１の継手体１２の下流側の端面には、この第１の継手体１２の軸方向に対して所定の角度に傾斜して突出した接続部としての受口部２６が一体に設けられている。
【００２１】
この受口部２６には、第１の継手体１２の下流側に向かって第１の拡径部３１および第２の拡径部３２が順次形成されており、これら第１の拡径部３１および第２の拡径部３２により、受口部２６は第１の継手体１２に対して下流側へと段状に順次拡径されている。そして、第１の継手体１２の下流側の端部である受口部２６の先端側の内周縁には、凹溝状の下流側取付凹部３３が形成されており、この下流側取付凹部３３よりも下流側の内周面には、第１の継手体１２の軸方向に断続的に縮径された環状の係止爪部３４が設けられている。
【００２２】
また、第１の継手体１２の外周面には、断面視矩形状の一対の把持部３５が突出して設けられている。
【００２３】
一方、第２の継手体１３の上流側の端面には、第２の継手体１３の軸方向に対して所定の角度に傾斜して突出した接続部としての被嵌合部４１となっている。ここで、第２の継手体１３に対する被嵌合部４１の傾斜角度は、第１の継手体１２に対する受口部２６の傾斜角度と等しくなっている。
【００２４】
さらに、被嵌合部４１の周囲である外周面には、円環凹溝状の嵌合溝４３が周方向に全周に亘って形成されている。そして、この嵌合溝４３には、シールパッキン４４が嵌合されている。
【００２５】
ここで、シールパッキン４４は、図１に示すように、例えばＳＢＲ、すなわちスチレンブタジエンゴムなどの弾性を有する部材にて円環状に成形されたパッキン本体４５を有しており、このパッキン本体４５には、パッキン本体４５の内周側に中心軸方向に向けて突出した断面視略矩形状の第１のシール部４６が全周に亘って一体に設けられている。
【００２６】
この第１のシール部４６は、図２に示すように、シールパッキン４４を嵌合溝４３に嵌合した状態で第１の継手体１２に第２の継手体１３を嵌挿した際に、嵌合溝４３の底面部に液密に圧接される。
【００２７】
また、第１のシール部４６には、第１の切欠部としての第１の段差部５１が断面視略三角形状に全周に亘って切り欠き形成されている。この第１の段差部５１により、嵌合溝４３の底面部に対する第１のシール部４６の当接面積が減少し、第１の継手体１２に第２の継手体１３を嵌挿した際に、図２に示すように、第１のシール部４６の一部のみが嵌合溝４３の底面部に圧接される。
【００２８】
さらに、図１に示すように、第１のシール部４６の先端側は、凸弧状の円弧状シール部５２となっている。この円弧状シール部５２は、図２に示すように、シールパッキン４４を嵌合溝４３に嵌合した際に、この嵌合溝４３の底面部の円弧状の両側縁部に沿って圧接される。
【００２９】
そして、第１のシール部４６には、第１の彎曲部５３が一体に延設されている。この第１の彎曲部５３は、パッキン本体４５の軸方向の一端側である排水の下流側に延設され、かつパッキン本体４５の軸方向の他端側である排水の上流側へと略逆く字状に折り返し彎曲されている。
【００３０】
また、この第１の彎曲部５３には、第２の彎曲部５４が一体に延設されている。この第２の彎曲部５４は、パッキン本体４５の軸方向の他端側である排水の上流側に延設され、かつパッキン本体４５の軸方向の一端側である下流側、すなわち第１の彎曲部５３の折り返し方向と反対方向に略く字状に折り返し彎曲されている。
【００３１】
また、この第２の彎曲部５４には、第２のシール部５５が一体に延設されている。この第２のシール部５５は、シールパッキン４４を嵌合溝４３に嵌合させた状態で先端側が第２の継手体１３の外方に突出し、第１の継手体１２に第２の継手体１３を嵌挿した際に第１の継手体１２の受口部２６の周囲である第１の拡径部３１の内周面に液密に圧接される。
【００３２】
さらに、第２のシール部５５には、第２の切欠部としての第２の段差部５６が断面視略三角形状に全周に亘って切り欠き形成されている。この第２の段差部５６により、第１の拡径部３１に対する第２のシール部５５の当接面積が減少し、第１の継手体１２に第２の継手体１３を嵌挿した際に、図２に示すように、第２のシール部５５が第１の拡径部３１の内周面の２点に、円環線状に圧接される。
【００３３】
上記第１の彎曲部５３および第２の彎曲部５４により、シールパッキン４４は断面視で略Ｓ字状に形成されている。このため、シールパッキン４４のパッキン本体４５は、径方向にばね状となって弾性が向上しているとともに、第１の彎曲部５３および第２の彎曲部５４の裏側が、それぞれ凹状の屈曲部５７，５８となっている。
【００３４】
さらに、図３および図４に示すように、第２の継手体１３の外周面の嵌合溝４３よりも下流側には、係止部６１が第２の継手体１３の周方向に全周に亘って径方向に突出して設けられている。この係止部６１は、第１の継手体１２に第２の継手体１３を嵌挿した際に、第１の継手体１２の下流側取付凹部３３に係合され、かつ受口部２６の係止爪部３４により抜け止めされる。
【００３５】
そして、第２の継手体１３の外周面の係止部６１よりも下流側には、外周突出部６２が径方向に突出して設けられている。この外周突出部６２は、第１の継手体１２に第２の継手体１３を嵌挿した際に、第１の継手体１２の下流側の端面に対向して位置している。
【００３６】
また、第２の継手体１３の流出側は、流出側の開口方向に向けて突出する流出口６３となっており、この流出口６３は、小型マンホールの受口側に挿入されて連通される。さらに、第２の継手体１３のこの流出口６３側の外縁には、この流出口６３の開口方向に縮径された縮径部６４が設けられており、この縮径部６４により、第２の継手体１３の流出口が小型マンホールの受口側に容易に挿入できるようになっている。
【００３７】
そして、第２の継手体１３の外周面には、第２の継手体１３の径方向にリブ状に突出した矩形状の一対の把持部６５が一体に設けられている。さらに、これら把持部６５を把持して第２の継手体１３を回り止めした状態で把持部３５を把持して第１の継手体１２を周方向に回転させることにより、第２の継手体１３に対して第１の継手体１２が摺動し、図１および図２に示すように、第１の継手体１２と第２の継手体１３との角度を、所定の角度間に自在に変更可能となっている。
【００３８】
次に、上記第１の実施の形態の作用を説明する。
【００３９】
まず、第２の継手体１３の嵌合溝４３にシールパッキン４４を嵌合させた状態で、第２の継手体１３の被嵌合部４１を第１の継手体１２の受口部２６に嵌挿し、第２の継手体１３の係止部６１を第１の継手体１２の下流側取付凹部３３に係合させ、受口部２６の係止爪部３４により抜け止めする。
【００４０】
このとき、図２および図３に示すように、第１の継手体１２の第１の拡径部３１と嵌合溝４３との間でシールパッキン４４が径方向に弾性変形する。
【００４１】
この結果、シールパッキン４４の第１のシール部４６は、第１の段差部５１により第１の彎曲部５３側の部分が嵌合溝４３の底面部に液密に圧接されるとともに、円弧状シール部５２が嵌合溝４３の底面部の円弧状の両側縁部に沿って圧接される。
【００４２】
一方、シールパッキン４４の第２のシール部５５の先端側は、第１の拡径部３１および第２の継手体１３の外周面の間に挟持され、第２の段差部５６が設けられた第２のシール部５５が第１の拡径部３１の内周面に、例えば２点、円環線状に液密に圧接される。
【００４３】
この結果、第１の継手体１２の受口部２６と第２の継手体１３の被嵌合部４１とが液密に接続されて、自在管継手１１が形成される。
【００４４】
この状態で、第２の継手体１３の把持部６５を把持して回り止めした状態で、第１の継手体１２の把持部３５を把持してこの第１の継手体１２を第２の継手体１３に対して周方向に回転させ、第１の継手体１２と第２の継手体１３との角度を所望の角度に調整する。
【００４５】
次いで、第２の継手体１３の流出口６３の外周縁部に滑剤などを塗布し、この流出口６３側を小型マンホールの受口側に挿入して接合する。
【００４６】
さらに、第１の継手体１２の流入口１４を被接続管に挿入して接合し、小型マンホールと下水本管とを接続して下水管路を形成する。
【００４７】
ここで、例えば自在管継手１１に内圧が掛かった際、すなわち正圧の際には、シールパッキン４４の屈曲部５７により液密性を確保する。
【００４８】
一方、自在管継手１１に外圧が掛かった際、すなわち負圧の際には、シールパッキン４４の屈曲部５８により液密性を確保する。
【００４９】
上述したように、上記第１の実施の形態によれば、弾性を有する部材にて成形した環状のパッキン本体４５に、環状の嵌合溝４３に液密に圧接される第１のシール部４６を設け、この第１のシール部４６から第１の彎曲部５３を排水の下流側に延設して上流側に折り返し彎曲し、この第１の彎曲部５３から第２の彎曲部５４を排水の下流側に延設して上流側に折り返し彎曲するとともに、この第２の彎曲部５４に、第１の拡径部３１に液密に圧接される第２のシール部５５を延設する。この結果、第１の彎曲部５３および第２の彎曲部５４が排水の上流側および下流側にそれぞれ彎曲して上流側および下流側に屈曲部５７，５８を形成するとともに、第１の彎曲部５３および第２の彎曲部５４によりパッキン本体４５の径方向の弾性が向上して第１のシール部４６および第２のシール部５５がそれぞれ嵌合溝４３および第１の拡径部３１に確実に圧接されるため、正圧および負圧のいずれに対しても液密性を向上できる。
【００５０】
また、第１のシール部４６に第１の段差部５１を切り欠き形成し、第２のシール部５５に第２の段差部５６を切り欠き形成することにより、第１のシール部４６および第２のシール部５５の当接面積が減少するため、これら第１のシール部４６および第２のシール部５５にパッキン本体４５の弾性力がより確実に加わり、第１のシール部４６および第２のシール部５５をより強く圧接することなく液密性をより向上でき、かつ自在管継手１１を回転操作する際に、第１のシール部４６および第２のシール部５５による摩擦抵抗が小さくなるため、自在管継手１１の回転操作に必要な外力（回転操作力）が低減し、操作性を向上できる。
【００５１】
さらに、第２のシール部５５の先端側に円弧状シール部５２を設け、この円弧状シール部５２が嵌合溝４３の底面部の円弧状の両側縁部に沿って圧接されることにより、液密性をさらに向上できる。
【００５２】
次に、本発明の第２の実施の形態の構成を図５を参照して説明する。
【００５３】
図５において、７１は排水管の管継手を示し（以下、管継手７１と記載する）、この管継手７１は、例えば地中に埋設されている図示しない下水本管と下水本管とを接続する継手体であり、例えばＰＶＣ（塩化ビニル樹脂）などの合成樹脂にて略円筒状に成形されている。
【００５４】
また、管継手７１は、下水本管としての被接続管７２に上流側が接続された継手本体７３を備えている。
【００５５】
さらに、この継手本体７３には、上流側の端面に拡径状に形成された接続部としての受口部７４が突出して一体に設けられている。被接続管７２の接続部７５は、この受口部７４内に挿入されている。
【００５６】
また、受口部７４の周囲である内周には、環状の嵌合溝７６が周方向に全周に亘って設けられており、この嵌合溝７６には、シールパッキン７７が嵌合されている。
【００５７】
このシールパッキン７７は、上記図１ないし図４に示す実施の形態のシールパッキン４４の内周側の形状と外周側の形状とを反転させた形状を有している。すなわち、シールパッキン７７は、例えばＳＢＲ（スチレンブタジエンゴム）などの弾性を有する部材にて円環状に成形されたパッキン本体８１を備え、このパッキン本体８１には、外周側に径方向に向けて突出した断面視略矩形状の第１のシール部８２が全周に亘って一体に設けられている。
【００５８】
この第１のシール部８２は、シールパッキン７７を嵌合溝７６に嵌合した状態で被接続管７２を継手本体７３に嵌挿した際に、嵌合溝７６の底面部に液密に圧接される。
【００５９】
また、第１のシール部８２には、第１の切欠部としての第１の段差部８３が断面視略三角形状に全周に亘って切り欠き形成されている。この第１の段差部８３により、嵌合溝７６の底面部に対する第１のシール部８２の当接面積が減少し、被接続管７２を継手本体７３に嵌挿した際に、第１のシール部８２の一部が嵌合溝７６の底面部に圧接される。
【００６０】
さらに、第１のシール部８２の先端側は、凸弧状の円弧状シール部８４となっている。この円弧状シール部８４は、シールパッキン７７を嵌合溝７６に嵌合した際に、この嵌合溝７６の底面部の円弧状の両側縁部に沿って圧接される。
【００６１】
そして、第１のシール部８２には、第１の彎曲部８５が一体に延設されている。この第１の彎曲部８５は、パッキン本体８１の軸方向の一端側である排水の上流側に延設され、かつパッキン本体８１の軸方向の他端側である排水の下流側へと略く字状に折り返し彎曲されている。
【００６２】
また、この第１の彎曲部８５には、第２の彎曲部８６が一体に延設されている。この第２の彎曲部８６は、パッキン本体８１の軸方向の他端側である排水の下流側に延設され、かつパッキン本体８１の軸方向の一端側である上流側、すなわち第１の彎曲部８５の折り返し方向と反対方向に略逆く字状に折り返し彎曲されている。
【００６３】
さらに、この第２の彎曲部８６は、第２のシール部９１が一体に延設されている。この第２のシール部９１は、シールパッキン７７を嵌合溝７６に嵌合させた状態で先端側が継手本体７３の内方に突出し、被接続管７２を継手本体７３に嵌挿した際に接続部７５の周囲である外周面に液密に圧接される。
【００６４】
そして、第２のシール部９１には、第２の切欠部としての第２の段差部９２が断面視略三角形状に全周に亘って切り欠き形成されている。この第２の段差部９２により、接続部７５に対する第２のシール部９１の当接面積が減少し、被接続管７２を継手本体７３に嵌挿した際に、第２のシール部９１が被接続管７２の下流側の外周面の２点に、円環線状に圧接される。
【００６５】
上記第１の彎曲部８５および第２の彎曲部８６により、シールパッキン７７は断面視で略Ｓ字状に形成されている。このため、シールパッキン７７のパッキン本体８１は、径方向にばね状となって弾性が向上しているとともに、第１の彎曲部８５および第２の彎曲部８６の裏側が、それぞれ凹状の屈曲部９３，９４となっている。
【００６６】
そして、継手本体７３の受口部７４の突出基端側の内周面には、位置決め段部９５が全周に亘って形成されている。この位置決め段部９５に被接続管７２の下流側の端部が当接することにより、継手本体７３に対して被接続管７２が位置決めされる。
【００６７】
次に、上記第２の実施の形態の作用を説明する。
【００６８】
まず、継手本体７３の嵌合溝７６にシールパッキン７７を嵌合させた状態で、継手本体７３の受口部７４に被接続管７２の接続部７５を、位置決め段部９５に当接するまで嵌挿する。
【００６９】
このとき、被接続管７２の接続部７５と嵌合溝７６との間でシールパッキン７７が径方向に弾性変形する。
【００７０】
このため、シールパッキン７７の第１のシール部８２は、第１の段差部８３により第１の彎曲部８５側の部分が嵌合溝７６の底面部に液密に圧接されるとともに、円弧状シール部８４が嵌合溝７６の底面部の円弧状の両側縁部に沿って圧接される。
【００７１】
また、シールパッキン７７の第２のシール部９１の先端側は、接続部７５の外周面および受口部７４の内周面の間に挟持され、第２の段差部９２が設けられた第２のシール部９１が第１の接続部７５の外周面に、例えば２点、円環線状に液密に圧接される。
【００７２】
この結果、被接続管７２と継手本体７３とが液密に接続されて、管継手７１により下水本管と下水本管とを接続して下水管路を形成する。
【００７３】
ここで、管継手７１に外圧が掛かった際、すなわち負圧の際には、シールパッキン７７の屈曲部９３により液密性を確保する。
【００７４】
一方、例えば管継手７１に内圧が掛かった際、すなわち正圧の際には、シールパッキン７７の屈曲部９４により液密性を確保する。
【００７５】
上述したように、弾性を有する部材にて成形した環状のパッキン本体８１に、嵌合溝７６の底面部に液密に圧接される第１のシール部８２を設け、この第１のシール部８２から第１の彎曲部８５を排水の下流側に延設して上流側に折り返し彎曲し、この第１の彎曲部８５から第２の彎曲部８６を排水の上流側に延設して下流側に折り返し彎曲するとともに、この第２の彎曲部８６に、接続部７５の外周面に液密に圧接される第２のシール部９１を延設する。この結果、第１の彎曲部８５および第２の彎曲部８６が排水の上流側および下流側にそれぞれ彎曲して上流側および下流側に屈曲部９３，９４を形成するとともに、第１の彎曲部８５および第２の彎曲部８６によりパッキン本体８１の径方向の弾性が向上して第１のシール部８２および第２のシール部９１がそれぞれ嵌合溝７６および接続部７５に圧接されるため、正圧および負圧のいずれに対しても液密性を向上できる。
【００７６】
また、第１のシール部８２に第１の段差部８３を切り欠き形成し、第２のシール部９１に第２の段差部９２を切り欠き形成することにより、第１のシール部８２および第２のシール部９１の当接面積が減少するため、これら第１のシール部８２および第２のシール部９１にパッキン本体８１の弾性力がより確実に加わり、第１のシール部８２および第２のシール部９１をより強く圧接することなく液密性をより向上できる。
【００７７】
さらに、第１のシール部８２の先端側に円弧状シール部８４を設け、この円弧状シール部８４が嵌合溝７６の底面部の円弧状の両側縁部に沿って圧接されることにより、液密性をさらに向上できる。
【００７８】
なお、上記各実施の形態において、自在管継手１１および管継手７１の細部の構造については、上記各実施の形態の構造に限定されるものではない。
【００７９】
また、他の実施の形態として、他の様々な管継手などにも適用できる。
【００８０】
【実施例】
以下、上記第１の実施の形態の排水管の管継手用シールパッキンの一実施例を、表１を参照して説明する。
【００８１】
本実施例では、上記第１の実施の形態の排水管の管継手用シールパッキンの正圧および負圧に対する液密性、および管継手の回転操作力などを、試験条件を変化させつつサンプル１およびサンプル２にて試験した。なお、比較例として、図６および図７に示す従来例の排水管の管継手用シールパッキンを用いた。
【００８２】
まず、回転操作力についての試験（操作力試験）は、管継手の組付時、１日後、３日後および１週間後の回転操作に必要なトルクを、サンプル１、サンプル２および比較例にてそれぞれ２回ずつ測定した。
【００８３】
次いで、正圧に対する液密性の試験（水圧試験）は、約０．０５ＭＰａおよび約０．１０ＭＰａの水圧を１分間かけた状態で液密性をそれぞれ確認した後、０．０５ＭＰａずつ水圧を上昇させてサンプル１および比較例にてそれぞれ試験した。尚、０．１５ＭＰａ〜０．２５ＭＰａの水圧下での試験結果は省略する。
【００８４】
さらに、負圧に対する液密性の試験（偏平負圧試験）は、荷重を加えてパッキン本体を偏平にした状態で０．０７８ＭＰａの負圧を１分間かけ、各偏平量および各偏平荷重下でのサンプル１および比較例の液密性をそれぞれ確認した。
【００８５】
これら各試験の結果を、表１に示す。
【００８６】
【表１】

【００８７】
この表１に示すように、操作力試験においては、比較例のトルクが１日後の１回目に１７．００と非常に大きく、１週間後の１回目には２５．５４と、さらに大きくなっていたのに対し、サンプル１およびサンプル２は、殆どトルクが変化しなかった。この結果、サンプル１およびサンプル２が比較例よりも長期に亘って良好な回転操作性を維持できることが分かる。
【００８８】
また、水圧試験においては、比較例が水圧０．３５ＭＰａ以上では水漏れを生じたのに対し、サンプル１は水圧を０．４０ＭＰａまでかけても液密性を維持できた。この結果、サンプル１が比較例よりも正圧に対して高い液密性を有していることが分かる。
【００８９】
さらに、偏平負圧試験においては、比較例が偏平量６％（９．９ｍｍ）、偏平荷重５．１７ＫＮで水漏れを生じたのに対し、サンプル１は偏平量８％（１３．２ｍｍ）、偏平荷重６．４４ＫＮまで水漏れを生じなかった。この結果、サンプル１が比較例よりも負圧に対して高い液密性を有していることが分かる。
【００９０】
以上により、上記第１の実施の形態の排水管の管継手用シールパッキンの効果を確認できた。
【００９１】
【発明の効果】
請求項１記載の排水管の管継手用シールパッキンによれば、弾性を有する部材にて成形した環状のパッキン本体に、管継手の一方の筒状体およびこの筒状体に接続される他方の筒状体のいずれか一方の接続部の周囲に設けられた環状の嵌合溝に液密に圧接される第１のシール部を設け、この第１のシール部から排水の上流側および下流側のいずれか一方に延設して折り返し彎曲された第１の彎曲部を設け、この第１の彎曲部から排水の上流側および下流側のいずれか他方に延設して第１の彎曲部と反対方向に折り返し彎曲した第２の彎曲部を延設するとともに、この第２の彎曲部に、一方の筒状体および他方の筒状体のいずれか他方の接続部の周囲に液密に圧接される第２のシール部を延設する。この結果、第１の彎曲部および第２の彎曲部が排水の上流側および下流側にそれぞれ彎曲し、かつこれら第１の彎曲部および第２の彎曲部によりパッキン本体の径方向の弾性が向上して第１のシール部および第２のシール部が確実に圧接されるため、正圧および負圧のいずれに対しても液密性を向上できる。
【００９２】
請求項２記載の排水管の管継手用シールパッキンによれば、弾弾性を有する部材にて成形した環状のパッキン本体に、継手本体の接続部の内周に設けられた環状の嵌合溝に液密に圧接される第１のシール部を設け、この第１のシール部から排水の上流側および下流側のいずれか一方に延設して折り返し彎曲された第１の彎曲部を設け、この第１の彎曲部から排水の上流側および下流側のいずれか他方に延設して第１の彎曲部と反対方向に折り返し彎曲した第２の彎曲部を延設するとともに、この第２の彎曲部に、被接続管の接続部の外周に液密に圧接される第２のシール部を延設する。この結果、第１の彎曲部および第２の彎曲部が排水の上流側および下流側にそれぞれ彎曲し、かつこれら第１の彎曲部および第２の彎曲部によりパッキン本体の径方向の弾性が向上して第１のシール部および第２のシール部が確実に圧接されるため、正圧および負圧のいずれに対しても液密性を向上できる。
【００９３】
請求項３記載の排水管の管継手用シールパッキンによれば、第１のシール部に第１の切欠部を切り欠き形成し、第２のシール部に第２の切欠部を切り欠き形成することにより、第１のシール部および第２のシール部の当接面積が減少するため、これら第１のシール部および第２のシール部にパッキン本体の弾性力がより確実に加わり、第１のシール部および第２のシール部をより強く圧接することなく液密性をより向上できる。
【図面の簡単な説明】
【図１】本発明の排水管の管継手用シールパッキンの第１の実施の形態を示す縦断側面図である。
【図２】同上排水管の管継手用シールパッキンの嵌合状態を示す縦断側面図である。
【図３】同上排水管の管継手用シールパッキンを示す縦断側面図である。
【図４】同上排水管の管継手用シールパッキンを示す縦断側面図である。
【図５】本発明の排水管の管継手用シールパッキンの第２の実施の形態を示す縦断側面図である。
【図６】従来例の排水管の管継手用シールパッキンを示す縦断側面図である。
【図７】同上排水管の管継手用シールパッキンの嵌合状態を示す縦断側面図である。
【符号の説明】
１１　　排水管の管継手としての自在管継手
１２　　一方の筒状体としての第１の継手体
１３　　他方の筒状体としての第２の継手体
４３，７６　　嵌合溝
４４，７７　　排水管の管継手用シールパッキン
４５，８１　　パッキン本体
４６，８２　　第１のシール部
５１，８３　　第１の切欠部としての第１の段差部
５３，８５　　第１の彎曲部
５４，８６　　第２の彎曲部
５５，９１　　第２のシール部
５６，９２　　第２の切欠部としての第２の段差部
７１　　排水管の管継手としての管継手
７２　　被接続管
７３　　継手本体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seal packing for a pipe joint of a drainage pipe attached to a pipe joint provided with one tubular body and the other tubular body connected to the tubular body.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a seal packing for a pipe joint of this type of drainage pipe, for example, a configuration disclosed in Patent Literature 1 is known. More specifically, as shown in FIGS. 6 and 7, this type of seal packing is such that an annular packing main body 1 is formed in a substantially rectangular shape in cross-sectional view, and is provided on one end side of the packing main body 1 in the axial direction. A concave bent portion 2 is provided, and

seal portions

3 and 4 are formed on the outer peripheral portion and the inner peripheral portion of the packing body 1 on both sides of the bent portion 2.
[0003]
Then, the second joint member 7 is attached to the first joint member 5 in a state where the seal portion 4 is brought into contact with the fitting groove 6 provided on the inner peripheral surface of the first joint member 5 and the packing body 1 is fitted. And the

seal portions

3 and 4 are pressed against the bottom surface of the fitting groove 6 and the outer peripheral surface of the second joint body 7 to ensure liquid tightness.
[0004]
[Patent Document 1]
JP-A-7-293759 (page 3, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, in the above-described seal packing, since the bent portion 2 is formed only on one end side in the axial direction of the packing main body 1, although the liquid tightness with respect to either the positive pressure or the negative pressure can be ensured, the positive pressure is maintained. There is a problem that it is not easy to ensure liquid tightness with respect to either one of the pressure and the negative pressure.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and an object of the present invention is to provide a seal packing for a pipe joint of a drain pipe capable of improving liquid tightness under both positive pressure and negative pressure.
[0007]
[Means for Solving the Problems]
The seal packing for a pipe joint of a drain pipe according to claim 1 is a seal packing attached to a pipe joint having one tubular body and the other tubular body connected to the tubular body, and has elasticity. An annular packing body fitted into an annular fitting groove provided around one connecting portion of one of the cylindrical body and the other cylindrical body, and The packing body includes a first seal portion that is liquid-tightly pressed against the fitting groove, and a first curved portion that extends from the first seal portion to one of the upstream side and the downstream side of the drainage and is bent back. A second curved portion extending from the first curved portion to either the upstream side or the downstream side of the drainage and bent back in a direction opposite to the first curved portion; One cylindrical body and the other cylindrical body extending from the second curved portion It is obtained by a second sealing portion which is pressed against the fluid-tight around the other one of the connecting portions.
[0008]
An annular packing body formed of a member having elasticity is provided around one connecting portion of one tubular body of the pipe joint and the other tubular body connected to the tubular body. A first seal portion which is pressed against the annular fitting groove in a liquid-tight manner, and extends from the first seal portion to one of the upstream side and the downstream side of the drainage so as to be bent back. And a second curved portion which extends from the first curved portion to either the upstream side or the downstream side of the drainage and is bent in a direction opposite to the first curved portion is extended. At the same time, a second seal portion, which is liquid-tightly pressed around the other connecting portion of one of the cylindrical body and the other cylindrical body, is extended on the second curved portion. As a result, the first curved portion and the second curved portion bend toward the upstream side and the downstream side of the wastewater, respectively, and the radial elasticity of the packing body is improved by the first curved portion and the second curved portion. As a result, the first seal portion and the second seal portion are securely pressed against each other, so that the liquid tightness is improved with respect to both positive pressure and negative pressure.
[0009]
The seal packing for a pipe joint of a drainage pipe according to claim 2, which is a seal packing attached to a joint body of a pipe joint connected to a connected pipe, wherein the seal packing is formed of an elastic member, and is connected to the joint body. An annular packing body fitted in an annular fitting groove provided on the inner periphery of the portion, the packing body having a first seal portion which is pressed against the fitting groove in a liquid-tight manner, A first curved portion that extends from the first seal portion to one of the upstream side and the downstream side of the drainage and is bent back; and the other one of the upstream side and the downstream side of the drainage from the first curved portion. And a second curved portion that is folded back in a direction opposite to the first curved portion, and extends from the second curved portion, and is liquid-tightly attached to an outer periphery of a connecting portion of the connected pipe. And a second seal portion to be pressed.
[0010]
Then, a first seal portion, which is liquid-tightly pressed against an annular fitting groove provided on the inner periphery of the connection portion of the joint body, is provided on an annular packing body formed of an elastic member, and A first curved portion which extends from the seal portion to one of the upstream side and the downstream side of the drainage and is bent back; and from the first curved portion, one of the upstream side and the downstream side of the drainage A second curved portion, which is extended to the other side and bent back in a direction opposite to the first curved portion, is extended, and the second curved portion is liquid-tightly pressed against the outer periphery of the connection portion of the pipe to be connected. The second seal part to be extended is extended. As a result, the first curved portion and the second curved portion bend toward the upstream side and the downstream side of the wastewater, respectively, and the radial elasticity of the packing body is improved by the first curved portion and the second curved portion. As a result, the first seal portion and the second seal portion are securely pressed against each other, so that the liquid tightness is improved with respect to both positive pressure and negative pressure.
[0011]
According to a third aspect of the present invention, there is provided the seal packing for a pipe joint of a drain pipe according to the first or second aspect, wherein the first seal portion is formed by notching the first seal portion. , And the second seal portion has a second cutout portion formed by cutting out the second seal portion.
[0012]
A first cutout is formed in the first seal portion, and a second cutout is formed in the second seal portion, so that the first seal portion and the second seal portion are notched. Since the contact area is reduced, the elastic force of the packing body is more reliably applied to the first seal portion and the second seal portion, and the first seal portion and the second seal portion are not pressed against each other more strongly. Liquid tightness is further improved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a configuration of a first embodiment of a seal packing for a pipe joint of a drainage pipe according to the present invention will be described with reference to FIGS. 1 to 4.
[0014]
3 and 4, reference numeral 11 denotes a universal pipe joint as a pipe joint of a drainage pipe. The universal pipe joint 11 is used, for example, for inspecting or cleaning a sewage main pipe (not shown) embedded in the ground. The joint body is connected to the receiving side of a small manhole (not shown), and is formed in a substantially cylindrical shape with, for example, a synthetic resin such as PVC (Poly Vinyl Chloride), that is, a vinyl chloride resin.
[0015]
Further, the universal pipe joint 11 includes a substantially cylindrical first joint body 12 as one cylindrical body and a substantially cylindrical second joint body 13 as the other cylindrical body. Here, the first joint body 12 has an inflow side which is one end side in the axial direction, that is, the upstream side is connected to a connected pipe as a sewage main pipe, and the other end side of the first joint body 12 in the axial direction. The inflow side, ie, the upstream end face, which is one end side in the axial direction of the second joint body 13 is inserted and connected to the outflow side, ie, the downstream end face, and slides in the circumferential direction of the end faces. It is movably joined. On the other hand, the outflow side, that is, the downstream side, which is the other end side in the axial direction of the second joint body 13, is connected to the receiving side of the small manhole.
[0016]
Further, the upstream side of the first joint body 12 is an inflow port 14 protruding toward the opening direction on the outflow side, and the inflow port 14 is inserted into and communicated with the connected pipe. At the inner edge of the opening of the inflow port 14, a mounting recess 15 having a groove shape is provided over the entire circumference of the first joint body 12 in the circumferential direction.
[0017]
The inflow side packing 21 formed into an annular shape with an elastic member such as SBR (Styrene Butadiene Rubber), that is, styrene butadiene rubber, is fitted into the mounting recess 15.
[0018]
The entire outer peripheral surface of the inflow-side packing 21 is an outer seal portion 22 as a groove seal portion that is pressed against the mounting recessed portion 15. An inner seal portion 23 as an inner contact portion protruding into a shape is provided integrally. That is, the inflow-side packing 21 is formed in a substantially rectangular shape in a cross-sectional view in which the inflow-side bent portion 24 is provided on the downstream side of the first joint body 12.
[0019]
The inner seal portion 23 has a distal end protruding from the inner periphery of the first joint body 12 in a state where the inflow side packing 21 is fitted into the mounting recess 15, and is pressed against the outer peripheral surface of the connected pipe. Ensure liquid tightness.
[0020]
Further, a positioning step portion 25 for positioning the connected pipe inserted from the inflow port 14 is formed over the entire circumference on the inner peripheral surface of the substantially central region in the axial direction of the first joint body 12. . Further, on the downstream end surface of the first joint body 12, a receiving part 26 as a connecting part projecting at a predetermined angle with respect to the axial direction of the first joint body 12 is integrally provided. Have been.
[0021]
A first enlarged diameter portion 31 and a second enlarged diameter portion 32 are sequentially formed in the receiving portion 26 toward the downstream side of the first joint body 12, and these first enlarged diameter portions 31 are formed. With the second enlarged diameter portion 32, the receiving portion 26 is sequentially increased in diameter stepwise toward the downstream side with respect to the first joint body 12. A groove-like downstream mounting recess 33 is formed on the inner peripheral edge of the distal end side of the receiving portion 26 which is the downstream end of the first joint body 12. An annular locking claw portion 34 whose diameter is reduced intermittently in the axial direction of the first joint body 12 is provided on the inner peripheral surface on the downstream side.
[0022]
In addition, a pair of grips 35 having a rectangular shape in cross section are provided to protrude from the outer peripheral surface of the first joint body 12.
[0023]
On the other hand, the upstream end face of the second joint body 13 has a fitted part 41 as a connecting part which is inclined and protrudes at a predetermined angle with respect to the axial direction of the second joint body 13. . Here, the inclination angle of the fitted portion 41 with respect to the second joint body 13 is equal to the inclination angle of the socket 26 with respect to the first joint body 12.
[0024]
Further, on the outer peripheral surface around the fitted portion 41, an annular concave groove-shaped fitting groove 43 is formed over the entire circumference in the circumferential direction. A seal packing 44 is fitted in the fitting groove 43.
[0025]
Here, as shown in FIG. 1, the seal packing 44 has a packing body 45 formed into an annular shape with an elastic member such as SBR, that is, styrene-butadiene rubber. The first seal portion 46 having a substantially rectangular shape in cross section, which protrudes toward the center axis direction on the inner peripheral side of the packing body 45, is provided integrally over the entire periphery.
[0026]
As shown in FIG. 2, when the second joint body 13 is inserted into the first joint body 12 with the seal packing 44 fitted in the fitting groove 43, The bottom surface of the fitting groove 43 is pressed in a liquid-tight manner.
[0027]
In the first seal portion 46, a first step portion 51 as a first notch portion is formed by cutting out in a substantially triangular shape in cross section over the entire circumference. Due to the first step portion 51, the contact area of the first seal portion 46 with the bottom surface of the fitting groove 43 is reduced, and when the second joint body 13 is inserted into the first joint body 12, As shown in FIG. 2, only a part of the first seal portion 46 is pressed against the bottom surface of the fitting groove 43.
[0028]
Further, as shown in FIG. 1, the distal end side of the first seal portion 46 is a convex arc-shaped seal portion 52. As shown in FIG. 2, when the seal packing 44 is fitted into the fitting groove 43, the arc-shaped seal portion 52 is pressed along the arc-shaped both side edges of the bottom surface of the fitting groove 43. You.
[0029]
A first curved portion 53 is integrally extended from the first seal portion 46. The first curved portion 53 extends downstream of the drainage, which is one end of the packing body 45 in the axial direction, and is substantially opposite to the upstream side of the drainage, which is the other end of the packing body 45 in the axial direction. It is folded back in the shape of a letter.
[0030]
Further, the first curved portion 53 is integrally provided with a second curved portion 54. The second curved portion 54 extends on the upstream side of the drainage, which is the other end of the packing body 45 in the axial direction, and is located on the downstream side, which is one end of the packing body 45 in the axial direction, that is, the first curved portion. The portion 53 is bent back in a substantially rectangular shape in a direction opposite to the direction in which the portion 53 is turned back.
[0031]
Further, a second seal portion 55 extends integrally with the second curved portion 54. The second seal portion 55 has a distal end projecting outward from the second joint body 13 in a state where the seal packing 44 is fitted into the fitting groove 43, and the second joint body 12 is attached to the first joint body 12. When the fitting 13 is inserted, the fitting 13 is liquid-tightly pressed against the inner peripheral surface of the first enlarged diameter portion 31 around the receiving portion 26 of the first joint body 12.
[0032]
Further, a second step portion 56 as a second notch portion is formed in the second seal portion 55 so as to be cut in a substantially triangular shape in cross section over the entire circumference. Due to the second step portion 56, the contact area of the second seal portion 55 with the first enlarged diameter portion 31 is reduced, and when the second joint body 13 is inserted into the first joint body 12, As shown in FIG. 2, the second seal portion 55 is pressed against two points on the inner peripheral surface of the first enlarged diameter portion 31 in an annular line shape.
[0033]
Due to the first curved portion 53 and the second curved portion 54, the seal packing 44 is formed in a substantially S shape in a sectional view. For this reason, the packing body 45 of the seal packing 44 has a spring-like shape in the radial direction to improve elasticity, and the back sides of the first curved portion 53 and the second curved portion 54 have concave bent portions, respectively. 57 and 58.
[0034]
Further, as shown in FIGS. 3 and 4, on the outer peripheral surface of the second joint body 13, on the downstream side of the fitting groove 43, the locking portion 61 is formed over the entire circumference in the circumferential direction of the second joint body 13. Are provided so as to protrude in the radial direction. When the second joint body 13 is fitted into the first joint body 12, the locking part 61 is engaged with the downstream mounting recess 33 of the first joint body 12, and The locking claw portion 34 prevents it from coming off.
[0035]
An outer peripheral projection 62 is provided on the outer peripheral surface of the second joint body 13 downstream of the locking portion 61 so as to protrude in the radial direction. When the second joint body 13 is inserted into the first joint body 12, the outer peripheral projecting portion 62 is located to face the downstream end surface of the first joint body 12.
[0036]
The outflow side of the second joint body 13 is an outflow port 63 protruding toward the opening direction of the outflow side, and this outflow port 63 is inserted and communicated with the receiving side of the small manhole. . Further, on the outer edge of the second joint body 13 on the outlet 63 side, a reduced diameter portion 64 reduced in diameter in the opening direction of the outlet 63 is provided. Of the joint body 13 can be easily inserted into the receiving side of the small manhole.
[0037]
A pair of rectangular gripping portions 65 protruding in a rib shape in the radial direction of the second joint body 13 are integrally provided on the outer peripheral surface of the second joint body 13. Further, by gripping the gripping portion 35 and rotating the first joint body 12 in the circumferential direction in a state where the gripping portion 65 is gripped and the second joint body 13 is prevented from rotating, the second joint body 13 is rotated. The first joint body 12 slides, and as shown in FIGS. 1 and 2, the angle between the first joint body 12 and the second joint body 13 is freely changed to a predetermined angle. It is possible.
[0038]
Next, the operation of the first embodiment will be described.
[0039]
First, in a state where the seal packing 44 is fitted in the fitting groove 43 of the second joint body 13, the fitted portion 41 of the second joint body 13 is inserted into the receiving portion 26 of the first joint body 12. The engagement portion 61 of the second joint body 13 is engaged with the downstream mounting concave portion 33 of the first joint body 12, and is locked by the engagement claw portion 34 of the socket 26.
[0040]
At this time, as shown in FIGS. 2 and 3, the seal packing 44 is elastically deformed in the radial direction between the first enlarged diameter portion 31 of the first joint body 12 and the fitting groove 43.
[0041]
As a result, the first seal portion 46 of the seal packing 44 has the first step portion 51 in which the portion on the first curved portion 53 side is pressed against the bottom surface of the fitting groove 43 in a liquid-tight manner and has an arc shape. The seal portion 52 is pressed against the arc-shaped both side edges of the bottom surface of the fitting groove 43.
[0042]
On the other hand, the distal end side of the second seal portion 55 of the seal packing 44 is sandwiched between the outer peripheral surface of the first enlarged diameter portion 31 and the outer peripheral surface of the second joint body 13, and the second step portion 56 is provided. The second seal portion 55 is pressed against the inner peripheral surface of the first enlarged diameter portion 31 in a liquid-tight manner, for example, at two points in an annular shape.
[0043]
As a result, the receiving portion 26 of the first joint body 12 and the fitted portion 41 of the second joint body 13 are connected in a liquid-tight manner, and the universal pipe joint 11 is formed.
[0044]
In this state, in a state where the grip portion 65 of the second joint body 13 is gripped and detented, the grip portion 35 of the first joint body 12 is gripped and the first joint body 12 is connected to the second joint body 12. By rotating in a circumferential direction with respect to the body 13, the angle between the first joint body 12 and the second joint body 13 is adjusted to a desired angle.
[0045]
Next, a lubricant or the like is applied to the outer peripheral edge of the outlet 63 of the second joint body 13, and the outlet 63 side is inserted into and joined to the receiving side of the small manhole.
[0046]
Further, the inflow port 14 of the first joint body 12 is inserted into and joined to the connected pipe, and the small manhole and the sewage main pipe are connected to form a sewage pipe.
[0047]
Here, for example, when the internal pressure is applied to the universal pipe joint 11, that is, at the time of the positive pressure, the bent portion 57 of the seal packing 44 ensures liquid tightness.
[0048]
On the other hand, when external pressure is applied to the universal pipe joint 11, that is, at the time of negative pressure, liquid tightness is ensured by the bent portion 58 of the seal packing 44.
[0049]
As described above, according to the first embodiment, the first seal portion 46 that is liquid-tightly pressed against the annular fitting groove 43 is attached to the annular packing body 45 formed of an elastic member. The first curved portion 53 extends from the first seal portion 46 to the downstream side of the drainage and is bent back to the upstream side, and the second curved portion 54 is drained from the first curved portion 53. A second seal portion 55 is provided on the second curved portion 54 so as to extend downward on the downstream side and bend back to the upstream side, and to be in liquid-pressure contact with the first enlarged-diameter portion 31. As a result, the first curved portion 53 and the second curved portion 54 are curved toward the upstream side and the downstream side of the drainage to form

bent portions

57 and 58 on the upstream side and the downstream side, respectively, and the first curved portion is formed. The elasticity of the packing body 45 in the radial direction is improved by the 53 and the second curved portion 54, so that the first seal portion 46 and the second seal portion 55 are securely connected to the fitting groove 43 and the first enlarged diameter portion 31, respectively. , The liquid tightness can be improved with respect to both positive pressure and negative pressure.
[0050]
In addition, the first seal portion 46 is formed by cutting out the first step portion 51 and the second seal portion 55 is formed by cutting out the second step portion 56, so that the first seal portion 46 and the first Since the contact area of the second seal portion 55 is reduced, the elastic force of the packing body 45 is more reliably applied to the first seal portion 46 and the second seal portion 55, and the first seal portion 46 and the second Liquid tightness can be further improved without pressing the seal portion 55 more strongly, and the frictional resistance of the first seal portion 46 and the second seal portion 55 decreases when the universal pipe joint 11 is rotated. Therefore, the external force (rotational operation force) required for the rotation operation of the universal joint 11 is reduced, and the operability can be improved.
[0051]
Further, an arc-shaped seal portion 52 is provided on the distal end side of the second seal portion 55, and the arc-shaped seal portion 52 is pressed along the arc-shaped both side edges of the bottom surface of the fitting groove 43, whereby Liquid tightness can be further improved.
[0052]
Next, a configuration of a second exemplary embodiment of the present invention will be described with reference to FIG.
[0053]
In FIG. 5, reference numeral 71 denotes a pipe joint of a drain pipe (hereinafter, referred to as a pipe joint 71). The pipe joint 71 connects, for example, a sewage main pipe (not shown) buried in the ground and the sewage main pipe. The joint body is formed in a substantially cylindrical shape with a synthetic resin such as PVC (vinyl chloride resin).
[0054]
The pipe joint 71 includes a joint body 73 whose upstream side is connected to a connected pipe 72 as a sewage main pipe.
[0055]
Further, the joint main body 73 is integrally provided with a receiving portion 74 as a connecting portion formed in an enlarged diameter on the upstream end surface. The connecting portion 75 of the connected pipe 72 is inserted into the receiving portion 74.
[0056]
An annular fitting groove 76 is provided on the inner periphery around the receiving portion 74 over the entire circumference in the circumferential direction, and a seal packing 77 is fitted into the fitting groove 76. ing.
[0057]
The seal packing 77 has a shape obtained by reversing the shape on the inner peripheral side and the outer peripheral side of the seal packing 44 of the embodiment shown in FIGS. That is, the seal packing 77 includes a packing body 81 formed in an annular shape with an elastic member such as SBR (styrene butadiene rubber), and the packing body 81 protrudes radially outwardly. A first seal portion 82 having a substantially rectangular shape in a cross-sectional view is provided integrally over the entire circumference.
[0058]
The first seal portion 82 is liquid-tightly pressed against the bottom surface of the fitting groove 76 when the connected pipe 72 is fitted into the joint body 73 with the seal packing 77 fitted in the fitting groove 76. Is done.
[0059]
In the first seal portion 82, a first step portion 83 as a first notch portion is formed by cutting out in a substantially triangular shape in cross section over the entire circumference. The first stepped portion 83 reduces the contact area of the first seal portion 82 with the bottom surface of the fitting groove 76, and when the connected pipe 72 is inserted into the joint main body 73, the first seal Part of the portion 82 is pressed against the bottom surface of the fitting groove 76.
[0060]
Further, the distal end side of the first seal portion 82 is a convex arc-shaped seal portion 84. When the seal packing 77 is fitted in the fitting groove 76, the arc-shaped seal portion 84 is pressed along the arc-shaped both side edges of the bottom surface of the fitting groove 76.
[0061]
The first seal portion 82 has a first curved portion 85 extending integrally therewith. The first curved portion 85 extends to the upstream side of the drainage, which is one end side in the axial direction of the packing main body 81, and substantially extends to the downstream side of the drainage, which is the other end side in the axial direction of the packing main body 81. It is folded back into a letter shape.
[0062]
The first curved portion 85 is integrally provided with a second curved portion 86. The second curved portion 86 extends downstream of the drainage, which is the other end of the packing body 81 in the axial direction, and is located on the upstream side, which is one end of the packing body 81 in the axial direction, that is, the first curved portion. The portion 85 is folded back and bent in a direction substantially opposite to the direction in which the portion 85 is folded back.
[0063]
Further, in the second curved portion 86, a second seal portion 91 is integrally extended. The second seal portion 91 has a distal end projecting inward from the joint body 73 in a state where the seal packing 77 is fitted in the fitting groove 76, and is connected when the connected pipe 72 is fitted into the joint body 73. It is liquid-tightly pressed against the outer peripheral surface around the portion 75.
[0064]
In the second seal portion 91, a second step portion 92 as a second notch portion is cut out in a substantially triangular shape in cross section over the entire circumference. The contact area of the second seal portion 91 with the connection portion 75 is reduced by the second step portion 92, and the second seal portion 91 is covered when the connected pipe 72 is inserted into the joint body 73. Two points on the outer peripheral surface on the downstream side of the connection pipe 72 are pressed into an annular line shape.
[0065]
Due to the first curved portion 85 and the second curved portion 86, the seal packing 77 is formed in a substantially S shape in a sectional view. For this reason, the packing body 81 of the seal packing 77 has a spring-like shape in the radial direction to improve elasticity, and the back sides of the first curved portion 85 and the second curved portion 86 have concave bent portions. 93 and 94.
[0066]
A positioning step 95 is formed over the entire circumference on the inner peripheral surface of the joint body 73 on the base end side of the receiving portion 74. When the downstream end of the connected pipe 72 abuts on the positioning step 95, the connected pipe 72 is positioned with respect to the joint body 73.
[0067]
Next, the operation of the second embodiment will be described.
[0068]
First, in a state where the seal packing 77 is fitted in the fitting groove 76 of the joint body 73, the connecting portion 75 of the connected pipe 72 is fitted into the receiving portion 74 of the joint body 73 until it comes into contact with the positioning step 95. Insert.
[0069]
At this time, the seal packing 77 elastically deforms in the radial direction between the connection portion 75 of the connected pipe 72 and the fitting groove 76.
[0070]
For this reason, the first seal portion 82 of the seal packing 77 is configured such that the portion on the first curved portion 85 side is pressed against the bottom portion of the fitting groove 76 in a liquid-tight manner by the first step portion 83, and has an arc shape. The seal portion 84 is pressed along the arcuate side edges of the bottom surface of the fitting groove 76.
[0071]
Further, the tip end side of the second seal portion 91 of the seal packing 77 is sandwiched between the outer peripheral surface of the connection portion 75 and the inner peripheral surface of the receiving portion 74, and the second step portion 92 having the second step portion 92 is provided. Are pressed against the outer peripheral surface of the first connecting portion 75 in a liquid-tight manner, for example, at two points in an annular line shape.
[0072]
As a result, the connected pipe 72 and the joint body 73 are connected in a liquid-tight manner, and the pipe joint 71 connects the sewage main pipe to the sewage main pipe to form a sewage pipe.
[0073]
Here, when external pressure is applied to the pipe joint 71, that is, at the time of negative pressure, liquid tightness is ensured by the bent portion 93 of the seal packing 77.
[0074]
On the other hand, for example, when an internal pressure is applied to the pipe joint 71, that is, at a positive pressure, the bent portion 94 of the seal packing 77 ensures liquid tightness.
[0075]
As described above, the first sealing portion 82 is provided on the annular packing body 81 formed of an elastic member so as to be pressed against the bottom surface of the fitting groove 76 in a liquid-tight manner. The first curved portion 85 extends downstream from the drainage and is bent back to the upstream side, and the second curved portion 86 extends from the first curved portion 85 to the upstream side of the drainage and extends downstream. A second seal portion 91 is provided on the second curved portion 86 so as to be pressed against the outer peripheral surface of the connection portion 75 in a liquid-tight manner. As a result, the first curved portion 85 and the second curved portion 86 bend toward the upstream side and the downstream side of the drainage to form bent portions 93 and 94 on the upstream side and the downstream side, respectively. Since the radial elasticity of the packing body 81 is improved by the 85 and the second curved portion 86, the first seal portion 82 and the second seal portion 91 are pressed against the fitting groove 76 and the connection portion 75, respectively. Liquid tightness can be improved for both positive pressure and negative pressure.
[0076]
In addition, the first seal portion 82 is formed by notching the first step portion 83, and the second seal portion 91 is formed by notch formation of the second step portion 92, so that the first seal portion 82 and the second Since the contact area of the second seal portion 91 is reduced, the elastic force of the packing body 81 is more reliably applied to the first seal portion 82 and the second seal portion 91, and the first seal portion 82 and the second seal portion 91 are formed. The liquid tightness can be further improved without pressing the seal portion 91 more strongly.
[0077]
Further, an arc-shaped seal portion 84 is provided on the distal end side of the first seal portion 82, and the arc-shaped seal portion 84 is pressed along the arc-shaped both side edges of the bottom surface of the fitting groove 76, so that Liquid tightness can be further improved.
[0078]
In each of the above embodiments, the detailed structure of the universal joint 11 and the pipe joint 71 is not limited to the structure of each of the above embodiments.
[0079]
Further, as another embodiment, the present invention can be applied to other various pipe joints and the like.
[0080]
【Example】
Hereinafter, an example of the seal packing for a pipe joint of the drainage pipe according to the first embodiment will be described with reference to Table 1.
[0081]
In this example, the liquid-tightness of the pipe joint seal packing of the drainage pipe of the first embodiment with respect to the positive pressure and the negative pressure, the rotational operating force of the pipe joint, and the like were measured while changing the test conditions. And sample 2. As a comparative example, a seal packing for a pipe joint of a conventional drainage pipe shown in FIGS. 6 and 7 was used.
[0082]
First, in the test for the rotational operation force (operating force test), the torque required for the rotational operation after 1 day, 3 days and 1 week at the time of assembling the pipe joint was measured for Sample 1, Sample 2, and Comparative Example. Each was measured twice.
[0083]
Next, in a liquid tightness test (hydraulic test) with respect to a positive pressure, after confirming the liquid tightness while applying a water pressure of about 0.05 MPa and about 0.10 MPa for 1 minute, the water pressure is increased by 0.05 MPa. Then, a test was performed on each of the sample 1 and the comparative example. The test results under a water pressure of 0.15 MPa to 0.25 MPa are omitted.
[0084]
Further, in the liquid tightness test (negative negative pressure test) against a negative pressure, a negative pressure of 0.078 MPa is applied for 1 minute in a state where the packing body is flattened by applying a load, and each flattening amount and each flat load are applied. The liquid tightness of Sample 1 and Comparative Example was confirmed.
[0085]
Table 1 shows the results of these tests.
[0086]
[Table 1]

[0087]
As shown in Table 1, in the operation force test, the torque of the comparative example was extremely large at 17.00 the first time after one day, and further increased to 25.54 at the first time one week later. On the other hand, the torque of Sample 1 and Sample 2 hardly changed. As a result, it can be seen that Sample 1 and Sample 2 can maintain good rotation operability over a longer period than the Comparative Example.
[0088]
In the water pressure test, water leakage occurred in the comparative example at a water pressure of 0.35 MPa or more, whereas the sample 1 was able to maintain liquid tightness even when the water pressure was increased to 0.40 MPa. As a result, it is understood that Sample 1 has higher liquid tightness with respect to positive pressure than the Comparative Example.
[0089]
Further, in the flattened negative pressure test, the comparative example leaked water at a flattened amount of 6% (9.9 mm) and a flattened load of 5.17 KN, whereas the sample 1 had a flattened amount of 8% (13.2 mm). Water leakage did not occur up to a flat load of 6.44 KN. As a result, it is understood that Sample 1 has higher liquid tightness against negative pressure than the comparative example.
[0090]
From the above, the effect of the seal packing for the pipe joint of the drainage pipe of the first embodiment was confirmed.
[0091]
【The invention's effect】
According to the seal packing for a pipe joint of a drainage pipe according to the first aspect, one tubular body of the pipe joint and the other connected to the tubular body are attached to an annular packing body formed of an elastic member. A first seal portion, which is pressed in a liquid-tight manner, is provided in an annular fitting groove provided around one of the connection portions of the cylindrical body, and upstream and downstream of drainage from the first seal portion. And a first curved portion which is folded back and provided is provided on one of the first curved portion, and the first curved portion is extended from the first curved portion to the other one of the upstream side and the downstream side of the drainage. A second curved portion that is folded back in the opposite direction is extended, and the second curved portion is liquid-tightly pressed around one of the cylindrical member and the other cylindrical member around the other connecting portion. The second seal part to be extended is extended. As a result, the first curved portion and the second curved portion bend toward the upstream side and the downstream side of the wastewater, respectively, and the radial elasticity of the packing body is improved by the first curved portion and the second curved portion. Since the first seal portion and the second seal portion are securely pressed against each other, the liquid tightness can be improved with respect to both positive pressure and negative pressure.
[0092]
According to the seal packing for a pipe joint of a drain pipe according to the second aspect, the annular packing body formed of a member having elasticity and the annular fitting groove provided on the inner periphery of the connection portion of the joint body. A first seal portion which is pressed against the liquid tightly is provided, and a first curved portion which is extended from the first seal portion to one of the upstream side and the downstream side of the drainage and is bent back is provided. A second curved portion that extends from the first curved portion to the other of the upstream side and the downstream side of the drainage and that is bent back in a direction opposite to the first curved portion is extended, and the second curved portion is formed. A second seal portion that is liquid-tightly pressed against the outer periphery of the connection portion of the connected pipe is extended to the portion. As a result, the first curved portion and the second curved portion bend toward the upstream side and the downstream side of the wastewater, respectively, and the radial elasticity of the packing body is improved by the first curved portion and the second curved portion. Since the first seal portion and the second seal portion are securely pressed against each other, the liquid tightness can be improved with respect to both positive pressure and negative pressure.
[0093]
According to the third aspect of the present invention, the first seal portion is formed with the first cutout portion, and the second seal portion is formed with the second cutout portion. Accordingly, the contact area between the first seal portion and the second seal portion is reduced, so that the elastic force of the packing main body is more reliably applied to the first seal portion and the second seal portion, and the first seal portion and the second seal portion are applied. Liquid tightness can be further improved without pressing the seal portion and the second seal portion more strongly.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional side view showing a first embodiment of a seal packing for a pipe joint of a drainage pipe according to the present invention.
FIG. 2 is a longitudinal sectional side view showing a fitting state of a pipe joint seal packing of the drain pipe.
FIG. 3 is a longitudinal sectional side view showing a seal packing for a pipe joint of the same drainage pipe.
FIG. 4 is a longitudinal sectional side view showing a seal packing for a pipe joint of the drain pipe.
FIG. 5 is a vertical sectional side view showing a second embodiment of a seal packing for a pipe joint of a drainage pipe according to the present invention.
FIG. 6 is a longitudinal sectional side view showing a seal packing for a pipe joint of a conventional drain pipe.
FIG. 7 is a longitudinal sectional side view showing a fitting state of a pipe joint seal packing of the drain pipe.
[Explanation of symbols]
11 Universal fittings as drain fittings
12. First joint body as one cylindrical body
13 The second joint body as the other cylindrical body
43,76 Fitting groove
44,77 Seal packing for fittings of drainage pipes
45, 81 Packing body
46, 82 First seal part
51, 83 First step portion as first cutout portion
53,85 first curved portion
54, 86 Second curved portion
55, 91 Second seal part
56,92 Second step portion as second notch
71 Pipe fittings as drain pipe fittings
72 Connected pipe
73 Fitting body

Claims

A seal packing attached to a pipe joint having one tubular body and the other tubular body connected to the tubular body,
An annular packing body formed of an elastic member and fitted in an annular fitting groove provided around one of the connection portions of one of the cylindrical body and the other cylindrical body; ,
This packing body is
A first seal portion pressed against the fitting groove in a liquid-tight manner;
A first curved portion which is extended from the first seal portion to one of the upstream side and the downstream side of the drainage and is bent back;
A second curved portion extending from the first curved portion to either the upstream side or the downstream side of the drainage and bent back in a direction opposite to the first curved portion;
A second seal portion extending from the second curved portion and being liquid-tightly pressure-contacted around one of the connecting portions of the one cylindrical member and the other cylindrical member. Seal packing for drainage pipe fittings.

A seal packing attached to a joint body of a pipe joint connected to a connected pipe,
An annular packing main body formed of an elastic member and fitted in an annular fitting groove provided on an inner periphery of a connection portion of the joint main body,
This packing body is
A first seal portion pressed against the fitting groove in a liquid-tight manner;
A first curved portion which is extended from the first seal portion to one of the upstream side and the downstream side of the drainage and is bent back;
A second curved portion extending from the first curved portion to either the upstream side or the downstream side of the drainage and bent back in a direction opposite to the first curved portion;
And a second seal portion extending from the second curved portion and being liquid-tightly pressed against the outer periphery of the connection portion of the connected pipe.

The first seal portion has a first notch formed by notching the first seal portion,
The seal packing for a pipe joint of a drainage pipe according to claim 1 or 2, wherein the second seal portion has a second cutout portion formed by cutting out the second seal portion.