JP3853122B2

JP3853122B2 - Oil pipe backflow prevention device

Info

Publication number: JP3853122B2
Application number: JP34069499A
Authority: JP
Inventors: 賢治米澤
Original assignee: Piolax Inc
Current assignee: Piolax Inc
Priority date: 1999-11-30
Filing date: 1999-11-30
Publication date: 2006-12-06
Anticipated expiration: 2019-11-30
Also published as: JP2001158243A

Description

【０００１】
【発明の属する技術分野】
本発明は、給油口と燃料タンクとを接続する給油管内に配置され、燃料タンク内部の燃料が給油口へ逆流することを防ぐ逆流防止装置に関するものである。
【０００２】
【従来の技術】
例えば、自動車で山道を走った後、給油のために給油口の蓋を開けると、燃料が噴出してくる場合がある。これは、振動により攪拌された燃料の蒸気圧が上がり、燃料タンクが加圧状態となることにより起こる。このような燃料の逆流を防止するために、従来、燃料タンク内部の給油管が接続される部分に、逆流防止弁を取付けていた。しかし、逆流防止弁を燃料タンク内部に取付けると、例えば弁体が外れた場合に修理が不可能になる等の問題があった。
【０００３】
そこで、例えば、実公平７−５４０２４号には、筒状のバルブボデー内に回転軸により回動自在に支持された弁体を備え、バルブボデーは、その一端の開口部外周に突出し周方向に分割されたフランジ部と、該フランジを分割する切欠部分に設けた抜止突起とを有する逆流防止装置が開示されている。
【０００４】
この逆流防止装置は、バルブボデーの前記フランジ部と反対側の端部を、給油口に連結された第１給油管の端部内周に、前記フランジと前記第１給油管の端面とが当接するまで挿入する。そして、燃料タンクに連結されたゴム等の弾性材質からなる第２給油管の端部を、前記フランジ及び前記第１給油管の端部外周に外挿し、前記第１給油管と前記第２給油管とを連結する。
【０００５】
この逆流防止装置では、弁体の修理が必要な場合には、第２給油管を抜き出すことによって、バルブボデーを容易に取外すことができる。更に、第１給油管、第２給油管及び燃料タンクが別体であるため生産性を向上でき、弾性材質からなる第２給油管を使用することで組み付け作業性を向上できる。
【０００６】
【発明が解決しようとする課題】
しかし、実公平７−５４０２４号に開示された逆流防止装置では、第２給油管の内面に当接するフランジが分割されているため、このフランジの切欠き部から燃料が第１給油管側へ漏洩するため、燃料の逆流量を許容管理幅の中に精度良くおさめることができないという問題があった。
【０００７】
そこで、本発明の目的は、燃料の逆流量を許容管理幅の中に精度良くおさめることができる給油管の逆流防止装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記目的を達成するために、本発明の第１は、給油口と燃料タンクとを接続する給油管内に配置され、燃料タンク内部の燃料が給油口へ逆流することを防ぐ逆流防止装置において、前記給油口に基端が連結され、先端部に環状の凸部が形成された第１給油管と、前記燃料タンクに一端が連結された、弾性材質の第２給油管と、全体として筒状であって、その一端は前記第１給油管の先端に挿入される挿入筒部をなし、他端は弁体を囲むガイド筒部をなし、両者の間に環状の鍔部が形成され、内部には前記弁体が接離する弁座が設けられた弁ケースと、この弁ケースの前記ガイド筒部の内側に回動可能に取付けられ、常時は前記弁座に当接して流路を塞ぎ、前記第１給油管側から流体圧がかかると前記弁座から離れて流路を開口させる弁体とを有する逆止弁とを備え、前記逆止弁の前記挿入筒部が前記第１給油管の先端に挿入され、前記第１給油管の先端が前記鍔部に当接され、前記ガイド筒部、前記鍔部及び前記第１給油管の先端外周に、前記第２給油管の他端が外挿されて、前記鍔部が前記第２給油管の内周に食い込み、前記第２給油管は、前記凸部に被せられた部分が弾性変形して拡径しており、前記弁体は、前記ガイド筒部の内周に設けられた軸受部に支軸を介して回転可能に取付けられた弁板を有し、前記弁板の外周は、前記ガイド筒部の内周に沿った円弧状部分と、前記支軸と平行な直線状部分とを有し、前記挿入筒部の前記軸受部に近接した部分は、流体の流れの下流側に向けてテーパ状に内周側に突出し、前記弁座の弁体の直線状部分が当接する部分の背面側に至る斜面をなしていると共に、その外周側はテーパ状の凹部をなしており、この凹部の上流側の一端に連結されると共に、そこから下流側に向かって斜め外方にたわみ可能に延出して、前記第１給油管に挿入されたとき、前記第１給油管の内周に係合する係止爪が形成されていることを特徴とする給油管の逆流防止装置を提供するものである。
【０００９】
上記第１の発明によれば、逆止弁の挿入筒部が、給油口に一端が連結された第１給油管の他端に挿入され、燃料タンクに一端が連結された弾性材質の第２給油管の他端が、前記逆止弁のガイド筒部、鍔部及び前記第１給油管の先端外周に外挿され、前記鍔部が前記第２給油管の内周に食い込んでいるので、燃料タンクの燃料が、弁ケースの外壁と第２給油管の内壁との隙間を通って給油口側へ漏洩することを防止でき、その結果、燃料の逆流量を許容管理幅の中に精度良くおさめることができる。
【００１０】
また、弾性材質の第２給油管を備え、燃料タンクと第１給油管とを弾性的に連結するので、前記燃料タンクと前記第１給油管とを容易に組み付けることができると共に、逆止弁が故障したときには、第２給油管を抜き出して逆止弁を第１給油管から容易に取外すことができる。
更に、挿入筒部の軸受部に近接した部分は、流体の流れの下流側に向けてテーパ状に内周側に突出しているので、給油口から供給される燃料がテーパに沿って流れ、スムーズに弁座の内周に導かれるので、弁ケースに作用する衝撃力を緩和することができる。
また、外周側はテーパ状の凹部をなしており、この凹部の一端から外方に延出して、第１給油管に挿入されたとき、第１給油管の内周に係合する係止爪が形成されているので、逆止弁は第１供給管にしっかりと固定され、抜け落ちを防ぐことができる。
【００１１】
本発明の第２は、上記第１の発明において、前記弁板の前記円弧状部分を囲む前記ガイド筒部の部分は連続した周壁をなし、前記弁板の前記直線状部分を囲む前記ガイド筒部の部分は断続した周壁をなす給油管の逆流防止装置を提供するものである。
【００１２】
上記第２の発明によれば、ガイド筒部の弁板の円弧状部分を囲む部分が連続した周壁をなしているため、その部分において弾性材質の第２給油管が縮径力によって内側に食い込むことが阻止されるので、弁板の回動が第２給油管の内壁に干渉されることがない。また、ガイド筒部の弁板の直線状部分を囲む部分は断続した周壁をなしているため、弾性材質の第２給油管が縮径力によって内側に食い込むので、弁ケースと第２給油管との間に働く摩擦力を増やす作用をもたらす。この摩擦力は、給油口から供給される燃料が軸受部の背面にぶつかり弁ケースに作用する衝撃力に対抗するため、弁ケースが衝撃力により傾斜することを防ぐことができる。
【００１３】
本発明の第３は、上記第１の発明において、前記係止爪を内側にたわませたとき、そのたわみ量を規制するストッパ部が前記凹部の他端に設けられている給油管の逆流防止装置を提供するものである。
【００１６】
上記第３の発明によれば、係止爪を内側にたわませたとき、そのたわみ量を規制するストッパ部が前記凹部の他端に設けられているので、係止爪の過撓による破損を防止することができる。
【００１７】
本発明の第４は、上記第１〜３の発明のいずれかにおいて、前記弁体は、前記ガイド筒部の内周に設けられた軸受部に支軸を介して回転可能に取付けられた弁板を有し、前記支軸は、前記弁板から立設されたアームを介して、前記弁板の面に対して流体の流れの下流方向に所定間隔離れて平行に取付けられ、前記弁板が前記流路を開口するように回動したとき、前記弁板の前記支軸側の縁部と前記弁座との間にも、流体の流通を可能にする間隙が形成されるように構成されている給油管の逆流防止装置を提供するものである。
【００１８】
上記第４の発明によれば、支軸は、弁板の面に対して流体の流れの下流方向に所定間隔離れて平行に取付けられ、弁板が流路を開口するように回動したとき、弁板の支軸側の縁部と弁座との間にも、流体の流通を可能にする間隙が形成されるように構成されているので、上記隙間を通る流体が弁板の裏面（閉塞時に下流側に位置する面）に沿って流れるため、弁板の円弧状の縁部と弁ケース内壁との隙間を通る流体による弁板裏面の渦の発生を抑制し、給油時の流れを安定させて抵抗を少なくすることができる。
本発明の第５は、上記第１〜４の発明のいずれかにおいて、前記逆止弁の挿入筒部の外周には、前記第１給油管の環状の凸部の内側に嵌合する係止突起が形成されている給油管の逆流防止装置を提供するものである。
【００１９】
【発明の実施の形態】
図１〜７には、本発明による給油管の逆流防止装置の１実施形態が示されている。図１は逆止弁の外観を示す斜視図、図２は逆止弁の分解斜視図、図３は逆止弁の正面図（Ａ）、側面図（Ｂ）及び背面図（Ｃ）、図４は係止爪を示す要部拡大図、図５は第１給油管及び第２給油管に逆止弁を挿入した状態を示す側断面図、図６は第１給油管及び第２給油管に逆止弁を挿入した状態における係止爪を示す要部拡大断面図、図７は弁体周囲の流れを示す側断面図である。
【００２０】
図１〜図３に示すように、逆止弁１００は弁体２００と弁ケース３００とからなる。前記弁体２００は、棒状の支軸２１０と、円を直線で切欠いた形（かまぼこ形）でその外周が円弧状部分２２１と直線状部分２２２とからなる板状の弁板２２０と、軸心が同一になるように並んだ二つの巻回部２３１が連結部２３３を介して連結され、両方の巻端部２３２が延出された形状のばね２３０とで構成されている。前記支軸２１０は前記弁板２２０の面に対して所定間隔離れて平行に取付けられ、前記ばね２３０は、前記二つの巻回部２３１が前記支軸２１０の両端部に外挿され、前記連結部２３３が前記弁板２２０に当接し、巻端部２３２が弁ケース３００に係合するように取付けられる。
【００２１】
前記支軸２１０は、弁板２２０の、流体の流れの下流側に位置する面に平行に立設された一対の板状アーム２１１、２１１を介して、前記弁板２２０の上記下流側に位置する面に対して所定間隔離れて平行に取付けられている。なお、前記支軸２１０及び弁板２２０は、耐圧性を有し、燃料に対する耐腐食性を有するものであれば、材質は限定されないが、成形のしやすさを考慮した場合、熱可塑性樹脂等の合成樹脂による一体成形品が好適である。また、前記ばね２３０の材質は、燃料に浸漬しても劣化しないものであれば限定されないが、燃料に対する耐食性を有する金属が好適である。
【００２２】
前記弁ケース３００は、弁体２００を囲むガイド筒部３１０と、このガイド筒部３１０の一方の端面に、環状の鍔部３３０を介して連接された挿入筒部３２０とを有し、全体として略円筒状をなす。
【００２３】
弁ケース３００の鍔部３３０が位置する部分の内周には、前記弁板２２０が適合するかまぼこ形の開口部を有する弁座３１５が形成されている。弁座３１５の周縁において、前記弁板２２０の直線状部分２２２が当接する部分の近傍には、ガイド筒部３１０の内方に向けて突出された軸受部３１４が形成されている。この軸受部３１４は、長軸方向に述びるスリットを有する円筒形状をなし、このスリットを通して、前記弁体２００の支軸２１０が嵌合され、回転可能に保持されるようになっている。弁座３１５の内縁部はテーパ状をなし、これに対応して前記弁板２２０の外縁部もテーパ状をなしていて、弁板２２０が弁座３１５にシール性よく当接するようになっている。
【００２４】
また、前記弁板２２０を前記軸受部３１４に装着したとき、前記ガイド筒部３１０の弁板２２０の直線状部分２２２を囲む部分は、切欠部３１３を有する断続した周壁３１２となっている。一方、ガイド筒部３１０の弁板２２０の円弧状部分２２１を囲む部分は、連続した周壁３１１となっている。
【００２５】
図４、５に示すように、前記挿入筒部３２０の内周には、前記弁座３１５の前記弁板２２０の直線状部分２２２が当接する部分の背面側に向かって、内方に突出するテーパ状の斜面３２５が形成されている。そして、挿入筒部３２０の外周の上記斜面３２５に対応する部分は、テーパ状の凹部３２３をなしている。この凹部３２３の一端には、斜め外方に向けて突出する係止爪３２１が連接されており、上記凹部３２３の他端には、上記係止爪３２１の内側へのたわみ量を規制するストッパ部３２４が設けられている。また、前記挿入筒部３２０の外周の前記凹部３２３に対向する部分には、係止突起３２２が形成されている。
【００２６】
上記弁ケース３００は、耐圧性を有し、燃料に対する耐腐食性を有するものであれば、材質は限定されないが、成形のしやすさを考慮した場合、熱可塑性樹脂等の合成樹脂による一体成形品が好適である。
【００２７】
前記弁体２００は、前記支軸２１０の、前記板状アーム２１１，２１１で挟まれた中央近傍を、前記軸受部３１４に嵌め込むことによって回動可能に保持される。また、前記支軸２１０の両端に回巻部２３１を装着された前記ばね２３０の連結部２３３が弁板２２０の背面に係合し、前記巻端部２３２が前記弁ケース３００の弁座３１５近傍に係合している。そのため、前記弁板２２０は前記支軸２１０を軸心として回動可能であると共に、前記ばね２３０により前記弁座３１５に当接する方向に常時付勢されている。なお、例えば燃料タンクの内圧が上昇したときには、前記弁板２２０は、前記ばね２３０がなくても前記弁座３１５に圧接されるため、前記ばね２３０は必ずしも必要なものではない。
【００２８】
弁板２２０の支軸２１０は、前述したように、一対の板状のアーム２１１，２１１を介して、弁板２２０に対して下流側に所定間隔をおいて平行に設けられているので、軸受部３１４による支軸２１０の支持位置（弁板２２０の回転中心）は、弁座３１５の位置よりも下流側に偏位している。
【００２９】
第１給油管４００は、いわゆるフィラーチューブと呼ばれており、燃料に対する耐圧性、耐腐食性を有する金属管で構成されている。第１給油管４００の図示しない基端部は自動車の給油口に連結され、先端部には環状の凸部４１０を有している。第２給油管５００は、天然ゴム、合成ゴム、合成樹脂エラストマー等で形成され、その基端部は上記第１給油口４００の先端部に外挿されて連結され、その先端部は図示しない燃料タンクの導入口に連結されている。前記逆止弁１００は、その挿入筒部３２０を前記第１給油管４００の先端部内周に挿入され、この第１給油管４００の先端部外周に前記のように第２給油管５００の基端部が外挿されて、逆止弁１００は、給油口と燃料タンクとを連結する給油管内に配置されることになる。
【００３０】
前記逆止弁１００の挿入筒部３２０を第１給油管４００の先端部に挿入するとき、係止爪３２１は第１給油管４００の先端部に押されて凹部３２３の方に撓むので、挿入を続けることができる。そして、前記第１給油管４００の先端部が前記係止爪３２１の最も突出した部分を乗り越えると、係止爪３２１の最も突出した部分及び係止突起３２２が、第１給油管４００の環状の凸部４１０（内側から見ると凹部）の内側に嵌合して抜け止めされる。また、第１給油管４００の先端が鍔部３３０に当接して、それ以上の挿入を阻止される。こうして、逆止弁１００は、第１給油管４００の先端部内周にしっかりと固定される。なお、図４の想像線で示すように、前記係止爪３２１が過度に変形した場合は、その先端がストッパ部３２４に達し、それ以上の変形ができない構造となっている。そのため、前記係止爪３２１は、前記第１給油管４００に挿入される時に、過度の変形により破損する虞れがない。
【００３１】
こうして、前記逆止弁１００を第１給油管４００の先端部内周に挿入した後、第２給油管５００の基端部を前記第１給油管４００の先端部外周に被せる。この場合、第２給油管５００の基端部を、まず逆止弁１００のガイド筒部３１０の外周に被せ、更に鍔部３３０を乗り越えさせ、第１給油管４００の凸部４１０を乗り越えさせて、第２給油管５００の先端部が第１給油管４００の端部から所定距離の位置に達するまで外挿すればよい。なお、前記第２給油管５００は弾性材質からなっており、前記鍔部３３０及び前記凸部４１０を乗り越えるときには、拡径するように弾性変形するので、容易に挿入することができる。また、第２給油管５００を外挿した後、その外周にホースバンドを取付けてもよい。
【００３２】
図６に示すように、逆止弁１００を挿入した第１給油管４００の外周に、第２給油管５００を外挿させた状態において、逆止弁１００の切れ目のない連続した環状の鍔部３３０は、第１給油管４００より外方に突出して、前記第２給油管５００の内面に食い込む。このため、燃料が、前記第２給油管５００側から、前記弁ケース３００の外壁と前記第２給油管５００の内壁の隙間を通って、第１給油管４００側へ漏洩することを防止できる。なお、上記鍔部３３０の食い込み量、すなわち、環状の鍔部３３０が第１給油管４００の外周より外方に突出する高さは、０．３〜０．９ｍｍとすることが好ましい。
【００３３】
更に、第２給油管５００の内周は、逆止弁１００のガイド筒部３１０の断続した周壁３１２における切欠部３１３に食い込むため、その部分における弁ケース３００と第２給油管５００との間に働く摩擦力を増やす作用をもたらす。この摩擦力は、燃料が弁ケース３００のテーパ部３２５に衝突したときの押圧力に対抗するため、弁ケース３００が燃料の圧力により傾斜する虞れがない。なお、前記テーパ部３２５は、給油口から供給される燃料を弁座３１５の内周に導くので、流れをスムーズにして流動抵抗を軽減する作用をなす。また、ガイド筒部３１０の連続した周壁３１１は、前記第２給油管５００の内方への食い込みを防止し、弁板２２０の回動動作が妨げられないようにしている。
【００３４】
次に、この逆流防止装置の作動について説明する。
図７（Ａ）の矢印で示すように、ガイド筒部３１０から挿入筒部３２０に向かう流れがあるとき、すなわち、燃料タンクから給油口に燃料が逆流する時は、ばね２３０の押力及び逆流体の圧力により、弁板２２０が弁座３１５に密着し、流路を閉塞する。そのため、燃料タンクから給油口に燃料が逆流することが防止される。更に、連続した環状の鍔部３３０が、弾性材質の第２給油管５００の内周に食い込んでシール性を高めるため、燃料が逆止弁１００の外周を通って第１給油管４００側に洩れることがなく、燃料の逆流量を許容管理幅の中に精度良くおさめることができる。
【００３５】
図７（Ｂ）〜（Ｄ）の矢印で示すように、挿入筒部３２０からガイド筒部３１０に向かう流れがあるとき、すなわち、給油口から給油した燃料が燃料タンクに向かって流れるときは、流体の圧力がばね２３０の力に対抗して弁板２２０を押し、流路を開放する。そのため、給油口から燃料タンクに向かって燃料が流れることができる。
【００３６】
この場合、図７（Ａ）に示すように、弁体２００は、支軸２１０が弁板２２０に対して下流側に所定間隔離れて平行に配置されているので、弁板２２０の上縁角部２２０ａと支軸２１０との間に、軸垂直方向に見たときにはＸ₀の間隔があり、軸方向に見たときにはＹ₀の間隔がある。そして、弁板２２０が開いてその角度が図７（Ｂ）、（Ｃ）、（Ｄ）と変化するに従って、上記軸方向に見たときの間隔はＹ₀→Ｙ₁→Ｙ₂→Ｙ₃と変化し、それらの大きさはＹ₀＜Ｙ₁＜Ｙ₂≒Ｙ₃の関係となっている。
【００３７】
このように、弁板２２０が開くと、弁板２２０の上縁角部２２０ａと支軸２１０との間に、軸方向から見たときに大きな間隔が開き、それによって弁板２２０の直線状部分２２２と弁座３１５との間隙を通る背面側の流れイが発生する。この流れイによって、弁板２２０の円弧状部分２２１と弁座３１５との間隙を通る流れロによる、弁板２２０の背面側における渦流の発生が防止され、流量が増しても、乱流が発生することなく、給油時の流れを安定させて抵抗を少なくすることができる。
【００３８】
【発明の効果】
以上説明したように、本発明によれば、逆止弁の弁ケースに設けた鍔部が、弾性材質からなる第２給油管の内周に食い込むことにより、燃料タンクの燃料が、弁ケースの外壁と第２給油管の内壁との隙間を通って給油口側へ漏洩することを防止でき、その結果、燃料の逆流量を許容管理幅の中に精度良くおさめることができる。
【００３９】
また、逆止弁を挿入した第１給油管の外周に、弾性材質の第２給油管を被せて装着するようにしたので、燃料タンクと給油管とを容易に組み付けることができると共に、逆止弁が故障したときには、第２給油管を抜き出して逆止弁を第１給油管から容易に取外すことができる
【図面の簡単な説明】
【図１】本発明の逆流防止装置の１実施形態に用いられる逆止弁の外観を示す斜視図である。
【図２】同逆止弁の分解斜視図である。
【図３】同逆止弁の三面図である。
【図４】同逆止弁における係止爪を示す要部拡大図である。
【図５】同実施形態において、第１給油管及び第２給油管に逆止弁を挿入した状態を示す側断面図である。
【図６】同実施形態において、第１給油管及び第２給油管に逆止弁を挿入した状態における係止爪を示す要部拡大断面図である。
【図７】同実施形態における弁体周囲の流れを示す側断面図である。
【符号の説明】
１００逆止弁
２００弁体
２１０支軸
２２０弁板
２３０ばね
３００弁ケース
３１０ガイド筒部
３２０挿入筒部
３３０鍔部
４００第１給油管
５００第２給油管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a backflow prevention device that is disposed in a fuel supply pipe that connects a fuel supply port and a fuel tank and prevents the fuel inside the fuel tank from flowing back to the fuel supply port.
[0002]
[Prior art]
For example, after running on a mountain road with an automobile, fuel may be ejected when the lid of the filler opening is opened for refueling. This occurs when the vapor pressure of the fuel agitated by vibration increases and the fuel tank enters a pressurized state. In order to prevent such a backflow of fuel, a backflow prevention valve has been conventionally attached to a portion to which a fuel supply pipe inside the fuel tank is connected. However, when the backflow prevention valve is mounted inside the fuel tank, there is a problem that, for example, when the valve body is detached, the repair becomes impossible.
[0003]
Therefore, for example, Japanese Utility Model Publication No. 7-54024 includes a valve body rotatably supported by a rotating shaft in a cylindrical valve body, and the valve body projects to the outer periphery of the opening at one end thereof in the circumferential direction. A backflow prevention device having a divided flange portion and a retaining protrusion provided at a notch portion that divides the flange is disclosed.
[0004]
In this backflow prevention device, the flange and the end face of the first oil supply pipe abut the end of the valve body opposite to the flange part on the inner periphery of the end of the first oil supply pipe connected to the oil supply port. Insert until Then, an end of a second oil supply pipe made of an elastic material such as rubber connected to the fuel tank is extrapolated to the outer periphery of the flange and the end of the first oil supply pipe, and the first oil supply pipe and the second oil supply pipe are inserted. Connect the tube.
[0005]
In this backflow prevention device, when the valve body needs to be repaired, the valve body can be easily removed by extracting the second oil supply pipe. Furthermore, since the first oil supply pipe, the second oil supply pipe, and the fuel tank are separate, productivity can be improved, and assembly workability can be improved by using the second oil supply pipe made of an elastic material.
[0006]
[Problems to be solved by the invention]
However, in the backflow prevention device disclosed in Japanese Utility Model Publication No. 7-54024, the flange contacting the inner surface of the second oil supply pipe is divided, so that fuel leaks from the notch portion of the flange to the first oil supply pipe side. Therefore, there is a problem that the reverse flow rate of the fuel cannot be kept within the allowable management range with high accuracy.
[0007]
Accordingly, an object of the present invention is to provide a backflow prevention device for a fuel supply pipe that can accurately control a back flow rate of fuel within an allowable management width.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is a backflow prevention device that is disposed in a fuel supply pipe that connects a fuel supply port and a fuel tank and prevents the fuel inside the fuel tank from flowing back to the fuel supply port. A first oil supply pipe having a base end connected to the oil supply opening and an annular convex part formed at the tip end, a second oil supply pipe made of an elastic material, one end connected to the fuel tank, and a tubular shape as a whole. One end of which forms an insertion cylinder inserted into the tip of the first oil supply pipe, the other end forms a guide cylinder surrounding the valve body, and an annular flange is formed between the two. Is a valve case provided with a valve seat that contacts and separates the valve body, and is rotatably attached to the inside of the guide tube portion of the valve case, and normally contacts the valve seat to close the flow path. A valve body that opens the flow path away from the valve seat when fluid pressure is applied from the first oil supply pipe side; A check valve, and the insertion cylinder portion of the check valve is inserted into the tip of the first oil supply pipe, the tip of the first oil supply pipe is brought into contact with the flange portion, the guide cylinder portion, The other end of the second oil supply pipe is extrapolated to the outer periphery of the flange and the tip of the first oil supply pipe, the flange is bitten into the inner periphery of the second oil supply pipe, and the second oil supply pipe is The portion covered by the convex portion is elastically deformed to increase the diameter, and the valve body is rotatably attached to a bearing portion provided on the inner periphery of the guide tube portion via a support shaft. An outer periphery of the valve plate has an arcuate portion along the inner periphery of the guide tube portion, and a linear portion parallel to the support shaft, and the bearing portion of the insertion tube portion The adjacent portion protrudes toward the inner peripheral side in a tapered shape toward the downstream side of the fluid flow, and reaches the back side of the portion where the linear portion of the valve body of the valve seat contacts. It has a surface and its outer peripheral side forms a tapered recess, and is connected to one end on the upstream side of this recess and extends so as to be able to bend obliquely outward from there to the downstream side. And a locking claw for engaging with the inner periphery of the first oil supply pipe when it is inserted into the first oil supply pipe.
[0009]
According to the first aspect of the present invention, the insertion cylinder portion of the check valve is inserted into the other end of the first oil supply pipe whose one end is connected to the fuel supply port, and the second elastic material whose one end is connected to the fuel tank. Since the other end of the oil supply pipe is extrapolated to the outer periphery of the guide cylinder part, the flange part and the first oil supply pipe of the check valve, the flange part bites into the inner periphery of the second oil supply pipe. The fuel in the fuel tank can be prevented from leaking through the gap between the outer wall of the valve case and the inner wall of the second refueling pipe to the refueling port. As a result, the reverse flow rate of the fuel can be accurately controlled within the allowable control range. I can stop you.
[0010]
Further, since the second oil supply pipe made of an elastic material is provided and the fuel tank and the first oil supply pipe are elastically connected, the fuel tank and the first oil supply pipe can be easily assembled, and a check valve When a failure occurs, the second oil supply pipe can be extracted and the check valve can be easily removed from the first oil supply pipe.
Further, since the portion of the insertion tube portion adjacent to the bearing portion projects toward the inner peripheral side in a tapered shape toward the downstream side of the fluid flow, the fuel supplied from the fuel filler port flows along the taper and smoothly. Therefore, the impact force acting on the valve case can be reduced.
Further, the outer peripheral side has a tapered recess, and a locking claw that extends outward from one end of the recess and engages with the inner periphery of the first oil supply pipe when inserted into the first oil supply pipe. Therefore, the check valve is firmly fixed to the first supply pipe and can be prevented from falling off.
[0011]
According to a second aspect of the present invention, in the first aspect, the guide tube portion surrounding the arc-shaped portion of the valve plate forms a continuous peripheral wall, and the guide tube surrounds the linear portion of the valve plate. The portion provides a backflow prevention device for an oil supply pipe having an intermittent peripheral wall.
[0012]
According to the second aspect of the invention, since the portion surrounding the arc-shaped portion of the valve plate of the guide cylinder portion forms a continuous peripheral wall, the second oil supply pipe made of an elastic material bites inward by the reduced diameter force at that portion. Therefore, the rotation of the valve plate is not interfered with the inner wall of the second oil supply pipe. Moreover, since the part surrounding the linear part of the valve plate of the guide cylinder part forms an intermittent peripheral wall, the second oil supply pipe made of an elastic material bites inward by the diameter reducing force, so that the valve case and the second oil supply pipe It brings about the effect of increasing the frictional force that works between the two. Since this frictional force opposes the impact force that acts on the valve case when the fuel supplied from the fuel filler collides with the back surface of the bearing portion, the valve case can be prevented from being inclined by the impact force.
[0013]
According to a third aspect of the present invention, in the first aspect of the present invention, when the locking claw is bent inward, a stopper portion for restricting the amount of deflection is provided at the other end of the recess, and the back flow of the oil supply pipe A prevention device is provided.
[0016]
According to the third aspect of the present invention, when the locking claw is bent inward, the stopper portion for restricting the amount of bending is provided at the other end of the recess, so that the locking claw is damaged due to over-flexion. Can be prevented.
[0017]
A fourth aspect of the present invention is the valve according to any one of the first to third aspects, wherein the valve body is rotatably attached to a bearing portion provided on an inner periphery of the guide tube portion via a support shaft. And the support shaft is mounted in parallel to the valve plate surface at a predetermined interval in the downstream direction of the flow of the fluid via an arm erected from the valve plate, and the valve plate Is configured such that a gap is formed between the edge of the valve plate on the support shaft side and the valve seat when the valve is rotated so as to open the flow path. An oil supply pipe backflow prevention device is provided.
[0018]
According to the fourth aspect of the present invention, the support shaft is attached in parallel to the valve plate surface in the downstream direction of the fluid flow at a predetermined interval, and when the valve plate is rotated so as to open the flow path. Since the gap that allows the fluid to flow is formed also between the edge of the valve plate on the support shaft side and the valve seat, the fluid passing through the gap is allowed to pass through the back surface of the valve plate ( The flow at the time of refueling is suppressed by suppressing the generation of vortices on the back surface of the valve plate due to the fluid passing through the gap between the arc-shaped edge of the valve plate and the inner wall of the valve case. It is possible to stabilize and reduce resistance.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the outer periphery of the insertion tube portion of the check valve is engaged with the inner side of the annular convex portion of the first oil supply pipe. The present invention provides a backflow prevention device for an oil supply pipe in which a protrusion is formed.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
1 to 7 show an embodiment of a backflow prevention device for an oil supply pipe according to the present invention. 1 is a perspective view showing the appearance of the check valve, FIG. 2 is an exploded perspective view of the check valve, and FIG. 3 is a front view (A), a side view (B), a rear view (C), and a view of the check valve. 4 is an enlarged view of a main portion showing the locking claw, FIG. 5 is a side sectional view showing a state where a check valve is inserted into the first oil supply pipe and the second oil supply pipe, and FIG. 6 is a first oil supply pipe and a second oil supply pipe. FIG. 7 is a side cross-sectional view showing the flow around the valve element, and FIG. 7 is a side cross-sectional view showing the flow around the valve body.
[0020]
As shown in FIGS. 1 to 3, the check valve 100 includes a valve body 200 and a valve case 300. The valve body 200 includes a rod-like support shaft 210, a plate-shaped valve plate 220 having a circular cutout shape (kamaboko-shaped), an outer periphery of which is an arc-shaped portion 221 and a linear portion 222, and a shaft center. Are formed by a spring 230 having a shape in which both winding end portions 232 are extended. The support shaft 210 is attached in parallel to the surface of the valve plate 220 at a predetermined distance, and the spring 230 has the two winding portions 231 extrapolated at both ends of the support shaft 210 so that the connection The portion 233 contacts the valve plate 220 and is attached so that the winding end 232 engages with the valve case 300.
[0021]
The support shaft 210 is positioned on the downstream side of the valve plate 220 via a pair of plate-like arms 211 and 211 erected in parallel to the surface of the valve plate 220 positioned on the downstream side of the fluid flow. It is attached parallel to the surface to be separated at a predetermined interval. The support shaft 210 and the valve plate 220 are not limited in material as long as they have pressure resistance and corrosion resistance to fuel. However, in consideration of ease of molding, a thermoplastic resin, etc. An integrally molded product of the above synthetic resin is suitable. The material of the spring 230 is not limited as long as it does not deteriorate even when immersed in the fuel, but a metal having corrosion resistance to the fuel is suitable.
[0022]
The valve case 300 has a guide cylinder part 310 surrounding the valve body 200, and an insertion cylinder part 320 connected to one end face of the guide cylinder part 310 via an annular flange 330, as a whole. It has a substantially cylindrical shape.
[0023]
A valve seat 315 having a kamaboko-shaped opening to which the valve plate 220 is fitted is formed on the inner periphery of the portion of the valve case 300 where the collar portion 330 is located. A bearing portion 314 that protrudes inward of the guide tube portion 310 is formed in the periphery of the valve seat 315 in the vicinity of the portion where the linear portion 222 of the valve plate 220 abuts. The bearing portion 314 has a cylindrical shape having a slit described in the major axis direction, and the support shaft 210 of the valve body 200 is fitted through the slit to be held rotatably. The inner edge of the valve seat 315 is tapered, and the outer edge of the valve plate 220 is also tapered correspondingly, so that the valve plate 220 abuts the valve seat 315 with good sealing performance. .
[0024]
Further, when the valve plate 220 is mounted on the bearing portion 314, a portion surrounding the linear portion 222 of the valve plate 220 of the guide tube portion 310 is an intermittent peripheral wall 312 having a notch portion 313. On the other hand, a portion surrounding the arc-shaped portion 221 of the valve plate 220 of the guide tube portion 310 is a continuous peripheral wall 311.
[0025]
As shown in FIGS. 4 and 5, the inner periphery of the insertion tube portion 320 protrudes inward toward the back side of the portion where the linear portion 222 of the valve plate 220 of the valve seat 315 contacts. A tapered slope 325 is formed. And the part corresponding to the said slope 325 of the outer periphery of the insertion cylinder part 320 has comprised the taper-shaped recessed part 323. As shown in FIG. A locking claw 321 that projects obliquely outward is connected to one end of the recess 323, and a stopper that regulates the amount of deflection to the inside of the locking claw 321 at the other end of the recess 323. A portion 324 is provided. Further, a locking projection 322 is formed on a portion of the outer periphery of the insertion tube portion 320 facing the recess 323.
[0026]
The material of the valve case 300 is not limited as long as it has pressure resistance and corrosion resistance to fuel. However, in consideration of ease of molding, the valve case 300 is integrally formed of a synthetic resin such as a thermoplastic resin. Goods are preferred.
[0027]
The valve body 200 is rotatably held by fitting the vicinity of the center of the support shaft 210 between the plate-like arms 211 and 211 into the bearing portion 314. Further, the connecting portion 233 of the spring 230 with the winding portion 231 mounted on both ends of the support shaft 210 engages the back surface of the valve plate 220, and the winding end portion 232 is near the valve seat 315 of the valve case 300. Is engaged. Therefore, the valve plate 220 can be rotated about the support shaft 210 as an axis, and is always urged by the spring 230 in a direction in contact with the valve seat 315. For example, when the internal pressure of the fuel tank rises, the valve plate 220 is pressed against the valve seat 315 without the spring 230, so the spring 230 is not necessarily required.
[0028]
As described above, the support shaft 210 of the valve plate 220 is provided in parallel to the valve plate 220 at a predetermined interval downstream from the valve plate 220 via the pair of plate-like arms 211 and 211. The support position of the support shaft 210 by the portion 314 (the rotation center of the valve plate 220) is offset downstream from the position of the valve seat 315.
[0029]
The first oil supply pipe 400 is called a so-called filler tube, and is composed of a metal pipe having pressure resistance and corrosion resistance against fuel. A base end portion (not shown) of the first oil supply pipe 400 is connected to an oil supply port of the automobile, and an annular convex portion 410 is provided at the front end portion. The second oil supply pipe 500 is formed of natural rubber, synthetic rubber, synthetic resin elastomer, or the like, and its base end portion is externally connected to the front end portion of the first oil supply port 400, and the front end portion is a fuel (not shown). Connected to the tank inlet. The check valve 100 has its insertion cylinder portion 320 inserted into the inner periphery of the distal end portion of the first oil supply pipe 400, and the base end of the second oil supply pipe 500 is inserted into the outer periphery of the distal end portion of the first oil supply pipe 400 as described above. The part is extrapolated, and the check valve 100 is disposed in a fuel supply pipe that connects the fuel supply port and the fuel tank.
[0030]
When the insertion tube portion 320 of the check valve 100 is inserted into the distal end portion of the first oil supply pipe 400, the locking claw 321 is pushed by the distal end portion of the first oil supply pipe 400 and bends toward the recess 323. You can continue the insertion. When the tip end portion of the first oil supply pipe 400 gets over the most protruding portion of the locking claw 321, the most protruding portion of the locking claw 321 and the locking protrusion 322 are formed in the annular shape of the first oil supply pipe 400. It is fitted inside the convex portion 410 (a concave portion when viewed from the inside) and is prevented from coming off. Further, the tip of the first oil supply pipe 400 comes into contact with the flange portion 330 and further insertion is prevented. Thus, the check valve 100 is firmly fixed to the inner periphery of the distal end portion of the first oil supply pipe 400. As shown by the imaginary line in FIG. 4, when the locking claw 321 is deformed excessively, the tip thereof reaches the stopper portion 324 and cannot be further deformed. Therefore, the locking claw 321 is not likely to be damaged due to excessive deformation when inserted into the first oil supply pipe 400.
[0031]
Thus, after the check valve 100 is inserted into the inner periphery of the distal end portion of the first oil supply pipe 400, the base end portion of the second oil supply pipe 500 is put on the outer periphery of the distal end portion of the first oil supply pipe 400. In this case, the base end portion of the second oil supply pipe 500 is first put on the outer periphery of the guide cylinder portion 310 of the check valve 100, and further over the flange portion 330, and over the convex portion 410 of the first oil supply pipe 400. The tip of the second oil supply pipe 500 may be extrapolated until it reaches a predetermined distance from the end of the first oil supply pipe 400. The second oil supply pipe 500 is made of an elastic material. When the second oil supply pipe 500 gets over the flange portion 330 and the convex portion 410, the second oil supply tube 500 is elastically deformed so as to expand its diameter, so that it can be easily inserted. Moreover, after extrapolating the second oil supply pipe 500, a hose band may be attached to the outer periphery thereof.
[0032]
As shown in FIG. 6, in the state where the second oil supply pipe 500 is extrapolated on the outer periphery of the first oil supply pipe 400 into which the check valve 100 is inserted, a continuous annular flange of the check valve 100 is provided. 330 protrudes outward from the first oil supply pipe 400 and bites into the inner surface of the second oil supply pipe 500. Therefore, it is possible to prevent the fuel from leaking from the second oil supply pipe 500 side to the first oil supply pipe 400 side through the gap between the outer wall of the valve case 300 and the inner wall of the second oil supply pipe 500. In addition, it is preferable that the amount of biting of the flange 330, that is, the height at which the annular flange 330 protrudes outward from the outer periphery of the first oil supply pipe 400, is 0.3 to 0.9 mm.
[0033]
Furthermore, since the inner periphery of the second oil supply pipe 500 bites into the notch 313 in the intermittent peripheral wall 312 of the guide tube part 310 of the check valve 100, the valve case 300 and the second oil supply pipe 500 in that portion are interposed between them. The effect of increasing the working frictional force is brought about. Since this frictional force opposes the pressing force when the fuel collides with the tapered portion 325 of the valve case 300, there is no possibility that the valve case 300 is inclined due to the fuel pressure. The tapered portion 325 guides the fuel supplied from the fuel filler port to the inner periphery of the valve seat 315, so that the flow is smoothed and the flow resistance is reduced. Further, the continuous peripheral wall 311 of the guide cylinder portion 310 prevents the second oil supply pipe 500 from biting inward so that the rotation operation of the valve plate 220 is not hindered.
[0034]
Next, the operation of this backflow prevention device will be described.
As shown by the arrow in FIG. 7A, when there is a flow from the guide cylinder part 310 toward the insertion cylinder part 320, that is, when the fuel flows backward from the fuel tank to the fuel filler port, the pushing force and the reverse of the spring 230 are reversed. Due to the pressure of the fluid, the valve plate 220 comes into close contact with the valve seat 315 and closes the flow path. This prevents fuel from flowing backward from the fuel tank to the fuel filler opening. Further, since the continuous annular flange 330 bites into the inner periphery of the second oil supply pipe 500 made of an elastic material and improves the sealing performance, the fuel leaks through the outer periphery of the check valve 100 to the first oil supply pipe 400 side. Therefore, the reverse flow rate of the fuel can be accurately controlled within the allowable control range.
[0035]
As shown by arrows in FIGS. 7B to 7D, when there is a flow from the insertion tube portion 320 toward the guide tube portion 310, that is, when the fuel supplied from the fuel supply port flows toward the fuel tank, The pressure of the fluid presses the valve plate 220 against the force of the spring 230 and opens the flow path. Therefore, fuel can flow from the fuel filler port toward the fuel tank.
[0036]
In this case, as shown in FIG. 7A, the valve body 200 has the support shaft 210 arranged in parallel to the valve plate 220 on the downstream side at a predetermined distance, so that the upper edge angle of the valve plate 220 is When viewed in the direction perpendicular to the axis, there is an interval of X ₀ between the portion 220a and the support shaft 210, and there is an interval of Y ₀ when viewed in the axial direction. Then, as the valve plate 220 opens and its angle changes as shown in FIGS. 7B, 7C, and 7D, the interval when viewed in the axial direction is Y ₀ → Y ₁ → Y ₂ → Y _3. And their sizes are in a relationship of Y ₀ <Y ₁ <Y ₂ ≈Y ₃ .
[0037]
Thus, when the valve plate 220 is opened, a large space is opened between the upper edge corner portion 220a of the valve plate 220 and the support shaft 210 when viewed from the axial direction. A back surface flow a through the gap between the valve seat 315 and the valve seat 315 occurs. This flow (a) prevents vortices from occurring on the back side of the valve plate 220 due to the flow passing through the gap between the arc-shaped portion 221 of the valve plate 220 and the valve seat 315, and turbulence is generated even if the flow rate increases. Without this, the flow during refueling can be stabilized and the resistance can be reduced.
[0038]
【The invention's effect】
As described above, according to the present invention, the flange provided in the valve case of the check valve bites into the inner periphery of the second oil supply pipe made of an elastic material, so that the fuel in the fuel tank is It is possible to prevent leakage to the fuel filler port side through the gap between the outer wall and the inner wall of the second oil supply pipe, and as a result, the reverse flow rate of the fuel can be accurately kept within the allowable management width.
[0039]
In addition, since the second oil supply pipe made of elastic material is put on the outer periphery of the first oil supply pipe into which the check valve is inserted, the fuel tank and the oil supply pipe can be easily assembled and the check valve When the valve breaks down, the second oil supply pipe can be pulled out and the check valve can be easily removed from the first oil supply pipe.
FIG. 1 is a perspective view showing the appearance of a check valve used in an embodiment of a backflow prevention device of the present invention.
FIG. 2 is an exploded perspective view of the check valve.
FIG. 3 is a three-side view of the check valve.
FIG. 4 is an enlarged view of a main part showing a locking claw in the check valve.
FIG. 5 is a side sectional view showing a state in which a check valve is inserted in the first oil supply pipe and the second oil supply pipe in the embodiment.
FIG. 6 is an enlarged cross-sectional view of a main part showing a locking claw in a state where a check valve is inserted into a first oil supply pipe and a second oil supply pipe in the same embodiment;
FIG. 7 is a side sectional view showing the flow around the valve body in the same embodiment.
[Explanation of symbols]
100 check valve 200 valve body 210 support shaft 220 valve plate 230 spring 300 valve case 310 guide cylinder part 320 insertion cylinder part 330 collar part 400 first oil supply pipe 500 second oil supply pipe

Claims

In a backflow prevention device that is arranged in a fuel supply pipe that connects a fuel supply port and a fuel tank and prevents the fuel inside the fuel tank from flowing back to the fuel supply port,
A first oil supply pipe having a base end connected to the oil supply port and an annular protrusion formed at the tip;
A second oil supply pipe made of an elastic material, one end of which is connected to the fuel tank;
It has a cylindrical shape as a whole, one end of which forms an insertion tube portion inserted into the tip of the first oil supply pipe, the other end forms a guide tube portion surrounding the valve body, and an annular flange portion is formed between the two. A valve case with a valve seat that contacts and separates the valve body, and is rotatably mounted inside the guide tube portion of the valve case, and is always in contact with the valve seat. A check valve having a valve body that closes the flow path and opens the flow path away from the valve seat when fluid pressure is applied from the first oil supply pipe side;
The insertion cylinder part of the check valve is inserted into the tip of the first oil supply pipe, the tip of the first oil supply pipe is brought into contact with the flange part, the guide cylinder part, the flange part, and the first oil supply The other end of the second oil supply pipe is extrapolated to the outer periphery of the tip of the pipe, the flange portion bites into the inner periphery of the second oil supply pipe, and the second oil supply pipe is covered with the convex part. Is elastically deformed and expanded in diameter,
The valve body includes a valve plate rotatably attached to a bearing portion provided on an inner periphery of the guide tube portion via a support shaft, and an outer periphery of the valve plate is an inner periphery of the guide tube portion. An arc-shaped portion along the straight line, and a linear portion parallel to the support shaft,
A portion of the insertion tube portion adjacent to the bearing portion projects toward the inner peripheral side in a tapered shape toward the downstream side of the fluid flow, and on the back side of the portion where the linear portion of the valve body of the valve seat abuts. And has a tapered recess on the outer periphery.
When connected to one end on the upstream side of the recess, and extends so as to be able to bend obliquely outward from there and inserted into the first oil supply pipe, the inner circumference of the first oil supply pipe The backflow prevention device of the oil supply pipe is characterized in that a locking claw that engages with the oil supply pipe is formed.

The portion of the guide tube portion surrounding the arc-shaped portion of the valve plate forms a continuous peripheral wall, and the portion of the guide tube portion surrounding the linear portion of the valve plate forms an intermittent peripheral wall. Backflow prevention device for oil supply pipes.

The backflow prevention device for an oil supply pipe according to claim 1, wherein when the locking claw is deflected inward, a stopper portion for restricting the amount of deflection is provided at the other end of the recess.

The valve body includes a valve plate rotatably attached to a bearing portion provided on an inner periphery of the guide tube portion via a support shaft, and the support shaft is an arm erected from the valve plate. The valve plate is attached in parallel to the face of the valve plate at a predetermined interval in the downstream direction of the fluid flow, and when the valve plate is rotated so as to open the flow path, the valve plate The oil supply pipe according to any one of claims 1 to 3, wherein a gap that allows fluid to flow is formed also between an edge portion on a support shaft side and the valve seat. Backflow prevention device.

The locking protrusion which fits into the inner periphery of the cyclic | annular convex part of the said 1st oil supply pipe is formed in the outer periphery of the insertion cylinder part of the said non-return valve. Backflow prevention device for oil supply pipes.