JP3777313B2

JP3777313B2 - Rotary valve seal structure in variable intake system

Info

Publication number: JP3777313B2
Application number: JP2001273063A
Authority: JP
Inventors: 禧好穐谷; 勝檜波田; 康行米倉
Original assignee: Keihin Corp
Current assignee: Astemo Ltd
Priority date: 2001-09-10
Filing date: 2001-09-10
Publication date: 2006-05-24
Anticipated expiration: 2021-09-10
Also published as: JP2003083072A

Description

【０００１】
【発明の属する技術分野】
本発明は、可変吸気装置におけるロータリーバルブのシール構造に関し、特に、吸気通路構造体における吸気通路の長さを変化させるべく吸気通路構造体に回動可能に支承されるロータリーバルブの外周に、リング状となり得る一対の円弧状シール部と、両円弧状シール部間を結ぶ一対のバー状シール部とを有する合成樹脂製のシール部材が装着されるようにしたロータリーバルブのシール構造の改良に関する。
【０００２】
【従来の技術】
従来、かかるシール構造は、たとえば米国特許第６１３８６２８号公報等で既に知られており、シール部材を装着するためにロータリーバルブの外周に設けられる装着溝は、シール部材のうち円弧状シール部を嵌合させる一対の環状溝部と、シール部材のうち両バー状シール部を嵌合させる一対の直線状溝部とを有し、円弧状シール部は、その外周面が吸気通路構造体の支持孔内面に接触することでリング状となり、両バー状シール部の外側面は、円弧状シール部の外周面と面一であることから支持孔の内面に弾発接触する。また装着溝のうち両直線状溝部には、両円弧状シール部がリング状となるのに応じてバー状シール部を接触させるシール面と、ロータリーバルブの周方向に沿って前記シール面とは反対側からバー状シール部に対向する背部側面とがそれぞれ形成されており、バー状シール部および前記背部側面の相互対向面は平坦に形成されている。
【０００３】
【発明が解決しようとする課題】
ところで、このような可変吸気装置はエンジンの吸気系に用いられるものであり、エンジンの吸気脈動での圧力波によってロータリーバルブの周方向に沿う力がシール部材に作用し、シール部材のバー状シール部には、装着溝のうち直線状溝部のシール面に対して近接・離反する方向の力が作用する。これによりバー状シール部がシール面から離反したときに、直線状溝部の背部側面にバー状シール部が近接することになるが、上記従来のものでは、バー状シール部および前記背部側面の相互対向面が平坦に形成されているので、背部側面およびバー状シール部間での空気の流通を阻止することができず、ロータリーバルブの周方向でシール部材のシール効果が低下してしまうことになる。
【０００４】
本発明は、かかる事情に鑑みてなされたものであり、吸気脈動での圧力波がシール部材に作用してもロータリーバルブの周方向でのシール部材のシール効果を維持し得るようにした可変吸気装置におけるロータリーバルブのシール構造を提供することを目的とする。
【課題を解決するための手段】
上記目的を達成するために、請求項１記載の発明は、一端を吸気室に連通させた吸気通路の途中を前記吸気室に連通させる状態、ならびに吸気通路の途中および吸気室間を遮断する状態を切換えるロータリーバルブが、吸気通路構造体の支持孔に回動可能に挿入され、一対の環状溝部ならびに両環状溝部間を結ぶ一対の直線状溝部を有してロータリーバルブの外周に設けられる装着溝に、前記支持孔の内面に外周面が接触することで周方向両端を重合させたリング状となるようにして前記両環状溝部にそれぞれ嵌合される一対の円弧状シール部と、それらの円弧状シール部の外周面と面一となる外側面を有するとともに前記両円弧状シール部の周方向２箇所を相互に結んで前記両直線状溝部にそれぞれ嵌合される一対のバー状シール部とから成る合成樹脂製のシール部材が装着され、前記両環状溝部内で前記両円弧状シール部がリング状となるのに応じて前記バー状シール部を接触させるシール面と、ロータリーバルブの周方向に沿って前記シール面とは反対側からバー状シール部に対向する背部側面とが前記両直線状溝部にそれぞれ形成される可変吸気装置において、前記両バー状シール部および前記背部側面の相対向面間に隙間を設けると共に、その相対向面の少なくとも一方には、他方側に突出して該相対向面間にラビリンスを形成する突条がバー状シール部の長手方向に沿って延びるようにして一体に設けられることを特徴とする。
【０００５】
このような請求項１記載の発明の構成によれば、吸気脈動での圧力波によってロータリーバルブの周方向に沿う力がシール部材に作用するのに応じて、シール部材のバー状シール部が直線状溝部のシール面から離反する方向に移動すると、直線状溝部の背部側面に隙間を挟んで対向するバー状シール部が該背部側面に近接することになるが、バー状シール部および背部側面の少なくとも一方に突条が一体に突設されており、バー状シール部および背部側面間の隙間がごく小さくなる上、バー状シール部および背部側面の相対向面間には前記突条によりラビリンスが形成されてシール効果が高められるので、バー状シール部がシール面から離反した状態におけるロータリーバルブおよびバー状シール部間の空気の洩れを極力抑制することができ、ロータリーバルブの周方向でのシール部材のシール効果を高く維持することができる。
【０００６】
また請求項２記載の発明は、上記請求項１記載の発明の構成に加えて、前記両バー状シール部の両円弧状シール部側の両端は薄肉部として形成され、前記突条が、前記薄肉部を除いて両バー状シール部に突設されることを特徴とし、かかる構成によれば、突条が突設されるバー状シール部の剛性がその長手方向全長にわたって高くなってしまうことを回避し、薄肉部とした両バー状シール部の両端部に充分な可撓性を持たせることで、ロータリーバルブへのシール部材の装着作業を容易とすることができる。
【０００７】
【発明の実施の形態】
以下、本発明の実施形態を、添付の図面に示した本発明の実施例に基づいて説明する。図１〜図８は本発明の第１実施例を示すものであり、図１は吸気通路構造体およびロータリーバルブの分解斜視図、図２はエンジンの高速運転状態での吸気通路構造体およびロータリーバルブの縦断面図、図３は図２の３−３線断面図、図４はエンジンの低、中速運転状態での吸気通路構造体およびロータリーバルブの縦断面図、図５は図４の要部拡大図、図６はシール部材の側面図、図７は図６の７−７線拡大断面図、図８は図５の８部拡大図である
先ず図１および図２において、この可変吸気装置の吸気通路構造体１１は、４気筒エンジンに対応したものであり、合成樹脂から成る複数たとえば３つの接合部材を相互に溶着して構成され、吸気室１２を形成するサージタンク部１３と、吸気室１２に連なる吸気通路１４，１４…をそれぞれ形成するようにして一端がサージタンク部１３に共通に接続される４つの相互に独立した分岐管部１５，１５…と、各分岐管部１５，１５…の他端に共通に連設されるエンジン取付け用フランジ１６とを備える。
【０００８】
各分岐管部１５，１５…の配列方向に沿うサージタンク部１３の一端には大気導入口１７が設けられており、この大気導入口１７には図示しないスロットルボディを介してエアクリーナが接続され、スロットルボディにおけるスロットル開度に対応した量の大気が吸気室１２に導入される。
【０００９】
サージタンク部１３の下部に一端が接続される各分岐管部１５，１５…は、略Ｃ字状に彎曲するように形成されて水平方向に並列配置されており、各分岐管部１５，１５…の他端に共通に連設されるエンジン取付け用フランジ１６がサージタンク部１３の上方に配置される。
【００１０】
図３を併せて参照して、吸気通路構造体１１には、吸気室１２に一端を開口させるとともに他端を吸気通路１４，１４…の途中に開口させるバイパス通路１８…が設けられており、吸気室１２内からバイパス通路１８…および吸気通路１４，１４…を経てエンジンに至るまでの吸気通路長は、吸気室１２内から吸気通路１４，１４…を経てエンジンに至るまでの吸気通路長よりも短く設定される。
【００１１】
エンジン回転数に応じて各バイパス通路１８…の連通・遮断を切換えることにより吸気通路構造体１１における吸気通路長が切換えられるものであり、各バイパス通路１８…の連通・遮断を切換えるロータリーバルブ２０が、吸気通路構造体１１に回動可能に支承される。
【００１２】
吸気通路構造体１１には、バイパス通路１８…の中間部を横切る横断面円形の支持孔２１が設けられており、各バイパス通路１８…に個別に対応した通路孔２２…を有して円柱状に形成されるロータリーバルブ２０が、支持孔２１内に回動可能に挿入される。
【００１３】
ロータリーバルブ２０の軸方向両端には弁軸２３，２４が同軸に固定されており、それらの弁軸２３，２４が吸気通路構造体１１に回動可能に支承される。
【００１４】
前記弁軸２３の一端側にはアーム２６の基端が固定され、アーム２６の先端部に、アクチュエータ２７のロッド２８が連結される。該アクチュエータ２７は、前記弁軸２３，２４の軸線と直交する平面内に作動軸線を有するダイヤフラム式のものであり、エンジン回転数に応じて前記ロッド２８を軸方向に作動させる。而してエンジンの低、中速回転領域では吸気室１２の負圧がアクチュエータ２７に導入され、それに応じてアクチュエータ２７はロッド２８を図３で右動させ、それによりロータリーバルブ２０は、図４で示すように、各バイパス通路１８…を閉じる側に回動する。またエンジンの高速回転領域ではアクチュエータ２７はロッド２８を図３で左動させ、それによりロータリーバルブ２０は、図２および図３で示すように、各バイパス通路１８…を開放する位置に回動する。
【００１５】
アクチュエータ２７が備えるアクチュエータケース２９は、合成樹脂から成るケース部材３０と、該ケース部材３０に締結される合成樹脂製のカバー３１とから成る。アクチュエータケース２９の一部であるケース部材３０は、カバー３１と共働してアクチュエータケース２９を構成すべく椀状に構成されるものであるが、このケース部材３０には、ロッド２８および弁軸２３の連結部を覆って吸気通路構造体１１側に締結されるカバー部３０ａが一体に連設される。
【００１６】
カバー部３０ａは、該カバー部３０ａおよび吸気通路構造体１１間に挟まれる合成樹脂製の取付け板３２を介して吸気通路構造体１１に締結される。而して、カバー部３０ａおよび取付け板３２は、カバー部３０ａおよび取付け板３２に挿通されるとともに吸気通路構造体１１にねじ込まれるようにしたたとえば３本のボルト３３…によって共締めされることで吸気通路構造体１１に締結され、またカバー部３０ａは、たとえば２本のボルト３４…により取付け板３２に締結される。
【００１７】
ところで、ロータリーバルブ２０の回動位置は、弁軸２３の一端側に連結されるアクチュエータ２７に、弁軸２３の軸線に沿う方向の外方側で隣接するように配置される検出器３５で検出されるものであり、該検出器３５は、弁軸２３の一部を覆ってカバー部３０ａに取付けられる。
【００１８】
而して検出器３５は、弁軸２３の一端を覆うようにしてカバー部３０ａに締結される検出器ハウジング３６と、弁軸２３と一体に回動すべく該弁軸２３に取付けられるマグネット等の被検出部３７と、被検出部３７を非接触で検出すべく検出器ハウジング３６内に固定配置されるホールＩＣや磁電変換素子等の検出部３８とを備えるものであり、弁軸２３に接触することなく該弁軸２３の回動位置すなわちロータリーバルブ２０の作動位置を検出可能である。
【００１９】
図５を併せて参照して、ロータリーバルブ２０の外周には、各通路孔２２…毎に１つの合成樹脂から成るシール部材４０Ａ…が装着されるものであり、各シール部材４０…を装着するための装着溝４３…がロータリーバルブ２０の外周に設けられる。
【００２０】
装着溝４３は、通路孔２２をロータリーバルブ２０の軸方向両側から挟む位置に配置される一対の環状溝部４４，４４と、図４および図５で示すようにロータリーバルブ２０がバイパス通路１８を遮断した状態で吸気通路１４の途中側への支持孔２１の開口端を支持孔２１の周方向両側からシールする位置で前記両環状溝部４４，４４間を結ぶ一対の直線状溝部４５，４５とから成る。
【００２１】
図６および図７を併せて参照して、シール部材４０Ａは、支持孔２１の内面に外周面が接触することで周方向両端を重合させたリング状となるようにして前記両環状溝部４４，４４にそれぞれ嵌合される一対の円弧状シール部４１，４１と、それらの円弧状シール部４１，４１の外周面と面一となる外側面を有するとともに前記両円弧状シール部４１，４１の周方向２箇所を相互に結んで前記両直線状溝部４５，４５にそれぞれ嵌合される一対のバー状シール部４２Ａ，４２Ａとから成る。
【００２２】
図８において、直線状溝部４５，４５には、円弧状シール部４１，４１が支持孔２１の内面に外周面を接触させることにより前記両環状溝部４４，４４内でリング状となるのに応じて、バー状シール部４２Ａが接触するシール面４５ａと、ロータリーバルブ２０の周方向に沿って前記シール面４５ａとは反対側からバー状シール部４２Ａに隙間を挟んで対向する背部側面４５ｂとがそれぞれ形成されるものであり、バー状シール部４２Ａおよび背部側面４５ｂの相対向面の少なくとも一方、この実施例ではバー状シール部４２Ａ側の対向面に、背部側面４５ｂ側に突出する３つの突条４６，４６，４６がバー状シール部４２Ａの長手方向に沿って延びるようにして一体に設けられる。
【００２３】
しかも図６で明示するように、両バー状シール部４２Ａ…の両円弧状シール部４１，４１側の両端は薄肉部４７，４７として形成され、突条４６…は、薄肉部４７，４７を除いて両バー状シール部４２Ａ…に突設される。
【００２４】
また図１で明示するように、装着溝４５における環状溝部４４，４４の周方向少なくとも１箇所には係合凹部４８がそれぞれ設けられ、シール部材４０Ａにおける円弧状シール部４１，４１には、係合凹部４８に係合する係合突部４９がそれぞれ一体に設けられる。これによりロータリーバルブ２０の周方向に沿う方向でのシール部材４０Ａの移動が極力抑制される。
【００２５】
次にこの第１実施例の作用について説明すると、シール部材４０Ａをロータリーバルブ２０の外周の装着溝４３に装着した状態で、ロータリーバルブ２０を吸気通路構造体１１の支持孔２１に挿入すると、シール部材４０Ａにおける両円弧状シール部４１，４１の外周面が支持孔２１の内周面に接触することにより、両円弧状シール部４１，４１は装着溝４３の環状溝部４４，４４内で周方向両端を重合させたリング状となる。
【００２６】
このように円弧状シール部４１，４１がリング状となることにより、シール部材４０Ａの両バー状シール部４２Ａ，４２Ａは、それらのシール部４２Ａ，４２Ａを嵌合させている直線状溝部４５，４５のシール面４５ａ…に接触することになる。すなわち両バー状シール部４２Ａ，４２Ａは、両円弧状シール部４１，４１の外周面とともに支持孔２１の内面の外側面を密接させ、ロータリーバルブ２０の周方向一側で両バー状シール部４２Ａ，４２Ａが直線状溝部４５，４５のシール面４５ａ…に密接することになり、それにより、ロータリーバルブ２０が閉じている状態での該ロータリーバルブ２０の周方向でのロータリーバルブ２０および吸気通路構造体１１間のシールが、一対のバー状シール部４２Ａ，４２Ａでなされることになる。
【００２７】
ところで、エンジンの吸気脈動での圧力波によってロータリーバルブ２０の周方向に沿う力がシール部材４０Ａに作用することがあり、その場合、シール部材４０Ａのバー状シール部４２Ａ，４２Ａには、装着溝４３のうち直線状溝部４５，４５のシール面４５ａ…に対して近接・離反する方向の力が作用する。このためバー状シール部４２Ａがシール面４５ａから離反したときには、直線状溝部４５の背部側面４５ｂにバー状シール部４２Ａが近接することになる。
【００２８】
しかるにバー状シール部４２Ａ，４２Ａには、背部側面４５ｂ…側に突出する３つの突条４６…がバー状シール部４２Ａ，４２Ａの長手方向に沿って延びるようにして一体に設けられている。したがってバー状シール部４２Ａがシール面４５ａから離反する方向に移動して背部側面４５ｂにバー状シール部４２Ａが近接すると、バー状シール部４２Ａおよび背部側面４５ｂ間の隙間がごく小さくなる。したがってバー状シール部４２Ａがシール面４５ａから離反した状態におけるロータリーバルブ２０およびバー状シール部４２Ａ間の空気の洩れを極力抑制することができ、ロータリーバルブ２０の周方向でのシール部材４０Ａのシール効果を高く維持することができる。
【００２９】
しかもこの第１実施例では、３つの突起４６…がバー状シール部４２Ａに突設されており、バー状シール部４２Ａが背部側面４５ｂに近接したときには、バー状シール部４２Ａが背部側面４５ｂ間にラビリンスを形成するようにしてシール効果を高めることができる。
【００３０】
またバー状シール部４２Ａ，４２Ａの両円弧状シール部４１，４１側の両端は薄肉部４７…として形成されており、突条４６…が、前記薄肉部４７…を除いて両バー状シール部４２Ａ，４２Ａに突設されるので、突条４６…が突設されるバー状シール部４２Ａ，４２Ａの剛性がその長手方向全長にわたって高くなってしまうことを回避し、薄肉部４７…とした両バー状シール部４２Ａ，４２Ａの両端部に充分な可撓性を持たせることで、ロータリーバルブ２０へのシール部材４０Ａの装着作業を容易とすることができる。
【００３１】
図９で示す第２実施例のように、シール部材４０Ｂのバー状シール部４２Ｂに２つの突条４６，４６が設けられるようにしてもよい。
【００３２】
以上、本発明の実施例を説明したが、本発明は上記実施例に限定されるものではなく、特許請求の範囲に記載された本発明を逸脱することなく種々の設計変更を行うことが可能である。
【００３３】
たとえば上記各実施例では、シール部材のバー状シール部に突条が設けられたが、直線状溝部の背部側面にバー状シール部側に突出する突条が設けられてもよく、またバー状シール部および背部側面のいずれにも突条が設けられるようにしてもよい。
【００３４】
【発明の効果】
以上のように請求項１記載の発明によれば、合成樹脂製シール部材のバー状シール部とロータリバルブにおける直線状溝部の背部側面との相対向面間に隙間を設けると共に、その相対向面の少なくとも一方には、他方側に突出して該相対向面間にラビリンスを形成する突条がバー状シール部の長手方向に沿って延びるようにして一体に設けられるので、吸気脈動での圧力波によってシール部材のバー状シール部が直線状溝部のシール面から離反する方向に移動しても、バー状シール部および背部側面間の隙間をごく小さくできる上、バー状シール部および背部側面の相対向面間には前記突条によりラビリンスが形成されてシール効果が高められ、これにより、バー状シール部がシール面から離反した状態におけるロータリーバルブおよびバー状シール部間の空気の洩れを極力抑制することができ、ロータリーバルブの周方向でのシール部材のシール効果を高く維持することができる。
【００３５】
また請求項２記載の発明によれば、突条が突設されるバー状シール部の剛性がその長手方向全長にわたって高くなってしまうことを回避し、両バー状シール部の両端部に充分な可撓性を持たせることで、ロータリーバルブへのシール部材の装着作業を容易とすることができる。
【図面の簡単な説明】
【図１】第１実施例の吸気通路構造体およびロータリーバルブの分解斜視図
【図２】エンジンの高速運転状態での吸気通路構造体およびロータリーバルブの縦断面図
【図３】図２の３−３線断面図
【図４】エンジンの低、中速運転状態での吸気通路構造体およびロータリーバルブの縦断面図
【図５】図４の要部拡大図
【図６】シール部材の側面図
【図７】図６の７−７線拡大断面図
【図８】図５の８部拡大図
【図９】第２実施例のシール部材の図７に対応した断面図
【符号の説明】
１１・・・吸気通路構造体
１２・・・吸気室
１４・・・吸気通路
２０・・・ロータリーバルブ
２１・・・支持孔
４０Ａ，４０Ｂ・・・シール部材
４１・・・円弧状シール部
４２Ａ，４２Ｂ・・・バー状シール部
４３・・・装着溝
４４・・・環状溝部
４５・・・直線状溝部
４５ａ・・・シール面
４５ｂ・・・背部側面
４６・・・突条
４７・・・薄肉部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seal structure of a rotary valve in a variable intake device, and more particularly, to a ring on the outer periphery of a rotary valve that is rotatably supported by an intake passage structure so as to change the length of the intake passage in the intake passage structure. The present invention relates to an improvement in the seal structure of a rotary valve in which a synthetic resin seal member having a pair of arc-shaped seal portions that can be shaped and a pair of bar-shaped seal portions connecting both arc-shaped seal portions is mounted.
[0002]
[Prior art]
Conventionally, such a seal structure is already known, for example, in US Pat. No. 6,138,628, and the mounting groove provided on the outer periphery of the rotary valve for mounting the seal member fits the arc-shaped seal portion of the seal member. A pair of annular grooves to be mated with each other and a pair of linear grooves to fit both bar-shaped seal portions of the seal member. The arc-shaped seal portion has an outer peripheral surface on the inner surface of the support hole of the intake passage structure. The contact forms a ring shape, and the outer surfaces of both bar-shaped seal portions are flush with the inner surface of the support hole because they are flush with the outer peripheral surface of the arc-shaped seal portion. In addition, the linear groove portion of the mounting groove includes a seal surface that contacts the bar-shaped seal portion in accordance with the circular arc-shaped seal portions being ring-shaped, and the seal surface along the circumferential direction of the rotary valve. A back portion side surface facing the bar-shaped seal portion is formed from the opposite side, and the mutually opposing surfaces of the bar-shaped seal portion and the back portion side surface are formed flat.
[0003]
[Problems to be solved by the invention]
By the way, such a variable intake device is used for an intake system of an engine, and a force along the circumferential direction of the rotary valve acts on the seal member due to a pressure wave in the intake air pulsation of the engine, and a bar-shaped seal of the seal member A force in a direction approaching / separating from the seal surface of the linear groove portion of the mounting groove acts on the portion. As a result, when the bar-shaped seal portion is separated from the seal surface, the bar-shaped seal portion comes close to the back side surface of the linear groove portion. Since the opposing surface is formed flat, the air flow between the back side surface and the bar-shaped seal portion cannot be prevented, and the sealing effect of the seal member in the circumferential direction of the rotary valve is reduced. Become.
[0004]
The present invention has been made in view of such circumstances, and the variable intake air that can maintain the sealing effect of the seal member in the circumferential direction of the rotary valve even if the pressure wave due to the intake pulsation acts on the seal member. An object of the present invention is to provide a sealing structure for a rotary valve in an apparatus.
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a state in which the middle of the intake passage having one end communicated with the intake chamber is communicated with the intake chamber, and a state in which the middle of the intake passage and between the intake chambers are blocked. The rotary valve is inserted into the support hole of the intake passage structure so as to be rotatable, and has a pair of annular grooves and a pair of linear grooves connecting the two annular grooves, and is provided on the outer periphery of the rotary valve. In addition, a pair of arc-shaped seal portions that are respectively fitted in the annular groove portions so as to form a ring shape in which both ends in the circumferential direction are superposed by contacting the outer peripheral surface with the inner surface of the support hole, and their circles A pair of bar-shaped seal portions that have an outer surface that is flush with the outer peripheral surface of the arc-shaped seal portion and that are connected to the two linear groove portions by mutually connecting two circumferential directions of the arc-shaped seal portions; From A seal member made of synthetic resin is attached, and a seal surface that contacts the bar-shaped seal portion in accordance with the circular arc-shaped seal portions being ring-shaped in the annular groove portions, and a circumferential direction of the rotary valve And a back side surface facing the bar-shaped seal portion from the side opposite to the seal surface along the linear groove portions, respectively, in the variable intake device, the opposing surfaces of the bar-shaped seal portion and the back side surface A gap is provided between them, and at least one of the opposing surfaces is integrally provided with a protrusion that protrudes to the other side to form a labyrinth between the opposing surfaces so as to extend along the longitudinal direction of the bar-shaped seal portion. It is provided in.
[0005]
According to such a configuration of the first aspect of the present invention, the bar-shaped seal portion of the seal member is linear in response to the force along the circumferential direction of the rotary valve acting on the seal member due to the pressure wave due to the intake pulsation. moving in the direction away from the sealing surface of the Jo groove, a bar-like seal portion that face each other across the gap at the back side of the linear groove portion becomes to close to the back side surface of the bar-shaped seal portion and the back side A protrusion is integrally provided on at least one side, the gap between the bar-shaped seal portion and the back side surface is extremely small , and a labyrinth is formed between the opposing surfaces of the bar-shaped seal portion and the back side surface by the protrusion. since being formed sealing effect is enhanced, can be bar-shaped sealing portion is suppressed as much as possible the leakage of air between the rotary valve and the bar-shaped sealing portion in a state in which separated from the sealing surface It is possible to maintain a high sealing effect of the sealing member in the circumferential direction of the rotary valve.
[0006]
In addition to the configuration of the invention described in claim 1, the invention described in claim 2 is characterized in that both ends of the bar-shaped seal portions on both arc-shaped seal portions are formed as thin-walled portions, and the protrusions are It is characterized in that it is provided on both bar-like seal portions except for the thin-walled portion, and according to such a configuration, the rigidity of the bar-like seal portion on which the protrusion is provided is increased over the entire length in the longitudinal direction. By avoiding this, and providing sufficient flexibility at both end portions of both bar-shaped seal portions that are thin-walled portions, the mounting operation of the seal member to the rotary valve can be facilitated.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings. 1 to 8 show a first embodiment of the present invention, FIG. 1 is an exploded perspective view of an intake passage structure and a rotary valve, and FIG. 2 is an intake passage structure and a rotary when the engine is operating at high speed. 3 is a cross-sectional view taken along line 3-3 of FIG. 2, FIG. 4 is a vertical cross-sectional view of an intake passage structure and a rotary valve in a low and medium speed operation state of the engine, and FIG. 5 is a cross-sectional view of FIG. 6 is a side view of the seal member, FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6, and FIG. 8 is an enlarged view of 8 part of FIG. 5. First, in FIG. 1 and FIG. The intake passage structure 11 of the intake device corresponds to a four-cylinder engine, and is configured by welding a plurality of, for example, three joining members made of synthetic resin to each other, and a surge tank portion 13 that forms an intake chamber 12. , The intake passages 14, 14. The four independent branch pipe parts 15, 15... Having one end commonly connected to the surge tank part 13 and the other end of each branch pipe part 15, 15. And an engine mounting flange 16.
[0008]
An air inlet 17 is provided at one end of the surge tank 13 along the arrangement direction of the branch pipe portions 15, 15... An air cleaner is connected to the air inlet 17 via a throttle body (not shown). An amount of air corresponding to the throttle opening in the throttle body is introduced into the intake chamber 12.
[0009]
Each branch pipe part 15, 15... Of which one end is connected to the lower part of the surge tank part 13 is formed so as to bend in a substantially C shape and is arranged in parallel in the horizontal direction, and each branch pipe part 15, 15. An engine mounting flange 16 provided in common with the other end of the... Is disposed above the surge tank portion 13.
[0010]
Referring also to FIG. 3, the intake passage structure 11 is provided with bypass passages 18 that open at one end to the intake chamber 12 and open the other end in the middle of the intake passages 14, 14. The intake passage length from the inside of the intake chamber 12 to the engine through the bypass passage 18 and the intake passages 14, 14... Is larger than the intake passage length from the inside of the intake chamber 12 to the engine through the intake passages 14, 14. Is also set short.
[0011]
The intake passage length in the intake passage structure 11 is switched by switching communication / blocking of each bypass passage 18 depending on the engine speed, and a rotary valve 20 for switching communication / blocking of each bypass passage 18. The intake passage structure 11 is rotatably supported.
[0012]
The intake passage structure 11 is provided with a circular support hole 21 having a circular cross section across the intermediate portion of the bypass passages 18, and has a cylindrical shape with passage holes 22 individually corresponding to the bypass passages 18. The rotary valve 20 is formed in the support hole 21 so as to be rotatable.
[0013]
Valve shafts 23 and 24 are coaxially fixed to both ends of the rotary valve 20 in the axial direction, and these valve shafts 23 and 24 are rotatably supported by the intake passage structure 11.
[0014]
A proximal end of an arm 26 is fixed to one end side of the valve shaft 23, and a rod 28 of an actuator 27 is connected to a distal end portion of the arm 26. The actuator 27 is a diaphragm type having an operating axis in a plane orthogonal to the axis of the valve shafts 23 and 24, and operates the rod 28 in the axial direction according to the engine speed. Thus, in the low and medium speed rotation regions of the engine, the negative pressure in the intake chamber 12 is introduced into the actuator 27. In response, the actuator 27 moves the rod 28 to the right in FIG. As shown in FIG. 1, the bypass passages 18 are rotated to the side of closing. Further, in the high-speed rotation region of the engine, the actuator 27 moves the rod 28 to the left in FIG. 3, so that the rotary valve 20 is rotated to a position where each bypass passage 18 is opened as shown in FIGS. .
[0015]
The actuator case 29 provided in the actuator 27 includes a case member 30 made of synthetic resin and a cover 31 made of synthetic resin fastened to the case member 30. The case member 30 which is a part of the actuator case 29 is configured in a bowl shape to cooperate with the cover 31 to form the actuator case 29. The case member 30 includes a rod 28 and a valve shaft. A cover portion 30a that covers the connecting portion 23 and is fastened to the intake passage structure 11 side is integrally provided.
[0016]
The cover portion 30a is fastened to the intake passage structure 11 via a synthetic resin mounting plate 32 sandwiched between the cover portion 30a and the intake passage structure 11. Thus, the cover portion 30a and the mounting plate 32 are inserted into the cover portion 30a and the mounting plate 32 and are tightened together by, for example, three bolts 33 that are screwed into the intake passage structure 11. The cover 30a is fastened to the intake passage structure 11, and the cover 30a is fastened to the mounting plate 32 by two bolts 34, for example.
[0017]
By the way, the rotational position of the rotary valve 20 is detected by a detector 35 disposed adjacent to the actuator 27 connected to one end side of the valve shaft 23 on the outer side in the direction along the axis of the valve shaft 23. The detector 35 covers a part of the valve shaft 23 and is attached to the cover portion 30a.
[0018]
Thus, the detector 35 includes a detector housing 36 that is fastened to the cover portion 30a so as to cover one end of the valve shaft 23, a magnet that is attached to the valve shaft 23 so as to rotate integrally with the valve shaft 23, and the like. And a detection unit 38 such as a Hall IC or a magnetoelectric conversion element fixedly arranged in the detector housing 36 so as to detect the detection unit 37 in a non-contact manner. The rotating position of the valve shaft 23, that is, the operating position of the rotary valve 20 can be detected without contact.
[0019]
Referring also to FIG. 5, a seal member 40 </ b> A made of a synthetic resin is mounted on the outer periphery of the rotary valve 20 for each passage hole 22, and each seal member 40 is mounted. Mounting grooves 43 are provided on the outer periphery of the rotary valve 20.
[0020]
The mounting groove 43 includes a pair of annular grooves 44 and 44 disposed at positions sandwiching the passage hole 22 from both axial sides of the rotary valve 20, and the rotary valve 20 blocks the bypass passage 18 as shown in FIGS. 4 and 5. From the pair of linear groove portions 45, 45 connecting the annular groove portions 44, 44 at positions where the opening end of the support hole 21 to the midway side of the intake passage 14 is sealed from both sides in the circumferential direction of the support hole 21 Become.
[0021]
Referring to FIGS. 6 and 7 together, the sealing member 40A is configured so that the outer circumferential surface contacts the inner surface of the support hole 21 to form a ring shape in which both circumferential ends are overlapped, 44 and a pair of arc-shaped seal portions 41, 41 fitted respectively to the arc-shaped seal portions 41, 41 and an outer surface that is flush with the outer peripheral surface of the arc-shaped seal portions 41, 41 and It consists of a pair of bar-shaped seal portions 42A and 42A that are connected to the two linear groove portions 45 and 45 by connecting two places in the circumferential direction.
[0022]
In FIG. 8, according to the linear groove portions 45, 45, the arc-shaped seal portions 41, 41 are ring-shaped in the annular groove portions 44, 44 by bringing the outer peripheral surface into contact with the inner surface of the support hole 21. Thus, a seal surface 45a that contacts the bar-shaped seal portion 42A, and a back side surface 45b that faces the bar-shaped seal portion 42A across the gap from the opposite side of the seal surface 45a along the circumferential direction of the rotary valve 20. Each of the three protrusions projecting toward the back side surface 45b is formed on at least one of the opposing surfaces of the bar-shaped seal portion 42A and the back side surface 45b, in this embodiment, on the opposing surface on the bar-shaped seal portion 42A side. The strips 46, 46, 46 are integrally provided so as to extend along the longitudinal direction of the bar-shaped seal portion 42A.
[0023]
Moreover, as clearly shown in FIG. 6, both ends of the bar-shaped seal portions 42 </ b> A on both arc-shaped seal portions 41, 41 side are formed as thin portions 47, 47, and the protrusions 46. Except for the two bar-shaped seal portions 42A.
[0024]
Further, as clearly shown in FIG. 1, an engagement recess 48 is provided in at least one circumferential direction of the annular groove portions 44, 44 in the mounting groove 45, and the arc-shaped seal portions 41, 41 in the seal member 40A are engaged with each other. Engaging protrusions 49 that engage with the mating recesses 48 are integrally provided. Thereby, the movement of the sealing member 40A in the direction along the circumferential direction of the rotary valve 20 is suppressed as much as possible.
[0025]
Next, the operation of the first embodiment will be described. When the rotary valve 20 is inserted into the support hole 21 of the intake passage structure 11 with the seal member 40A mounted in the mounting groove 43 on the outer periphery of the rotary valve 20, the seal is sealed. When the outer peripheral surfaces of both arc-shaped seal portions 41, 41 in the member 40 </ b> A are in contact with the inner peripheral surface of the support hole 21, both arc-shaped seal portions 41, 41 are circumferential in the annular groove portions 44, 44 of the mounting groove 43. It becomes a ring shape in which both ends are polymerized.
[0026]
Since the arc-shaped seal portions 41 and 41 are in a ring shape in this way, both the bar-shaped seal portions 42A and 42A of the seal member 40A are fitted with the linear groove portions 45 and the seal portions 42A and 42A. 45 of the sealing surface 45a. That is, both the bar-shaped seal portions 42A and 42A bring the outer surface of both the arc-shaped seal portions 41 and 41 into close contact with the outer surface of the inner surface of the support hole 21, and both the bar-shaped seal portions 42A on one side in the circumferential direction of the rotary valve 20. , 42A are in close contact with the seal surfaces 45a of the linear grooves 45, 45, so that the rotary valve 20 and the intake passage structure in the circumferential direction of the rotary valve 20 in a state where the rotary valve 20 is closed. The seal between the bodies 11 is made by a pair of bar-shaped seal portions 42A and 42A.
[0027]
By the way, the force along the circumferential direction of the rotary valve 20 may act on the seal member 40A due to the pressure wave caused by the intake air pulsation of the engine. In this case, the bar-shaped seal portions 42A and 42A of the seal member 40A have a mounting groove. 43, a force in a direction approaching or separating from the seal surfaces 45a of the linear groove portions 45, 45 acts. For this reason, when the bar-shaped seal portion 42A is separated from the seal surface 45a, the bar-shaped seal portion 42A comes close to the back side surface 45b of the linear groove portion 45.
[0028]
However, the bar-shaped seal portions 42A and 42A are integrally provided with three protrusions 46 projecting toward the back side surface 45b to extend along the longitudinal direction of the bar-shaped seal portions 42A and 42A. Therefore, when the bar-shaped seal portion 42A moves away from the seal surface 45a and the bar-shaped seal portion 42A comes close to the back side surface 45b, the gap between the bar-shaped seal portion 42A and the back side surface 45b becomes very small. Therefore, air leakage between the rotary valve 20 and the bar-shaped seal portion 42A in a state where the bar-shaped seal portion 42A is separated from the seal surface 45a can be suppressed as much as possible, and the seal of the seal member 40A in the circumferential direction of the rotary valve 20 can be suppressed. The effect can be kept high.
[0029]
In addition, in this first embodiment, the three protrusions 46 are projected from the bar-shaped seal portion 42A, and when the bar-shaped seal portion 42A is close to the back side surface 45b, the bar-shaped seal portion 42A is between the back side surface 45b. Thus, the labyrinth can be formed to enhance the sealing effect.
[0030]
Further, both ends of the bar-shaped seal portions 42A, 42A on both arc-shaped seal portions 41, 41 side are formed as thin-walled portions 47 ..., and the protrusions 46 ... except for the thin-walled portions 47 ... are both bar-shaped seal portions. Since the protrusions 42A and 42A project, the bar-shaped seal portions 42A and 42A, on which the protrusions 46 are projected, are prevented from increasing in rigidity over the entire length in the longitudinal direction, and the thin portions 47 are formed. By attaching sufficient flexibility to both end portions of the bar-shaped seal portions 42A and 42A, the mounting operation of the seal member 40A to the rotary valve 20 can be facilitated.
[0031]
As in the second embodiment shown in FIG. 9, but it may also be so that the two protrusions 46, 46 into bars seal portion 42B of the sealing member 40B is provided.
[0032]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.
[0033]
For example, in each of the above embodiments, a protrusion is provided on the bar-shaped seal portion of the seal member. However, a protrusion protruding toward the bar-shaped seal portion may be provided on the back side surface of the linear groove portion. A protrusion may be provided on both the seal part and the back side surface.
[0034]
【The invention's effect】
As described above, according to the first aspect of the present invention , a gap is provided between the opposed surfaces of the bar-shaped seal portion of the synthetic resin sealing member and the back side surface of the linear groove portion of the rotary valve, and the opposed surfaces thereof. At least one of the ribs is integrally provided with a protrusion that protrudes toward the other side and forms a labyrinth between the opposing surfaces so as to extend along the longitudinal direction of the bar-shaped seal portion. seal bar shape seal portion of the member is moved in a direction away from the sealing surface of the linear groove portion, on which the gaps between the bar-shaped seal portion and the back side can very small, bar-shaped seal portion and the back side relative by between facing surfaces labyrinth is formed sealing effect is enhanced by the protrusion, thereby, the rotary valve and the bar in the state where a bar-like seal portion is moved away from the sealing surface Leakage of air between the sealing portion can be a minimized, it is possible to maintain a high sealing effect of the sealing member in the circumferential direction of the rotary valve.
[0035]
According to the invention described in claim 2, it is possible to avoid that the rigidity of the bar-shaped seal portion on which the protrusion is provided is increased over the entire length in the longitudinal direction, and sufficient for both ends of both bar-shaped seal portions. By giving flexibility, the mounting | wearing operation | work of the sealing member to a rotary valve can be made easy.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of an intake passage structure and a rotary valve according to a first embodiment. FIG. 2 is a longitudinal sectional view of the intake passage structure and a rotary valve when the engine is operating at high speed. Cross-sectional view taken along line -3 [FIG. 4] A longitudinal cross-sectional view of the intake passage structure and the rotary valve when the engine is operating at low and medium speeds. [FIG. 7 is an enlarged sectional view taken along line 7-7 in FIG. 6. FIG. 8 is an enlarged view of part 8 in FIG. 5. FIG. 9 is a sectional view corresponding to FIG. 7 of the seal member of the second embodiment .
11 ... intake passage structure 12 ... intake chamber 14 ... intake passage 20 ... rotary valve 21 ... supporting hole 40A, 40 B ... seal member 41 ... arcuate seal portion 42A , 42 B ... bar-shaped sealing portion 43 ... mounting groove 44 ... annular groove 45 ... linear groove 45a ... sealing surface 45b ... back side 46 ... projection 47 ...・ Thin part

Claims

A state where one end of the intake passage (14) communicated with the intake chamber (12) communicates with the intake chamber (12), and a state where the intake passage (14) and the intake chamber (12) are blocked. A rotary valve (20) for switching is rotatably inserted into the support hole (21) of the intake passage structure (11), and a pair of annular grooves (44) and a pair of linear grooves connecting the annular grooves (44). A ring shape in which both ends in the circumferential direction are superposed on the mounting groove (43) provided on the outer periphery of the rotary valve (20) having a groove portion (45) by bringing the outer peripheral surface into contact with the inner surface of the support hole (21). A pair of arc-shaped seal portions (41) that are respectively fitted to the annular groove portions (44), and an outer surface that is flush with the outer peripheral surface of the arc-shaped seal portions (41). And both arc-shaped seals ( A pair of bar-shaped sealing portion, wherein the tie to each other in the circumferential direction two portions are fitted on both straight groove (45) of 1) (42A, 42 B) from the made of synthetic resin of the sealing member (40A, 40 B ) is mounted, and seal surfaces (42A , 42B ) are brought into contact with each other in accordance with the circular arc-shaped seal portions (41) being ring-shaped in the annular groove portions (44). 45a) and a back side surface (45b) facing the bar-shaped seal portions (42A , 42B ) from the opposite side of the seal surface (45a) along the circumferential direction of the rotary valve (20). (45) In each variable intake device formed,
A gap is provided between the opposing surfaces of the bar-shaped seal portions (42A , 42B ) and the back side surface (45b), and at least one of the opposing surfaces protrudes to the other side to protrude between the opposing surfaces. A seal structure for a rotary valve in a variable intake device, characterized in that the protrusion (46) forming the labyrinth is integrally provided so as to extend along the longitudinal direction of the bar-shaped seal portions (42A , 42B ).

Both ends of the bar-shaped seal portions (42A , 42B ) on both arc-shaped seal portions (41) side are formed as thin-walled portions (47), and the protrusions (46) are formed except for the thin-walled portions (47). 2. The rotary valve sealing structure in a variable intake system according to claim 1, wherein the two bar-shaped sealing portions (42A , 42B ) are projected.