JP4511763B2

JP4511763B2 - Engine exhaust gas purification device

Info

Publication number: JP4511763B2
Application number: JP2001138231A
Authority: JP
Inventors: 浩志井之川
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2001-05-09
Filing date: 2001-05-09
Publication date: 2010-07-28
Anticipated expiration: 2021-05-09
Also published as: JP2002332832A

Description

【０００１】
【発明の属する技術分野】
本発明は、排気通路の内部にチューブ式排気ガス浄化装置およびハニカム式排気ガス浄化装置を配置したエンジンの排気ガス浄化装置に関する。
【０００２】
【従来の技術】
自動二輪車の排気通路に形成した膨張室の内部に、パンチングメタルをチューブ状に形成した担体に触媒を担持した２個のチューブ式排気ガス浄化装置を、排気ガス流れ方向の上流側および下流側に２段に配置したものが、特開平１０−３０４３２号公報により公知である。上記エンジンの排気ガス浄化装置によれば、上流側のチューブ式排気ガス浄化装置の反応熱で排気ガスを昇温させ、下流側の排気ガス浄化装置に高温の排気ガスを供給して排気ガス浄化性能を高めることができる。
【０００３】
【発明が解決しようとする課題】
ところで上記従来のものは、小径に形成された上流側のチューブ式排気ガス浄化装置の後端が、大径に形成された下流側のチューブ式排気ガス浄化装置の前端に緩く嵌合しており、しかも担体をパンチングメタルで形成した上流側のチューブ式排気ガス浄化装置は、パンチ孔を通して排気ガスが内側から外側に逃げるため、上流側のチューブ式排気ガス浄化装置を通過して昇温した排気ガスの全量を下流側のチューブ式排気ガス浄化装置に供給することができなかった。
【０００４】
またハニカム状に形成した担体に触媒を担持したハニカム式排気ガス浄化装置は、チューブ式排気ガス浄化装置に比べて排気ガス浄化性能が高い一方、ハニカムのセルの板厚が薄く触媒の担持層の厚みも薄いため、耐熱温度が低いという特性を有している。従って、ハニカム式排気ガス浄化装置およびチューブ式排気ガス浄化装置を組み合わせて使用する場合に、ハニカム式排気ガス浄化装置の耐熱温度を考慮しながら最大限の排気ガス浄化性能を発揮させる必要がある。
【０００５】
本発明は前述の事情に鑑みてなされたもので、排気通路にハニカム式排気ガス浄化装置およびチューブ式排気ガス浄化装置を配置したエンジンの排気ガス浄化装置において、排気ガス浄化性能の向上および耐久性の向上を図ることを目的とする。
【０００６】
【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に記載された発明によれば、チューブ状に形成した担体に触媒を担持したチューブ式排気ガス浄化装置を排気通路の内部に配置したエンジンの排気ガス浄化装置において、ハニカム状に形成した担体に触媒を担持したハニカム式排気ガス浄化装置を、チューブ式排気ガス浄化装置の排気ガス流れ方向の上流端に一体に結合すると共に、その結合部の近傍を、排気通路に設けた支持手段を介して排気通路の内面に支持したことを特徴とするエンジンの排気ガス浄化装置が提案される。
【０００７】
上記構成によれば、ハニカム式排気ガス浄化装置をチューブ式排気ガス浄化装置の排気ガス流れ方向の上流端に一体に結合したので、ハニカム式排気ガス浄化装置における触媒反応で昇温した高温の排気ガスをチューブ式排気ガス浄化装置に供給して排気ガス浄化性能を高めることができる。しかもハニカム式排気ガス浄化装置はハニカム状に形成した担体に触媒を担持した構造であるため、そこを通過して昇温した排気ガスの全量をチューブ式排気ガス浄化装置に供給することが可能となり、チューブ式排気ガス浄化装置の排気ガス浄化性能を効果的に高めることができる。またハニカム式排気ガス浄化装置は排気ガスの昇温を主たる目的とするので小型のもので済み、排気ガスの流通抵抗の増加を最小限に抑えてエンジン出力の低下を防止することができるだけでなく、低グレードの触媒を使用することができるのでコストアップを最小限に抑えることができる。更にハニカム式排気ガス浄化装置およびチューブ式排気ガス浄化装置が一体化されているため、それらを排気通路に取り付ける取付部材の部品点数を最小限に抑えることができる。
【０００８】
また請求項２に記載された発明によれば、請求項１の構成に加えて、前記ハニカム式排気ガス浄化装置の横断面形状を前記チューブ式排気ガス浄化装置の横断面形状に略一致させたことを特徴とするエンジンの排気ガス浄化装置が提案される。
【０００９】
上記構成によれば、ハニカム式排気ガス浄化装置およびチューブ式排気ガス浄化装置の横断面形状が略一致しているので、それらの排気通路の内部への取付けが容易になる。
【００１０】
また請求項３に記載された発明によれば、請求項１の構成に加えて、前記チューブ式排気ガス浄化装置の排気ガス流れ方向の上流端に一体に結合した前側の前記ハニカム式排気ガス浄化装置とは別個に形成された後側のハニカム式排気ガス浄化装置が、該チューブ式排気ガス浄化装置の排気ガス流れ方向の下流端に一体に結合されることを特徴とするエンジンの排気ガス浄化装置が提案される。
【００１１】
上記構成によれば、チューブ式排気ガス浄化装置の上流端に一体に結合した前側のハニカム式排気ガス浄化装置とは別個に形成された後側のハニカム式排気ガス浄化装置が、該チューブ式排気ガス浄化装置の下流端に一体に結合されるので、排気ガスの浄化効果を一層高めることができる。
【００１２】
また請求項４に記載された発明によれば、請求項１又２の構成に加えて、前記チューブ式排気ガス浄化装置の中央後寄りの位置が、排気通路に設けた後部支持手段を介して排気通路の内面に支持されることを特徴とするエンジンの排気ガス浄化装置が提案される。
【００１３】
さらに請求項５に記載された発明によれば、請求項３の構成に加えて、前記チューブ式排気ガス浄化装置の下流端と前記後側のハニカム式排気ガス浄化装置との結合部の近傍が、排気通路に設けた後部支持手段を介して排気通路の内面に支持されることを特徴とするエンジンの排気ガス浄化装置が提案される。
【００１４】
【発明の実施の形態】
以下、本発明の実施形態を、添付図面に示した本発明の実施例に基づいて説明する。
【００１５】
図１〜図４は本発明の第１実施例を示すもので、図１は自動二輪車の全体側面図、図２は自動二輪車の排気通路の要部断面図、図３は図２の３−３線断面図、図４は図２の４−４線断面図である。
【００１６】
図１に示すように、自動二輪車Ｖは、車体フレーム１１の前端に設けたヘッドパイプ１２に左右操向可能に支持したフロントフォーク１３を備えており、そのフロントフォーク１３の上端および下端にバーハンドル１４および前輪Ｗｆが設けられる。また車体フレーム１１にピボット１５を介して上下揺動可能に支持したリヤフォーク１６の後端に後輪Ｗｒが設けられており、その後輪Ｗｒは車体フレーム１１の中央下部に搭載したエンジンＥにより無端チェーン１７を介して駆動される。エンジンＥのシリンダヘッド１８の前面に接続された排気通路１９は後方に屈曲して車体後方に延び、後輪Ｗｒの右側面に配置したマフラー２０に接続される。排気通路１９は、排気ガス流れ方向の上流側に配置されてシリンダヘッド１８に接続された排気管２１と、排気ガス流れ方向の下流側に配置されてマフラー２０に接続された膨張室２２とに分割されており、膨張室２２の上流側部分にチューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４が設けられる。
【００１７】
図２〜図４から明らかなように、膨張室２２は左半体２２ａおよび右半体２２ｂを溶接Ｗ１，Ｗ２により一体化してなり、その内部に収納されるチューブ式排気ガス浄化装置２３は、多数の小孔２５ａ…を有するパンチングメタルを円形断面のチューブ状に形成した担体２５の表面に触媒を担持させたものである。またチューブ式排気ガス浄化装置２３の前端に溶接により結合されたハニカム式排気ガス浄化装置２４は、金属平板に金属波板を溶接したものを円形断面に巻き付けて形成したハニカム構造体２６と、そのハニカム構造体２６の外周を囲む円形断面のケーシング２７とで構成される担体２８を備えており、ハニカム構造体２６の表面およびケーシング２７の内周面に触媒が担持される。
【００１８】
チューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４は同一直径（例えば、３５ｍｍ）の円筒形状であるが、チューブ式排気ガス浄化装置２３の長さ（例えば、２５９ｍｍ）に比べて、ハニカム式排気ガス浄化装置２４の長さは遙に短く（例えば、４０ｍｍ）形成される。尚、ハニカム式排気ガス浄化装置２４の前端は、排気管２１および膨張室２２の接続部の近傍に位置しており、その接続部の内径は例えば５０ｍｍである。
【００１９】
図３から明らかなように、チューブ式排気ガス浄化装置２３の中央後寄りの位置が、後部支持手段２９を介して膨張室２２の内面に支持される。後部支持手段２９は、チューブ式排気ガス浄化装置２３の担体２５の外周に嵌合するインナーパイプ３０と、膨張室２２の内面に溶接Ｗ３，Ｗ３されたステー３１と、２分割されて溶接Ｗ４，Ｗ４により一体化され、その一方がステー３１に溶接Ｗ５，Ｗ５されたアウターパイプ３２，３２と、インナーパイプ３０およびアウターパイプ３２，３２間に配置された耐熱性を有するスチールウール等の弾性材３３とから構成される。
【００２０】
図４から明らかなように、チューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４の結合部の近傍が、前部支持手段３４を介して膨張室２２の内面に支持される。前部支持手段３４の構造は後部支持手段２８のそれと同じであるため、前部支持手段３４の各部材に前記後部支持手段２８の対応する部材と同じ符号を付すことで、重複する説明を省略する。
【００２１】
次に、上記構成を備えた本発明の第１実施例の作用について説明する。
【００２２】
エンジンＥの排気ポートから出た排気ガスは排気管２１、膨張室２２およびマフラー２０を経て外部に排出され、その間に膨張室２２の内部に配置したハニカム式排気ガス浄化装置２４およびチューブ式排気ガス浄化装置２３により有害成分が浄化される。排気ガス流れ方向の上流側に配置された小型のハニカム式排気ガス浄化装置２４は、排気ガスの浄化というよりも排気ガスの昇温を主たる目的としており、そこを通過する排気ガスを担体２８に担持した触媒と反応させて浄化する際の反応熱で、該排気ガスを昇温させる。その結果、ハニカム式排気ガス浄化装置２４に直結された下流側のチューブ式排気ガス浄化装置２３に高温の排気ガスを流入させ、主たる排気ガス浄化装置であるチューブ式排気ガス浄化装置２３を有効に機能させて排気ガスの浄化効果を高めることができる。
【００２３】
以上のように、排気通路１９の膨張室２２に配置したチューブ式排気ガス浄化装置２３の前端に小型のハニカム式排気ガス浄化装置２４を一体に接続したので、排気ポートの直下流にいわゆる直下型の排気ガス浄化装置を設けずとも、ハニカム式排気ガス浄化装置２４の排気ガス昇温効果によりチューブ式排気ガス浄化装置２３を有効に機能させ、排気ガス浄化効果を高めることができる。また直下型の排気ガス浄化装置が不要になり、しかも新たに付加したハニカム式排気ガス浄化装置２４は小型のもので済むため、全体として排気通路１９における排気ガスの流通抵抗を減少させてエンジンＥの出力低下を最小限に抑えることが可能となる。またハニカム式排気ガス浄化装置２４は排気ガスの昇温を主たる目的としているため、その担体２８や触媒に低グレードのものを使用することが可能になってコストダウンに寄与することができる。
【００２４】
更に、ハニカム式排気ガス浄化装置２４は、そこに流入した排気ガスの全量をチューブ式排気ガス浄化装置２３に供給することができるので、ハニカム式排気ガス浄化装置２４で昇温した高温の排気ガスをチューブ式排気ガス浄化装置２３に効率的に供給して排気ガス浄化性能を高めることができる。また何れも円筒状に形成されたチューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４は同一直径を有して同軸かつ一体に結合されているため、両排気ガス浄化装置２３，２４を共通の支持手段２９，３４で支持することが可能になって部品点数の削減に寄与することができるだけでなく、膨張室２２の内部における配置も容易になる。
【００２５】
次に、図５および表１、表２に基づいて第１参考例および第２参考例を説明する。
【００２６】
第１、第２参考例は、排気通路１９の膨張室２２の排気ガス流れ方向の上流側にチューブ式排気ガス浄化装置２３を配置し、その下流側に離間してハニカム式排気ガス浄化装置２４を配置したものである。チューブ式排気ガス浄化装置２３は第１実施例と同じ後部支持手段２９および前部支持手段３４を介して膨張室２２の内面に支持されており、またハニカム式排気ガス浄化装置２４は膨張室２２の後部に設けた多数の通孔３５ａ…を有する隔壁３５の中央部を貫通するように支持される。
【００２７】
【表１】

【００２８】
【表２】

【００２９】
表１には第１参考例のチューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４の諸元が示され、表２には第２参考例のチューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４の諸元が示される。尚、表２に示す第２参考例は、チューブ式排気ガス浄化装置２３を内外に配置した２重構造の担体２５を備えたものである。
【００３０】
表１の第１参考例では、チューブ式排気ガス浄化装置２３の触媒担持面の面積ＳｔがＳｔ＝４２３ｃｍ²であり、ハニカム式排気ガス浄化装置２４の触媒担持面の面積ＳｈがＳｈ＝１８６５ｃｍ²であり、面積Ｓｔを面積Ｓｈで除した値Ｓｔ／ＳｈはＳｔ／Ｓｈ＝０．２３となる。
【００３１】
表２の第２参考例では、チューブ式排気ガス浄化装置２３の触媒担持面の総面積ＳｔがＳｔ＝４９０ｃｍ²であり、ハニカム式排気ガス浄化装置２４の触媒担持面の面積ＳｈがＳｈ＝１８６５ｃｍ²であり、面積Ｓｔを面積Ｓｈで除した値Ｓｔ／ＳｈはＳｔ／Ｓｈ＝０．２６となる。
【００３２】
このように、比Ｓｔ／Ｓｈが０．２以上の場合は、ハニカム式排気ガス浄化装置２４が必要以上に温度上昇することを防止しながら排気ガスの浄化性能を確保することができるが、比Ｓｔ／Ｓｈが０．２未満になると、ハニカム式排気ガス浄化装置２４が必要以上に温度上昇する。
【００３３】
一般に、チューブ式排気ガス浄化装置２３は高温に対する耐久性が高いが排気ガスの浄化効果が低く、逆にハニカム式排気ガス浄化装置２４は高温に対する耐久性が低いが排気ガスの浄化効果が高いという特性を有している。従って、仮に高温に対する耐久性が低いハニカム式排気ガス浄化装置２４を上流側に配置すると、排気ガス中の生ガス成分との反応により発生する反応熱でハニカム式排気ガス浄化装置２４が必要以上に温度上昇する可能性がある。
【００３４】
そこで第１参考例および第２参考例では、高温に対する耐久性が高いチューブ式排気ガス浄化装置２３を排気ガス流れ方向の上流側に配置し、排気ガス中の生ガス成分の一部を反応させて該生ガス成分の濃度を低下させることで、下流側に配置したハニカム式排気ガス浄化装置２４における反応熱の発生を抑制して必要以上の温度上昇を未然に防止しながら、その排気ガス浄化性能を有効に発揮させることができる。そしてハニカム式排気ガス浄化装置２４の必要以上の温度上昇を防止するためには、チューブ式排気ガス浄化装置２３の触媒担持面の面積Ｓｔと、ハニカム式排気ガス浄化装置２４の触媒担持面の面積Ｓｈとが、Ｓｔ／Ｓｈ≧０．２の関係を満たすことが必要となる。
【００３５】
次に、図６に基づいて本発明の第２実施例を説明する。
【００３６】
第２実施例は、前述した第１実施例に、前述した第１，第２参考例を組み合わせたものであり、排気通路１９の膨張室２２の上流側部分に、直列に接続された１個のチューブ式排気ガス浄化装置２３および２個のハニカム式排気ガス浄化装置２４，２４が設けられる。チューブ式排気ガス浄化装置２３は、多数の小孔２５ａ…を有するパンチングメタルを円形断面のチューブ状に形成した担体２５の表面に触媒を担持させたものである。またチューブ式排気ガス浄化装置２３の前端および後端に溶接により結合されたハニカム式排気ガス浄化装置２４，２４は、金属平板に金属波板を溶接したものを円形断面に巻き付けて形成したハニカム構造体２６と、そのハニカム構造体２６の外周を囲む円形断面のケーシング２７とで構成される担体２８を備えており、ハニカム構造体２６の表面およびケーシング２７の内周面に触媒が担持される。チューブ式排気ガス浄化装置２３およびハニカム式排気ガス浄化装置２４，２４は同一直径（例えば、３５ｍｍ）の円筒形状であるが、チューブ式排気ガス浄化装置２３の長さ（例えば、２５９ｍｍ）に比べて、ハニカム式排気ガス浄化装置２４，２４の長さは遙に短く（例えば、４０ｍｍ）形成される。
【００３７】
チューブ式排気ガス浄化装置２３および前側のハニカム式排気ガス浄化装置２４の結合部の近傍が前部支持手段３４を介して膨張室２２の内面に支持され、同様にチューブ式排気ガス浄化装置２３および後側のハニカム式排気ガス浄化装置２４の結合部の近傍が後部支持手段２９を介して膨張室２２の内面に支持される。前部支持手段３４および後部支持手段２９の構造は、図３および図４で説明したものと同じである。
【００３８】
本第２実施例は、第１実施例のチューブ式排気ガス浄化装置２３の後端に更に第２のハニカム式排気ガス浄化装置２４を付加したものに相当し、これにより第１実施例の作用効果に加えて、排気ガスの浄化効果を一層高めるという更なる作用効果を達成することができる。
【００３９】
以上、本発明の実施例を詳述したが、本発明はその要旨を逸脱しない範囲で種々の設計変更を行うことが可能である。
【００４０】
例えば、実施例では自動二輪車ＶのエンジンＥを例示したが、本発明は四輪車用のエンジンや他の任意の用途のエンジンに対して適用することができる。またハニカム式排気ガス浄化装置２４の担体２８は、六角形の隔壁を組み合わせた厳密な意味でのハニカム構造である必要はない。
【００４１】
【発明の効果】
以上のように請求項１に記載された発明によれば、ハニカム式排気ガス浄化装置をチューブ式排気ガス浄化装置の排気ガス流れ方向の上流端に一体に結合したので、ハニカム式排気ガス浄化装置における触媒反応で昇温した高温の排気ガスをチューブ式排気ガス浄化装置に供給して排気ガス浄化性能を高めることができる。しかもハニカム式排気ガス浄化装置はハニカム状に形成した担体に触媒を担持した構造であるため、そこを通過して昇温した排気ガスの全量をチューブ式排気ガス浄化装置に供給することが可能となり、チューブ式排気ガス浄化装置の排気ガス浄化性能を効果的に高めることができる。またハニカム式排気ガス浄化装置は排気ガスの昇温を主たる目的とするので小型のもので済み、排気ガスの流通抵抗の増加を最小限に抑えてエンジン出力の低下を防止することができるだけでなく、低グレードの触媒を使用することができるのでコストアップを最小限に抑えることができる。更にハニカム式排気ガス浄化装置およびチューブ式排気ガス浄化装置が一体化されているため、それらを排気通路に取り付ける取付部材の部品点数を最小限に抑えることができる。
【００４２】
また請求項２に記載された発明によれば、ハニカム式排気ガス浄化装置およびチューブ式排気ガス浄化装置の横断面形状が略一致しているので、それらの排気通路の内部への取り付けが容易になる。
【００４３】
また請求項３に記載された発明によれば、チューブ式排気ガス浄化装置の上流端に一体に結合した前側のハニカム式排気ガス浄化装置とは別個に形成された後側のハニカム式排気ガス浄化装置が、該チューブ式排気ガス浄化装置の下流端に一体に結合されるので、前記請求項１の発明の効果に加えて、排気ガスの浄化効果を一層高めることができる。
【図面の簡単な説明】
【図１】本発明の第１実施例に係る自動二輪車の全体側面図
【図２】自動二輪車の排気通路の要部断面図
【図３】図２の３−３線断面図
【図４】図２の４−４線断面図
【図５】第１，第２参考例に係る自動二輪車の排気通路の要部断面図
【図６】本発明の第２実施例に係る自動二輪車の排気通路の要部断面図
【符号の説明】
１９排気通路
２３チューブ式排気ガス浄化装置
２４ハニカム式排気ガス浄化装置
２５担体
２８担体
２９後部支持手段
３４前部支持手段 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas purification device for an engine in which a tube type exhaust gas purification device and a honeycomb type exhaust gas purification device are arranged inside an exhaust passage.
[0002]
[Prior art]
Inside the expansion chamber formed in the exhaust passage of the motorcycle, two tube-type exhaust gas purification devices carrying a catalyst on a carrier in which punching metal is formed in a tube shape are provided upstream and downstream in the exhaust gas flow direction. A two-stage arrangement is known from Japanese Patent Laid-Open No. 10-30432. According to the exhaust gas purification device for an engine, the exhaust gas is heated by the reaction heat of the upstream tube-type exhaust gas purification device, and the high-temperature exhaust gas is supplied to the downstream exhaust gas purification device to purify the exhaust gas. Performance can be increased.
[0003]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional one, the rear end of the upstream tubular exhaust gas purification device formed with a small diameter is loosely fitted to the front end of the downstream tubular exhaust gas purification device formed with a large diameter. In addition, the upstream-side tube-type exhaust gas purification device in which the carrier is formed of punching metal exhausts through the punch hole so that the exhaust gas escapes from the inside to the outside. The entire amount of gas could not be supplied to the downstream tubular exhaust gas purification device.
[0004]
In addition, the honeycomb type exhaust gas purification device in which the catalyst is supported on the carrier formed in the honeycomb shape has higher exhaust gas purification performance than the tube type exhaust gas purification device, while the honeycomb cell plate thickness is thin and the catalyst support layer is thin. Since the thickness is small, it has a characteristic that the heat-resistant temperature is low. Therefore, when the honeycomb type exhaust gas purification device and the tube type exhaust gas purification device are used in combination, it is necessary to exert the maximum exhaust gas purification performance in consideration of the heat resistance temperature of the honeycomb type exhaust gas purification device.
[0005]
The present invention has been made in view of the above circumstances, and in an exhaust gas purification device for an engine in which a honeycomb type exhaust gas purification device and a tube type exhaust gas purification device are arranged in an exhaust passage, the exhaust gas purification performance is improved and the durability is improved. The purpose is to improve.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the invention described in claim 1, exhaust gas purification of an engine in which a tube-type exhaust gas purification device in which a catalyst is supported on a carrier formed in a tube shape is disposed inside an exhaust passage. In the apparatus, a honeycomb type exhaust gas purification device in which a catalyst is supported on a support formed in a honeycomb shape is integrally coupled to the upstream end in the exhaust gas flow direction of the tube type exhaust gas purification device, and in the vicinity of the coupling portion, An engine exhaust gas purifying apparatus characterized in that it is supported on the inner surface of the exhaust passage through support means provided in the exhaust passage is proposed.
[0007]
According to the above configuration, since the honeycomb type exhaust gas purification device is integrally coupled to the upstream end in the exhaust gas flow direction of the tube type exhaust gas purification device, the high temperature exhaust gas whose temperature is increased by the catalytic reaction in the honeycomb type exhaust gas purification device. Gas can be supplied to the tube-type exhaust gas purification device to enhance the exhaust gas purification performance. Moreover, since the honeycomb type exhaust gas purification device has a structure in which a catalyst is supported on a carrier formed in a honeycomb shape, it becomes possible to supply the entire amount of exhaust gas that has passed through and heated to the tube type exhaust gas purification device. The exhaust gas purification performance of the tube-type exhaust gas purification device can be effectively enhanced. In addition, the honeycomb exhaust gas purification device mainly aims at raising the temperature of the exhaust gas, so it can be small, and it can not only prevent an increase in exhaust gas flow resistance but also prevent a decrease in engine output. Since a low grade catalyst can be used, the cost increase can be minimized. Furthermore, since the honeycomb type exhaust gas purification device and the tube type exhaust gas purification device are integrated, it is possible to minimize the number of parts of the mounting member for attaching them to the exhaust passage.
[0008]
According to the invention described in claim 2, in addition to the first aspect, and substantially aligned with the cross-sectional shape of the honeycomb type exhaust gas purification device in the cross sectional shape of the tube type exhaust gas purifying device An exhaust gas purification device for an engine characterized by this is proposed.
[0009]
According to the above configuration, since the cross-sectional shapes of the honeycomb type exhaust gas purification device and the tube type exhaust gas purification device are substantially the same, it is easy to mount them inside the exhaust passage.
[0010]
Further, according to the invention described in claim 3, in addition to the configuration of claim 1, the honeycomb exhaust gas purification on the front side integrally coupled to the upstream end in the exhaust gas flow direction of the tube type exhaust gas purification device. An exhaust gas purification device for an engine, wherein a honeycomb type exhaust gas purification device on the rear side formed separately from the device is integrally coupled to a downstream end of the tube type exhaust gas purification device in an exhaust gas flow direction. A device is proposed.
[0011]
According to the above configuration, the honeycomb exhaust gas purification device on the rear side formed separately from the front honeycomb exhaust gas purification device integrally joined to the upstream end of the tube type exhaust gas purification device has the tube type exhaust gas purification device. Since it is integrally coupled to the downstream end of the gas purification device, the exhaust gas purification effect can be further enhanced.
[0012]
According to the invention described in claim 4, in addition to the structure of claim 1 or 2, the central rear position of the tube type exhaust gas purifying device is provided via the rear support means provided in the exhaust passage. An exhaust gas purifying device for an engine, which is supported on the inner surface of an exhaust passage, is proposed.
[0013]
Further, according to the invention described in claim 5, in addition to the structure of claim 3, the vicinity of the connecting portion between the downstream end of the tube type exhaust gas purification device and the honeycomb type exhaust gas purification device on the rear side is provided. An engine exhaust gas purification device is proposed which is supported on the inner surface of the exhaust passage through a rear support means provided in the exhaust passage.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.
[0015]
1 to 4 show a first embodiment of the present invention. FIG. 1 is an overall side view of a motorcycle, FIG. 2 is a cross-sectional view of an essential part of an exhaust passage of the motorcycle, and FIG. FIG. 4 is a cross-sectional view taken along line 3 and FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.
[0016]
As shown in FIG. 1, the motorcycle V includes a front fork 13 that is supported by a head pipe 12 provided at the front end of a vehicle body frame 11 so as to be steerable left and right, and bar handles at the upper and lower ends of the front fork 13. 14 and a front wheel Wf are provided. A rear wheel Wr is provided at the rear end of the rear fork 16 supported on the vehicle body frame 11 via a pivot 15 so as to be swingable up and down. The rear wheel Wr is endless by an engine E mounted at the center lower part of the vehicle body frame 11. It is driven via the chain 17. An exhaust passage 19 connected to the front surface of the cylinder head 18 of the engine E is bent rearward and extends rearward of the vehicle body, and is connected to a muffler 20 disposed on the right side surface of the rear wheel Wr. The exhaust passage 19 is disposed on the upstream side in the exhaust gas flow direction and connected to the cylinder head 18, and on the downstream side in the exhaust gas flow direction and connected to the muffler 20. A tube-type exhaust gas purification device 23 and a honeycomb-type exhaust gas purification device 24 are provided in the upstream portion of the expansion chamber 22.
[0017]
As is apparent from FIGS. 2 to 4, the expansion chamber 22 is formed by integrating the left half 22a and the right half 22b by welding W1 and W2, and the tube-type exhaust gas purifying device 23 accommodated therein includes A catalyst is supported on the surface of a carrier 25 in which a punching metal having a large number of small holes 25a is formed in a tube shape with a circular cross section. Further, the honeycomb type exhaust gas purification device 24 joined to the front end of the tube type exhaust gas purification device 23 by welding is a honeycomb structure 26 formed by winding a metal flat plate with a metal corrugated plate wound around a circular cross section, A carrier 28 including a casing 27 having a circular cross section surrounding the outer periphery of the honeycomb structure 26 is provided, and a catalyst is supported on the surface of the honeycomb structure 26 and the inner peripheral surface of the casing 27.
[0018]
The tube-type exhaust gas purification device 23 and the honeycomb-type exhaust gas purification device 24 have a cylindrical shape with the same diameter (for example, 35 mm), but the honeycomb type is longer than the length of the tube-type exhaust gas purification device 23 (for example, 259 mm). The length of the exhaust gas purifying device 24 is very short (for example, 40 mm). Note that the front end of the honeycomb type exhaust gas purification device 24 is located in the vicinity of the connection portion between the exhaust pipe 21 and the expansion chamber 22, and the inner diameter of the connection portion is, for example, 50 mm.
[0019]
As is apparent from FIG. 3, the position of the tube-type exhaust gas purification device 23 near the center rear is supported on the inner surface of the expansion chamber 22 via the rear support means 29. The rear support means 29 includes an inner pipe 30 fitted to the outer periphery of the carrier 25 of the tube-type exhaust gas purification device 23, a stay 31 welded to the inner surface of the expansion chamber 22, and welded W3, W3.

Outer pipes

32 and 32, which are integrated by W4 and one of which is welded W5 and W5 to stay 31, and elastic material 33 such as steel wool having heat resistance disposed between inner pipe 30 and

outer pipes

32 and 32. It consists of.
[0020]
As is clear from FIG. 4, the vicinity of the coupling portion of the tube type exhaust gas purification device 23 and the honeycomb type exhaust gas purification device 24 is supported on the inner surface of the expansion chamber 22 via the front support means 34. Since the structure of the front support means 34 is the same as that of the rear support means 28, the same reference numerals as those of the corresponding members of the rear support means 28 are assigned to the respective members of the front support means 34, thereby omitting redundant description. To do.
[0021]
Next, the operation of the first embodiment of the present invention having the above configuration will be described.
[0022]
Exhaust gas emitted from the exhaust port of the engine E is discharged to the outside through the exhaust pipe 21, the expansion chamber 22 and the muffler 20, and the honeycomb type exhaust gas purifying device 24 and the tube type exhaust gas disposed inside the expansion chamber 22 between them. Harmful components are purified by the purification device 23. The small honeycomb type exhaust gas purification device 24 arranged on the upstream side in the exhaust gas flow direction mainly aims at raising the temperature of the exhaust gas rather than purifying the exhaust gas, and the exhaust gas passing therethrough is transferred to the carrier 28. The exhaust gas is heated by the reaction heat when it is purified by reacting with the supported catalyst. As a result, high-temperature exhaust gas is caused to flow into the downstream tube-type exhaust gas purification device 23 directly connected to the honeycomb-type exhaust gas purification device 24, and the tube-type exhaust gas purification device 23, which is the main exhaust gas purification device, is effectively used. The exhaust gas purification effect can be enhanced by functioning.
[0023]
As described above, since the small honeycomb exhaust gas purification device 24 is integrally connected to the front end of the tube type exhaust gas purification device 23 disposed in the expansion chamber 22 of the exhaust passage 19, a so-called direct type is provided immediately downstream of the exhaust port. Even if the exhaust gas purification device is not provided, the tubular exhaust gas purification device 23 can function effectively by the exhaust gas temperature raising effect of the honeycomb type exhaust gas purification device 24, and the exhaust gas purification effect can be enhanced. Further, the direct exhaust gas purifying device is not required, and the newly added honeycomb type exhaust gas purifying device 24 is small, so that the exhaust gas flow resistance in the exhaust passage 19 is reduced as a whole and the engine E is reduced. Can be minimized. Moreover, since the honeycomb type exhaust gas purification device 24 is mainly intended to raise the temperature of the exhaust gas, it is possible to use a low-grade carrier 28 or catalyst, which can contribute to cost reduction.
[0024]
Further, since the honeycomb type exhaust gas purification device 24 can supply the entire amount of exhaust gas flowing into the honeycomb type exhaust gas purification device 23, the high temperature exhaust gas heated by the honeycomb type exhaust gas purification device 24. Can be efficiently supplied to the tube-type exhaust gas purification device 23 to enhance the exhaust gas purification performance. Further, since the tube-type exhaust gas purification device 23 and the honeycomb-type exhaust gas purification device 24, both of which have a cylindrical shape, have the same diameter and are connected coaxially and integrally, the two exhaust

gas purification devices

23, 24 are connected to each other. Not only can it be supported by the common support means 29 and 34, which contributes to a reduction in the number of parts, but also the arrangement inside the expansion chamber 22 is facilitated.
[0025]
Next, a first reference example and a second reference example will be described based on FIG. 5 and Tables 1 and 2.
[0026]
In the first and second reference examples, a tubular exhaust gas purification device 23 is disposed upstream of the expansion chamber 22 in the exhaust passage 19 in the exhaust gas flow direction, and the honeycomb exhaust gas purification device 24 is spaced apart downstream thereof. Is arranged. The tube-type exhaust gas purification device 23 is supported on the inner surface of the expansion chamber 22 via the same rear support means 29 and front support means 34 as in the first embodiment, and the honeycomb type exhaust gas purification device 24 is expanded to the expansion chamber 22. It supports so that the center part of the partition 35 which has many through-holes 35a ... provided in the rear part may be penetrated.
[0027]
[Table 1]

[0028]
[Table 2]

[0029]
In Table 1 specifications of the tube type exhaust gas purification device 23 and the honeycomb-type exhaust gas purifying apparatus 24 of the first reference example is shown, the second reference example shown in Table 2 of the tube type exhaust gas purification device 23 and the honeycomb formula The specifications of the exhaust gas purification device 24 are shown. The second reference example shown in Table 2 includes a double structure carrier 25 in which a tube type exhaust gas purifying device 23 is arranged inside and outside.
[0030]
In the first reference example of Table 1, the area St of the catalyst carrying surface of the tube type exhaust gas purification device 23 is St = 423 cm ² , and the area Sh of the catalyst carrying surface of the honeycomb type exhaust gas purification device 24 is Sh = 1865 cm ^2. The value St / Sh obtained by dividing the area St by the area Sh is St / Sh = 0.23.
[0031]
In the second reference example of Table 2, the total area St of the catalyst support surface of the tube type exhaust gas purification device 23 is St = 490 cm ² , and the area Sh of the catalyst support surface of the honeycomb type exhaust gas purification device 24 is Sh = 1865 cm. ^The value St / Sh obtained by dividing the area St by the area Sh is St / Sh = 0.26.
[0032]
As described above, when the ratio St / Sh is 0.2 or more, the exhaust gas purification device 24 can ensure the exhaust gas purification performance while preventing the temperature from rising more than necessary. When St / Sh becomes less than 0.2, the temperature of the honeycomb type exhaust gas purification device 24 rises more than necessary.
[0033]
In general, the tube-type exhaust gas purification device 23 has high durability against high temperatures, but the exhaust gas purification effect is low. Conversely, the honeycomb type exhaust gas purification device 24 has low durability against high temperatures, but the exhaust gas purification effect is high. It has characteristics. Therefore, if the honeycomb type exhaust gas purification device 24 having low durability against high temperatures is disposed upstream, the honeycomb type exhaust gas purification device 24 is more than necessary due to the reaction heat generated by the reaction with the raw gas component in the exhaust gas. The temperature may rise.
[0034]
Therefore, in the first reference example and the second reference example, the tube-type exhaust gas purifying device 23 having high durability against high temperatures is arranged on the upstream side in the exhaust gas flow direction, and a part of the raw gas component in the exhaust gas is reacted. By reducing the concentration of the raw gas component, the generation of reaction heat is suppressed in the honeycomb type exhaust gas purification device 24 disposed on the downstream side, and an excessive temperature rise is prevented before the exhaust gas purification. The performance can be exhibited effectively. And in order to prevent the temperature rise more than necessary of the honeycomb type exhaust gas purification device 24, the area St of the catalyst carrying surface of the tube type exhaust gas purification device 23 and the area of the catalyst carrying surface of the honeycomb type exhaust gas purification device 24 It is necessary for Sh to satisfy the relationship of St / Sh ≧ 0.2.
[0035]
Next, a second embodiment of the present invention will be described with reference to FIG.
[0036]
The second embodiment is a combination of the first embodiment described above and the first and second reference examples described above, and one piece connected in series to the upstream portion of the expansion chamber 22 of the exhaust passage 19. Tube type exhaust gas purification device 23 and two honeycomb type exhaust

gas purification devices

24, 24 are provided. The tube-type exhaust gas purifying device 23 has a catalyst supported on the surface of a carrier 25 in which a punching metal having a large number of small holes 25a is formed in a tube shape with a circular cross section. Further, the honeycomb type exhaust

gas purification devices

24, 24 connected to the front end and the rear end of the tube type exhaust gas purification device 23 by welding are formed by winding a metal flat plate with a metal corrugated plate wound around a circular cross section. A carrier 28 comprising a body 26 and a casing 27 having a circular cross section surrounding the outer periphery of the honeycomb structure 26 is provided, and a catalyst is supported on the surface of the honeycomb structure 26 and the inner peripheral surface of the casing 27. The tube-type exhaust gas purification device 23 and the honeycomb-type exhaust

gas purification devices

24, 24 have a cylindrical shape with the same diameter (for example, 35 mm), but are longer than the length of the tube-type exhaust gas purification device 23 (for example, 259 mm). The lengths of the honeycomb type exhaust

gas purification devices

24, 24 are very short (for example, 40 mm).
[0037]
The vicinity of the coupling portion of the tube-type exhaust gas purification device 23 and the front-side honeycomb-type exhaust gas purification device 24 is supported on the inner surface of the expansion chamber 22 via the front support means 34. Similarly, the tube-type exhaust gas purification device 23 and The vicinity of the coupling portion of the honeycomb type exhaust gas purification device 24 on the rear side is supported on the inner surface of the expansion chamber 22 via the rear support means 29. The structures of the front support means 34 and the rear support means 29 are the same as those described with reference to FIGS.
[0038]
The second embodiment corresponds to a structure in which a second honeycomb exhaust gas purification device 24 is further added to the rear end of the tube type exhaust gas purification device 23 of the first embodiment, and thereby the operation of the first embodiment. In addition to the effect, it is possible to achieve a further effect of further enhancing the exhaust gas purification effect .
[0039]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0040]
For example, in the embodiment, the engine E of the motorcycle V is illustrated, but the present invention can be applied to an engine for a four-wheeled vehicle or an engine for any other purpose. Further, the carrier 28 of the honeycomb type exhaust gas purification device 24 does not need to have a strict honeycomb structure in which hexagonal partition walls are combined.
[0041]
【The invention's effect】
As described above, according to the first aspect of the present invention, the honeycomb type exhaust gas purification device is integrally coupled to the upstream end of the tube type exhaust gas purification device in the exhaust gas flow direction. Exhaust gas purification performance can be improved by supplying the high-temperature exhaust gas heated by the catalytic reaction to the tube-type exhaust gas purification device. Moreover, since the honeycomb type exhaust gas purification device has a structure in which a catalyst is supported on a carrier formed in a honeycomb shape, it is possible to supply the entire amount of exhaust gas that has passed through the catalyst and heated up to the tube type exhaust gas purification device. The exhaust gas purification performance of the tube-type exhaust gas purification device can be effectively enhanced. In addition, the honeycomb exhaust gas purification device mainly aims at raising the temperature of the exhaust gas, so it can be small, and it can not only prevent an increase in exhaust gas flow resistance but also prevent a decrease in engine output. Since a low grade catalyst can be used, the cost increase can be minimized. Furthermore, since the honeycomb type exhaust gas purification device and the tube type exhaust gas purification device are integrated, the number of parts of the mounting member for attaching them to the exhaust passage can be minimized.
[0042]
Further, according to the invention described in claim 2, since the cross-sectional shapes of the honeycomb type exhaust gas purification device and the tube type exhaust gas purification device are substantially the same, it is easy to attach them inside the exhaust passage. Become.
[0043]
According to the third aspect of the present invention, the rear-side honeycomb exhaust gas purification device formed separately from the front-side honeycomb exhaust gas purification device integrally coupled to the upstream end of the tube-type exhaust gas purification device. Since the device is integrally coupled to the downstream end of the tubular exhaust gas purification device, the exhaust gas purification effect can be further enhanced in addition to the effect of the first aspect of the invention.
[Brief description of the drawings]
FIG. 1 is an overall side view of a motorcycle according to a first embodiment of the present invention . FIG. 2 is a cross-sectional view of an essential part of an exhaust passage of the motorcycle. sectional view taken along line 4-4 of FIG. 2 and FIG. 5 first exhaust passage of a motorcycle according to a second embodiment of the cross section of a main portion of the exhaust passage of the motorcycle [6] the present invention according to a second reference example Cross-sectional view of the main part 【Explanation of symbols】
19 Exhaust passage 23 Tube type exhaust gas purification device 24 Honeycomb type exhaust gas purification device 25 Carrier 28 Carrier
29 rear support means
34 front support means

Claims

In an engine exhaust gas purification device in which a tube type exhaust gas purification device (23) having a catalyst supported on a carrier (25) formed in a tube shape is disposed inside an exhaust passage (19),
A honeycomb type exhaust gas purification device (24) having a catalyst supported on a honeycomb-shaped carrier (28) is integrally coupled to the upstream end of the tube type exhaust gas purification device (23) in the exhaust gas flow direction. An exhaust gas purifying apparatus for an engine, characterized in that the vicinity of the coupling portion is supported on the inner surface of the exhaust passage (19) through support means (34) provided in the exhaust passage (19) .

2. The engine exhaust gas according to claim 1, wherein a cross-sectional shape of the honeycomb-type exhaust gas purification device (24) is substantially matched with a cross-sectional shape of the tube-type exhaust gas purification device (23). Purification equipment.

Rear honeycomb exhaust gas purification formed separately from the front honeycomb exhaust gas purification device (24) integrally coupled to the upstream end in the exhaust gas flow direction of the tube exhaust gas purification device (23). The exhaust gas purification device for an engine according to claim 1 , wherein the device (24) is integrally coupled to a downstream end of the tubular exhaust gas purification device (23) in the exhaust gas flow direction .

The central rear position of the tubular exhaust gas purification device (23) is supported on the inner surface of the exhaust passage (19) via the rear support means (29) provided in the exhaust passage (19). The engine exhaust gas purification device according to claim 1 or 2.

A rear support means (29) provided in the exhaust passage (19) is provided in the vicinity of the connecting portion between the downstream end of the tubular exhaust gas purification device (23) and the rear honeycomb exhaust gas purification device (24). The exhaust gas purification device for an engine according to claim 3, wherein the exhaust gas purification device is supported by an inner surface of the exhaust passage (19) through the exhaust passage.