EXHAUST DEVICE OF ENGINE

• Main Authors: KIYOSUE RYO, HATSUHIRA TSUGIO, UCHIDA KENJI
• Format: Patent
• Language: English; Japanese
• Published: 07.06.2018
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To suppress radiation of exhaust heat in an exhaust passage without significantly increasing costs and manufacturing man-hour.SOLUTION: An exhaust device 20 of an engine body 1 is the exhaust device of an engine including a cylinder 2 for burning air-fuel mixture, and includes an exhaust manifold 21, a catalyst device 22 and a silencer 23, and a common exhaust pipe 30 connecting them, successively arranged in this order from an upstream side of an exhaust gas flow. The common exhaust pipe 30 includes an upstream exhaust pipe 31 connecting the exhaust manifold 21 and the catalyst device 22, and a downstream exhaust pipe 32 connecting the catalyst device 22 and a silencer 23. The upstream exhaust pipe 31 has a structure to reduce exhaust loss caused by escaping of the exhaust heat to the external. In other words, an inner wall surface 31A of the upstream exhaust pipe 31 is a grooved inner wall surface on which a plurality of fine grooves 40 extended in a flowing direction of an exhaust gas, are closely arranged.SELECTED DRAWING: Figure 1 【課題】コスト及び製造工数を大きく増加させることなく、排気通路における排気熱の放熱を抑制する。【解決手段】エンジン本体１の排気装置２０は、燃料と空気との混合気が燃焼する気筒２を備えたエンジンの排気装置であり、排気流の上流側から順に配置された、排気マニホールド２１、触媒装置２２及びサイレンサ２３と、これらを繋ぐ共用排気管３０とを備える。共用排気管３０は、排気マニホールド２１と触媒装置２２との間を繋ぐ上流排気管３１と、触媒装置２２とサイレンサ２３との間を繋ぐ下流排気管３２とを含む。上流排気管３１には、排気熱が外部に逃げることにより発生する排気損失を低減する構造が施与されている。すなわち、上流排気管３１の内壁面３１Ａは、排気の流動方向に延びる複数の微細溝４０が密に配列された溝付き内壁面とされている。【選択図】図１