EXHAUST DEVICE OF MULTI-CYLINDER ENGINE

• Main Authors: KATO JIRO, SUMI SHINJI, MURATA NORIHISA, KOGA TATSUYA
• Format: Patent
• Language: English; Japanese
• Published: 23.06.2016
• Subjects: BLASTING; COMBUSTION ENGINES; COMBUSTION ENGINES IN GENERAL; CONTROLLING COMBUSTION ENGINES; 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; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INTERNAL-COMBUSTION PISTON ENGINES; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To suppress the lowering of a scavenging effect in a dynamic pressure exhaust system while securing the favorable vehicle mountability of the exhaust system.SOLUTION: An exhaust device which is arranged so as to extend rearward from a multi-cylinder engine comprises: a plurality of independent exhaust pipes which are arranged at respective cylinders in order from an upstream side in a flow direction of an exhaust gas, whose upstream ends are connected to exhaust ports of the cylinders, and whose downstream ends are bundled; a single exhaust pipe connected to the downstream ends of the independent exhaust pipes; and a catalyst device which is connected to a downstream end of the single exhaust pipe, and purifies the exhaust gas which is derived from the single exhaust pipe. The single exhaust pipe includes: a throttle part whose flow passage area becomes smaller as it goes toward a downstream side; an aggregated pipe which is connected to a downstream end of the throttle part, and has a straight part which linearly extends while maintaining an inside diameter of the throttle part; and a loop pipe which is connected to a downstream end of the aggregated pipe, and bent into a loop shape. An inside diameter of an upstream end of the loop pipe is expanded larger than an inside diameter of the straight part.SELECTED DRAWING: Figure 3 【課題】排気装置の良好な車両搭載性を確保しつつ、動圧排気系における掃気効果の低下を抑制すること。【解決手段】多気筒エンジンから後方へ延びるように配置された排気装置であって、排気ガスの流れ方向における上流側から順に、気筒毎に設けられるとともに上流端部が気筒の排気ポートに接続され下流端部が束ねられた複数の独立排気管と、独立排気管の下流端部に接続された単一排気管と、単一排気管の下流端部に接続され、単一排気管から導出された排気ガスを浄化する触媒装置とを備え、単一排気管は、下流側ほど流路面積が小さくなる絞り部および絞り部の下流端部に接続されるとともに絞り部の内径を維持しつつ直線状に延びるストレート部を有する集合管と、集合管の下流端部に接続されてループ状に屈曲したループ管とを含み、ループ管の上流端部の内径は、ストレート部の内径に対して拡径されている。【選択図】図３