Exhaust System of Engine

摘要

To provide an exhaust system of an engine capable of reducing exhaust noise and improving an output of the engine. An exhaust system of an engine includes an exhaust pipe (61) connected to an exhaust port of an engine (50); and a muffler (62) attached to a downstream end of the exhaust pipe (61) and configured to reduce exhaust noise, the muffler (62) includes an inner cylinder part (71) connected to the downstream end of the exhaust pipe (61), an outer cylinder part (72) configured to cover an outside of the inner cylinder part (61), and noise absorbing materials (91), (92), (93) disposed between the inner cylinder part 61 and the outer cylinder part (72), a plurality of first communication holes (81) providing communication between with an inside and an outside of the inner cylinder part (71) is formed in an upstream portion (71a) of the inner cylinder part (71), a plurality of second communication holes (82) providing communication between the inside and the outside of the inner cylinder part (71) is formed in a downstream portion (71b) of the inner cylinder part (71), and the plurality of first communication holes (81) includes guide walls (85) extending toward the inside of the inner cylinder part (71) and inlet openings (86) formed by the guide walls (85) and opened toward an upstream side of exhaust.