VARIABLE EXHAUST NOISE STRUCTURE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a variable exhaust noise structure for an engine capable of continuously varying engine exhaust noise with simple operation and capable of preventing lowering of output of the engine. SOLUTION: An end cap 4 forming an atmosphere opening port 3 is fitted onto a tail end of a muffler body 2. An adjusting shaft 7 having a screw part 5 at a front end and a nut 6 at a rear end is rotatably attached on a central shaft supporting part 8 of the end cap 4. A pair of semicircular vane valves 10 are rotatably supported on a supporting shaft 9 fixed on the end cap 4. The vane valve 10 and a moving piece 11 are linked by a link 12. The vane valve 10 is backwardly tilted around the supporting shaft 9 through the link 12 by operating the nut 6. Thus, an exhaust gas passage area between the vane valves 10 and the atmosphere open port 3 is made variable to vary the exhaust noise.