Patent ID: 6755279
Filing Date: 2004-06-29
Classification: F01N

Abstract:
A controllable muffler system for use with an engine that produces a power by burning fuel, comprising:a first passage section extending from said engine for having an exhaust gas of the engine flow therethrough, said first passage section having a catalytic converter mounted thereon; a dual passage section including second and third passage sections which extend separately from an end of said first passage section, said second passage having a control valve for controlling the flow rate of the exhaust gas flowing therethrough; a fourth passage section extending from respective ends of said second and third passage sections to the open air, said fourth passage section having a rear muffler mounted thereon; and a control unit which controls said control valve of the second passage section in accordance with an operation condition of the engine, wherein the dual passage section is arranged downstream of the first passage in a direction of flow of the exhaust gas.