VARIABLE FLUX MUFFLER TYPED SINGLE MUFFLER EXHAUST SYSTEM IN VEHICLE

A variable muffler type single exhaust device for vehicle is provided to suppress exhaust noise by forming the low output exhaust gas discharge path and the high output exhaust gas discharge path at the same time and enhance engine output by regulating the opening and closing of the valve according to the pressure of exhaust gas. A variable muffler type single exhaust device for vehicle comprises an exhaust pipe(1) connected to an exhaust manifold, a catalytic converter(3) mounted on the path of the exhaust pipe, and a variable muffler(5) varying the emission quantity of exhaust gas according to the engine output. The variable muffler comprises a housing body(6) having a leading end partitioning off the internal space into first to third chambers(a,b,c) and front and rear baffles(7,8), and a valve(14) which opens when the back pressure of exhaust gas increases. The variable muffler discharges the exhaust gas through only the third chamber when the inside back pressure of the variable muffler is low, and through the first and second chambers when the inside back pressure of the variable muffler is high.