Method for interlocking engine exhaust sound with traveling mode and exhaust system for smart vehicle

An exhaust system comprising:

• a muffler for discharging an exhaust gas coming from an engine to a first tail pipe and a second tail pipe to an atmosphere, wherein the first tail pipe and the second tail pipe are connected to the muffler;
• an electronic variable valve provided on the first tail pipe, and forming a valve opening in an internal space of the first tail pipe;
• and
• an exhaust sound change system configured for recognizing one of a SMART DRIVE MODE-ECO state, a SMART DRIVE MODE-COMFORT state, and a SMART DRIVE MODE-SPORT state as a vehicle traveling state in a SMART SHIFT control in a SMART DRIVE MODE, and changing the valve opening of the electronic variable valve according to an accelerator pedal stroke,
• wherein the muffler includes:
• a housing forming an internal space therein;
• a pair of a first baffle and a second baffle for partitioning the internal space of the housing into a first chamber, a second chamber, and a third chamber;
• an inlet tube for introducing the exhaust gas to send a portion of the introduced exhaust gas to the first chamber through a punching hole;
• a 1IN-2OUT Y-shaped tube for sending a portion of branched exhaust gas of remaining introduced exhaust gas coming from the inlet tube to the first tail pipe to form a first exhaust sound tone change section and sending remaining branched exhaust gas to the third chamber to form a third exhaust sound tone change section;
• and
• a second external connection tube for introducing an internal exhaust gas coming from the first chamber to send the internal exhaust gas to the second tail pipe to discharge the internal exhaust gas and sending a portion of the internal exhaust gas through the punching hole to the third chamber to form a second exhaust sound tone change section.