Patent ID: 7150147

Claim:
An exhaust system comprising: an exhaust passage that allows exhaust gas discharged from an internal combustion engine to pass therethrough; a primary exhaust emission control unit including a catalyst to purify the exhaust gas; a first exhaust heat collecting unit including a thermoelectric element that converts thermal energy of the exhaust gas into electric energy, the exhaust passage being divided into a first passage provided with the primary exhaust emission control unit, and having a first inlet and a first outlet, defining a first flowpath, with an upstream end and a downstream end, and a cut-off valve downstream of the catalyst, and a second passage provided with the first exhaust heat collecting device including the thermoelectric element and having a second inlet and a second outlet, and an outlet door, the second outlet and the outlet door being downstream of the cut-off valve in said first passage; and a controller that controls said cut-off valve, wherein said cut-off valve is responsive to a signal from said controller, wherein in response to said signal from said controller, said cut-off valve either opens to allow exhaust gas to flow through said first passage, or closes to allow exhaust gas to flow through said second passage to said outlet door, said outlet door being closed when said cut-off valve is open, said outlet door being open when said cut-off valve is closed, and wherein said signal to open or shut said cut-off valve is sent based on a temperature in the catalyst.