| 摘要 |
PROBLEM TO BE SOLVED: To supply secondary air to such an extent that oxygen may not be insufficient and improve poisonous emission control performance by providing a first catalyst device and a second catalyst device having catalyst heating means to the exhaust system of an internal combustion engine, and providing a secondary air supply means upstream the first catalyst device. SOLUTION: A first catalyst device 7 is arranged very close to an exhaust manifold 3, hereby, catalytic converter rhodium is heated at the approximately same time when an engine is started, and the temperature of the catalytic converter rhodium is rapidly raised to an operating temperature so that emissions can be effectively trapped at the time of cold starting of an internal combustion engine 1. A second catalyst device 25 is arranged downstream the first catalyst device 7 through an exhaust pipe 9, and secondary air supply means 200 is arranged between the first and second catalyst devices. Therefore, a secondary air amount to be flowed upstream from the first catalyst device 25 is controlled to be diminished at the time of cold starting of the internal combustion engine 1, and a great deal of the secondary air amount is controlled to be flowed after emission temperature detected by an emission temperature sensor reaches a predetermined temperature. |
