| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine capable of improving exhaust gas characteristics in wide operation range by effectively using function of a secondary air supply device. <P>SOLUTION: The secondary air supply device 40 has a function selectively supplying air taken from outside of an engine to each exhaust port and and downstream of three-way catalyst in a exhaust pipe 33 as secondary air. An ECU of the engine 1 drives an air pump 41 when the three-way catalyst provided in the exhaust pipe 33 is overheated. Secondary air is supplied to downstream of the three-way catalyst by controlling a three way valve 46 to connect a pump passage 43 and a catalyst downstream side passage 45 and shut off an exhaust port side passage 44 and both passage 43, 45. <P>COPYRIGHT: (C)2004,JPO |
