| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an engine control device which restrains increase of exhaust gas pressure loss due to existence of an exhaust upstream catalyst to the minimum. <P>SOLUTION: Since one exhaust valve 1G is opened and closed and another exhaust valve 1H is kept under a valve close condition under a specific operation condition up to middle speed middle load before completion of engine warming up or a specific operation condition of low speed light load after completion of warming up that requires exhaust emission control by the exhaust upstream catalyst 3, whole quantity of exhaust gas is introduced to the exhaust gas upstream catalyst 3 from one exhaust port 1E and whole hydrocarbon in exhaust gas is effectively converted. At that time, since a compressor charges intake air to the engine by operation of a motor generator of a turbocharger, necessary supercharge pressure is secured. Since another exhaust valve 1H is kept under the close condition only under the specific operation condition of the engine and another exhaust valve 1H is opened and closed under normal operation condition, increase of exhaust gas pressure loss caused by existence of the exhaust gas upstream catalyst 3 is restrained to the minimum. <P>COPYRIGHT: (C)2008,JPO&INPIT |
