| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a high compression ratio by sufficiently raising compression-end pressure in transition drive at a low load, and to improve exhaust emission. <P>SOLUTION: An engine 10 includes a supercharger 32, a VVT 38 which variably sets a phase of an intake valve 28, and a variable valve mechanism 40 which variably sets an operation angle and a lift amount of the intake valve 28. An ECU 50 calculates a valve-closing time of the intake valve 28 at which the compression-end pressure in a cylinder becomes maximum as the most suitable valve-closing time on the basis of at least the number of revolutions the engine and the operation angle and the valve-closing time of the intake valve 28, and then performs control so that an actual valve-closing time becomes the most suitable valve-closing time at the transition operation by using the VVT 38 at the low load. By this arrangement, the compression-end pressure and the effective compression ratio can be raised as much as possible without reducing the operation angle and the lift amount of the intake valve 28, and THC in exhaust gas can effectively be reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
