| 摘要 |
<p>A combustion control apparatus for an engine (1) having a variable valve timing mechanism (13a, 13b) is disclosed which is capable of varying valve timings of an exhaust valve (7) and an intake valve (6), which is adapted to establish a combustion mode to be either one of the following three modes, namely a four-cycle compression ignition combustion mode at a low and medium load area, a two-cycle spark ignition combustion mode at a high load area, and a four-cycle spark ignition combustion mode at a high speed area. Further, the apparatus establishes the valve timings of the exhaust and intake valves (7, 6) so as to form a negative overlap period in which both exhaust and intake valves (7, 6) concurrently close in the neighborhood of the exhaust top dead center (TDC), when the combustion mode is established to be the compression ignition combustion mode and establishes the valve timings of the exhaust and intake valves (7, 6) so as to carry out a gas exchange once per one revolution of the engine (1), when the combustion mode is established to be the two-cycle spark ignition combustion mode. <IMAGE></p> |
