To provide a combustion control device for an internal combustion engine capable of expanding an operating range by compressed self-ignition combustion to a high load side and a low load side.
An ECU 1 calculates request load T and engine speed N based on an accelerator opening signal and a crank angle sensor signal. Based on this calculated result, whether a combustion pattern is spark ignition combustion or self-ignition combustion is decided by a combustion pattern deciding part 2. When the combustion pattern is decided as self-ignition combustion, a self- ignition combustion control part 4 selects a first four-stroke cycle operation constituted of intake stroke, compression stroke, expansion stroke and exhaust stroke and a second four-stroke cycle operation which is constituted of intake compression stroke, expansion stroke, compression stroke and expansion exhaust stroke and performs combustion two times during a four-stroke cycle. A cycle switching control part 5 controls a variable valve timing mechanism 19 and realizes intake/exhaust valve timing for the first or second four-stroke cycle.
TANIYAMA TAKESHI
SAKAKIDA AKIHIRO
