| 摘要 |
<P>PROBLEM TO BE SOLVED: To properly switch a gas flow passage from a cylinder independent state to a two-cylinder connected state while preventing emission performance from lowering in a transient period of switching. <P>SOLUTION: When an operation mode is switched between a normal operation mode for introducing fresh air to each cylinder and independently burning each cylinder and a special operation mode for burning at the air-fuel ratio of preceding cylinders 2A and 2D which is in a lean air-fuel ratio larger than a theoretical air-fuel ratio while bringing specified cylinders into the two-cylinder connected state in the partial load area of the engine, introducing burned gas of the lean air-fuel ratio from the preceding cylinders 2A and 2D to succeeding cylinders 2B and 2C, and burning the burned gas together with a newly supplied fuel in the succeeding cylinders, the gas flow passage is brought into the two-cylinder connected state and a transient operation mode for stopping combustion in the preceding cylinders 2A and 2D and burning by a compression self-ignition in the succeeding cylinders 2B and 2C is interposed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
