| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem such as generation of misfire by executing combustion wherein a rate of inert gas supplied in a combustion chamber is much more than a rate of inert gas in which a soot generating rate peaks and the soot is hardly generated, and inhibiting combustion wherein the soot is hardly generated when a period rotating speed is not less than prescribed rotating speed. SOLUTION: In a diesel engine 1, a part of exhaust gas is returned to an intake side for recirculation through an EGR passage 29 in order to suppressing the generation of NOx, a combustion temperature falls down in a combustion chamber with increase in an EGR gas rate, and a generating rate of NOx is reduced in association with reduction of the temperature. When an EGR rate exceeds some limit, a rate of smoke is rapidly increased. The EGR gas rate is further increased after the rate of smoke exceeds a peak level a condition becomes an operating condition in which soot is hardly generated. When period rotating speed exceeds not less than prescribed rotating speed during performing a combustion operation in a low temperature, the combustion operation is inhibited. It is thus possible to solve such a failure that a combustion condition is deteriorated and misfire is generated. |
