Excess air factor control device for internal combustion engine

摘要

A basic target excess air factor tLAMBDAO and a target fresh air intake amount tQac are set base upon the operation condition of an engine (30). A target excess air factor tLAMBDA is calculated by multiplying the ratio of a real fresh air intake amount rQac as detected by a sensor (16) and the target fresh air intake amount tQac by the basic target excess air factor tLAMBDAO. A fuel injector (9) is controlled so that the amount of fuel injected thereby converges to a target fuel injection amount tQf which corresponds to the target excess air factor tLAMBDA. It is possible to prevent variation of the output torque of the engine (30) accompanying a rich spike by this control, even if the basic target excess air factor tLAMBDAO varies abruptly, since the fuel injection amount varies in correspondence to the variation of the real fresh air intake amount rQac.