| 摘要 |
PURPOSE:To make the titled controller irresponsive to variation of air-fuel ratio due to distribution between cylinders, when controlling to random air-fuel ratio through a linear air-fuel ratio sensor for producing an output approximately proportional to the engine air-fuel ratio, by providing a band insensitive to an air-fuel ratio error signal. CONSTITUTION:An air-fuel ratio controller will obtain an error Ie between target air-fuel ratio Ii and actual air-fuel ratio Iphi in an error amplifier ERI then an output proportional to said error Ie and an output produced through time integration of said error Ie are added in an adder/amplifier SUM. Thereafter its output is converted by a pulse width operator Gr into pulse width and applied onto a solenoid e valve Gf to feed fuel Qf through said solenoid valve Gf to an engine GE. Here, an operational amplifier GS having such characteristic as to produce a proportional output for an error input Ie higher than predetermined level but not produce an output for lower level error input Ie is provided in the prestage of a proportional amplifier GP for producing an output proportional to said error Ie. |
