Air-fuel ratio controlling apparatus

Abstract

Abstract PURPOSE:To enable to control the air-fuel ratio without delay even when abrupt change in the conditions of engine operation is caused, by controlling the air-fuel ratio to an optimum value by correcting the injection quantity of fuel according to a correction value obtained from the deviation between the actual temperature of exhaust gas and a target temperature of the same. CONSTITUTION:In operation of an engine, judgement is made by a control circuit 20 whether the engine load represented by the ratio Q/N of the output signals of a sensor 11 for detecting the quantity of intake air and an engine-speed sensor 11 is higher than a prescribed value. In case of YES, a correction value K2 depending on the temperature of exhaust gas is calculated. That is, the target temperature of exhaust gas is calculated from the engine speed N, and a correction factor K2i is searched from a predetermined table on the basis of the deviation between the aimed temperature of exhaust gas and the data representing the actual temperature 5 of exhaust gas. A new correction value K2 is obtained by adding or subtracting the correction factor K2i to and from the previous correction value K2, and the base injection quantity of fuel determined according to the conditions of engine operation is corrected by the new correction value K2.

Inventors

• 👤 Katsuhiko Nakabayashi
• 👤 中林　勝彦
• 👤 Shigehiko Tajima
• 👤 薫彦 田島
• 👤 Hiroshi Tamura
• 👤 浩 田村

Bibliographic Details