Air-fuel ratio control device for internal combustion engine

Abstract

Abstract PURPOSE:To improve specific fuel consumption without damaging drive feeling and drivability, by a method wherein, by setting a value of a target air-fuel ratio in a lean region at each gear position, an air-fuel ratio is switched to an optimum target value responding to the gear position. CONSTITUTION:A runnings state detecting means (a), detecting the running state of an engine, and a gear position detecting means (b), detecting the gear position of a transmission, are provided, and output signals therefrom are inputted to a target set means (c). In the target set means (c), a target air-fuel ratio is set according to an engine load. At least at a part of a constant running time, the target air-fuel ratio is selected at a value on the lean side from the theoretical air-fuel ratio, and the value of the target air-fuel ratio in a lean region is decided according to a gear position. A control means (e), controlling an intake air amount or an amount of fed fuel, is driven and controlled by means of a control means (d) so that an air-fuel ratio is adjusted to a decided target value.

Inventors

• 👤 Masaaki Uchida
• 👤 正明 内田
• 👤 Hiromichi Miwa
• 👤 博通 三輪
• 👤 Hatsuo Nagaishi
• 👤 初雄 永石
• 👤 Hiroshi Miwakeichi
• 👤 三分一　寛

Bibliographic Details