Air-fuel ratio controller for internal combustion engine

Abstract

Abstract PURPOSE:To improve the purifying efficiency for exhaust gas by setting the aimed air-fuel ratio to a prescribed wave form having a prescribed cycle and amplitude so that the air-fuel ratio variation in which the purifying efficiency for exhaust gas becomes max. is generated and by controlling the actual air-fuel ratio. CONSTITUTION:A wide range air-fuel ratio sensor 8 installed in the exhaust pipe 7 of an internal combustion engine 1 detects the air-fuel ratio in the range from a rich side to a lean side. A controller 9 feedback-controls an injector 6 installed in a suction pipe 2 so that the actual value detected by the sensor 8 accords with a previously set aimed value. Further, an exhaust gas purifying device 10 is installed in the exhaust pipe 7. In this constitution, the driving pulse width of the injector 6 is varied according to at least one parameter which represents the prescribed cycle, amplitude and the operation state of the internal combustion engine 1, and is controlled so as to satisfy the optimum purifying condition of the exhaust gas purifying device 10.

Inventors

• 👤 Hitoshi Inoue
• 👤 Ryoji Nishiyama
• 👤 Shinichi Nishida
• 👤 Masaya Kominami

Bibliographic Details