Air-fuel ratio controller

Abstract

Abstract PURPOSE: To improve the purification effect at deceleration of an engine by fixing the last idling duty ratio which is stored and determined from the signal of a throttle valve and a negative pressure signal applied to a system used for controlling an air- fuel ratio on the basis of an O 2 sensor. CONSTITUTION: Main- and slow-air bleeds 6, 11 of a carburetor 1 are communicated with air corrective passages 7, 12, respectively each end of which is equipped with a solenoid valve 13, 14. The solenoid valves 13, 14 are feedback-controlled by a control circuit 18 to which the signal of an O 2 sensor 17 attached to the upper wall of an exhaust pipe 16 is put. The signals of an opening detector 25 for a throttle valve 8 and of a negative pressure detector 24 for a suction pipe 23 are sent to the circuit 18 via a holding circuit 28. At deceleration of an engine, the duty ratio required by the last idling opening is settled by the circuit 28. The suitable air-fuel ratio is determined by the ratio so that fuel is prevented from being enriched. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Makoto Yomo
• 👤 Hisashi Osano
• 👤 Takuro Morozumi

Bibliographic Details