Air=fuel ratio controller for catalyser engine vehicle

摘要

A controller for the air/fuel ratio of an opposed-cylinder (boxer) type engine and V-6, V-8 or V-12 engines with separate inlet manifolds for the two cylinder banks, joined below the throttle flap, and separate exhaust pipes (5, 7) from each exhaust manifold passing through primary catalysers (21, 22), before being linked by a collector pipe (8) attached to a secondary catalyser (23). Oxygen sensors (25, 26) are provided in the exhaust pipes between manifold and primary catalyser. One feeds a signals to a discriminator circuit (31) to establish a weak or rich condition and both feed signals to a phase difference detector (33). The discriminator outputs to a circuit (32) setting a correction factor for the air/fuel ratio. The phase difference detector outputs to a balancing circuit (34) for the injectors (11, 12).