초록 ▼

A method and system for controlling the amount of secondary air introduced into a vehicle's exhaust gases in order to maintain a desired catalyst air/fuel ratio for a predetermined engine air/fuel ratio. First, a quantity of primary air flow necessary to maintain the predetermined engine air/fuel ra

A method and system for controlling the amount of secondary air introduced into a vehicle's exhaust gases in order to maintain a desired catalyst air/fuel ratio for a predetermined engine air/fuel ratio. First, a quantity of primary air flow necessary to maintain the predetermined engine air/fuel ratio is determined. Next, a quantity of secondary air flow necessary to maintain the desired catalyst air/fuel ratio is determined. Finally, a controller controls the amount of secondary air introduced into the vehicle's exhaust gases based on the determined quantity of secondary air flow.

대표청구항 ▼

[ What is claimed is:] [1.] For use with vehicle having an internal combustion engine which emits exhaust gasses, an intake manifold for providing primary air flow, an air pump driven directly from the engine to provide a secondary air flow, and a catalytic converter for treating the exhaust gases,

[ What is claimed is:] [1.] For use with vehicle having an internal combustion engine which emits exhaust gasses, an intake manifold for providing primary air flow, an air pump driven directly from the engine to provide a secondary air flow, and a catalytic converter for treating the exhaust gases, a method for controlling the quanity of secondary air provided by the air pump so as to maintain a desired catalyst air/fuel ratio independently of the driving condition of the vehicle, the method comprising:sensing an oxygen content of the untreated exhaust gas and generating a corresponding oxygen content signal;determining a quantity of primary air/flow necessary to obtain a desired air/fuel ratio for the engine based on the oxygen content signal;controlling the primary air flow provided by the intake manifold based on the desired air/fuel ratio for the engine;determining a quantity of secondary air flow necessary to maintain the desired catalyst air/fuel ratio based on the determined quantity of primary air/flow; andactivating a control valve disposed between the air pump and the catalytic converter to control the quantity of secondary air provided by the air pump based on the determined quantity of secondary air.