Air fuel ratio control apparatus for internal combustion engines
AssigneeNippondenso Co., Ltd.
InventorJunya Morikawa
Life of this patent
Estimating the term…
Abstract
In a fuel vapor purge mechanism, the fuel vapor generated from a fuel tank and stored in a canister undergoes flow volume control with a purge solenoid valve while being introduced to an intake system of the engine via a purge passageway. Meanwhile, in an air/fuel ratio feedback control system, by means of a linear air/fuel ratio sensor mounted on an exhaust system of the engine, the air/fuel ratio of air-fuel mixture of fuel and intake air including the fuel vapor. If a change amount of a purge ratio the fuel vapor goes above a determined value, there is compensation of the air/fuel ratio compensation coefficient FAF concerned with the feedback control based on the change ratio.
Claims6
An air/fuel ratio control apparatus for internal combustion engines comprising:
- a fuel injection valve for injecting fuel supplied from a fuel tank into an engine;
- a canister storing therein fuel vapor generated in the fuel tank;
- a purge passage for leading the fuel vapor stored in the canister to an air intake portion of the engine;
- a flow control valve disposed in the purge passage for controlling a flow amount of the fuel vapor led through the purge passage in accordance with an intake air amount of the engine;
- an air/fuel ratio sensor disposed in an exhaust portion of the engine for detecting, from an exhaust gas of the engine, an air/fuel ratio of mixture of air and fuel including the fuel vapor supplied to the engine;
- feedback control means for controlling, in accordance with the detected air/fuel ratio, an amount of the fuel injected from the fuel injection valve thereby to control the air/fuel ratio of the mixture to a target value;
- and
- compensation means for compensating, by a change amount of ratio of the flow amount of the fuel vapor relative to the intake air amount, a compensation coefficient used in the feedback control means.
Dependencies are inferred from the claim text.