Control apparatus for internal combustion engine

Abstract

An engine ECU executes a program including the step of detecting engine start, the step of detecting, when rapid catalyst warm-up is necessary, the temperature of the engine coolant THW, the step of estimating, when the THW is lower than a predetermined threshold value, the amount of fuel sticking to the wall surface of an intake port and calculating a cold-state increase correction value Q (P) for an intake manifold injector, the step of changing the DI ratio r to satisfy the cold-state increase correction value Q (P), and the step of performing the rapid catalyst warm-up.

Description

[0001] This nonprovisional application is based on Japanese Patent Application No. 2005-078285 filed with the Japan Patent Office on Mar. 18, 2005, the entire contents of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a control apparatus for an internal combustion engine including a first fuel injection mechanism (in-cylinder injector) for injecting fuel into a cylinder and a second fuel injection mechanism (intake manifold injector) for injecting fuel into an intake manifold or intake port. In particular, the invention relates to a control apparatus for an internal combustion engine for use in the case where a catalyst for cleaning exhaust gases is rapidly warmed up. [0004] 2. Description of the Background Art [0005] An internal combustion engine is well-known that includes an intake manifold injector for injecting fuel into an engine intake manifold and an in-cylinder injector for inj...

AI Technical Summary

Benefits of technology

[0012] An object of the present invention is to provide a control apparatus for an internal combustion engine having a first fuel injection mechanism for injecting fuel into a cylinder and a second fuel injection mechanism for injecting fuel into an intake manifold, performing, in a favorable manner, rapid warm-up of an exhaust cleaning catalyst at the start of the internal combustion engine while causing no increase in total fuel quantity by considering fuel sticking to the wall surface in a cold state.

Problems solved by technology

Since such a region is not generated, flame is easily propagated and unburned fuel (HC) is unlikely to be generated.

In contrast, since the intake manifold injector injects fuel into the low-temperature intake port, atomization is not in a favorable state.

In other words, some fuel sticks to the wall surface of the intake port, resulting in poor atomization.

Therefore, the total fuel quantity (the sum of the quantity of fuel injected from the in-cylinder injector and the quantity of fuel injected from the intake manifold injector to which the amount of fuel sticking to the wall surface is added) increases to cause deterioration in fuel economy and exhaust components.

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