US 6,602,165 B2Granted

Control system for direct injection spark ignition internal combustion engine

AssigneeHonda Giken Kogyo Kabushiki Kaisha

InventorsKen Ogawa, Yasunori Ehara

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Abstract

A control system for a direct injection spark ignition engine connected to an automatic transmission that modifies engine power in accordance with a selected one of shift programs (a normal mode for improved fuel economy and a power mode for improved performance). A torque required by the engine is determined based on the detected engine speed and the engine load in accordance with characteristics corresponding to the selected shift program. And, an engine operation mode is determined to one of three modes including a stoichiometric air/fuel ratio operation mode in which a desired air/fuel ratio is set to a stoichiometric air/fuel ratio and two lean-bum operations mode in which the desired air/fuel ratio is set to be leaner than the stoichiometric air/fuel ratio. The desired air/fuel ratio is used to correct the fuel injection amount to be supplied to the engine. With this, it becomes possible to produce the acceleration as expected by the vehicle operator throughout the operating conditions with less degradation of fuel economy, when the shift program is switched to the power mode.

Claims23

Dependent claims

A system for controlling an internal combustion engine in which gasoline fuel is directly injected into cylinder combustion chambers and is ignited by a spark plug, and an automatic transmission connected to the engine to modify engine power in accordance with a selected one of shift programs, comprising:

engine operating condition detecting means for detecting operating conditions of the engine including at least an engine speed and an engine load;
required torque determining means for determining a torque required by the engine based on the detected engine speed and the engine load in accordance with ones, of characteristics predetermined separately for the shift programs, that are corresponding to the selected shift program;
operation mode determining means for determining an operation mode of the engine to one of at least three operation modes comprising a stoichiometric air/fuel ratio operation mode in which a desired air/fuel ratio to be supplied to the engine is set to a stoichiometric air/fuel ratio and lean-burn operation modes including at least a pre-mixture combustion operation mode in which the desired air/fuel ratio is set to be leaner than the stoichiometric air/fuel ratio and a stratified combustion operation mode in which the desired air/fuel ratio is set to be leaner than that of the pre-mixture combustion operation mode, based on at least the determined required torque;
output fuel injection amount determining means for determining an output fuel injection amount to be supplied to the engine by correcting a basic fuel injection amount, determined based on the detected engine operating conditions, by the set desired air/fuel ratio of the determined operation mode;
and
fuel injector which directly injects fuel into the combustion chamber of the engine determined based on the output fuel injection amount.

3 more elements

A method of controlling an internal combustion engine in which gasoline fuel is directly injected into cylinder combustion chambers and is ignited by a spark plug, and an automatic transmission connected to the engine to modify engine power in accordance with a selected one of shift programs, comprising the steps of:

(a) detecting operating conditions of the engine including at least an engine speed and an engine load;
(b) determining a torque required by the engine based on the detected engine speed and the engine load in accordance with ones, of characteristics predetermined separately for the shift programs, that are corresponding to the selected shift program;
(c) determining an operation mode of the engine to one of at least three operation modes comprising a stoichiometric air/fuel ratio operation mode in which a desired air/fuel ratio to be supplied to the engine is set to a stoichiometric air/fuel ratio and lean-burn operation modes including at least a pre-mixture combustion operation mode in which the desired air/fuel ratio is set to be leaner than the stoichiometric air/fuel ratio and a stratified combustion operation mode in which the desired air/fuel ratio is set to be leaner than that of the pre-mixture combustion operation mode, based on at least the determined required torque;
(d) determining an output fuel injection amount to be supplied to the engine by correcting a basic fuel injection amount, determined based on the detected operating conditions, by the set desired air/fuel ratio of the determined operation mode;
and
(e) injecting fuel into the combustion chamber of the engine determined based on the output fuel injection amount.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/067,239Filed 7 Feb 2002
Priority: JP 2001-0308417 Feb 2001
Published: US 2002/0107107 A18 Aug 2002
Granted: 5 Aug 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification31 codes

F02D 41/3076
According to or using specific or several modes of combustion: with special conditions for selecting a mode of combustion, e.g. for starting, for…
F02D 41/023
In relation with elements of the transmission: in relation with the gear ratio shifting
F02D 41/1475
Characterised by the regulation method: regulating the air fuel ratio at a value other than stoichiometry
B60W 2510/0638
Combustion engines, Gas turbines: engine speed