Apparatus for detecting concentration of vapor fuel in lean-burn internal combustion engine, and applied apparatus thereof

An apparatus for controlling a supply of a vapor fuel in a lean-burn internal combustion engine, comprising:

• a purge passageway for purging, into an intake system, a vapor fuel generated from fuel storing means for storing the fuel of said internal combustion engine;
• purge control means for controlling a quantity of the vapor fuel introduced into said intake system from said purge passageway in accordance with an operating state of said internal combustion engine;
• concentration learning means for detecting the concentration of the vapor fuel purged by said purge control means into said intake system;
• and
• combustion control means for switching over a homogeneous combustion operation and a lean-burn operation in accordance with the operating state of said internal combustion engine, said concentration learning means including:
• learning judging means for judging whether or not the vapor fuel concentration is required to be learned during the lean-burn operation of said internal combustion engine;
• and
• operation switch-over means for switching over said internal combustion engine from the lean-burn operation to the homogeneous combustion operation when said learning judging means judges that the concentration learning is required,
• wherein the concentration of the vapor fuel is learned under the homogeneous combustion operation.

An apparatus for controlling a supply of a vapor fuel in a lean-burn internal combustion engine, comprising:

• a purge passageway for purging, into an intake system, a vapor fuel generated from fuel storing means for storing the fuel of said internal combustion engine;
• purge control means for controlling a quantity of the vapor fuel introduced into said intake system from said purge passageway in accordance with an operating state of said internal combustion engine;
• concentration learning means for detecting the concentration of the vapor fuel purged by said purge control means into said intake system;
• and
• combustion control means for switching over a homogeneous combustion operation and a lean-burn operation in accordance with the operating state of said internal combustion engine,
• wherein said concentration learning means, when switched over to the homogeneous combustion operation from the lean-burn operation in accordance with the operating state, performs the learning of the concentration of the vapor fuel under the homogeneous combustion operation.