Spark ignition engine and method of controlling combustion of the engine

A spark ignition engine, comprising:

• turbulence generating means for generating turbulence in an exhaust flow in an exhaust passage;
• a fuel injection valve for directly injecting fuel into a combustion chamber;
• and
• fuel injection control means for controlling fuel injection timing by the fuel injection valve, wherein:
• the fuel injection control means instructs the fuel injection valve to inject fuel at an expansion stroke in the case where the temperature of the engine is lower than the predetermined temperature.

A spark ignition engine, comprising:

• ignition timing control means for controlling ignition timing by an ignition plug;
• a fuel injection valve for directly injecting fuel into a combustion chamber;
• and
• fuel injection control means for controlling fuel injection timing by the fuel injection valve, wherein:
• the penetration of fuel spray injected from the fuel injection valve in the direction of an ignition plug is made longer than that in the direction of a piston;
• in the case where the temperature of the engine is lower than the predetermined temperature, the fuel injection control means instructs the fuel injection valve to inject fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• and
• the ignition timing control means makes ignition timing immediately before a compression stroke top dead center or later.

A spark ignition engine, comprising:

• ignition timing control means for controlling ignition timing by an ignition plug;
• a fuel injection valve for directly injecting fuel into a combustion chamber;
• fuel injection control means for controlling fuel injection timing by the fuel injection valve;
• and
• longitudinal vortex generating means for generating a forward longitudinal vortex in a combustion chamber, wherein:
• in the case where the temperature of the engine is lower than the predetermined temperature, the longitudinal vortex generating means generates a forward longitudinal vortex in the combustion chamber;
• the fuel injection control means instructs the fuel injection valve to inject fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• and
• the ignition timing control means makes ignition timing immediately before a compression stroke top dead center or later.

A spark ignition engine, comprising:

• ignition timing control means for controlling ignition timing by an ignition plug;
• a fuel injection valve for directly injecting fuel into a combustion chamber;
• fuel injection control means for controlling fuel injection timing by the fuel injection valve;
• and
• longitudinal vortex generating means for generating a forward longitudinal vortex in the combustion chamber, wherein:
• the penetration of fuel spray injected from the fuel injection valve in the direction of an ignition plug is made longer than that in the direction of a piston;
• in the case where the temperature of the engine is lower than the predetermined temperature, the longitudinal vortex generating means generates a forward longitudinal vortex in the combustion chamber;
• the fuel injection control means instructs the fuel injection valve to inject fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• and
• the ignition timing control means makes ignition timing immediately before a compression stroke top dead center or later.

A spark ignition engine, comprising:

• ignition timing control means for controlling ignition timing by an ignition plug;
• a fuel injection valve for directly injecting fuel into a combustion chamber;
• fuel injection control means for controlling fuel injection timing by the fuel injection valve;
• fuel pressure controlling means for controlling the pressure of fuel supplied to the fuel injection valve;
• and
• fluctuation detecting means for detecting the magnitude of the fluctuation of engine speed or torque fluctuation, wherein:
• in the case where the temperature of the engine is lower than the predetermined temperature, the fuel injection control means instructs the fuel injection valve to inject fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• the fuel pressure controlling means controls fuel pressure so that the magnitude of the fluctuation of engine speed or torque fluctuation is a predetermined value or less;
• and
• the ignition timing control means delays ignition timing to the extent possible.

A combustion control method of a spark ignition engine, which generates turbulence in an exhaust flow in an exhaust passage;

• and
• injects fuel directly into a combustion chamber;
• and
• in the case where the temperature of the engine is lower than the predetermined temperature, inject fuel in an expansion stroke.

A combustion control method of a spark ignition engine, which makes penetration of injected fuel spray in the direction of an ignition plug longer than that in the direction of a piston;

• and
• in the case where the temperature of the engine is lower than the predetermined temperature, injects fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• and
• makes ignition timing immediately before a compression stroke top dead center or later.

A combustion control method of a spark ignition engine, which:

• in the case where the temperature of the engine is lower than the predetermined temperature, generates a forward longitudinal vortex in a combustion chamber;
• injects fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• and
• makes ignition timing immediately before a compression stroke top dead center or later.

A combustion control method of a spark ignition engine, which makes penetration of injected fuel spray in the direction of an ignition plug longer than that in the direction of a piston;

• in the case where the temperature of the engine is lower than the predetermined temperature, generates a forward longitudinal vortex in a combustion chamber;
• injects fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• and
• makes ignition timing immediately before or later a compression stroke top dead center.

A combustion control method of a spark ignition engine, which:

• in the case where the temperature of the engine is lower than the predetermined temperature, injects fuel in the second half of a compression stroke so that the air-fuel ratio is in the vicinity of the theoretical air-fuel ratio;
• regulates the injection pressure of fuel so that the magnitude of the fluctuation of engine speed or torque fluctuation is a predetermined value or less;
• and
• delays ignition timing to the extent possible.