In-cylinder injection type internal combustion engine

An in-cylinder injection type internal combustion engine for injecting a fuel into a combustion chamber from a fuel injection valve arranged to confront said combustion chamber, comprising:

• operation mode setting means for setting at least a first operation mode for injecting the fuel in a suction stroke while making an air/fuel ratio feedback control performing a stoichiometric air/fuel ratio as a first target air/fuel ratio;
• oxygen concentration detecting means having a first output turning point at which the output changes in said first operation mode in accordance with an oxygen concentration in an exhaust gas between a first output value indicating a rich air/fuel ratio and a second output value indicating a lean air/fuel ratio;
• and
• fuel control means for controlling the fuel to be fed from said fuel injection valve according to said first operation mode and the output of said oxygen concentration detecting means in response to a drive state of said internal combustion engine,
• wherein said operation mode setting means sets a second operation mode for increasing emissions of reduced components and excess oxygen by performing the compression stroke injection at a second target air/fuel ratio leaner than said first target air/fuel ratio, and
• wherein said fuel control means makes a fuel control according to said second operation mode, whereby said oxygen concentration detecting means shifts the first output turning point thereof to a second output turning point at which the output changes on a leaner side than said first output turning point between said first output value and said second output value.

An in-cylinder injection type internal combustion engine for injecting a fuel into a combustion chamber from a fuel injection valve arranged to confront said combustion chamber, comprising:

• air/fuel ratio detecting means disposed in an exhaust passage of said internal combustion engine for detecting an exhaust air/fuel ratio;
• and
• operation mode switching means having a first operation mode for injecting the fuel in a suction stroke while making an air/fuel ratio feedback control performing a stoichiometric air/fuel ratio as a first target air/fuel ratio, and a second operation mode for injecting the fuel in a compression stroke while making an air/fuel ratio control, based on an output of said air/fuel ratio detecting means, to perform a predetermined air/fuel ratio in the vicinity of the stoichiometric air/fuel ratio as a second target air/fuel ratio,
• wherein said operation mode switching means switches the operation mode to said first operation mode when said internal combustion engine is in a medium/high load drive state demanding an improvement in output characteristics, and the operation mode to said second operation mode when said internal combustion engine is in a drive state demanding a temperature rise of the catalyst of an exhaust purifying catalyst.