PURPOSE: To provide sufficient stratified combustion at a low speed and reduce inconsistent combustion which is liable to occur in such a case.
CONSTITUTION: In an in-cylinder fuel injection type two-cycle internal combustion engine which has a cylinder head 14 provided with a fuel injection valve 50 and a spark plug 21, a piston 11 has the recessed portion 11a on the top combustion chamber side and the protruded portion 11b protruded to the recessed portion 11a on the combustion chamber side and the spark plug 21 has the electrode portion 21a faced into the recessed portion near the protruded portion, while the fuel injection of a fuel injection valve 50 is directed to the protruded portion 11b and so arranged that fuel directed to the protruded portion 11b can hit on the protruded portion 11b, be reflected and directed to the electrode portion 21a. On the other hand, the opening/closing timing of the fuel infection valve 50 and the sparking timing of the spark plug 21 at a low speed are set near the top dead center of the piston 11 and controlled so that at least a part of fuel directed to the electrode portion 21a can be passed therethrough during discharging of the electrode portion 21a.
SAITO SENJU
NISHIMURA SEIICHI
