PURPOSE: To improve the mixture of fuel and air in the main combustion chamber so as to promote combustion and reduce fuel consumption and discharged gas by providing a projected part disposed on the base of a piston cavity with groove parts of a number corresponding to auxiliary chamber jet holes in such a manner as to incline from the axial direction of the auxiliary chamber jet hole to the intake swirl direction.
CONSTITUTION: The base of a piston cavity is provided with a projected part for covering the most part of an auxiliary chamber mouthpiece tip part 9 when a piston 6 is near the top dead center, and the projected part is provided with groove parts 11 of a number corresponding to the auxiliary chamber jet holes 3. The axis of the groove part 11 is inclined at an angle 6 to be directed to the axial direction of the auxiliary chamber jet hole 3 on the center side and be pointed in the leeward direction of intake swirl on the outside. Thus, jet gas from the auxiliary chamber jet hole 3 at the time of expansion stroke of an engine generates a speed component in the intake swirl direction, and interference loss between both members is decreased, so that ban intake swirl in the piston cavity is increased so as to promote mixture of fuel and air and improve fuel consumption and discharged gas.
IMOTO KOJI
OMURA TADAO
Next Patent: COMBUSTION CHANBER OF AUXILIARY CHAMBER TYPE INTERNAL COMBUSTION ENGINE