Fuel injection type internal combustion engine

Claim 1

An internal combustion engine comprising: an engine body having at least one cylinder bore formed therein and having an inner end wall which closes one end of said at least one cylinder bore; a piston reciprocally movable in said at least one cylinder bore and having a top face which faces said inner end wall, said top face and said inner end wall defining a combustion chamber therebetween, said top face having a cavity formed thereon and having a bottom wall; a projection formed on the bottom wall of said cavity within said cavity and having an impingement face which faces said inner end wall; a fuel injector arranged on said inner end wall and having a nozzle bore directed toward said impingement face to cause a large part of fuel injected from said nozzle bore to impinge upon said impingement face and to create a richer air-fuel mixture layer around said projection at an end of a compression stroke, said injector completing its injection of fuel before said piston reaches a top dead center position; and means for generating a spark to ignite said layer, said spark generating means being arranged on said inner end wall to come in proximity to a sidewall of said projection and in contact with said richer air-fuel mixture layer at the end of the compression stroke.