Patent ID: 6209512
Filing Date: 2001-04-03
Classification: F02B,F02F,Y02T

Abstract:
A two- or four-stroke vehicle comprising, within a cylinder block (2) closed by a cylinder head (6), at least one cylinder (3) within which a piston (4) moves, said piston having a head (5), the cylinder (3) receiving air via at least one induction or intake duct (16), there being provided for the combustion products at least one exhaust duct (17) operationally connected to said cylinder, said intake duct (16) and said exhaust duct (17) each being provided with at least one respective valve member (18,19) subjected to operator means (28) returning said valve member (18,19) to the position in which it closes the respective duct (16,17), the valve members (18,19) being positioned by the side of the cylinder (3) and intercepting apertures (16A,17A) of the respective ducts (16,17) which open into at least one mixing chamber (13) positioned by the side of the cylinder (3) and communicating with it, said cylinder head (6) being substantially flat, the head (5) of the piston (4) comprising at least one surface recess (35), the engine further comprising at least an injector (40,140) located inside the cylinder head (6), and wherein said injector is structured and arranged to inject said fuel into a top portion of said cylinder and into said surface recess and wherein said mixing chamber maintains communication with said cylinder throughout an entire stroke of said piston including when said piston is at a top dead center position whereby optimum stratification of the explosive mixture above the piston (4) is obtained and optimum engine operation is achieved, in particular when the engine operates at low load.