Stratified burning internal combustion engine

A stratified burning internal combustion engine comprising:

• a combustion chamber defined by an inner wall of a cylinder, a top wall of a piston fitted in the cylinder and a lower wall of a cylinder head,
• ignition means centrally disposed on the lower wall of the cylinder head,
• two intake ports having intake openings in the lower wall of the cylinder head, respectively, said intake openings being arranged on one side of an imaginary plane containing an axis of the cylinder, whereby air is inducted from the respective intake openings toward an opposite side of the imaginary plane along the lower wall of the cylinder head to form mutually-parallel tumble flows in the same direction within substantially the entirety of the combustion chamber,
• intake valves having a valve stem extending across the respective ports, whereby the corresponding intake openings are selectively opened or closed,
• longitudinal partitions disposed inside the respective intake ports so that an interior of each of the intake ports is divided into a central passage on a side of said ignition means and a side passage, and
• fuel feed means for feeding fuel into the central passages of the intake ports, whereby stratified tumble flows are formed in the combustion chamber during an intake stroke,
• wherein a downstream end of a surface of each longitudinal partition, said surface facing the corresponding central passage, is offset toward a longitudinal central axis of the corresponding central passage compared with a part of the surface of the longitudinal partition, said part being upstream of the downstream end.

A stratified burning internal combustion engine comprising:

• a combustion chamber defined by an inner wall of a cylinder, a top wall of a piston fitted in the cylinder and a lower wall of a cylinder head,
• ignition means centrally disposed on the lower wall of the cylinder head,
• two intake ports having intake openings in the lower wall of the cylinder head, respectively, said intake openings being arranged on one side of an imaginary plane containing an axis of the cylinder, whereby air is inducted from the respective intake openings toward an opposite side of the imaginary plane along the lower wall of the cylinder head to form mutually-parallel tumble flows in the same direction within substantially the entirety of the combustion chamber,
• intake valves having a valve stem extending across the respective ports, whereby the corresponding intake openings are selectively opened or closed,
• longitudinal partitions disposed inside the respective intake ports so that an interior of each of the intake ports is divided into a central passage on a side of said ignition means and a side passage, and
• fuel feed means for feeding fuel into the central passages of the intake ports, whereby stratified tumble flows are formed in the combustion chamber during an intake stroke,
• wherein each longitudinal partition is provided only on a side upstream of the valve stem in the corresponding intake port.