| 摘要 |
PROBLEM TO BE SOLVED: To provide a combustion chamber structure of a 2-valve internal combustion engine where knocking is prevented in the internal combustion engine.SOLUTION: In an internal combustion engine, there are an intake valve port (42) and an exhaust valve port (43) opened on a ceiling plane (50) of a cylinder head (17) each which is positioned opposite each other about a cylinder axis (C) being a central axis of a cylinder bore (16b) with the ports facing a combustion chamber (40). In a combustion chamber structure of the internal combustion engine, the inside of a piston-side squish surface (62) formed along the outer peripheral edge of the top face (60t) is shaped concavely to form a piston-side recess (61) on a top face (60t) of a piston (60), and the piston-side recess (61) is shaped into an elliptical shape to substantially surround a bevel part (46p) of an intake valve (46) and a bevel part (47p) of an exhaust valve (47) on the major-axis-direction both sides in a cylinder-axial-direction view. |
