COMBUSTION CHAMBER STRUCTURE FOR ENGINE

Japanese Patent JP2022083616

A

To actualize similar combustion at the same engine speed and the same load between engines different in displacement.SOLUTION: A combustion chamber structure for an engine where a geometric compression ratio is set in a range of 13.5-15.5 includes a combustion chamber 6 defined by a crown surface 50 of a piston 5, the inner wall surface of a cylinder 2, and a pent-roof type ceiling surface 6U. On the crown surface 50 of the piston 5, a convex upheaval part is formed by an exhaust side inclined surface 53 rising from the exhaust side to the center part, an intake side inclined surface 54 rising from the intake side to the center part, and a plane 55 provided continuously between these upper ends. A mountain height h of the upheaval part and a stroke Ls as a length where the piston 5 moves from a top dead center to a bottom dead center in the cylinder axis direction satisfy a relationship of 0.045