| 摘要 |
A cylinder direct injection internal combustion engine is configured to include a spark plug arranged in the top of a combustion chamber ceiling, and a fuel injection valve for directly injecting fuel into the combustion chamber. Furthermore, when the rising/falling direction of a piston is a vertical direction, the direction along an axis line of a piston pin is a longitudinal direction, and the direction orthogonal to the vertical and longitudinal directions is a horizontal direction, the combustion chamber ceiling of the cylinder direct injection internal combustion engine has a pair of head-side squish-creating surfaces provided to a prescribed region including an intake-side end edge and a prescribed region including an exhaust-side end edge, the head-side squish-creating surfaces being inclined upward from the outer edge of the combustion chamber toward the center of the combustion chamber. A piston top surface is provided with a pair of piston-side squish-creating surfaces inclined upward from the outer peripheral edge toward the center part of the piston top surface, the piston-side squish-creating surfaces facing the head-side squish-creating surfaces, and a flat surface part that widens in the horizontal direction within a range enclosed by the pair of piston-side squish-creating surfaces and widens in the longitudinal direction as far as the outer peripheral edge. The flat surface part is positioned higher than the bottom end of the piston-side squish-creating surfaces. |
