| 摘要 |
PROBLEM TO BE SOLVED: To provide a cylinder head 1 with an exhaust port 6 for each cylinder 2 of an internal combustion engine, wherein heat of exhaust gas can be efficiently recovered at high rotational speed of the internal combustion engine.SOLUTION: Projected line parts 7, 8 projected inward in the radial direction are arranged on the inner peripheral surface of the exhaust port 6 in the upper dead center-side area of the cylinder 2 in the Y direction of the center axis thereof so that the projected line parts are extended from the upstream side of the flow direction of the exhaust gas to the downstream side. In the upstream-side area of the projected line part 7 or 8, the projected amount thereof is made larger gradually toward the downstream side thereof from the upstream end. Accordingly, the ridge line of the projected line parts 7, 8 in the upstream-side area is inclined with respect to the center axis 100 of an inside opening of the exhaust port 6. The angle &thetas;of the inclination is set to be an obtuse angle. |
