| 摘要 |
PURPOSE:To secure sufficient intake valve area while decreasing a combustion period in an engine provided with at least three intake valves per cylinder by specifying positional relations including inclination between each intake valve and discharge valve. CONSTITUTION:In three intake valves 5 which open/close an intake passage 1, the intermediate intake valve 5 faces a combustion chamber 3 with a smaller inclination to an axis l1 of a cylinder (a) than those of a discharge valves 6. Both side discharge valves 6 are provided to cross a center line l3 which passes the center of combustion chamber 3 and is parallel to a plurality of camshafts 9, 10. A wall surface 17 which faces inside the cylinder (a) and has a larger inclination to the axis l1 thereof than that of a lower end face 5a of the intermediate intake valve 5 is formed on a lower surface of a cylinder head (b) and outside the intermediate intake valve 5. Both side intake valves 5 face the combustion chamber 3 with a larger inclination to the axis l1 of the cylinder (a) than that of the intermediate intake valve 5. |
