| 摘要 |
PURPOSE:To improve machining easiness of an internal combustion engine by providing at least three intake valves in order to enable the respective intake valves to be arranged at the identical angle to be in parallel one another in the case of providing a plurality of intake and exhaust valves per cylinder. CONSTITUTION:In a cylinder head facing a combustion chamber 14, three intake ports 15 are formed on one side facing the center of the combustion chamber 14 so as to arrange intake valves 17 on the respective intake ports 15. The respective intake valves 17 are provided with their valve axes included by mutually identical angle with respect to a center axis P of the combustion chamber 14 in order to be in parallel one another. Also, the upper/end part of a middle valve 17 and the upper/end parts of other valves 17 on both sides among the respective intake valves 17 are made to have different interval toward an intake cam axis 21. Operating performance of the intake valves 17 is improved as well as drilling work for holes 12A of a cylinder head 12 and supporting holes 19 of an intake valve is simplified by the above structure. |
