| 摘要 |
PURPOSE:To improve the efficiency of combustion of an engine in which an ignition plug, a single intake valve and a single exhaust valve are positioned in its cylinder head, by arranging the ignition plug and the valves in such a way that the axes of them extend in different radial directions. CONSTITUTION:If the invention is applied to a four-cycle and single cylinder engine of a motorcycle, intake and exhaust valves 20 and 21 are approximately symmetrically arranged laterally in the upper half section of the engine divided by a P-P line or a plane including the center axis of a cylinder and an ignition plug 22 is arranged in he lower half section thereof at approximately central part of the section. Additionally, the valve stems 23 and 24 of the valves 20 and 21 are inclined upwards and at such angles that they are opened in the lateral direction while the ignition plug 22 are arranged such that its longitudinal center axis is inclined downwards. The respective axes of the valves 23, 24 and the plug arranged to extend in the radial directions. The interior face of a combustion chamber 17 may be shaped in the approximately spherical form, hence improving combustion efficiency. |
