| 摘要 |
PROBLEM TO BE SOLVED: To optimize fuel economy and output performance irrespective of an engine model in an engine that includes a piston reciprocating in a cylinder bore, an intake valve and an exhaust valve.SOLUTION: In the engine, a stroke/bore diameter ratio that is a ratio of a stroke of the piston 11 to a bore diameter of the cylinder bore 21 is set as 1.15 to 1.25 and a valve holding angle θ between the intake valve 33 and the exhaust valve 34 is set as 41° ±1°. By defining the stroke/bore diameter ratio and the valve holding angle θ as such, the fuel economy and the output performance can be optimized irrespective of an engine model.SELECTED DRAWING: Figure 1 |
