| 摘要 |
PURPOSE:To try to improve combustion performance and exhaust character by setting a distance from the nozzle hole of a fuel injection valve to the valve hole of the first inlet valve, the diameter of the valve hole and dispersion angle of injected fuel in such a way as satisfying a specific relation among them. CONSTITUTION:The first inlet port 22 and the second inlet port are parallelly arranged in a cylinder head 21, and an open/close valve is provided in the second inlet port. Now, distance L from the nozzle hole of a fuel injection valve 25 for injecting fuel toward the valve hole 24a of the first inlet valve, diameter D of the valve hole 24a and dispersion angle theta of fuel injected from the fuel injection valve 25 are set in order to satisfy tan<-1>(2<1/2>D/2L)<=theta<=tan<-1>(D/ L). By the above situation, the greater part of fuel injected from the fuel injection valve 25 can be supplied to a combustion chamber 23 without adhering to the inner wall of the first inlet port 22, and its fuel particle diameter can be restrained below the specified value, so that diffusion and vaporization characters of fuel can be improved so as to maintain mixed air of good quality. |
