| 摘要 |
PROBLEM TO BE SOLVED: To avoid unstable stratified combustion caused by change in a spray pattern in a non-warm-up state at a low fuel temperature. SOLUTION: A fuel injection valve 15 directly injecting fuel in a cylinder is disposed to a side part of a combustion chamber 3, so that the fuel injection valve injects the fuel obliquely downward toward a piston top part 2. The fuel injection valve 15 has a vertically asymmetrical fuel spray F, and a spray upper end part F1 has the maximum penetration force as a lead spray and directed toward an electrode part of an ignition plug 14. When the fuel temperature is lower than a reference temperature, viscosity of fuel is increased and the spray is widely increased, and thereby a positional relation between the spray and the electrode part is changed, resulting in the unstable stratified combustion. In the present invention, since fuel pressure is corrected to be low when the fuel temperature is low, the spray pattern is brought close to a natural pattern to stabilize the stratified combustion. After the cold start, since the stratified lean combustion can be early started, the fuel economy is improved. COPYRIGHT: (C)2006,JPO&NCIPI
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