| 摘要 |
PURPOSE:To stably obtain the ignitability of spray of fuel, by optimizing the internal diameter of an ignition chamber and the relative position between a fuel injection valve and a spark plug, in the case of a reciprocating internal- combustion engine arranging the ignition chamber in a cylinder head. CONSTITUTION:An internal-combustion engine forms in its cylinder head 1 an ignition chamber 3 opened oppositely facing to a combustion chamber 2. Further the engine provides a fuel injection valve 4 and a spark plug 5 to be arranged appearing in the ignition chamber 3. Here the ignition chamber 3 forms its internal diameter D1 so as to be larger than the diameter D2 in an outlet of the ignition chamber 3 of spray of fuel injected from a nozzle and sphere 4A of the fuel injection valve 4. Next the relative position between the center of the nozzle end sphere 4A of the fuel injection valve 4 and a spark gap position 5A of the spark plug 5 is set to a range in a relation where L1=4-10mm in the axial direction while L2=2-7mm in the radial direction. In this way, stable ignitability for the spray of fuel is obtained in a wide range of an engine speed and load. |
