| 摘要 |
PURPOSE:To effect high speed flame spreading and reduction in exhaust of unburned HC by a method wherein a squishing projection is formed on top of a piston to divide a combustion chamber into a chamber at the center of the cylinder bore and a surrounding chamber to cause squishing action in the combustion chamber. CONSTITUTION:On top of the piston 12, the squishing projection 16 is provided in the combustion chamber which is formed with the cylinder head 10, cylinder block 11 and piston 12 so that the combustion chamber can be divided into the central combustion chamber 14 and the surrounding annular combustion chamber 15 at the top dead point of the piston 12. Those two different combustion chambers 14, 15 formed near the top dead point of the piston 12 can produce turbulent flow in those two combustion chambers 14, 15 by the squishing projection 16. Under such condition, upon ignition by the spark plug 23 which is fitted at the central combustion chamber 14, flames spread rapidly from the combustion chamber 14 to the combustion chamber 15. During the exhaust stroke, unbruned HC remains in the surrounding combustion chamber 15 but combustion gas is mainly discharged out of the exhaust valve 19 located at the central combustion chamber 14. |
