PURPOSE: To aim at improvement of the output of an engine by way of suppressing the occurrence of knocking and securing a stable combustion by placing an EGR (Exhaust gas recirculation) passage for the supply of EGR gas in such a manner that it points in the direction of a combustion chamber so as to produce the swirl of EGR gas around the outer periphery of the swirl of fresh air.
CONSTITUTION: The No.1 port 6a for supplying fresh air and the No.2 port 6b for supplying EGR gas are directed in the nearly tangential direction of a cylinder. Hereby, fresh air (arrow A) from an air intake passage 11, and EGR gas (arrow B) from an EGR passage 17 produce, in a combustion chamber 5, swirls centering round the shaft center O of the cylinder. In addition, the No.2 port 6b is located outside the No.1 port 6a, and the swirl of EGR gas flows, in layers, outside the swirl of fresh air. And accordingly, since there is in existence almost only fresh air around an ignition plug 23, a stable combustion can be secured, while, since EGR gas is present along the wall surface of the cylinder, the occurrence of knocking can also be suppressed.
NISHIDA MASAMI
SUGIYAMA MASAO
HIRATA TSUNEO
| JPS5171418A | 1976-06-21 |