| 摘要 |
PURPOSE:To stabilize the combustion of an engine upon low load operation to aim at enlarging the limits of lean mixture, by injecting a jet stream into a combustion chamber from an injection port in an auxiliary intake-air passage upon low load operation to increase the strength of swirl within the combustion chamber. CONSTITUTION:Since a high vacuum is effected in a first intake port 30 when an intake control valve 40 is closed upon low load operation of an engine, air in a carburettor 20 is sucked through an auxiliary intake port 42, and is then injected, as a jet stream as indicated by the arrow J, into a combustion chamber 16 from an injection port 56 through a gap between the bevel part of a first intake-air valve 36 and a valve seat 58. The jet stream J is turned into a swirl which is effected in the combustion chamber under action of a herical port 32, so that the strength of the swirl is increased. |
