| 摘要 |
PURPOSE:To sharply improve fuel consumption, by a method wherein, during running at a low load, evaporation of fuel is promoted through preheating of air-fuel mixture, and during running at a high load, preheating of intake air is stopped, and a cylinder is forced into a quiescent state through reflux of exhaust gas, where necessary CONSTITUTION:During running at a low load of an engine, an auxiliary suction passage 2 is closed by a valve body 15 of an upper stream control valve 14 and a valve body 13 of a downstream control valve 12, and air-fuel mixture is sucked through only a main suction passage 1. In which case, a part of high temperature exhaust gas flows in an auxiliary suction passage 2 through an exhaust gas intake pipe 17, and preheats air-fuel mixture, flowing through the adjoining main suction passage 1 to promote evaporation of fuel. During running at a high load, the air-fuel mixture is caused to flow in through the main and auxiliary passages 1 and 2 to stop preheating of intake air. A main air intake valve 7 is closed to force a cylinder into a qienscent state, where necessary, and a part of exhaust gas is fed in a cylinder 5 through utilization of the auxiliary suction passage 2 for reflux of exhaust gas. This sharply improves fuel consumption over a range of from a low load to a high load. |
