| 摘要 |
PURPOSE:To enable to raise the intake efficiency of an engine, by selecting either of stratified combustion or homogeneous combustion according to the engine load, and weakening the intensity of swirl at the time of homogeneous combustion as compared with that at the time of stratified combustion by a swirl control means. CONSTITUTION:At the time of low-load operation of an engine detected by a detecting means 17, a control unit 19 consisting of a microcomputer or the like controls the quantity of intake air to keep it constant by fully opening a throttle valve 14 and functions to cause stratified lean combustion by supplying stratifying fuel toward an igniting means 8 from an injection nozzle 9. When the engine load is raised to a prescribed value, the combustion mode is switched to homogenenus combustion by decreasing the quantity of stratifying fuel and starting supply of scattering fuel from an injection nozzle 12 to compensate the decreased quantity of fuel. Further, at the time of low-load operation of the engine, the control unit 19 functions to strengthen the swirl by closing a swirl control plate 16 by a swirl control means 18, and the swirl is weakened with lowering of the load. On the other hand, at the time of high-load operation when homogeneous combustion is employed, abnormal rise of the combustion speed is prevented by weakening the swirl and the intake efficiency is raised by reducing resistance to the intake-air flow. |
