| 摘要 |
PURPOSE:To reduce detrimental components in exhaust gas and to enhance the combustibility upon returning to all cylinder number running, by recirculating exhaust gas from operating cylinders to resting cylinders upon partial cylinder number running, and as well, recirculating exhaust gas from the resting cylinders to the intake-air side of the operating cyliners. CONSTITUTION:When shut-off valves 8a, 8b disposed in intake-air flow passages connected to a part of cylinders 3b, 3c in a multi-cylinder engine E are closed upon low-load running to shut-off the supply of fuel for conducting partial cylinder number operation, exhaust gas is recirculated from the exhaust gas pipe 13d of an operating side cylinder to the intake-air pipes 3b, 3c of resting cylinders through a passage 21 and a control valve 23 to heat the resting cylinders. Simultaneously, cooled exhaust gas is recirculated from the exhaust gas pipes 13b, 13c of the resting cylinders to an intake-air pipe through a passage 22 and a control valve 24 to enhance the effect of intrinsic exhaust gas recirculation. Further, since the resting cylinders are heated, the combustibility upon returning to all cylinder operation may be enhanced. |
