| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an EGR system for an internal combustion engine capable of introducing predetermined quantity of EGR gas to an intake side without dropping supercharger efficiency even in low rotation speed-middle rotation speed operation range in which exhaust gas quantity is small, and of improving trade-off relation of EGR rate and air fuel ratio in middle load operation range in a two stage supercharging system engine. <P>SOLUTION: The EGR system for an internal combustion engine including a two stage supercharging system is provided with a first and a second EGR passages 11, 12 by connecting an intake passage 3 between a low pressure stage compressor 5c and a high pressure stage compressor 6c with both of an exhaust passage 4 between a high pressure stage turbine 6t and a low pressure stage turbine 5t, and an exhaust passage 4 between an internal combustion engine main body 2 and the high pressure stage turbine 6t, and with an EGR control device opening and closing a first and a second EGR valves 12, 15 provided in each EGR passage 11, 12 respectively and adjusting valve opening. <P>COPYRIGHT: (C)2007,JPO&INPIT |
