| 摘要 |
<P>PROBLEM TO BE SOLVED: To execute fine EGR rate control and air fuel ratio control during middle speed middle load operation in a sequential type two stage supercharging system provided with a high pressure stage turbocharger and a low pressure stage turbocharger. <P>SOLUTION: In the two stage supercharging system 1 forming high pressure stage exhaust bypass passages 6d, 6e bypassing a high pressure stage turbine 6t out of a first bypass passage 6d provided with a small diameter valve 6f and a second bypass passage 6e provided with a large diameter valve 6g of which diameter is larger than that of the small diameter valve 6f, valve effective area of the small diameter valve 6f is set to 9.5-26.5% of necessary passage cross section area at a time of exhaust gas of the maximum total flow rate. <P>COPYRIGHT: (C)2007,JPO&INPIT |
