| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique suitably executing EGR by securing EGR control accuracy even when throttling an exhaust throttle valve when executing PM regenerating processing, in an EGR system for simultaneously using an HPL device and an LPL device. SOLUTION: This EGR system has: the exhaust throttle valve arranged in an exhaust passage on the downstream side of a turbine of a turbocharger; the HPL device having an HPL passage for connecting the exhaust passage on the upstream side of the turbine to an intake passage on the downstream side a compressor of the turbocharger and an HPL valve arranged in the HPL passage; the LPL device having an LPL passage for connecting the exhaust passage on the downstream side of the exhaust throttle valve to the intake passage on the upstream side of the compressor and an LPL valve arranged in the LPL passage; and an EGR control means for controlling an EGR gas quantity by con6trolling opening of the HPL valve and the LPL valve. The EGR system controls the EGR gas quantity by controlling the opening of the LPL valve by closing the HPL valve when opening of the exhaust throttle valve is throttled to closing side opening more than predetermined opening. COPYRIGHT: (C)2009,JPO&INPIT
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