| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve acceleration and emission when turbocharged engines are changed from such an exhaust gas recirculation phase as a low speed, partial load phase to an acceleration phase. SOLUTION: A turbocharged engine is provided with an exhaust gas reflux device for flowed back exhaust gas from the upstream side of the turbocharger turbine to the intake passage at least in a low-speed, partial-load operating phase. As an exhaust pressure control means for controlling exhaust pressure on the upstream side of the turbocharger turbine, variable blades are arranged to form nozzles whose opening are variable in relation to the turbocharger turbine. On the basis of the determination that an acceleration determination means 51 gives, a VGT control means 42 for controlling the variable blades opens them in the initial phase of acceleration from an exhaust gas reflux range, so that exhaust pressure drops on the upstream side of the turbine.</p> |
