| 摘要 |
PURPOSE:To control EGR properly under wide load region by performing interpolative operation of EGR valve drive data determined on the basis of the load and the rotation of engine in accordance to the engine operating condition under EGR control region and controlling EGR valve and an exhaust throttle valve. CONSTITUTION:Under operation of engine, a control circuit 19 will decide whether the output TW of a water temperature sensor 13 is higher than a setting level (50 deg.C, for example), and upon decision of YES, the outputs from a rotation sensor 15 and a load sensor 14 are taken in. Then interpolative operation is performed with correspondence to the engine operating condition on the basis of the control negative pressure map of EGR valve 5 prestored in ROM of the control circuit 19 to provide a control signal corresponding with the operation results to a negative pressure control valve 16. Consequently, the negative pressure from a vacuum pump 17 is fed through a negative pressure control valve 16 to respective diaphragm chamber 8, 40 of EGR valve 5 and an exhaust throttle valve 7 to control EGR to be fed through EGR path 4 to an intake system path 2 into correct level. |
