| 摘要 |
PURPOSE:To control the amount of recirculated exhaust gas to an optimal value determined by the operational conditions of a Diesel engine by way of feedback control, by comparing the actual value of the density of smoke in exhaust gas, obtained as an output signal of a detector, with an aimed value of the density of smoke in the exhaust gas corresponding to the optimal amount of recirculated exhaust gas that is determined by the operational conditions of the engine. CONSTITUTION:A signal relating to the position of a control sleeve 12, obtained as an output signal of a first pickup 13 attached to a fuel injection pump 10, is furnished to a control circuit 9 via a load detecting circuit 14. Similarly, a signal relating to the speed of rotation of a gear 16, obtained as an output signal of a second pickup 17, is also furnished to the control circuit 9 via a rotational speed detecting circuit 18. Further, a sensor 8 for detecting the density of smoke in exhaust gas, consisting of a light emitting diode and a phototransistor, is disposed in an exhaust passage 5 of a Diesel engine, and the output signal of the sensor 8 is compared in the control circuit 9 with an aimed value of the density of smoke in the exhaust gas corresponding to the optimal amount of recirculated exhaust gas that is determined by the load and the speed of the engine. With such an arrangement, the amount of exhaust gas to be recirculated is controlled by controlling a control valve 7 in an intake passage 3 to converge the deviation between the actual value and the aimed value of the density of smoke in the exhaust gas. |
