| 摘要 |
PURPOSE:To prevent increasing of smoke, HC and CO contained in the exhaust gas of a Diesel engine, by reducing the amount of recirculated exhaust gas at a highland through provision of a means for correcting the amount of recirculated exhaust gas according to the altitutde by use of expansion and contraction of a bellows. CONSTITUTION:According to the present invention, an EGR control valve 4 provided in an EGR passage 3 and a throttle valve 7 provided in an intake passage are both controlled by the negative pressure supplied from a vacuum pump 8, and the negative pressure is controlled by solenoid valve 9, 10 in response to a control signal produced by a control unit 11. The control unit 11 produces a control signal according to the output signal of a load detecting potentiometer 13 or other attached to a fuel injection pump 12. Here, arrangement is such that the output of the potentiometer 13 can be corrected according to the altitude. For this purpose, a resistance 21 is connected to a resistance 17 with which a contactor 20 of the potentiometer 13 connected to an accelerator pedal 18 is held in contact in a freely slidable manner, and a contactor 23 attached to an altitude correcting bellows 22 is held in sliding contact with the resistance 21. |
