JPS6113106B

PURPOSE:To correct the reduction of exhaust gas returning amount and maintain a required returning amount constantly by providing a return passage with a return control valve for detecting the pressure in the return passage and the reduction of the exhaust gas returning amount caused by the accumulation of carbon. CONSTITUTION:A return passage 4 is provided with a return control valve 5 consisting of a valve body 5a, a rod 5b, a diaphragm 5c, a negative pressure chamber 5d, an atmospheric pressure 5e, and a spring 5f, which is connected to a control device 9 via a negative pressure and an atmospheric pressure solenoid 7 and 8. Meanwhile, a load sensor 10, a revolution sensor 11, a pressure sensor 12, a valve position detecting sensor 13, and the first and the second memory device 14 and 15 are connected to the control device 9. In the control device 9, a target pressure computed by the memory device 15 is compared with an actual pressure from the pressure sensor on the basis of signals from the revolution sensor 11 and the negative pressure sensor 10, and in accordance with the difference thereof, the shift amount of the valve body 5a is increased more than the target shift amount in the memory device 14 for correction control.