RECIRCULATOR FOR EXHAUST GAS OF INTERNAL COMBUSTION ENGINE

PURPOSE:To prevent the deterioration of operating performance due to the lowering or leaning of air-fuel ratio by using a system in which the amount of exhaust gas to be circulated is reduced during an operation period when an air-fuel ratio sensor provided in the exhaust gas system sends out a lean signal. CONSTITUTION:An exhaust gas recirculation path 12 with an exhaust gas circulation amount regulating valve 16 is led to exhaust gas intake manifolds 10 and 14, through which exhaust gas is circulated. During the period when a throttle valve 22 is fully closed, the negative pressure of the intake pipe from the first load detection port 24 on right upstream is regulated and transmitted to the diaphragm chamber 16d of the control valve 16 through a pressure regulating valve 18 in order to control the opening degree. Also, an electromagnetic valve 42 by which negative pressure introduced through the second load detection port 46 is regulated by the air from an open air inlet 42a is provided to the pressure regulating valve 18. The electromagnetic valve 42 is controlled by a control circuit 48 receiving the signal of the air-fuel ratio sensor 40 provided to the exhaust gas manifold 10, and negative pressure transmitted in the diaphragm chamber 16d is weakened and lean air-fuel ratios.