To provide an exhaust gas circulating device for increasing an EGR amount by increasing an exhaust flow passing through an exhaust gas circulating passage bypassing an EGR cooler at the time of a low load operation requiring a large amount of EGR.
A first valve 23 is arranged, which regulates an exhaust gas amount in an exhaust gas circulating passage 21 by which a part of exhaust gas is refluxed to an intake passage through the exhaust gas circulating passage 21, and an EGR cooler 22 is arranged, which is arranged in this exhaust gas circulating passage 21 and cools exhaust gas. A second valve 25 regulating the exhaust gas amount passed though the inside of a passage, is arranged in an exhaust gas circulating passage 24 which is arranged in parallel with the exhaust gas circulating passage 21 and circulates exhaust gas to an intake system. The first valve 23 is controlled according to the operating condition of an engine, and also, in the case that the first valve 23 is approximately fully opened, the second valve 25 is controlled on the basis of an air excessive rate or a parameter which can adjust the air excessive rate.
Next Patent: RECYCLED EXHAUST GAS COOLING DEVICE