Abstract: An exhaust gas recirculation structure includes an EGR cooler and an EGR duct, and the EGR duct includes an inflow portion into which the exhaust gas flowing out from the EGR cooler flows, a flow path, and an outflow portion from which the exhaust gas flows out. The flow path is provided such that the height on the side of the inflow portion is lower than the height on the side of the outflow portion, and has a region in which the distance between the center line of a flow path cross section of the flow path and a line along the lowest end in the height direction gradually increases from the outflow portion side toward the inflow portion side.

Abstract: A valve (10) may be used with an internal combustion engine exhaust breathing system (12) and may include a body (60), a partition (62), and a plate (66). The body (60) may define a first port (70) that has a first interior surface (76), and may also define a second port (82) that has a second interior surface (84). The partition (62) may be located within the body (60), may at least partially separate the first port (70) and the second port (82) from each other, and may define an opening (104). The plate (66) may be dimensioned to seat and seal against the opening (104) and against the first and second interior surfaces (76, 84). The plate (66) may rotate, depending on predetermined factors, between a first position and a second position.

Abstract: A failure diagnosis apparatus for an exhaust pressure sensor for detecting the exhaust pressure in an exhaust gas recirculation passage which connects an exhaust passage and an intake passage of an internal combustion engine. A first preliminary determination that the exhaust pressure sensor is normal, is made when the engine is in a predetermined low load operating condition and a difference between the detected exhaust pressure and the atmospheric pressure is equal to or less than a first determination threshold value. A second preliminary determination that the exhaust pressure sensor is normal, is made when the engine is in a predetermined high load operating condition and the difference between the exhaust pressure detected by the exhaust pressure sensor and the atmospheric pressure is equal to or greater than a second determination threshold value. A final determination that the exhaust pressure sensor is normal, is made when both of the first and second preliminary determinations are made.

Abstract: An exhaust gas recirculation apparatus includes a housing connected with an EGR cooler via a mount face. The housing has a valve chamber accommodating a selector valve. The housing has a partition extending from the mount face close to the valve chamber to divide first and second exhaust ports opened in the mount face. A first passage leads exhaust gas into the EGR cooler through the valve chamber. A second passage recirculates exhaust gas to the intake passage through the EGR cooler and the valve chamber. A bypass passage leads exhaust gas from the engine through the valve chamber to bypass the EGR cooler. A rotation axis of the selector valve is perpendicular to an axis of the mount face, and offset away from the partition.

Abstract: A method for controlling EGR gas flow in an internal combustion engine during ongoing operation includes determining an engine operating point and a preferred EGR fraction for a cylinder charge based upon the engine operating point. A feed-forward command for controlling an external EGR gas flowrate to an engine intake manifold based upon the preferred EGR fraction for the cylinder charge is determined. An EGR ratio in the intake manifold is determined. And, the external EGR gas flowrate is controlled based upon the estimated EGR ratio in the intake manifold and the feed-forward command for controlling the external EGR gas flowrate.

Abstract: A control method of an EGR system of an engine capable of effectively performing an EGR control at a time of rapid acceleration. For this purpose, an intake air flow rate of the engine is obtained, and from a target EGR valve opening degree and a difference in pressure in front of and behind the EGR valve, a virtual EGR gas flow rate is arithmetically operated. A virtual EGR rate is obtained from the intake air flow rate, the fuel flow rate and the virtual EGR gas flow rate, and a difference from or a ratio to a target EGR rate obtained from the engine speed and the fuel flow rate is obtained. A command EGR valve opening degree is obtained from an EGR valve opening degree correction coefficient obtained from the difference or the ratio, and the target EGR valve opening degree, whereby the EGR vale is driven.