An EGR system is configured to allow a part of exhaust gas discharged from an engine to an intake passage to flow as EGR gas to an intake passage through an EGR passage to return to the engine. In the EGR system, a heating film is provided on an inner wall or an outer wall of at least one of the intake passage through which the EGR gas is allowed to flow and the EGR passage. At least a pair of a positive electrode and a negative electrode is provided to energize the heating film.

A vehicle engine 2 comprises an exhaust system having an exhaust manifold 12 and an exhaust purification device 18. The exhaust manifold 12 is disposed at a predetermined distance from a dash panel 106 constituting a body of the vehicle 100, the exhaust purification device 18 is disposed in a position overlapping a floor tunnel region 114, formed by a floor tunnel of the body, and is disposed below the exhaust manifold 12 and to one side of the center of the engine 2 in the cylinder-array direction, as viewed from the longitudinal direction of the vehicle 100. An exhaust purification device introduction passage 17 connecting the exhaust manifold 12 and the exhaust purification device 18 is disposed on the other side of the center of the exhaust manifold 12 in the cylinder-array direction, and extends below the exhaust manifold 12 to be connected to the exhaust purification device 18.

An intake system of an engine supplies gas at least containing fresh air to each cylinder. The system includes an EGR passage that communicates with an internal space of a downstream intake passage and introduces some EGR gas into the downstream intake passage. The EGR passage includes a projected section in a substantially polygonal or cylindrical shape that is projected to the internal space of the downstream intake passage. The projected section is formed in such a shape that a projection length H1 in an outer circumferential surface on an upstream side is longer than a projection length H2 in an outer circumferential surface on a downstream side.

An exhaust gas recirculation cooler may include a heat exchanger block including a first mounting flange, a diffuser including a second mounting flange, and at least one non-return valve arranged between the heat exchanger block and the diffuser. The exhaust gas recirculation cooler may also include a valve carrier which supports the at least one non-return valve and on which a gasket is arranged. The heat exchanger block may be connected via the first mounting flange directly to the second mounting flange of the diffuser. The valve carrier may be arranged between the heat exchanger block and the diffuser, and with the gasket may seal a sealing point between the first mounting flange and the second mounting flange. The diffuser may include an outwardly closed recess with a peripheral rim structured to accommodate the valve carrier. The rim may define the second mounting flange.

An exhaust gas recirculation cooler may include a heat exchanger block including a first mounting flange, a diffuser including a second mounting flange, and at least one non-return valve arranged between the heat exchanger block and the diffuser. The exhaust gas recirculation cooler may also include a valve carrier which supports the at least one non-return valve and on which a gasket is arranged. The heat exchanger block may be connected via the first mounting flange directly to the second mounting flange of the diffuser. The valve carrier may be arranged between the heat exchanger block and the diffuser, and with the gasket may seal a sealing point between the first mounting flange and the second mounting flange. The diffuser may include an outwardly closed recess with a peripheral rim structured to accommodate the valve carrier. The rim may define the second mounting flange.

Systems and methods are disclosed to recover waste heat from an engine fluid with a heat exchanger subsystem that includes a heat exchanger. The heat exchanger subsystem is thermally coupled to a working fluid and the engine fluid, so the waste heat from the engine fluid is transferred to the working fluid. The engine fluid is bypassed from the heat exchanger in response to a heat exchanger bypass condition.

A gas tube for an EGR cooler has such a structure that a metal plate having a flat plate shape is bent in a tube shape. The metal plate includes a core material, a sheath material clad on one surface of the core material or on both surfaces thereof, and an intermediate material clad between the core material and the sheath material so as to prevent magnesium from diffusing from the core material to the sheath material. The core material includes copper (Cu), silicon (Si), iron (Fe), magnesium (Mg), manganese (Mn), titanium (Ti), and aluminum (Al).

A gas tube for an EGR cooler has such a structure that a metal plate having a flat plate shape is bent in a tube shape. The metal plate includes a core material, a sheath material clad on one surface of the core material or on both surfaces thereof, and an intermediate material clad between the core material and the sheath material so as to prevent magnesium from diffusing from the core material to the sheath material. The core material includes copper (Cu), silicon (Si), iron (Fe), magnesium (Mg), manganese (Mn), titanium (Ti), and aluminum (Al).

An internal combustion engine includes a main body including an attachment portion; an EGR cooler including a portion fastened to the main body; and an EGR valve including a fixing portion fastened to the attachment portion with a bolt and a connection portion fastened to the EGR cooler. A pin is fixed to one of the fixing portion and the attachment portion. An insertion hole into which the pin is inserted is arranged in the other one of the fixing portion and the attachment portion. An inner diameter of the insertion hole is greater than an outer diameter of the pin, and a value obtained by subtracting the outer diameter of the pin from the inner diameter of the insertion hole is less than a value obtained by subtracting a shank diameter of the bolt from an inner diameter of a bolt hole in the fixing portion.

An internal combustion engine includes a main body including an attachment portion; an EGR cooler including a portion fastened to the main body; and an EGR valve including a fixing portion fastened to the attachment portion with a bolt and a connection portion fastened to the EGR cooler. A pin is fixed to one of the fixing portion and the attachment portion. An insertion hole into which the pin is inserted is arranged in the other one of the fixing portion and the attachment portion. An inner diameter of the insertion hole is greater than an outer diameter of the pin, and a value obtained by subtracting the outer diameter of the pin from the inner diameter of the insertion hole is less than a value obtained by subtracting a shank diameter of the bolt from an inner diameter of a bolt hole in the fixing portion.