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.

An EGR system is configured to allow a part of exhaust gas discharged from an engine to an exhaust passage to flow as an EGR gas to an intake passage through an EGR passage to return to the engine. The EGR system includes a heating film provided on an inner wall of at least one of the intake passage through which the EGR gas flows, i.e., an intake manifold, and the EGR passage, at least one pair of a positive electrode and a negative electrode to energize the heating film, a water temperature sensor and an intake temperature for detecting a warm-up state of the intake passage and the EGR passage, and an electronic control unit configured to control energization of the heating film from before start of EGR based on the detected warm-up state.

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.

A cooling device includes a case delimiting an air circulation enclosure. The case comprises an air intake opening intended to be connected to an air inlet, and an air outlet opening intended to be connected to a heat engine. The cooling device includes an exhaust gas driving device housed at least partially in the air circulation enclosure. The exhaust gas driving device includes at least one exhaust gas flow sensor, each flow sensor being housed entirely in the air circulation enclosure of the case.

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.

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.

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 intake device for a multi-cylinder engine includes an intake manifold, an intercooler, and a heat insulation member. The intake manifold has an intercooler housing that is a cylindrical body formed from a resin material and internally accommodates the intercooler; and an intake air distributor that is a cylindrical body formed of a metal material and has one opening connected to one opening of the intercooler housing, the intake air distributor distributing an intake air. The heat insulation member is interposed between another opening of the intake air distributor and the cylinder head in the multi-cylinder engine.

An intake device for a multi-cylinder engine includes an intake manifold, an intercooler, and a heat insulation member. The intake manifold has an intercooler housing that is a cylindrical body formed from a resin material and internally accommodates the intercooler; and an intake air distributor that is a cylindrical body formed of a metal material and has one opening connected to one opening of the intercooler housing, the intake air distributor distributing an intake air. The heat insulation member is interposed between another opening of the intake air distributor and the cylinder head in the multi-cylinder engine.

A supercharged internal combustion engine according to the present invention includes a compressor 16a that supercharges intake air; an EGR passage 22 that connects an intake passage 12 at the upstream side of the compressor 16a and an exhaust passage 14; an EGR valve 26 that is provided in the EGR passage 22 and regulates the flow rate of EGR gas that flows through the EGR passage 22 by opening and closing the EGR passage 22; and a heat insulator 30 that is provided on a surface of the EGR valve 26 that is exposed to the EGR passage 22 which is located at the upstream side in the EGR gas flow with respect to a seal portion by a seal surface 26a1 and a valve seat 28a when the EGR valve 26 is in the fully closed position.