An intake manifold provided in an internal combustion engine to be mounted in a vehicle includes: a plurality of intake-air branch pipes; an EGR chamber configured such that EGR gas is introduced into the EGR chamber; and a plurality of EGR ports communicating the plurality of intake-air branch pipes with the EGR chamber. A chamber bottom face is provided with a plurality of recessed zones so as to correspond to the plurality of EGR ports, each of the plurality of recessed zones is provided near an opening of its corresponding EGR port on an EGR-chamber side, and all planes constituting the each of the plurality of recessed zones is configured to be inclined so as to be placed on a mounting lower side toward a position closer to the opening, as compared with a position away from the opening.

A control apparatus for an internal combustion engine according to the invention is applied to an internal combustion engine in which EGR gas and condensed water generated by an EGR cooler are supplied into a cylinder. The control apparatus calculates an equivalence ratio of the internal combustion engine, and controls an EGR valve and a condensed water supply valve such that, when the equivalence ratio is high, a supply rate of the condensed water increases and a supply rate of the EGR gas decreases relative to when the equivalence ratio is low.

An intake apparatus includes an intake apparatus body including a plurality of intake pipes and a distribution passage including a gas passage before branching which includes a first gas passage through which the external gas flows in a first gas flow direction and a second gas passage through which the external gas flows in a second gas flow direction, the second gas passage curving relative to the first gas passage at a downstream, and a gas passage after branching including a third gas passage branched in the first gas flow direction relative to the second gas passage and a fourth gas passage branched in an opposite direction from the first gas flow direction relative to the second gas passage, an angle formed between the second gas passage and the third gas passage is smaller than an angle formed between the second gas passage and the fourth gas passage.

An engine having an integrated heat exchanger includes a cylinder head defining combustion chambers; an intercooler embedded at an intake side in the cylinder head and cooling intake gas by using a coolant; an EGR cooler embedded in the cylinder head and cooling exhaust gas, which is discharged from an exhaust side of the combustion chambers and recirculates to the intake side of the combustion chambers through an EGR passageway formed in the cylinder head; and an EGR distribution tube formed at an upper side in the cylinder head, supplied with the exhaust gas passing through the EGR cooler, and having distribution holes through which the exhaust gas is distributed into intake ports connected with the combustion chambers.

An engine having an integrated heat exchanger includes a cylinder head defining combustion chambers; an intercooler embedded at an intake side in the cylinder head and cooling intake gas by using a coolant; an EGR cooler embedded in the cylinder head and cooling exhaust gas, which is discharged from an exhaust side of the combustion chambers and recirculates to the intake side of the combustion chambers through an EGR passageway formed in the cylinder head; and an EGR distribution tube formed at an upper side in the cylinder head, supplied with the exhaust gas passing through the EGR cooler, and having distribution holes through which the exhaust gas is distributed into intake ports connected with the combustion chambers.

A dual path exhaust gas recirculation (EGR) system for an engine includes a common EGR intake path and first and second low pressure EGR paths including respective first and second EGR valves. The common EGR intake path is connected to the exhaust system downstream of a catalyst and includes an EGR cooler. The first EGR path is coupled directly to the EGR cooler and an inlet of a turbocompressor. The second EGR path is coupled directly to the EGR cooler and the intake system, thereby bypassing the turbocharger and an engine throttle valve. The engine includes an absence of any high pressure EGR path and the EGR valves are controlled such that the first EGR valve is closed and the second EGR valve is open at low engine speed and load operating conditions thereby providing EGR directly to the intake system that bypasses the turbocharger and throttle valve.

A dual path exhaust gas recirculation (EGR) system for an engine includes a common EGR intake path and first and second low pressure EGR paths including respective first and second EGR valves. The common EGR intake path is connected to the exhaust system downstream of a catalyst and includes an EGR cooler. The first EGR path is coupled directly to the EGR cooler and an inlet of a turbocompressor. The second EGR path is coupled directly to the EGR cooler and the intake system, thereby bypassing the turbocharger and an engine throttle valve. The engine includes an absence of any high pressure EGR path and the EGR valves are controlled such that the first EGR valve is closed and the second EGR valve is open at low engine speed and load operating conditions thereby providing EGR directly to the intake system that bypasses the turbocharger and throttle valve.

An engine system with exhaust gas recirculation includes a combustion engine, a flow mixer, and a turbocharger. An exhaust flow path and a charge air flow path each extend to an inlet of the flow mixer, and a mixed gas flow path extends between the outlet of the flow mixer and an intake manifold of the engine. A charge air heat exchanger is arranged along the charge air flow path to cool the charge air, and a mixed gas heat exchanger is arranged along the mixed gas flow path to cool mixed charge air and recirculated exhaust gas. The exhaust gas recirculation flow path does not extend through any heat exchangers.

An engine system with exhaust gas recirculation includes a combustion engine, a flow mixer, and a turbocharger. An exhaust flow path and a charge air flow path each extend to an inlet of the flow mixer, and a mixed gas flow path extends between the outlet of the flow mixer and an intake manifold of the engine. A charge air heat exchanger is arranged along the charge air flow path to cool the charge air, and a mixed gas heat exchanger is arranged along the mixed gas flow path to cool mixed charge air and recirculated exhaust gas. The exhaust gas recirculation flow path does not extend through any heat exchangers.

An exhaust-gas recirculation device is configured to be attached to a cylinder block including cylinders individually including built-in pistons and cause a portion of exhaust gas flowing through an exhaust system to recirculate to an intake system. The exhaust-gas recirculation device includes an intake manifold, a recirculation pipe, and a recirculation manifold. The intake manifold includes intake branches each including an intake passage communicating with an intake port and is configured to be disposed at the cylinder block. The recirculation pipe is coupled to an exhaust manifold capable of guiding the exhaust gas outward. The recirculation manifold includes recirculation branches each provided with a recirculation passage communicating with the intake passage via an introduction hole and is coupled to the recirculation pipe. The introduction hole has an inner diameter at a recirculation-passage side that is larger than an inner diameter at an intake-passage side.