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.

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.

In an intake apparatus of an internal combustion engine, an EGR gas inlet port of each of plural EGR gas distribution pipes is provided at a position at which a volume of an intake port from a surge tank to the EGR gas inlet port is equal to or greater than a volume of an EGR gas introduced to an intake pipe from each of the EGR gas distribution pipes during one cycle of the internal combustion engine and at a position towards the surge tank relative to a center of the intake port in a flow direction thereof.

An exhaust gas recirculation device for an engine including a plurality of cylinders and intake branch passages is provided. The exhaust gas recirculation device includes an exhaust chamber and distribution passages for the respective cylinders. The exhaust chamber is connected to an exhaust passage of the engine, and exhaust gas from the exhaust passage is introduced into the exhaust chamber. The distribution passages connect the exhaust chamber to the intake branch passages for the respective cylinders so as to recirculate the exhaust gas back into the intake branch passages. The flow passage area of a first portion of each of the distribution passages is smaller than the flow passage area of a second portion of each of the distribution passages. The first portion is connected to the corresponding intake branch passage, and the second portion is connected to the exhaust chamber.

An exhaust gas recirculation device for an engine including a plurality of cylinders and intake branch passages is provided. The exhaust gas recirculation device includes an exhaust chamber and distribution passages for the respective cylinders. The exhaust chamber is connected to an exhaust passage of the engine, and exhaust gas from the exhaust passage is introduced into the exhaust chamber. The distribution passages connect the exhaust chamber to the intake branch passages for the respective cylinders so as to recirculate the exhaust gas back into the intake branch passages. The flow passage area of a first portion of each of the distribution passages is smaller than the flow passage area of a second portion of each of the distribution passages. The first portion is connected to the corresponding intake branch passage, and the second portion is connected to the exhaust chamber.

An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

An engine system is provided, which includes an engine, a swirl control valve, and a controller. The engine includes a cylinder, a piston, and a fuel injection valve provided incliningly with respect to an axial direction of the piston and configured to directly inject fuel into the cylinder. The swirl control valve is provided inside an intake passage and generates a swirl flow inside the cylinder at least when the valve closes. When an engine load is below a given threshold, the controller controls the swirl control valve to close, and controls the fuel injection valve to inject fuel during an intake stroke. While the engine load is below the threshold, at a fixed engine speed, the controller controls to advance a fuel injection timing when the engine load is at a first load, compared with at a second load higher than the first load.

A gas distribution unit includes four EGR inflow ports connected one to each of a plurality of branch pipes of an intake unit provided with a collecting pipe and the branch pipes, a EGR chamber located upstream of and connected to the EGR inflow ports, and a branch passage part located upstream of and connected to the EGR chamber to uniformly distribute EGR gas introduced through a gas inflow port into the EGR chamber.

A gas distribution unit includes four EGR inflow ports connected one to each of a plurality of branch pipes of an intake unit provided with a collecting pipe and the branch pipes, a EGR chamber located upstream of and connected to the EGR inflow ports, and a branch passage part located upstream of and connected to the EGR chamber to uniformly distribute EGR gas introduced through a gas inflow port into the EGR chamber.

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.