Abstract: The center injection engine is an engine equipped with the direct injector and an ignition apparatus at center of a ceiling part of the combustion chamber. The positive tumble flow flows from the intake port side to the exhaust port side on the ceiling part side of the combustion chamber, and also flows from the exhaust port side to the intake port side on the piston top part side. The ECU calculates the injection timing of the direct injector based on the engine load. In the first injection control, the higher the engine load becomes, the more the end crank angle is retarded.

Abstract: The present invention separates radiation from an object by a polarization filter 3 into polarized light beams, causes one of the beams to enter a spectrum analyzer 7 through a first optical path, causes the other to enter the spectrum analyzer 7 through a second optical path, and measures the two-color ratio, while causes radiation of a blackbody 2 placed in a vacuum ultralow temperature thermostatic chamber 1 in a quasi-thermal equilibrium state at an ultralow temperature in vacuo to enter the polarization filter 3 through a third optical path, separates the radiation into polarized light beams, causes the beams to each enter the same optical paths as the respective optical paths for the radiation of the object, causes the beams to enter the spectrum analyzer 7, measures the two-color ratio, and accurately obtains the temperature of the object on the basis of these two two-color ratios.

Abstract: The center injection engine is an engine equipped with the direct injector and an ignition apparatus at center of a ceiling part of the combustion chamber. The positive tumble flow flows from the intake port side to the exhaust port side on the ceiling part side of the combustion chamber, and also flows from the exhaust port side to the intake port side on the piston top part side. The ECU calculates the injection timing of the direct injector based on the engine load. In the first injection control, the higher the engine load becomes, the more the end crank angle is retarded.

Abstract: In an upstream portion from a valve connecting surface that is formed in an opening of an intake port to a combustion chamber, an upper wall surface of the intake port continues from an upstream side end of the valve connecting surface and extends substantially straight and diagonally with respect to a ceiling surface on the intake port side. In addition, a cross-sectional shape of the portion in the intake port in a direction perpendicular to an axial direction of the intake port is a flat shape with an axis in a transverse direction being a long axis.

Abstract: An intake port of an internal combustion engine is connected to a combustion chamber and includes a connecting portion having a passage cross-sectional area that increases as the connecting portion approaches the combustion chamber, and an upstream portion connected to an upstream end of the connecting portion. The connecting portion is provided at its downstream end with a valve seat with which an umbrella part of an intake valve is brought into contact. At least one recess extending in an extending direction of the intake port and included in the connecting portion and the upstream portion is provided at least at one of two portions, the two portions located on both sides in an extending direction of an output shaft, of a peripheral surface of the intake port.

Abstract: The present invention separates radiation from an object by a polarization filter 3 into polarized light beams, causes one of the beams to enter a spectrum analyzer 7 through a first optical path, causes the other to enter the spectrum analyzer 7 through a second optical path, and measures the two-color ratio, while causes radiation of a blackbody 2 placed in a vacuum ultralow temperature thermostatic chamber 1 in a quasi-thermal equilibrium state at an ultralow temperature in vacuo to enter the polarization filter 3 through a third optical path, separates the radiation into polarized light beams, causes the beams to each enter the same optical paths as the respective optical paths for the radiation of the object, causes the beams to enter the spectrum analyzer 7, measures the two-color ratio, and accurately obtains the temperature of the object on the basis of these two two-color ratios.

Abstract: In an upstream portion from a valve connecting surface that is formed in an opening of an intake port to a combustion chamber, an upper wall surface of the intake port continues from an upstream side end of the valve connecting surface and extends substantially straight and diagonally with respect to a ceiling surface on the intake port side. In addition, a cross-sectional shape of the portion in the intake port in a direction perpendicular to an axial direction of the intake port is a flat shape with an axis in a transverse direction being a long axis.

Abstract: 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.

Abstract: An intake port of an internal combustion engine is connected to a combustion chamber and includes a connecting portion having a passage cross-sectional area that increases as the connecting portion approaches the combustion chamber, and an upstream portion connected to an upstream end of the connecting portion. The connecting portion is provided at its downstream end with a valve seat with which an umbrella part of an intake valve is brought into contact. At least one recess extending in an extending direction of the intake port and included in the connecting portion and the upstream portion is provided at least at one of two portions, the two portions located on both sides in an extending direction of an output shaft, of a peripheral surface of the intake port.

Abstract: High pressure regions (31H to 35H) and low pressure regions (31L to 34L) are created based on the exhaust gas flow at curves in an EGR pipe (30), thereby enabling the exhaust gas pressure at inlets (21b to 26b) of gas introduction passages (21a to 26a) to be adjusted. Accordingly, regardless of the number of cylinders or whether the lengths of the flow paths of the EGR pipe (30) are the same, the exhaust pressure at the inlets (21b to 26b) of the gas introduction passages (21a to 26a) can be appropriately adjusted so any difference in pressure of exhaust gas introduced into branch pipes (21 to 26) can be reduced. In this way, the EGR rates of the cylinders can be made closer or the same such that stable combustion can be achieved, thus enabling stable engine operation to be maintained. The EGR pipe (30) is arranged weaving closely between the branch pipes (21 to 26) so space efficiency can be improved and a sufficient amount of exhaust gas can be introduced evenly into the cylinders.

Abstract: High pressure regions (31H to 35H) and low pressure regions (31L to 34L) are created based on the exhaust gas flow at curves in an EGR pipe (30), thereby enabling the exhaust gas pressure at inlets (21b to 26b) of gas introduction passages (21a to 26a) to be adjusted. Accordingly, regardless of the number of cylinders or whether the lengths of the flow paths of the EGR pipe (30) are the same, the exhaust pressure at the inlets (21b to 26b) of the gas introduction passages (21a to 26a) can be appropriately adjusted so any difference in pressure of exhaust gas introduced into branch pipes (21 to 26) can be reduced. In this way, the EGR rates of the cylinders can be made closer or the same such that stable combustion can be achieved, thus enabling stable engine operation to be maintained. The EGR pipe (30) is arranged weaving closely between the branch pipes (21 to 26) so space efficiency can be improved and a sufficient amount of exhaust gas can be introduced evenly into the cylinders.

Abstract: An exhaust manifold has a first upstream pipe connected to an exhaust ports of a group of cylinders of within an engine; a second upstream pipe connected to exhaust ports of cylinders other than the group of cylinders; and a merging pipe that merges the downstream ends of the first and second upstream pipe. The first upstream pipe is formed by a plurality of pipes and each pipe of the plurality of pipes forms a separate exhaust path that extends from the exhaust ports to the inside the merging pipe, and the second upstream pipe encloses the plurality of pipes and forms, between an inner surface of the second upstream pipe and an outer surface of the plurality of pipes, a plurality of exhaust paths that extend from the exhaust ports other than the exhaust ports of the group of cylinders to the inside of the merging pipe.