Abstract: In a fastening structure that fastens an exhaust manifold to a cylinder head of an engine, a bolt that extends through a flange is inserted into and fixed to a bolt hole of the cylinder head. The flange includes a contact surface that contacts a coupling surface of the cylinder head, and an inclined surface that is inclined with respect to the contact surface. A clearance is provided between the bolt and the cylinder head inside the bolt hole in a range extending from the coupling surface of the cylinder head to a specified length.

Abstract: In a fastening structure that fastens an exhaust manifold to a cylinder head of an engine, a bolt that extends through a flange is inserted into and fixed to a bolt hole of the cylinder head. The flange includes a contact surface that contacts a coupling surface of the cylinder head, and an inclined surface that is inclined with respect to the contact surface. A clearance is provided between the bolt and the cylinder head inside the bolt hole in a range extending from the coupling surface of the cylinder head to a specified length.

Abstract: A low-temperature cooling water channel formed in the internal combustion engine includes a water jacket that covers at least one portion of a wall surface of an intake port. The intake port has a cooled wall surface that is covered by the water jacket, and a non-cooled wall surface that is not covered by the water jacket. An airflow control valve is provided on an intake-air upstream side of the cooled wall surface. The airflow control valve is configured to be capable of changing a ratio between a flow rate of intake air that flows along the side of the cooled wall surface and a flow rate of intake air that flows along the side of the non-cooled wall surface. The airflow control valve is preferably configured as a tumble control valve (TCV).

Abstract: A cylinder head includes: a cylinder head body; multiple fuel ports extending to cylinders from a sidewall surface of the cylinder head body, the sidewall surface being located on one side of a longitudinal axis, on which intake ports are disposed; multiple injection valve attachment bosses projecting from the sidewall surface, surrounding openings of the fuel ports, and adapted to attach cylinder fuel injection valves to the fuel ports; and multiple projections projecting from the sidewall surface and disposed adjacent to the corresponding injection valve attachment bosses. A cylinder block includes: a cylinder block body; and a sensor attachment boss projecting from a sidewall surface of the cylinder block body, the sidewall surface being located on the one side of the longitudinal axis, on which the sidewall surface of the cylinder head body is located. The sensor attachment boss is adapted to attach a knock sensor to the cylinder block.

Abstract: The cylinder head includes: an intake port; a low-temperature cooling water channel for circulating low-temperature cooling water; a high-temperature cooling water channel for circulating cooling water of a higher temperature than the cooling water flowing through the low-temperature cooling water channel; and a gas channel for recirculating a portion of blow-by gas or EGR gas to the intake port. The low-temperature cooling water channel is configured to include a first water jacket that covers at least one portion of the wall surface of the intake port on an intake-air upstream side relative to an opening end opening at a wall surface of the intake port from the gas channel.

Abstract: A cylinder head includes: a cylinder head body; multiple fuel ports extending to cylinders from a sidewall surface of the cylinder head body, the sidewall surface being located on one side of a longitudinal axis, on which intake ports are disposed; multiple injection valve attachment bosses projecting from the sidewall surface, surrounding openings of the fuel ports, and adapted to attach cylinder fuel injection valves to the fuel ports; and multiple projections projecting from the sidewall surface and disposed adjacent to the corresponding injection valve attachment bosses. A cylinder block includes: a cylinder block body; and a sensor attachment boss projecting from a sidewall surface of the cylinder block body, the sidewall surface being located on the one side of the longitudinal axis, on which the sidewall surface of the cylinder head body is located. The sensor attachment boss is adapted to attach a knock sensor to the cylinder block.

Abstract: A low-temperature cooling water channel formed in the internal combustion engine includes a water jacket that covers at least one portion of a wall surface of an intake port. The intake port has a cooled wall surface that is covered by the water jacket, and a non-cooled wall surface that is not covered by the water jacket. An airflow control valve is provided on an intake-air upstream side of the cooled wall surface. The airflow control valve is configured to be capable of changing a ratio between a flow rate of intake air that flows along the side of the cooled wall surface and a flow rate of intake air that flows along the side of the non-cooled wall surface. The airflow control valve is preferably configured as a tumble control valve (TCV).

Abstract: An internal combustion engine includes: a low-temperature cooling water circulation system including a low-temperature cooling water channel; a high-temperature cooling water circulation system including a high-temperature cooling water channel; an intake port including a first branch port part and a second branch port part that are connected to a common combustion chamber; and a swirl control device configured to restrict the inflow of intake air from the first branch port part to the combustion chamber to increase the strength of a swirl flow generated inside a cylinder. The low-temperature cooling water channel includes a water jacket that covers the periphery of the first branch port part.

Abstract: An internal combustion engine includes: a low-temperature cooling water circulation system including a low-temperature cooling water channel; a high-temperature cooling water circulation system including a high-temperature cooling water channel; an intake port including a first branch port part and a second branch port part that are connected to a common combustion chamber; and a swirl control device configured to restrict the inflow of intake air from the first branch port part to the combustion chamber to increase the strength of a swirl flow generated inside a cylinder. The low-temperature cooling water channel includes a water jacket that covers the periphery of the second branch port part.

Abstract: The cylinder head includes: an intake port; a low-temperature cooling water channel for circulating low-temperature cooling water; a high-temperature cooling water channel for circulating cooling water of a higher temperature than the cooling water flowing through the low-temperature cooling water channel; and a gas channel for recirculating a portion of blow-by gas or EGR gas to the intake port. The low-temperature cooling water channel is configured to include a first water jacket that covers at least one portion of the wall surface of the intake port on an intake-air upstream side relative to an opening end opening at a wall surface of the intake port from the gas channel.

Abstract: A cylinder head for a multi-cylinder internal combustion engine includes a plurality of exhaust ports provided for each of a plurality of cylinders arranged in line. The plurality of exhaust ports corresponding to each of the plurality of cylinders converge at a convergent portion at a downstream side. The exhaust ports respectively corresponding to at least two of the plurality of cylinders converge at the convergent portion.

Abstract: An internal combustion engine provided with a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to control a closing timing of an intake valve. An actual compression ratio and ignition timing in a predetermined standard state after completion of engine warm-up are stored in advance as a reference actual compression ratio and a reference ignition timing. When the engine temperature is low or the intake air temperature is low, at the time of engine high speed operation, the actual compression ratio is made to increase over the reference actual compression ratio, while at the time of engine low speed operation, the ignition timing is made to advance over the reference ignition timing.

Abstract: Precision of arithmetic operations on floating-point numbers is improved while also preventing an increase in the amount of processing. A second converter converts an exponent included in an exponent field according to an exponent conversion rule defined in accordance with a function. A storage stores in a table a value obtained by converting a mantissa field according to a mantissa conversion rule defined in accordance with the function. A retrieving unit derives an index of the table, by extracting the most significant 8 bits from the 23 bits constituting the mantissa field. The retrieving unit adds 1 to the mantissa field approximated by the most significant 8 bits so as to derive a second index. A deriving unit derives a tentative return value A and a tentative return value B. Further, the deriving unit interpolates between the tentative return value A and the tentative return value B so as to derive a return value of the function.

Abstract: A variable compression ratio internal engine including at least two block portions connected to each other and moveable relative to each other so that the compression ratio can be varied. The engine includes an input gear for inputting a rotation output from an output gear to the cam shaft. The input gear and a rotation transmission shaft are constituted to be able to slide relative to each other or the output gear and the rotation transmission shaft are constituted to be able to slide relative to each other in the direction of the movement of the one block portion relative to the other block portion such that the meshing between the input gear and the cam shaft side gear or the meshing between the output gear and the crank shaft side gear is maintained when the one block portion is moved relative to the other block portion.

Abstract: An internal combustion engine provided with a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to control a closing timing of an intake valve. An actual compression ratio and ignition timing in a predetermined standard state after completion of engine warm-up are stored in advance as a reference actual compression ratio and a reference ignition timing. When the engine temperature is low or the intake air temperature is low, at the time of engine high speed operation, the actual compression ratio is made to increase over the reference actual compression ratio, while at the time of engine low speed operation, the ignition timing is made to advance over the reference ignition timing.

Abstract: A variable compression ratio internal engine including at least two block portions connected to each other and moveable relative to each other so that the compression ratio can be varied. The engine includes an input gear for inputting a rotation output from an output gear to the cam shaft. The input gear and a rotation transmission shaft are constituted to be able to slide relative to each other or the output gear and the rotation transmission shaft are constituted to be able to slide relative to each other in the direction of the movement of the one block portion relative to the other block portion such that the meshing between the input gear and the cam shaft side gear or the meshing between the output gear and the crank shaft side gear is maintained when the one block portion is moved relative to the other block portion.

Abstract: Precision of arithmetic operations on floating-point numbers is improved while also preventing an increase in the amount of processing. A second converter converts an exponent included in an exponent field according to an exponent conversion rule defined in accordance with a function. A storage stores in a table a value obtained by converting a mantissa field according to a mantissa conversion rule defined in accordance with the function. A retrieving unit derives an index of the table, by extracting the most significant 8 bits from the 23 bits constituting the mantissa field. The retrieving unit adds 1 to the mantissa field approximated by the most significant 8 bits so as to derive a second index. A deriving unit derives a tentative return value A and a tentative return value B. Further, the deriving unit interpolates between the tentative return value A and the tentative return value B so as to derive a return value of the function.