Abstract: A spark-ignited internal combustion engine includes a variable compression ratio mechanism that changes a mechanical compression ratio and an actual compression ratio start timing-changing mechanism that changes a start timing at which actual compression starts. An actual compression ratio is changed according to the specific heat ratio of an intake gas that is supplied into a cylinder.

Abstract: In an internal combustion engine, a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to control the closing timing of an intake valve are provided. The mechanical compression ratio is held at a maximum mechanical compression ratio at the engine low load operation side and gradually made to decrease as the engine load increases at the engine high load operation side. The actual compression ratio is held nearly constant at the engine high load operation side and is made to decrease as the engine load decreases at the engine low load operation side.

Abstract: Disclosed is a spark ignition type internal combustion engine, which comprises a variable compression ratio mechanism capable of changing a mechanical compression ratio, and a variable valve timing mechanism capable of controlling the closing timing of an intake valve. The intake air flow to be fed to the inside of a combustion chamber is controlled mainly by changing the closing timing of an intake valve so that the mechanical compression ratio is set higher at an engine low-load running time than that at an engine high-load running time. The mechanical compression ratio at the engine low-load running time before completion of the warm-up of the internal combustion engine is set lower than that at the engine low-load running time after completion of the warm-up of the internal combustion engine.

Abstract: A valve drive system of internal combustion engine which operates at a high compression ratio cycle, which is provided with an intake cam 52a and intake cam 52b for operating intake valves 7a, 7b and a variable valve timing device 70 which can offset the operating timings of the intake valves 7a, 7b by the intake cam 52a and the operating timings of the intake valves 7a, 7b by the intake cam 52b from each other. The intake cam 52a and intake cam 52b include circular parts and cam noses. At least one of the cam nose of the intake cam 52a and cam nose of the intake cam 52b has a concentric circular part which is formed in a circular shape concentric with the circular part.

Abstract: The present variable compression ratio V-type internal combustion engine is a variable compression ratio V-type internal combustion engine which joins cylinder blocks of two cylinder groups and makes the joined cylinder block move relatively to a crankcase, wherein at each relative movement position of the joined cylinder block, the intake valve closing timings of the cylinders are controlled so that the actual compression ratios of the two cylinder groups become equal and thus the temperature difference and pressure difference in the cylinders at top dead center between the two cylinder groups are reduced.

Abstract: In an internal combustion engine, a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to control the closing timing of an intake valve are provided. At the time of engine low load operation, the mechanical compression is made the maximum so that the expansion ratio becomes 20 or more. Further, at the time of engine low load operation, in part of the operating region or all of the operating region, the actual compression ratio is lowered compared with the time of the engine high load operation and, at the time of engine low load operation, at least when the actual compression ratio is being lowered compared with the time of engine high load operation, the throttle valve is made to close.

Abstract: A spark-ignited internal combustion engine includes a variable compression ratio mechanism (A) that changes a mechanical compression ratio and an actual compression ratio start timing-changing mechanism (B) that changes a start timing at which actual compression starts. The maximum mechanical compression ratio while the engine is in operation is reduced with increase in engine speed.

Abstract: The present variable compression ratio V-type internal combustion engine is a variable compression ratio V-type internal combustion engine which joins cylinder blocks of two cylinder groups and makes the joined cylinder block move relatively to a crankcase, wherein the engine is provided with a first relative movement mechanism which is fastened to a first cylinder group side of the joined cylinder block through a plurality of supports and a second relative movement mechanism which is fastened to a second cylinder group side of the joined cylinder block through a plurality of supports. The number of the supports in each of the first relative movement mechanism and the second relative movement mechanism is made at least a number greater by exactly one than the number of cylinders of the first cylinder group and the second cylinder group, respectively.

Abstract: A spark ignition type internal combustion engine includes a plurality of cylinders and can stop combustion in part of these cylinders. Further, the spark ignition type internal combustion engine comprises a variable compression ratio mechanism (A) which can change an mechanical compression ratio, and a variable valve timing mechanism (B) which can control a closing timing of an intake valve. When idling part of the cylinders or increasing idled cylinders, the closing timing of an intake valve (7) moves in a direction which approaches an intake bottom dead center side, and the mechanical compression ratio of the operating cylinders falls. By idling part of the plurality of cylinders in this way, it is possible to realize a high heat efficiency even in a region where the engine load is low.

Abstract: The present variable compression ratio V-type internal combustion engine is a variable compression ratio V-type internal combustion engine which joins cylinder blocks of two cylinder groups and makes the joined cylinder block 10 move relatively to a crankcase along an arc-shaped path so as to move away from an engine crankshaft, wherein the arc-shaped path is set so that the mechanical compression ratio of one cylinder group and the mechanical compression ratio of the other cylinder group become equal when the cylinder block is at the lowest position closest to the engine crankshaft and when the cylinder block is at a specific position between the lowest position and a highest position which is furthest from the engine crankshaft.

Abstract: An engine provided with a variable timing mechanism (B) able to control a closing timing of an intake valve (7) and a variable compression ratio mechanism (A) able to change a mechanical compression ratio. At the time of engine startup, the closing timing of the intake valve (7) is made the most delayed position so that the least intake air is fed to the inside of the combustion chamber (5) and the mechanical compression ratio is made the maximum compression ratio.

Abstract: Provided is a spark ignition type internal combustion engine comprising a variable compression ratio mechanism (A) capable of changing a mechanical compression ratio, and a variable valve timing mechanism (B) capable of controlling the closing timing of an intake valve. At an engine low-load running time, the mechanical compression ratio is made so higher than that at an engine high-load running time that the expansion ratio may be 20 or higher. In case the vacuum in an engine intake passage is lower than the required vacuum, the opening of a throttle valve (17) is reduced, and the valve closing timing of the intake valve is controlled so that the intake air in a quantity according to the engine load may be fed to the inside of a combustion chamber in accordance with the opening of the throttle valve. As a result, a brake booster or the like can be properly activated in the internal combustion engine having its mechanical compression ratio enlarged at the engine low-load running time.

Abstract: In a variable compression ratio internal combustion engine that controls the compression of an internal combustion engine by changing the volume of the combustion chamber of the internal combustion engine in an axial direction of the cylinder, when a target compression ratio (?t) based on an operating condition of the internal combustion engine is at a reference compression ratio (?0) or greater (S102), the compression ratio is changed to the target compression ratio (S103). When the target compression ratio (?t) is lower than the reference compression ratio (?0) (S102), a control is executed to change the compression ratio and also to strength the tumble flow in the combustion chamber (S104).

Abstract: A variable compression ratio internal combustion engine rotates a camshaft to cause relative movement between a crankcase and a cylinder block. The camshaft has a shaft member, a cam member fixed to the shaft member, and a movable bearing member rotatable with respect to the shaft member. The cam member is rotatably housed in a cam housing hole formed in the crankcase, and the movable bearing member is rotatably housed a bearing housing hole formed in the cylinder block.

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 individually control the opening timing and closing timing of the intake valve. At the time of engine low load operation, the maximum expansion ratio is obtained by making the mechanical compression ratio maximum and, while the mechanical compression ratio is made maximum, the opening timing of the intake valve is maintained at a target opening timing of substantially intake top dead center in the noninterference region where no interference between the valve and the piston occurs.

Abstract: A high expansion ratio internal combustion engine includes: a variable compression ratio mechanism that varies a mechanical compression ratio of the internal combustion engine; and a variable valve train in which some valve(s) of a plurality of intake valves is phase-variable and the remaining valve(s) is phase-fixed, the variable valve train being configured such that a working angle of the phase-variable intake valve is larger than a working angle of the phase-fixed intake valve, wherein a valve-open timing of the phase-variable intake valve is retarded after a valve-open timing of the phase-fixed intake valve when the internal combustion engine is under low-load operating state.

Abstract: A silica structure includes mesoporous silica spheres; and connection portions each of which includes metal oxide, and each of which connects the mesoporous silica spheres to each other.

Abstract: In an internal combustion engine, a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to control the closing timing of an intake valve are provided. The mechanical compression ratio is made to be the maximum mechanical compression ratio at low load operation regions excluding idling operation, while during idling operation, the mechanical compression ratio is made lower than the maximum mechanical compression ratio.

Abstract: In a spark ignition type internal combustion engine that includes a variable compression ratio mechanism capable of changing the mechanical compression ratio, and a variable valve mechanism capable of changing valve characteristics of an intake valve or an exhaust valve, the variable valve mechanism is mechanically coupled to the variable compression ratio mechanism, and the variable valve mechanism is controlled in accordance with the compression ratio-changing operation amount of the variable compression ratio mechanism. The variable valve mechanism is coupled to the variable compression ratio mechanism without intervention of an electronic control unit. Therefore, the possibility of the interference between a piston and an intake valve resulting from an abnormality in a control system that includes an electronic control unit as an intervening unit can be eliminated.

Abstract: In an internal combustion engine, a variable compression ratio mechanism able to change a mechanical compression ratio and a variable valve timing mechanism able to control the closing timing of an intake valve are provided. The mechanical compression ratio is held at a maximum mechanical compression ratio at the engine low load operation side and gradually made to decrease as the engine load increases at the engine high load operation side. The actual compression ratio is held nearly constant at the engine high load operation side and is made to decrease as the engine load decreases at the engine low load operation side.