Abstract: A control pattern corresponding to a ultra high expansion cycle is executed, wherein an actual timing IVCa of an intake valve closing timing is controlled to agree with a steady adapted value IVCt, an actual value ?ma of a mechanical compression ratio is controlled to agree with a steady adapted value ?mt, and an ignition timing SA is controlled to agree with a steady adapted timing SAt. There are four cases that might be generated, including a case in which the IVCa is shifted toward a retard angle side or toward an advance angle side from the IVCt due to a response delay of a variable intake valve timing apparatus, and a case in which ?ma is shifted to a greater side or to a smaller side from the ?mt due to the response delay of a variable compression ratio mechanism.

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.

Abstract: In an internal combustion engine, a variable compression ratio mechanism able to change a mechanical compression ratio, a variable valve timing mechanism able to control the closing timing of the intake valve, and predicting means for predicting the temperature of the catalyst arranged in the engine exhaust passage are provided. When it is predicted that the temperature of the catalyst will fall to less than the activation temperature, the actual expansion ratio is lowered while maintaining the actual compression ratio the same or while increasing the actual compression ratio.

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 and controlling the closing timing of the intake valve (7) to control the amount of intake air fed into a combustion chamber (5). To obtain an output torque in accordance with the required torque even when the atmospheric pressure changes, when the atmospheric pressure falls, the closing timing of the intake valve (7) is made to approach intake bottom dead center and the mechanical compression ratio is reduced.

Abstract: A control device applied to a system having an engine configured such that an expansion ratio can be changed is characterized to comprise an expansion ratio acquisition part for acquiring the expansion ratio, and a temperature estimation part for estimating a temperature of an exhaust gas discharged from the engine or a member positioned in a passage for the exhaust gas.

Abstract: A spark ignition internal combustion engine in which, during an idling operation, the ignition timing is changed temporarily to the advance side or retard size with respect to the reference ignition timing so that when the engine speed deviates from the target idling speed, the engine speed becomes the target idling speed. When the actual compression ratio at the time of idling is changed, the reference ignition timing at the time of idling is made to move until the ignition timing at which the same generated torque of the engine is obtained.

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 miming 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: 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 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 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 ratio 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 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: 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: In a spark ignition type internal combustion engine that includes a variable compression ratio mechanism A capable of changing the mechanical compression ratio, and a variable valve mechanism B 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: A multi-cylinder engine is configured to be able to perform a selected cylinder operation in which combustion is stopped in some cylinders. The multi-cylinder engine includes an ignition-timing adjustment section. This ignition-timing adjustment section retards ignition timing of each operating cylinder when the number of operating cylinders is small or when the engine operates in a selected cylinder operation mode in which explosion occurs at irregular intervals. In such a case, the peak of cylinder internal pressure is lowered by ignition timing retard. Thus, vibration and noise can be suppressed effectively.

Abstract: A spark ignition internal combustion engine in which, during an idling operation, the ignition timing is changed temporarily to the advance side or retard size with respect to the reference ignition timing so that when the engine speed deviates from the target idling speed, the engine speed becomes the target idling speed. When the actual compression ratio at the time of idling is changed, the reference ignition timing at the time of idling is made to move until the ignition timing at which the same generated torque of the engine is obtained.

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 and controlling the closing timing of the intake valve (7) to control the amount of intake air fed into a combustion chamber (5). To obtain an output torque in accordance with the required torque even when the atmospheric pressure changes, when the atmospheric pressure falls, the closing timing of the intake valve (7) is made to approach intake bottom dead center and the mechanical compression ratio is reduced.

Abstract: A control apparatus calculates a exhaust gas air-fuel ratio of a plurality of cylinders, in which the operation angle of an intake valve is set to a predetermined operation angle, e.g., a maximum operation angle, based on a value output from an air-fuel ratio sensor so as to minimize a variation in an fuel injection quantity between the plurality of cylinders by that exhaust gas air-fuel ratio. That is, the exhaust gas air-fuel ratio of the plurality of cylinders, in which the valve opening characteristics of the intake valve and an exhaust valve are set such that the intake air amount to be introduced into the plurality of cylinders is limited by the opening amount of a throttle valve, for example, and not limited by the valve opening characteristics of the intake valve or the exhaust valve is calculated, and the variation in the fuel injection quantity among the plurality of cylinders is then reduced by that exhaust gas air-fuel ratio.

Abstract: A control device of a multicylinder internal combustion engine provided with a valve operating characteristic control means for controlling a valve operating characteristic of at least one of an intake valve and exhaust valve, which estimates an intake difference of cylinders and limits a control range of said valve operating characteristic in accordance with said estimated intake difference.

Abstract: The present invention relates to a device for detecting intake air amount variations among cylinders of a multiple-cylinder internal combustion engine, and makes it possible to accurately detect the intake air amount variations among the cylinders. The fuel injection amount is either increased or decreased from the injection amount for stoichiometric operation to determine the amount of a resulting change in the torque or rotation speed. The determined amount of the torque or rotation speed change is then output as an index value that indicates the degree of intake air amount variations among the cylinders.