Abstract: There is provided an ignition timing control device for an internal combustion engine capable of appropriately performing knock learning by performing knock learning adapted to an engine combustion phenomenon. The inventor has found the principle of a knock reduction effect due to ignition retard is that “if a combustion period moves toward the retard side, a cylinder volume during the combustion period increases, resulting in curbing of rise in the temperature and pressure of unburned gas”. An ignition timing control device according to the present invention is capable of new knock learning based on the principle, which learns a “cylinder volume rate”. The cylinder volume rate is a parameter determined from the amount of change in cylinder volume. Even when an operational status changes, learned ignition timing obtained from knock control means can be set to an appropriate value by reflecting the learned cylinder volume rate.

Abstract: There is provided an ignition timing control device for an internal combustion engine capable of appropriately performing knock learning by performing knock learning adapted to an engine combustion phenomenon. The inventor has found the principle of a knock reduction effect due to ignition retard is that “if a combustion period moves toward the retard side, a cylinder volume during the combustion period increases, resulting in curbing of rise in the temperature and pressure of unburned gas”. An ignition timing control device according to the present invention is capable of new knock learning based on the principle, which learns a “cylinder volume rate”. The cylinder volume rate is a parameter determined from the amount of change in cylinder volume. Even when an operational status changes, learned ignition timing obtained from knock control means can be set to an appropriate value by reflecting the learned cylinder volume rate.

Abstract: A control apparatus for an internal combustion engine of the present invention switches a steady-state characteristic that defines a relation between an engine load factor and a throttle opening degree between a high atmospheric pressure steady-state characteristic and a low atmospheric pressure steady-state characteristic in accordance with whether or not the atmospheric pressure is higher than a predetermined value. According to the low atmospheric pressure steady-state characteristic, a throttle opening degree corresponding to an identical engine load factor is set to a smaller value compared to the high atmospheric pressure steady-state characteristic in a medium load region, and the throttle opening degree is set so as to increase as the engine load factor increases towards a full load in a region on the side of a higher load factor than the medium load region.

Abstract: A base in-cylinder volume is corrected by a learned value to calculate a corrected in-cylinder volume. A difference of a crank angle which gives the corrected in-cylinder volume and the base crank angle is calculated as a “crank angle correction value”, and a base ignition timing is corrected by the crank angle correction value and feedback correction value. An in-cylinder volume at a crank angle where a combustion ratio became a set ratio at the previous combustion is calculated as a “previous in-cylinder volume VFp”, a difference ?VFp of the previous in-cylinder volume VFp with respect to the base in-cylinder volume VBp at the previous combustion is calculated, and the learned value ?VL is updated based on the in-cylinder volume difference VFp.

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: An internal combustion engine which is provided with a variable compression ratio mechanism which can change a mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve. A target operating point which can be reached after a fixed time without entering no-entry regions from the current operating point toward an operating point which satisfies the demanded intake air amount is calculated for an operating point which shows a combination of the mechanical compression ratio and the closing timing of the intake valve when the demanded intake air amount changes, and the mechanical compression ratio and the closing timing of the intake valve are made to change toward this target operating point.

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: In the present spark ignition internal combustion engine, a shortest self-ignition delay time ?min for a maximum cylinder internal pressure Pmax and a maximum cylinder internal temperature Tmax when equivolume combustion is realized is calculated by using a calculation formula which uses a cylinder internal pressure and a cylinder internal temperature to calculate an self-ignition delay time, and a knock limit ignition timing ITA is determined by the calculated shortest self-ignition delay time as the basis to determine.

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: An internal combustion engine which is provided with a variable compression ratio mechanism which can change a mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve. No-entry regions (X1, X2) are set for a combination of the mechanical compression ratio, the closing timing of the intake valve, and the intake air amount. Furthermore, a no-entry layer is set so as to surround the no-entry region (X2). When the demanded intake air amount is made to decrease and the operating point moves toward the no-entry region (X2), the operating point is prohibited from entering the no-entry layer whereby the operating point is blocked from entering the no-entry region (X2).

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 an electronic control unit that predicts 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: 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: An internal combustion engine which is provided with a variable compression ratio mechanism which can change a mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve. No-entry regions (X1, X2) are set for a combination of the mechanical compression ratio, the closing timing of the intake valve, and the intake air amount. Furthermore, a no-entry layer is set so as to surround the no-entry region (X2). When the demanded intake air amount is made to decrease and the operating point moves toward the no-entry region (X2), the operating point is prohibited from entering the no-entry layer whereby the operating point is blocked from entering the no-entry region (X2).

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: An internal combustion engine which is provided with a variable compression ratio mechanism which can change a mechanical compression ratio and a variable valve timing mechanism which can control a closing timing of an intake valve. A target operating point which can be reached after a fixed time without entering no-entry regions from the current operating point toward an operating point which satisfies the demanded intake air amount is calculated for an operating point which shows a combination of the mechanical compression ratio and the closing timing of the intake valve when the demanded intake air amount changes, and the mechanical compression ratio and the closing timing of the intake valve are made to change toward this target operating point.

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: 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: 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: 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.