A rotation adjusting device is controlled such that an engine speed rising rate at the time of acceleration request is made smaller when a turbocharging pressure is lower than the turbocharging pressure is higher. Therefore, an engine speed can be increased at such a low speed that a rising delay in the turbocharging pressure hardly occurs, in a low turbocharging pressure region. Further, when the rotation adjusting device is controlled such that the engine speed rising rate at the time of the acceleration request is set to a value corresponding to the turbocharging pressure, an MG2 torque is controlled to compensate for an insufficient drive torque of an actual engine torque for a request engine torque. Therefore, even when the engine torque is increased slowly by increasing the engine speed at a slow speed, the insufficient drive torque is compensated for by the MG2 torque.

Provided is an internal combustion engine control device capable of maintaining an activation temperature of a catalyst while suppressing deterioration of an exhaust gas in a hybrid engine. To this end, the internal combustion engine control device of the present invention controls an internal combustion engine in an engine for a hybrid vehicle. The internal combustion engine has a catalyst that purifies the harmful substances in the exhaust gas and a catalyst temperature detection unit that detects the temperature of the catalyst. Then, when the temperature of the catalyst detected by the catalyst temperature detection unit does not reach a predetermined temperature, the internal combustion engine control device performs a catalyst temperature rise control for increasing the temperature of the catalyst and performs motoring.

A method for starting a compression ignition engine having at least one cylinder with a reciprocating piston located therein, an intake valve configured to control the intake of air to an intake port of the cylinder and an exhaust valve configured to control the expulsion of gas from an exhaust port of the cylinder. The method includes the steps of: cranking the engine, conditioning intake air at the intake port of the cylinder to raise the temperature of air in the cylinder, controlling a valve timing the intake valve and/or the exhaust valve to allow the piston to compress the air within the cylinder, thereby increasing the temperature of the air within the cylinder, and injecting fuel into the cylinder when the air within the cylinder has been heated to a temperature sufficient to support compression ignition of a gasoline and air mixture within the cylinder.

In the method according to example embodiments, dynamic pressure oscillations in the inlet tract of the respective internal combustion engine are measured during normal operation, and from these a corresponding pressure oscillation signal is generated. A crankshaft phase angle signal is acquired at the same time. The pressure oscillation signal is used to determine an actual value of at least one characteristic of at least one selected signal frequency of the measured pressure oscillations in relation to the crankshaft phase angle signal, and the current compression ratio is determined on the basis of the determined actual value and using reference values of the corresponding characteristic of the respective same signal frequency for different compression ratios.

A rotation adjusting device is controlled such that an engine speed rising rate at the time of acceleration request is made smaller when a turbocharging pressure is lower than the turbocharging pressure is higher. Therefore, an engine speed can be increased at such a low speed that a rising delay in the turbocharging pressure hardly occurs, in a low turbocharging pressure region. Further, when the rotation adjusting device is controlled such that the engine speed rising rate at the time of the acceleration request is set to a value corresponding to the turbocharging pressure, an MG2 torque is controlled to compensate for an insufficient drive torque of an actual engine torque for a request engine torque. Therefore, even when the engine torque is increased slowly by increasing the engine speed at a slow speed, the insufficient drive torque is compensated for by the MG2 torque.

A device for controlling the compression rate of a variable compression ratio engine comprises: an actuating cylinder comprising a piston defining two chambers for receiving a pressure fluid, a pressure accumulator supplying the pressure fluid, a first fluid circuit connecting the upper chamber to the accumulator and comprising a first valve assembly for controlling the flow of the fluid in the first fluid circuit, and a second fluid circuit connecting the lower chamber to the accumulator and comprising a second valve assembly for controlling the flow of a fluid in the second fluid circuit. At least one of the fluid circuits comprises a bypass conduit arranged so as to connect one of the chambers to the accumulator. The bypass conduit comprises a non-return valve.

In the method according to example embodiments, dynamic pressure oscillations in the inlet tract of the respective internal combustion engine are measured during normal operation, and from these a corresponding pressure oscillation signal is generated. A crankshaft phase angle signal is acquired at the same time. The pressure oscillation signal is used to determine an actual value of at least one characteristic of at least one selected signal frequency of the measured pressure oscillations in relation to the crankshaft phase angle signal, and the current compression ratio is determined on the basis of the determined actual value and using reference values of the corresponding characteristic of the respective same signal frequency for different compression ratios.

An internal combustion engine variable operation system includes: an intake-side variable valve mechanism for controlling an opening timing and a closing timing of an intake valve of an internal combustion engine; an exhaust-side variable valve mechanism for controlling an opening timing and a closing timing of an exhaust valve of the internal combustion engine. At a cold start of the internal combustion engine, the exhaust-side variable valve mechanism sets the opening timing of the exhaust valve advanced at or close to a midpoint between top dead center and bottom dead center, and sets the closing timing of the exhaust valve advanced at a first preset advance-side point before top dead center, and the intake-side variable valve mechanism sets the opening timing of the intake valve retarded at a first preset retard-side point after top dead center.

Provided is an engine control device that can suppress an increase in PM/PN in an engine that performs a catalyst warm-up mode. To do so, the engine control device according to the present invention synchronously controls ignition timing and an actual compression ratio of the engine in the catalyst warm-up mode.

A device for controlling the compression rate of a variable compression ratio engine comprises: an actuating cylinder comprising a piston defining two chambers for receiving a pressure fluid, a pressure accumulator supplying the pressure fluid, a first fluid circuit connecting the upper chamber to the accumulator and comprising a first valve assembly for controlling the flow of the fluid in the first fluid circuit, and a second fluid circuit connecting the lower chamber to the accumulator and comprising a second valve assembly for controlling the flow of a fluid in the second fluid circuit. At least one of the fluid circuits comprises a bypass conduit arranged so as to connect one of the chambers to the accumulator. The bypass conduit comprises a non-return valve.