A control system for an engine including intake and exhaust valve phase variable devices and a control device is provided. At an engine temperature below a first determination temperature, the control is performed so that an exhaust valve close timing is at or retarded from the exhaust top dead center, an intake valve open timing is retarded from the exhaust valve close timing, and the fuel supply to the combustion chamber starts in an intake stroke on a retarding side of the exhaust valve close timing. At the engine temperature above the first determination temperature and below a second determination temperature, the control is performed so that a negative overlap with both the exhaust and intake valves closed during a period including the exhaust top dead center, or a positive overlap with both the exhaust and intake valves opened during a period including the exhaust top dead center, occurs.

A control device for an internal combustion engine includes an internal combustion engine and a valve opening-closing timing control device. The valve opening-closing timing control device has a phase adjustment mechanism for setting a relative rotation phase of a driving-side rotator and a driven-side rotator. The phase adjustment mechanism overlaps a timing of opening an intake valve with a timing of opening an exhaust valve, by setting, in a predetermined period, the relative rotation phase such that the exhaust valve closes after a top dead center position has been reached, and a bypass passage is provided that connects an exhaust passage of one cylinder that is in an exhaust process to the exhaust passage of another cylinder that is in an intake process at the same time as the exhaust process.

A method for operating an internal combustion engine, in particular of a motor vehicle, in an engine braking operating, having at least one engine braking mode and having at least one cylinder at least of a first cylinder bank, where the at least one cylinder has at least one outlet valve and at least one inlet valve, where, in a first engine braking mode, an outlet stroke of all outlet valves of the at least one cylinder of the first cylinder bank of the internal combustion engine is permanently switched off.

Various embodiments include a method for detecting deviations occurring in the valve drive of an internal combustion engine comprising: measuring dynamic pressure oscillations of intake air in an air intake tract of respective internal combustion engine during operation; calculating an inlet valve stroke phase difference and/or an outlet valve stroke phase difference based on the measured dynamic pressure oscillation; calculating a valve stroke phase deviation value with respect to a valve stroke phase reference value based on the calculated phase difference; and calculating a first valve drive deviation value based on the valve stroke phase deviation value.

A control device for an engine is provided, which includes variable intake and exhaust valve operating mechanisms, a supercharger provided to an intake passage and configured to boost intake air introduced into a cylinder, and a controller. The controller drives the supercharger when the engine operates in a boosted range. The controller controls the variable intake and exhaust valve operating mechanisms so that a valve overlap period during which intake and exhaust valves open simultaneously is formed, when the engine operates in a low-speed boosted range of the boosted range where the engine speed is less than a reference speed. The controller controls the variable exhaust valve operating mechanism so that the open timing of the exhaust valve is more advanced when the engine operates in a high-speed boosted range of the boosted range where the engine speed is greater than or equal to the reference speed.

An internal combustion engine system includes an internal combustion engine and a control device. A difference of an intake valve closing timing with respect to a compression top dead center is referred to as a first crank angle difference; a difference of an exhaust valve closing timing with respect to an exhaust top dead center is referred to as a second crank angle difference; and a difference between the first crank angle difference and the second crank angle difference is referred to as an intake/exhaust closing timing difference. The control device is configured to execute: a fuel cut processing; and a valve driving processing to control at least one of the intake valve closing timing and the exhaust valve closing timing such that the intake/exhaust closing timing difference becomes smaller during a fuel cut operation than during a non-fuel cut operation.

A storage device stores mapping data and association data. The mapping data defines a mapping that outputs an estimated value of the temperature of a catalyst using a warm-up operation amount variable and the previous value of the estimated value as an input. The association data associates the integrated value of an intake air amount of an internal combustion engine from the startup of the engine and the temperature of the catalyst. The execution device repeatedly calculates the estimated value based on the output of the mapping. When the correspondence relationship between the integrated value and the estimated value is different from the correspondence relationship between the integrated value and the temperature of the catalyst in the association data, the warm-up process is determined to have an anomaly.

A control device for an engine 1 including cylinders, and configured to perform a reduced-cylinder operation by idling some of cylinders. The control device includes a hydraulic valve-stopping mechanism 14b which closes the intake and exhaust valves 41, 51 of the cylinders in response to establishment of the reduced-cylinder operation execution condition, a hydraulic variable valve timing mechanism 19 capable of changing a phase of the exhaust valve 51 of the engine 1, and an ECU 110 which controls the valve-stopping mechanism 14b and the hydraulic variable valve timing mechanism 19. In response to establishment of the reduced-cylinder operation execution condition, the ECU 110 allows the hydraulic variable valve timing mechanism 19 to execute the phase change to the exhaust valve 51, and subsequently allows the valve-stopping mechanism 14b to bring the intake and exhaust valves 41, 51 of the cylinders into closed state.

A driving-side rotating body that rotates synchronously with a crankshaft of an internal combustion engine, a driven-side rotating body that is allowed to rotate relative to the driven-side rotating body and that rotates integrally with a camshaft that opens and closes an intake valve, and a phase adjustment mechanism for setting a relative rotation phase of the driving-side rotating body and the driven-side rotating body using a driving force of an electric motor are included. The phase adjustment mechanism is configured to be able to execute retarding control for setting the relative rotation phase to the retarding side until reaching a phase in which the internal combustion engine cannot be started and autonomous running is not possible even if fuel injection and ignition are performed in the internal combustion engine.

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.