In various aspects, internal combustion engines, engine controllers and methods of controlling engines are described. The engine includes a camshaft and a two cylinder sets. Cylinders in the first are deactivatable and cylinders in the second set may be fired at high or low output levels. The air charge for each fired working cycle is set based on whether a high or low torque output is selected. In some implementations, the camshaft is axially shiftable between first and second positions. First cam lobes are configured to cause their associated cylinders to intake a large air charge during intake strokes that occur when the camshaft is in the first position. Second cam lobes for cylinders in the second set cause their associated cylinders to intake a smaller air charge when the camshaft is in the second position. Second cam lobes for cylinders in the first set deactivate their associated cylinders.

A camshaft assembly for an internal combustion engine of a vehicle and method of operating the camshaft assembly to enhance engine braking performance through selective activation of a cam lobe having a brake gas recirculation contour. The camshaft assembly comprises an exhaust camshaft and a lobe pack on the exhaust camshaft, with the lobe pack including a plurality of cam lobes. At least one cam lobe of the plurality of cam lobes includes a brake gas recirculation cam contour having an exhaust stroke projection and a combustion stroke projection. The method switches to the cam lobe including the brake gas recirculation profile when certain criteria indicate that an engine braking mode is to be activated.

A control device for an internal combustion engine comprising a combustion control part controlling a fuel feed system and ozone feed system so as to form a difference in ozone concentration space-wise or time-wise in a combustion chamber 11 so that premixed gas burns by compression ignition in stages in the combustion chamber and an ozone malfunction judging part judging malfunction of the ozone feed system. The ozone malfunction judging part judges that the ozone feed system is malfunctioning when the self-ignition timing is retarded from the presumed self-ignition timing and the combustion noise is larger than the presumed combustion noise or when the self-ignition timing is advanced from the presumed self-ignition timing and the combustion noise is smaller than the presumed combustion noise.

A method for operating an internal combustion engine, involving the following steps: determining a target lambda value and measuring an actual lambda value for combustion in a combustion chamber of an internal combustion engine; establishing, in accordance with the target lambda value and the actual lambda value, a point in time for an intake valve associated with the combustion chamber to open; and opening the intake valve at the established point in time.

A PCM (100) selects one of a CI mode or an SI mode based on the operating conditions of the engine (1). In the CI mode, the engine (1) is operated by compression ignition combustion. In the SI mode, the engine (1) is operated by spark ignition combustion. if, while the engine (1) is being operated in the CI mode, a determination is made that an estimated value (Tc) of the catalyst temperature is lower than or equal to a warming start temperature (Ts), the PCM (100) further performs first warming control to assign four cylinders (18) as CI and SI cylinders, which perform the compression ignition combustion and the spark ignition combustion, respectively, such that the four cylinders (18) alternately perform the compression ignition combustion and the spark ignition combustion in accordance with the order of combustion of the cylinders.

A control system for internal combustion engines having four valves per cylinder. An inlet valve and an exhaust valve are controlled by a basic camshaft. Another inlet valve and another exhaust valve are controlled by a control camshaft. The two camshafts are connected to a crankshaft and engine torque is managed by an electronic control unit. The system comprises a motor/generator unit, connected to the control camshaft; a differential, connected to the crankshaft and to the control camshaft; a control shaft, connected to the differential; an actuator, connected to the control shaft; a one-way restrictor valve connected to a shut-off valve and to the actuator; an oil circuit, connected to the actuator by means of the shut-off valve and a control solenoid that acts on the shut-off valve.

Systems and methods for internal exhaust gas recirculation (iEGR) in internal combustion engines may utilize secondary intake valve lift events during an exhaust valve main event in lost motion valve actuation systems. The secondary intake valve lift event may occur at the beginning or end of the exhaust valve main event. Favorable intake valve lift profiles are obtained with the use of a reset component, which may perform a hydraulic reset on the lost motion component in order to ensure that the intake valve secondary lift event occurs optimally near the beginning of an exhaust valve main event. The reset component may be triggered using motion from an exhaust valvetrain, for example, by a triggering component such as a reset pad, on an exhaust rocker. The reset component may also be triggered on the basis of the intake rocker arm position, in which case a reset pad that is fixed to the engine head or fixed relative to the intake rocker motion may be used.

Provided is a valve control apparatus for an engine that opens and closes an exhaust valve and intake value of the engine while rotating in conjunction with a crankshaft of the engine, the valve control apparatus including an exhaust valve opening and closing device opening and closing the exhaust valve during a first exhaust valve opening period and an intake valve opening and closing device opening and closing the intake valve during a first intake valve opening period.

A control device for an internal combustion engine is configured to feed fuel to a combustion chamber in an intake stroke to form a homogeneous premix and make the homogeneous premix burn by flame propagation when a temperature of an engine body is less than a first threshold value, to feed fuel to the combustion chamber in the intake stroke to form a homogeneous premix and make the homogeneous premix burn by compression ignition when the temperature of the engine body is the first threshold value to less than a second threshold value larger than the first threshold value, and to directly feed fuel to the combustion chamber in a compression stroke to form a partial premix and make the partial premix burn by compression ignition when the temperature of the engine body is the second threshold value or more.

A method to control a four-stroke combustion engine, comprising at least one cylinder; a piston arranged in each cylinder; at least one inlet valve arranged in each cylinder which is connected with an inlet system; at least one first camshaft which controls each inlet valve; at least one exhaust valve arranged in each cylinder which is connected with an exhaust system; at least one second camshaft which controls each exhaust valve; and a crankshaft which controls each camshaft. At least one phase-shifting device is arranged between the crankshaft and the second camshaft, to phase-shift the second camshaft in relation to the crankshaft to a state, where the exhaust valve is controlled in such a way, that it is opened during the expansion stroke of the engine and closed during the exhaust stroke of the engine, to achieve engine braking through compression in the cylinders during the exhaust stroke.