A method for controlling the temperature of re-circulated exhaust gas in an internal combustion engine includes operating the internal combustion engine on a base line mode, receiving a signal indicative of an engine operating temperature, wherein the engine operating temperature is one of coolant temperature, exhaust temperature and oil temperature, comparing the engine operating temperature to a predetermined IEGR threshold, when the engine operating temperature is less than the predetermined IEGR threshold, activating an IEGR mode and activating an EEVO mode, and when the engine operating temperature is greater than the first predetermined IEGR threshold, deactivating the IEGR mode and deactivating the EEVO mode.

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.

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.

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.

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.

An internal combustion engine of reciprocating-piston type of construction is described which has a cylinder (2) with a cylinder head (1) and with an inlet valve (3) arranged in the cylinder head. An inlet line (4) is connected to the inlet valve (3), via which inlet line combustion air (5) can be fed to the cylinder (2). Furthermore, a compressed-air accumulator (6) is provided which is connected to the inlet line (4) by means of a controllable valve (7), wherein the inlet line (4) can be closed, with regard to its throughflow cross section, by means of a shut-off element (8). The valve (7) is controllable such that, on the basis of a control signal, compressed air (9) is fed from the compressed-air accumulator (6) into a region of the inlet line directly upstream of the inlet valve (3), wherein the shut-off element (8) is arranged sealingly on the cylinder head (1) and closes the cross section of the inlet line (4). The inlet valve (3) is briefly re-opened by means of an actuation element (24) during the compression stroke, and during said brief re-opening, compressed air (9) is fed from the compressed-air accumulator (6) into the cylinder (2), with the shut-off element (8) being held in its closed position. According to a second aspect, the compressed-air accumulator (6) can also be used to feed all of the combustion air to the cylinder (2) via an inlet reservoir (25) directly upstream of the inlet valve (3).

An internal combustion engine includes combustion chambers, each having a controllable intake valve controlling an intake port, a controllable exhaust valve controlling an exhaust port, a piston, and a fuel injector. An intake manifold is connected to the intake port of each chamber. In catalytic converter warm-up mode, each chamber is driven in four-stroke operation including a 720 crank angle degrees cycle, and opens the intake port, starting to open in 90-180 CAD, and fully closes the intake port in 180-270 CAD, opens the exhaust port during the power stroke, starting in 405-495 CAD, opens the intake port during the exhaust stroke, starting in 610-690 CAD, and fully closes the exhaust port during the exhaust stroke in 630-710 CAD. Exhaust gas is forced into the intake manifold by the piston, mixing fuel and exhaust in the intake manifold, and fully closes the intake port in 700 to 720+20 CAD.

The present disclosure relates to a method for operating an internal combustion engine (IO). The method includes generating a pressure pulse in an exhaust gas system of the internal combustion engine (IO). The method also includes supplying exhaust gas from a combustion chamber of a cylinder during an exhaust outlet stroke of the cylinder into an inlet channel of the cylinder by propagating the pressure pulse from the exhaust gas system into the combustion chamber of the cylinder. The method further includes supplying the exhaust gas from the inlet channel of the cylinder into the combustion chamber of the cylinder during an intake stroke of the cylinder. By means of internal residual gas control (residual exhaust gas control), the method permits the exhaust gas temperature to be raised in at low load without negatively influencing the full load performance of the internal combustion engine (IO).

In an internal combustion engine provided with an electro-hydraulic system for variable actuation of the intake valves of the engine, each cylinder has two intake valves, which are associated with two intake conduits and are controlled by a single cam of a camshaft through a single hydraulic circuit. The communication of the hydraulic actuators of the two intake valves with a discharge channel is controlled by two electrically-actuated control valves, both of an on/off two-position type, arranged in series with each other along a hydraulic line for communication between the a pressure volume and the discharge channel.

A method for controlling the temperature of re-circulated exhaust gas in an internal combustion engine includes operating the internal combustion engine on a base line mode, receiving a signal indicative of an engine operating temperature, wherein the engine operating temperature is one of coolant temperature, exhaust temperature and oil temperature, comparing the engine operating temperature to a predetermined IEGR threshold, when the engine operating temperature is less than the predetermined IEGR threshold, activating an IEGR mode and activating an EEVO mode, and when the engine operating temperature is greater than the first predetermined IEGR threshold, deactivating the IEGR mode and deactivating the EEVO mode.