Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include, responsive to a cold start of an engine: operating the engine with a number of unfired cylinders and a remaining number of fired cylinders each engine cycle, and adjusting exhaust mixing by adjusting an exhaust valve parameter of at least one unfired cylinder of the number of unfired cylinders. In this way, the unfired cylinders may provide the secondary air as well as increased mixing of the secondary air with burned exhaust gas from fired cylinders, thus increasing exotherm production in the exhaust system to increase a temperature of the catalyst.

Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include, during a cold start condition, operating an engine with a number of cylinders deactivated and a remaining number of cylinders active, and adjusting a first air charge within a deactivated cylinder of the number of cylinders relative to relative to a second air charge within an active cylinder of the remaining number of cylinders. In this way, an amount of secondary air provided to the exhaust system of the engine may be more robustly controlled, thus decreasing cooling of the exhaust system during the cold start condition that may otherwise occur due to excess secondary air.

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).

A valve opening and closing timing control device includes a driving-side rotating body, a driven-side rotating body, a stopper configured to determine a mechanical limit of a displacement region of a relative rotation phase, a phase control mechanism configured to change the relative rotation phase, and a control unit configured to control the electric motor so as to displace the actual phase detected by a phase sensor. A limit phase at which the stopper reaches an abutting state is set in advance when rotation of the electric motor is stopped while the internal combustion engine operates. Upon executing stop control of stopping the internal combustion engine, except when the actual phase is already the limit phase, the control unit executes braking control of limiting the rotation of the electric motor by controlling an electric current to be supplied to the electric motor.

An internal combustion engine for a motor vehicle includes a crankshaft, a camshaft, a cylinder, a piston movably disposed in the cylinder and coupled to the crankshaft for driving the crankshaft, a first gas exchange valve which is assigned to the cylinder, a first valve clearance compensation device, where via the first valve clearance compensation device the first gas exchange valve is displaceable between a first open position and a first closed position by a first cam of the camshaft, and a control unit. The control unit is configured to align the camshaft such that the first valve clearance compensation device is pressure-loaded in the idle state of the crankshaft by a plateau area assigned to the first cam to hold the first gas exchange valve in the first open position.

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.

Systems and methods for cold starting an internal combustion engine are described. In one example, the two amounts of fuel are injected into an engine cylinder during a cycle of the engine cylinder. The first amount of fuel is combusted to generate torque to rotate a crankshaft of the engine and the second amount of fuel is at least partially combusted in an exhaust system of the engine to increase exhaust gas temperature.

A split cycle internal combustion engine includes a combustion cylinder accommodating a combustion piston and a compression cylinder accommodating a compression piston. The engine also includes a controller arranged to receive an indication of a parameter associated with the combustion cylinder and/or a fluid associated therewith and to control an exhaust valve of the combustion cylinder in dependence on the indicated parameter to cause the exhaust valve to close during the return stroke of the combustion piston, before the combustion piston has reached its top dead centre position (TDC), when the indicated parameter is less than a target value for the parameter; and close on completion of the return stroke of the combustion piston, as the combustion piston reaches its top dead centre position (TDC), when the indicated parameter is equal to or greater than the target value for the parameter.

The disclosure relates to a method for controlling an internal combustion engine configured with a belt starter generator or an electric machine of a hybrid powertrain. The internal combustion engine includes a cylinder and a piston, which together delimit a working chamber. The internal combustion engine includes a variable valve actuation system for actuation of inlet valves of the working chambers, controlling the opening time and/or the closing time and/or the lift. A strategy for operating the internal combustion engine with a negative drive torque or when shutting down or when starting up the internal combustion includes controlling the inlet valves of individual or all working chambers in such a way that the transfer of fresh air from an intake section to an exhaust manifold is controlled and that the drag torque of the internal combustion is reduced.

A split cycle internal combustion engine includes a combustion cylinder accommodating a combustion piston and a compression cylinder accommodating a compression piston. The engine also includes a controller arranged to receive an indication of a parameter associated with the combustion cylinder and/or a fluid associated therewith and to control an exhaust valve of the combustion cylinder in dependence on the indicated parameter to cause the exhaust valve to close during the return stroke of the combustion piston, before the combustion piston has reached its top dead centre position (TDC), when the indicated parameter is less than a target value for the parameter; and close on completion of the return stroke of the combustion piston, as the combustion piston reaches its top dead centre position (TDC), when the indicated parameter is equal to or greater than the target value for the parameter.