Methods and systems are provided for variable valve actuation assembly. In one example, the variable valve actuation assembly may include a first pressure reservoir with a first pressure fluidly coupled to valve actuators and positioned below an engine valve. A second pressure reservoir with a second pressure is arranged directly below the first pressure reservoir and a hydraulic medium flows between the first and second pressure reservoirs.

Methods and systems are provided for variable valve actuation assembly. In one example, the variable valve actuation assembly may include a first pressure reservoir with a first pressure fluidly coupled to valve actuators and positioned below an engine valve. A second pressure reservoir with a second pressure is arranged directly below the first pressure reservoir and a hydraulic medium flows between the first and second pressure reservoirs.

A fully variable electro-hydraulic valve system having a buffering function, comprising: a camshaft (101), a valve assembly (106), a sliding sleeve (103), a spiral shaft (102), a piston (105), and a position restoring spring (104). The sliding sleeve (103) is fixed relative to an engine, the piston (105) abuts against the valve assembly (106), and the spiral shaft (102) is controlled by a cam surface of the camshaft (101) in the axial direction. sliding sleeve (103) is provided with a buffering oil hole (123) that communicates with a buffering cavity (R) and with a low-pressure oil circuit of the engine by means of a throttling device (124). When a valve is going to be seated, the piston collides with a buffering ring (121), and due to the effect of the throttling device, engine oil within the buffering cavity has a damping effect on the movement of the buffering ring.

A fully variable electro-hydraulic valve system having a buffering function, comprising: a camshaft (101), a valve assembly (106), a sliding sleeve (103), a spiral shaft (102), a piston (105), and a position restoring spring (104). The sliding sleeve (103) is fixed relative to an engine, the piston (105) abuts against the valve assembly (106), and the spiral shaft (102) is controlled by a cam surface of the camshaft (101) in the axial direction. sliding sleeve (103) is provided with a buffering oil hole (123) that communicates with a buffering cavity (R) and with a low-pressure oil circuit of the engine by means of a throttling device (124). When a valve is going to be seated, the piston collides with a buffering ring (121), and due to the effect of the throttling device, engine oil within the buffering cavity has a damping effect on the movement of the buffering ring.

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

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.

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.

An internal combustion engine includes an electro-hydraulic system for variable actuation of intake valves where each cylinder has two intake valves, associated with two intake conduits. A first conduit is generates within the cylinder a tumble motion of airflow introduced therein, when the intake valve associated thereto is at least partially opened. The second intake conduit generates within the cylinder a swirl motion of airflow introduced therein when the second intake valve is at least partially opened. A controller of controls one or more control valves to open only one of the intake valves of each cylinder in a condition of reduced engine operation, below a predetermined load and/or a predetermined speed of the engine, and to always open both intake valves in the remaining conditions of engine operation. The first intake valve is the only valve to be opened in the reduced engine operation condition.

An internal combustion engine includes an electro-hydraulic system for variable actuation of intake valves where each cylinder has two intake valves, associated with two intake conduits. A first conduit is generates within the cylinder a tumble motion of airflow introduced therein, when the intake valve associated thereto is at least partially opened. The second intake conduit generates within the cylinder a swirl motion of airflow introduced therein when the second intake valve is at least partially opened. A controller of controls one or more control valves to open only one of the intake valves of each cylinder in a condition of reduced engine operation, below a predetermined load and/or a predetermined speed of the engine, and to always open both intake valves in the remaining conditions of engine operation. The first intake valve is the only valve to be opened in the reduced engine operation condition.