A internally cooled poppet valve (2) with inertial pump (4) includes a valve body (20) having a valve head (22) and a valve stem (24). The valve body (20) has a closed cavity (26), in which a cooling fluid (28) is disposed. The inertial pump (4) is disposed in the valve body (20), which moves the cooling fluid (28) in the cavity during operation.

A valvetrain includes a rocker arm assembly basing a rocker arm and an electromagnetic latch assembly. An electromagnet of the latch assembly is housed within a chamber formed by the rocker arm. Passageways suitable for oil cooling of the electromagnet are formed through and inside the rocker arm. In some embodiments, oil for cooling is supplied through a pivot. In some embodiments, oil for cooling is obtained from oil splash. Oil cooling may allow modes of operation such as of dynamic cylinder deactivation and dynamic variable valve actuation to be used without overheating the electromagnet.

To find compromises in the relationship between the component costs of intake and exhaust valves and the downsizing of an engine and the relationship between the cooling performance and the followability of the intake and exhaust valves and coordinate these conflicting relationships as much as possible. A hollow valve encapsulating coolant having a good cooling function is used as an exhaust valve, which is exposed to a higher temperature environment than an the intake valve, to eliminate a disincentive to downsizing. In contrast, a hollow valve that has no coolant, relatively low component cost, light weight, and good followability is used as the intake valve, which does not need to have a better cooling function than the exhaust valve and needs to have better followability than the exhaust valve to improve combustion efficiency.

To find compromises in the relationship between the component costs of intake and exhaust valves and the downsizing of an engine and the relationship between the cooling performance and the followability of the intake and exhaust valves and coordinate these conflicting relationships as much as possible. A hollow valve encapsulating coolant having a good cooling function is used as an exhaust valve, which is exposed to a higher temperature environment than an the intake valve, to eliminate a disincentive to downsizing. In contrast, a hollow valve that has no coolant, relatively low component cost, light weight, and good followability is used as the intake valve, which does not need to have a better cooling function than the exhaust valve and needs to have better followability than the exhaust valve to improve combustion efficiency.

The invention relates to a system (100) for operating a valve of an internal combustion engine (10), said system comprising a primary fluid circuit (60) configured to define a fluid passageway for circulating a compressible fluid medium there through being operatively connectable to an actuator (92) of an actuated flow control valve (90, 95) of said internal combustion engine, thereby capable of delivering a valve opening force. The system further comprises: a secondary fluid circuit (80) configured to define a secondary fluid passageway for transporting a compressed fluid medium, and having an inlet passage (87) connectable to a cylinder for receiving the compressed fluid medium; and an auxiliary pressurized system (81) comprising a chamber (83) and at least one reciprocating member (82) operable in said chamber (83), said auxiliary pressurized system (81) being arranged in fluid communication with said secondary fluid circuit (80) and in fluid communication with said primary fluid circuit such that said at least one reciprocating member (82) pressurizes said primary fluid circuit when said compressed fluid medium of the secondary fluid circuit acts on said at least one reciprocating member (82).

Intake and exhaust cam shafts are disposed a cylinder head in a vertical direction. The cylinder head comprises a first through hole and a second through hole. The first through hole penetrates an upper surface deck from a deck surface towards a lower surface of the cylinder head. The deck surface is a surface constituting an upper surface deck of the cylinder head. The second through hole opens to a side surface of the cylinder head in which cam pulleys of intake and exhaust cam shafts are provided. The second through hole penetrates the upper surface deck along an axial direction of the intake and exhaust cam shafts. The second through hole is positioned vertically below an opening in the deck surface of the first through hole.

A valve seat ring for a gas exchange valve of a cylinder of an internal combustion engine includes: a one-part or multi-part main body defining a through-flow opening; and a valve seat region arranged on a portion of the main body in the region of the through-flow opening, a surface of the valve seat region forming a valve seat for a valve body of the gas exchange valve. At least into the main body at least one recess is introduced, which is at least partly filled with a solder material.

A internally cooled poppet valve (2) with inertial pump (4) includes a valve body (20) having a valve head (22) and a valve stem (24). The valve body (20) has a closed cavity (26), in which a cooling fluid (28) is disposed. The inertial pump (4) is disposed in the valve body (20), which moves the cooling fluid (28) in the cavity during operation.

An internal combustion engine includes: intake and exhaust ports; an intake valve including an intake valve shaft and an intake valve head; and an exhaust valve including an exhaust valve shaft and an exhaust valve head. The surface of the intake valve includes an intake-valve-head front surface exposed in a combustion chamber when the intake valve is closed and an intake-valve-head back surface exposed in the intake port when the intake valve is closed. The surface of the exhaust valve includes an exhaust-valve-head front surface exposed in the combustion chamber when the exhaust valve is closed and an exhaust-valve-head back surface exposed in the exhaust port when the exhaust valve is closed. The arithmetic mean roughness of the whole exhaust-valve-head back surface is greater than the arithmetic mean roughness of each of the whole intake-valve-head front surface, the whole intake-valve-head back surface and the whole exhaust-valve-head front surface.

The invention relates to a system (100) for operating a valve of an internal combustion engine (10), said system comprising a primary fluid circuit (60) configured to define a fluid passageway for circulating a compressible fluid medium there through being operatively connectable to an actuator (92) of an actuated flow control valve (90, 95) of said internal combustion engine, thereby capable of delivering a valve opening force. The system further comprises: a secondary fluid circuit (80) configured to define a secondary fluid passageway for transporting a compressed fluid medium, and having an inlet passage (87) connectable to a cylinder for receiving the compressed fluid medium; and an auxiliary pressurized system (81) comprising a chamber (83) and at least one reciprocating member (82) operable in said chamber (83), said auxiliary pressurized system (81) being arranged in fluid communication with said secondary fluid circuit (80) and in fluid communication with said primary fluid circuit such that said at least one reciprocating member (82) pressurizes said primary fluid circuit when said compressed fluid medium of the secondary fluid circuit acts on said at least one reciprocating member (82).