The present disclosure relates to a valve, preferably an exhaust gas or gas exchange valve, having a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge towards the outside which has a crest region. The valve, in order to reduce the mass of the bulge of the valve head, including a laterally outer part section of the edge region that is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section.

The present disclosure relates to a valve, preferably an exhaust gas or gas exchange valve, having a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge towards the outside which has a crest region. The valve, in order to reduce the mass of the bulge of the valve head, including a laterally outer part section of the edge region that is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section.

A valve seat insert of an engine has a valve seating surface including an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer and the inner curved segments. A sloping segment is oriented at an acute angle relative to the valve seat center axis, forming a venturi or a diffuser for gases entering or exiting the cylinder.

An apparatus (201) and method for controlling intake valves (23) in an internal combustion engine (5), as well as an internal combustion engine and a vehicle comprising the apparatus, and an electronic processor for performing the method is disclosed. The apparatus comprises a hydraulic system (3) configured to hydraulically actuate a first intake valve (23a) and a second intake valve (23b) of a first combustion chamber (25) of an internal combustion engine (5). The apparatus also includes a controller (9) configured to control the hydraulic system (3) in at least a first mode of operation and a second mode of operation. In the first mode of operation, the controller (9) is configured to control the hydraulic system (3) to cause lifting of the first and second intake valves (23a, 23b) of the first combustion chamber (25) during each intake stroke of a respective cylinder piston (27). In the second mode of operation, the controller (9) is configured to control the hydraulic system (3) to cause lifting of the first intake valve (23a) of the first combustion chamber (25) during an intake stroke of the respective cylinder piston (27) and disable actuation of the second intake valve (23b) of the first combustion chamber (25) during that intake stroke.

A valve seat insert for a gas exchange valve such as an intake valve controlling gas exchange of a cylinder includes an insert body having an inner peripheral surface, an outer peripheral surface, and a valve seating surface structured to contact the gas exchange valve at a closed position and profiled to limit valve recession thereof. The valve seating surface includes an arrangement of linear segments and curved segments forming wear crowns to contact the gas exchange valve at different wear states. The valve seat insert is further structured by way of the inner peripheral surface with an incoming flow crown, and a venturi extending from the incoming flow crown toward a throat of the valve seat insert. The venturi accelerates incoming gas flow.

A hydraulically variable gas exchange valve train for an internal combustion engine is proposed that includes a hydraulic housing with a pressure chamber, a pressure relief chamber, and a vent duct. The vent duct is connected hydraulically on a housing inner side via a restriction to the pressure relief chamber, and opens on the housing outer side below the pressure relief chamber with regard to a direction of gravity. The vent duct opens into a hydraulic reservoir, wherein the vent duct opening lies below a normal level of the hydraulic reservoir with regard to the direction of gravity.

A hydraulically variable gas exchange valve train for an internal combustion engine is proposed that includes a hydraulic housing with a pressure chamber, a pressure relief chamber, and a vent duct. The vent duct is connected hydraulically on a housing inner side via a restriction to the pressure relief chamber, and opens on the housing outer side below the pressure relief chamber with regard to a direction of gravity. The vent duct opens into a hydraulic reservoir, wherein the vent duct opening lies below a normal level of the hydraulic reservoir with regard to the direction of gravity.

In a hollow exhaust poppet valve including a fillet increasing in diameter toward a leading end, a stem, and a head and having a coolant within a hollow part formed from the head to the stem, the stem includes a first stem part on a base end side, and a second stem part integrated with the first stem part via a step part and integrated with the fillet, and the hollow part includes a first hollow part formed inside the first stem part, and a second hollow part formed inside the second stem part, the fillet, and the head in such fashion as to have a constant inner diameter greater than the first hollow part and formed so as to be continuous with the first hollow part via a tapered part or a curved part.

In a hollow exhaust poppet valve including a fillet increasing in diameter toward a leading end, a stem, and a head and having a coolant within a hollow part formed from the head to the stem, the stem includes a first stem part on a base end side, and a second stem part integrated with the first stem part via a step part and integrated with the fillet, and the hollow part includes a first hollow part formed inside the first stem part, and a second hollow part formed inside the second stem part, the fillet, and the head in such fashion as to have a constant inner diameter greater than the first hollow part and formed so as to be continuous with the first hollow part via a tapered part or a curved part.

Poppet valve for an internal combustion engine including a valve stem and a single circular valve head attached at one end of the valve stem. The valve head has a circular peripheral contour and an arcuate edge without any sharp elements to avoid turbulence and improve flow around the valve to therefore maximize flow velocity. This translates into increased cylinder breathing in the intake cycle and reducing back pressure in the exhaust cycle.