A cylinder head valve seat of an automobile vehicle includes a valve seat having a valve seat surface integrally joined to an engagement end. The engagement end includes multiple materials extending through a cross section of the engagement end. The multiple materials include: a first material having a first thermal conductivity; and a second material having a second thermal conductivity higher than the thermal conductivity of the first material, wherein the first material transitions into the second material.

A cooling system for a cylinder head of an internal combustion engine includes a cylindrical seat configured to engage an exhaust valve, a first coolant jacket, and a first conduit. The exhaust valve seat defines an annular cooling passage extending along a circumference of the cylindrical seat. A wall of the cylindrical seat defines a first opening into the annular cooling passage and a second opening into the annular cooling passage, where the first opening is positioned diametrically opposite to the second opening. The first coolant jacket is positioned adjacent to a fire-deck of the internal combustion engine. The first conduit fluidly couples the first coolant jacket to the at least one of the first opening and the second opening to the annular cooling passage in the exhaust valve seat.

Internal combustion piston engine includes a cylinder head partly defining two ducts and a combustion chamber, and poppet valves movably arranged in the cylinder head between positions allowing or preventing flow between the combustion chamber and the ducts. The poppet valve has a stem, a valve head having a hollow interior space, a lower surface facing the combustion chamber, an upper surface including a portion adjacent the stem, and a peripheral edge section that extends from the upper surface of the valve head to the lower surface. The valve head is formed separate from but connected to the valve stem in a manner to enclose the hollow space, for example, by a circumferential welding seam. The peripheral edge section contains an arcuate contact surface that extends from the upper to lower surfaces of the valve head and without any sharp edges between upper and lower surfaces.

A cylinder head valve seat of an automobile vehicle includes a valve seat having a valve seat surface integrally joined to an engagement end. The engagement end includes multiple materials extending through a cross section of the engagement end. The multiple materials include: a first material having a first thermal conductivity; and a second material having a second thermal conductivity higher than the thermal conductivity of the first material, wherein the first material transitions into the second material.

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.

A combustion-chamber structure of an engine comprises a combustion chamber which is partitioned by a cylinder block, a cylinder head, a piston, an intake valve, and an exhaust valve. The intake valve (exhaust valve) comprises an intake valve body including an umbrella part having a valve head and a valve face, a heat-insulation layer provided at the valve head and having smaller heat conductivity than the valve body, a heat-barrier layer provided to cover the valve head with the heat-insulation layer and having smaller heat conductivity than the valve body and the heat-insulation layer, and a heat-diffusion layer provided between the heat-insulation layer and the heat-barrier layer and having larger heat conductivity than the heat-insulation layer and the heat-barrier layer. The heat-diffusion layer comprises a contact portion which contacts with the cylinder head when the intake valve is closed.

A system includes an engine head that mounts to an engine block of a reciprocating engine, and the engine head includes an intake flow path, an exhaust flow path, a coolant flow path, and first and second sealing registers disposed on opposite sides of the coolant flow path. In addition, the first and second sealing registers are configured to receive a valve guide that supports a valve stem of an exhaust valve. Moreover, the first sealing register is disposed in a wall separating the exhaust flow path and the coolant flow path. Also, a first wall portion of the wall extends between the first sealing register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends from the first sealing register away from the first wall portion.

A system includes an engine head that mounts to an engine block of a reciprocating engine, and the engine head includes an intake flow path, an exhaust flow path, a coolant flow path, and first and second sealing registers disposed on opposite sides of the coolant flow path. In addition, the first and second sealing registers are configured to receive a valve guide that supports a valve stem of an exhaust valve. Moreover, the first sealing register is disposed in a wall separating the exhaust flow path and the coolant flow path. Also, a first wall portion of the wall extends between the first sealing register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends from the first sealing register away from the first wall portion.

A cooling system for a cylinder head of an internal combustion engine includes a cylindrical seat configured to engage an exhaust valve, a first coolant jacket, and a first conduit. The exhaust valve seat defines an annular cooling passage extending along a circumference of the cylindrical seat. A wall of the cylindrical seat defines a first opening into the annular cooling passage and a second opening into the annular cooling passage, where the first opening is positioned diametrically opposite to the second opening. The first coolant jacket is positioned adjacent to a fire-deck of the internal combustion engine. The first conduit fluidly couples the first coolant jacket to the at least one of the first opening and the second opening to the annular cooling passage in the exhaust valve seat.

A valve seat insert includes a top convex arcuate blend for improving fluid flow, and a valve seating surface for slowing down valve recession. The valve seating surface includes a radially outer convex arcuate segment defining an outer radius of curvature forming a first wear crown for contacting the valve at an early wear state, a radially inner convex arcuate segment defining an inner radius of curvature forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the radially outer convex arcuate segment and the radially inner convex arcuate segment.