Valve seat for the inlet valve in the cylinder head of a four cycle internal combustion engine

Claim 2

A valve seat for a suspended inlet valve in the cylinder head of a four-cycle internal combustion engine in which the axis of the valve stem is disposed generally in the vertical direction and the valve disc is arranged at the lower end of the valve stem, characterized in that the valve seat is provided with a sharp pointed annular edge about the entire circumference of the valve seat, said annular edge projecting only slightly into the combustion space substantially in the axial direction of the inlet valve as detaching step for precipitated fuel components flowing along the walls of the inlet channel so that the combustion air flowing with high velocity past the sharp annular edge tears off from said sharp edge any fuel that has crept along the walls of the sharp edge and takes along the fuel air distributed into the combustion space or throws the same against the disc of the inlet valve from where it evaporates and thus reaches the cylinder in vapor form, said sharp edge being disposed radially outwardly of the valve disc and projecting freely into the combustion space when the valve disc is in the closed condition, and characterized in that the sharp edge is formed by two annular converging surface portions, with the outer converging surface portion forming an angle substantially greater than 90* with the adjoining wall portion of the cylinder head adjoining the same outwardly thereof and defining at least in part the upper wall of the combustion space, and with the angle formed by said annular converging surface portions being substantially less than 90*.

Claim 3

A valve seat according to claim 1, characterized in that the sharp edge projects by about 0.5 to 1 mm. out of the plane of the valve seat.

Claim 4

A valve seat according to claim 2, with a valve seat ring inserted into the cylinder head, characterized in that the sharp edge is arranged at the valve seat ring.

Claim 5

A valve seat according to claim 1, with a valve seat ring inserted into the cylinder head, characterized in that the sharp edge is arranged at the valve seat ring.

Claim 6

A four-cycle internal combustion engine of the overhead-type with a cylinder head having an inlet channel valved by an overhead inlet valve normally seated against a valve seat and having a valve disc at the lower end of a valve stem, characterized in that means are provided to prevent fuel precipitated along the walls of the inlet channel from reaching the cylinder head walls, defining at least in part the upper portion a combustion chamber, by flowing past the valve seat ring having a conical seating surface with the cone apex disposed above the valve disc in the valve axis, including detaching means formed by a circumferentially disposed sharp edge projecting from the valve seat only slightly into the combustion space and pointing downwardly substantially in the axial direction of the inlet valve so that the combustion air flowing with high velocity past the sharp annular edge tears off from said sharp edge any fuel that has crept along the walls of the sharp edge and takes along the fuel air distributed into the combustion space or throws the same against the disc of the inlet valve from where it evaporates and thus reaches the cylinder in vapor form, said sharp edge being uncovered by said valve disc and projecting freely into the combustion space in all operating positions of the valve disc with the lowest point of said sharp edge projecting into the combustion space a distance at most equal to any operating position of the bottom surface of the valve disc, and characterized in that the sharp edge is formed by two annular converging surface portions, with the outer converging surface portion forming an angle substantially greater than 90* with the adjoining wall portion of the cylinder head adjoining the same outwardly thEreof and defining at least in part the upper wall of the combustion space, and withthe angle formed by said annular converging surface portions being substantially less than 90*.

Claim 7

A four-cycle internal combustion engine of the overhead-type with a cylinder head having an inlet channel valved by an overhead inlet valve normally seated against a valve seat and having a valve disc at the lower end of a valve stem, characterized in that means are provided to prevent fuel precipitated along the walls of the inlet channel from reaching the cylinder head walls, defining at least in part the upper portion a combustion chamber, by flowing past the valve seat ring having a conical seating surface with the cone apex disposed above the valve disc in the valve axis, including detaching means formed by a circumferentially disposed sharp edge projecting from the valve seat only slightly into the combustion space and pointing downwardly substantially in the axial direction of the inlet valve so that the combustion air flowing with high velocity past the sharp annular edge tears off from said sharp edge any fuel that has crept along the walls of the sharp edge and takes along the fuel air distributed into the combustion space or throws the same against the disc of the inlet valve from where it evaporates and thus reaches the cylinder in vapor form, said sharp edge being uncovered by said valve disc and projecting freely into the combustion space in all operating positions of the valve disc with the lowest point of said sharp edge projecting into the combustion space a distance at most equal to any operating position of the bottom surface of the valve disc, and characterized in that the sharp edge is formed by two annular converging surface portions, with the outer converging surface portion forming an angle substantially greater than 90* with the adjoining wall portion of the cylinder head adjoining the same outwardly thEreof and defining at least in part the upper wall of the combustion space, and withthe angle formed by said annular converging surface portions being substantially less than 90*.

Claim 8

An internal combustion engine according to claim 5, characterized in that the edge projects out of the plane of the plane of the valve seat by about 0.5 to 1 mm.

Claim 9

An internal combustion engine according to claim 5, characterized in that said means forms part of a valve seat ring in the cylinder head.

Claim 10

A valve seat for an inlet valve of an inlet chamber in the cylinder head of a four-cycle internal combustion engine of the overhead valve-type, in which the longitudinal axis of the valve stem of the inlet valve is disposed generally in the vertical direction and the valve disc is provided at the lower end of the valve stem, and in which conical sealing surface means are formed between complementary sealing surfaces at the valve seat and at the valve disc, the apex of the cone of said sealing surface means being arranged substantially in the longitudinal axis of the valve stem above the valve disc, characterized in that the valve seat is provided with a fuel detaching means in the form of a sharp edge projecting only a small distance downwardly into the combustion space substantially in the axial direction of the inlet valve as detaching step for precipitated fuel components precipitated and flowing along the walls of the inlet channel so that the combustion air flowing with high velocity past the sharp annular edge tears off from said sharp edge any fuel that has crept along the walls of the sharp edge and takes along the fuel air distributed into the combustion space or throws the same against the disc of the inlet valve from where it evaporates and thus reaches the cylinder in vapor form, the maximum diameter of the valve disc being smaller than the diameter of the tip of the sharp edge, and the lowest point of said sharp edge being generally within the area of the bottom surface of said valve disc, and characterized in that the sharp edge is formed by two annular converging surface portions, with the outer converging surface portion forming an angle substantially greater than 90* with the adjoining wall portion of the cylinder head adjoining the same outwardly thereof and defining at least in part the upper wall of the combustion space, and with the angle formed by said annular converging surface portions being substantially less than 90*.

Claim 11

A valve seat for an inlet valve of an inlet chamber in the cylinder head of a four-cycle internal combustion engine of the overhead valve-type, in which the longitudinal axis of the valve stem of the inlet valve is disposed generally in the vertical direction and the valve disc is provided at the lower end of the valve stem, and in which conical sealing surface means are formed between complementary sealing surfaces at the valve seat and at the valve disc, the apex of the cone of said sealing surface means being arranged substantially in the longitudinal axis of the valve stem above the valve disc, characterized in that the valve seat is provided with a fuel detaching means in the form of a sharp edge projecting only a small distance downwardly into the combustion space substantially in the axial direction of the inlet valve as detaching step for precipitated fuel components precipitated and flowing along the walls of the inlet channel so that the combustion air flowing with high velocity past the sharp annular edge tears off from said sharp edge any fuel that has crept along the walls of the sharp edge and takes along the fuel air distributed into the combustion space or throws the same against the disc of the inlet valve from where it evaporates and thus reaches the cylinder in vapor form, the maximum diameter of the valve disc being smaller than the diameter of the tip of the sharp edge, and the lowest point of said sharp edge being generally within the area of the bottom surface of said valve disc, and characterized in that the sharp edge is formed by two annular converging surface portions, with the outer converging surface portion forming an angle substantially greater than 90* with the adjoining wall portion of the cylinder head adjoining the same outwardly thereof and defining at least in part the upper wall of the combustion space, and with the angle formed by said annular converging surface portions being substantially less than 90*.

Claim 12

A valve seat according to claim 8, characterized in that said sharp edge extends about the entire circumference of the valve seat.

Claim 13

A valve seat according to claim 9, characterized in that the sealing surface means are exclusively rectilinear surfaces of portions of the generatrices of the cone.

Claim 14

A valve seat according to claim 10, characterized in that the valve seat and valve disc are provided with surface portions above and below the sealing surface portions of such shape that in the closed condition of the inlet valve, intersecting surfaces of a respective valve seat surface portion and valve disc surface portion define each an angle above and below the sealing surface means.

Claim 15

A valve seat according to claim 11, characterized in that the valve seat surface portion above the sealing surface means is substantially parallel to the adjacent surface portion of the inlet wall.

Claim 16

A valve seat according to claim 12, characterized in that said sharp edge projects into the combustion space from a plane containing the wall portion of the cylinder head adjoining the valve seat radially outwardly of the annular sharp edge.

Claim 17

A valve seat according to claim 13, characterized in that the sharp edge is arranged on the valve seat.

Claim 18

A valve seat according to claim 14, characterized in that the sharp edge projects by about 0.5 to 1 mm out of the bottom plane of the valve seat.

Claim 19

A valve seat according to claim 8, characterized in that the valve seat and valve disc are proVided with surface portions above and below the sealing surface portions of such shape that in the closed condition of the inlet valve, intersecting surfaces of a respective valve seat surface portion and valve disc surface portion define each an angle above and below the sealing surface means.

Claim 20

A valve seat according to claim 8, characterized in that the valve seat surface portion above the sealing surface means is substantially parallel to the adjacent surface portion of the inlet wall.

Claim 21

A valve seat according to claim 8, characterized in that said sharp edge projects into the combustion space from a plane containing the wall portion of the cylinder head adjoining the valve seat radially outwardly of the annular sharp edge.

Claim 22

A valve seat according to claim 8, characterized in that the sharp edge is arranged on the valve seat.

Claim 23

A valve seat according to claim 8, characterized in that the sharp edge projects by about 0.5 to 1 mm out of the bottom plane of the valve seat.

Claim 24

A valve seat according to claim 1, characterized in that the lowest point of said sharp annular edge is at a height corresponding generally to the order of the height of the lower surface of the valve disc and is generally unobstructed by any part of the valve disc.

Claim 25

A valve seat according to claim 21, characterized in that the lowest point of said sharp edge is located generally in the plane of the bottom surface of the valve disc when the latter is in its closed position.