Engine cylinder intake port

Claim 2

In an internal combustion engine, means defining a cylinder closed at one end and having an axis, means defining an inlet passage through the cylinder defining means and communicating with the cylinder through the closed end, and a poppet inlet valve including a stem and head having a valve axis and disposed in the passage for reciprocation on said valve axis to control communication of the inlet passage with the cylinder, said inlet passage being characterized by a throat of generally circular cross-section opening into the cylinder and adapted to be closed by the inlet valve, an entrance portion spaced from the throat and offset from the valve axis, and means defining a fluid flow path extending from the entrance portion toward and around opposite sides of the valve axis and below the valve head when open to the throat, said fluid flow path defining means having a top wall including first and second ramp portions and a shelf portion spaced from and opposite the throat, said ramp portions sloping downwardly and merging with the shelf portion on generally opposite sides of the valve axis, the ramp portions lying at steep angles to the shelf portion and one of the ramp portions having a substantially steeper angle than the other to slow and direct downwardly fluid flow passing the one of said sides of the valve axis below said one steeper ramp relative to the higher speed and less downward direction of flow passing the other of said sides of the valve axis, whereby preferential entry of swirl developing flow into the shelf area from below the ramp of lower slope is encouraged.

Claim 3

In an internal combustion engine, a cylinder having an axis, a cylinder head closing one end of the cylinder, means defining an inlet passage through the cylinder head and communicating with the cylinder through the closed end, and a poppet inlet valve having a valve axis and reciprocably disposed in the passage for controlling communication of the inlet passage with the cylinder, said inlet passage being characterized by a throat of generally circular cross-section opening into the cylinder and adapted to be closed by the inlet valve, an entrance portion spaced from the throat and offset from the valve axis, and means defining a fluid flow path extending from the entrance portion toward and around opposite sides of the valve axis to the throat portion, said fluid flow path defining means including a valve guide boss surrounding the valve axis and projecting part way into the flow path, and a top wall including first and second ramp portions and a shelf portion, said shelf portion extending from adjacent the end of the guide boss in generally spaced and opposing relation to the throat, and said ramp portions merging with the shelf portion adjacent the guide boss, said ramp portions sloping downwardly on opposite sides of the valve axis and at steep angles to the shelf portion, one of the ramp portions having a substantially steeper angle than the other, to slow and direct downwardly fluid flow in passing the one of said sides of the valve axis below said one steeper ramp relative to the higher speed and less downward direction of flow passing the other of said sides of the valve axis, whereby preferential entry of swirl developing flow into the shelf area from below the ramp of lower slope is encouraged.

Claim 4

In an internal combustion engine, a cylinder having an axis, a cylinder head closing one end of the cylinder, means defining an inlet passage through the cylinder head and communicating with the cylinder through the closed end, and a poppet inlet valve having a valve axis and reciprocably disposed in the passage for controlling communication of the inlet passage with the cylinder, said inlet passage being characterized by a throat of generally circular cross-section opening into the cylinder and adapted to be closed by the inlet valve, an entrance portion spaced from the throat and offset from the valve axis, and means defining a fluid flow path extending from the entrance portion toward and around opposite sides of the valve axis to the throat portion, said fluid flow path defining means including a valve guide boss surrounding the valve axis and projecting part way into the flow path, and a top wall including first and second ramp portions and a shelf portion, said shelf portion extending from adjacent the end of the guide boss in generally spaced and opposing relation to the throat, and said ramp portions merging with the shelf portion adjacent the guide boss, said ramp portions sloping downwardly on opposite sides of the valve axis and at steep angles to the shelf portion, one of the ramp portions having a substantially steeper angle than the other, to slow and direct downwardly fluid flow in passing the one of said sides of the valve axis below said one steeper ramp relative to the higher speed and less downward direction of flow passing the other of said sides of the valve axis, whereby preferential entry of swirl developing flow into the shelf area from below the ramp of lower slope is encouraged.

Claim 5

A combination as in claim 2 wherein said inlet passage is configured so that flow on said one side of the valve axis below the steeper ramp forms a greater angle with flow in the passage immediately upstream of the valve guide than does flow on said other side of the valve axis below the shallower ramp, said greater angle being as measured in a plane normal to the valve axis, whereby preferential flow into the shelf area from said other side of the valve axis is further encouraged.

Claim 6

A combination as in claim 3 wherein said valve guide boss includes a flow splitter having two faces tangent to opposite sides of the valve guide and intersecting in an upstream edge, one of said faces being associated with flow on said other side of the valve axis and lying substantially parallel to such flow, said one face being approximately aligned with fluid flow in the passage immediately upstream of the splitter and the other of said faces being disposed at a substantial angle to said flow.

Claim 7

In an internal combustion engine, a cylinder having an axis, a cylinder head closing one end of the cylinder, means defining an inlet passage through the cylinder head and communicating with the cylinder through the closed end, and a poppet inlet valve having a central axis offset to one side of the cylinder axis and reciprocably disposed in the passage for controlling communication of the inlet passage with the cylinder, said inlet passage being characterized by a throat of generally circular cross-section centered on said valve axis and opening into the cylinder adjacent one side thereof, said inlet valve being operative to open and close said throat opening, an entrance portion spaced from the throat and offset from the valve axis, and means defining a fluid flow path extending from the entrance portion toward and around opposite sides of the valve axis to the throat portion, said flow path around the valve axis being split into an inner leg adjacent the cylinder axis and in outer leg adjacent said side of the cylinder, said fluid flow path defining means including a valve guide boss surrounding the valve axis and including a valve guide boss surrounding the valve axis and projecting part way into the flow path between the inner and outer legs thereof, and a top wall including first and second ramp portions and a shelf portion, said shelf portion extending from adjacent the end of the guide boss in generally spaced and opposing relation to the throat, and said ramp portions merging with the shelf portion adjacent the guide boss, said ramp portions sloping downwardly on opposite sides of the guide boss and at steep angles to the shelf portion, one of the ramp portions forming a wall of the inner flow path and having a substantially steeper angle than the other, to slow and direct downwardly fluid flow in said inner leg relative to the higher speed and less downward direction of flow in the outer leg defined in part by the shallower ramp portion, whereby preferential entry of swirl developing flow into the shelf area from below the ramp of lower slope in encouraged.

Claim 8

In an internal combustion engine, a cylinder having an axis, a cylinder head closing one end of the cylinder, means defining an inlet passage through the cylinder head and communicating with the cylinder through the closed end, and a poppet inlet valve having a central axis offset to one side of the cylinder axis and reciprocably disposed in the passage for controlling communication of the inlet passage with the cylinder, said inlet passage being characterized by a throat of generally circular cross-section centered on said valve axis and opening into the cylinder adjacent one side thereof, said inlet valve being operative to open and close said throat opening, an entrance portion spaced from the throat and offset from the valve axis, and means defining a fluid flow path extending from the entrance portion toward and around opposite sides of the valve axis to the throat portion, said flow path around the valve axis being split into an inner leg adjacent the cylinder axis and in outer leg adjacent said side of the cylinder, said fluid flow path defining means including a valve guide boss surrounding the valve axis and including a valve guide boss surrounding the valve axis and projecting part way into the flow path between the inner and outer legs thereof, and a top wall including first and second ramp portions and a shelf portion, said shelf portion extending from adjacent the end of the guide boss in generally spaced and opposing relation to the throat, and said ramp portions merging with the shelf portion adjacent the guide boss, said ramp portions sloping downwardly on opposite sides of the guide boss and at steep angles to the shelf portion, one of the ramp portions forming a wall of the inner flow path and having a substantially steeper angle than the other, to slow and direct downwardly fluid flow in said inner leg relative to the higher speed and less downward direction of flow in the outer leg defined in part by the shallower ramp portion, whereby preferential entry of swirl developing flow into the shelf area from below the ramp of lower slope in encouraged.

Claim 9

A combination as in claim 5 wherein said inlet passage is configured so that flow in said outer leg is substantially tangential with said cylinder side and the flow direction of said inner leg forms a substantially greater angle with flow in the passage immediately upstream of the valve guide than does flow in said outer leg, said greater angle being measured in a plane normal to the cylinder axis whereby preferential flow into the shelf area from said outer leg is further encouraged.

Claim 10

A combination as in claim 6 wherein said shelf portion lies in a plane substantially normal to the cylinder axis.

Claim 11

A combination as in claim 7 wherein said valve guide boss includes a flow splitter having two faces tangent to opposite sides of the valve guide and intersecting in an upstream edge, one of said faces in part defining said outer leg of the flow path and being approximately aligned with the direction of fluid flow in the passage immediately upstream of the splitter and the other of said faces being disposed at a substantial angle to said upstream flow.