Fuel supply for a multi-cylinder internal combustion engine

Claim 1

A method for supplying a fuel to a single point fuel injected internal combustion engine comprising: producing a primary air flow in an air intake manifold; injecting fuel directly into the primary air flow in a direction substantially parallel to said primary air flow at the point of injection for atomization therein; producing an auxiliary air flow substantially parallel to said primary air flow around said primary air flow in the vicinity where the fuel injection is effected; guiding said primary air flow and injected fuel by said auxiliary air flow towards a riser portion of said air intake manifold for evaporating the injected fuel and for creating a uniform air/fuel mixture, said riser portion having a floor surface in contact with an exhaust passage; and adjusting the auxiliary air flow corresponding to the load condition on the engine for increasing said auxiliary air flow under substantially high load condition.

Claim 2

A method for supplying a fuel to a single point fuel injected internal combustion engine comprising: producing a primary air flow in an air intake manifold; injecting fuel directly into the primary air flow in a direction substantially parallel to said primary air flow at the point of injection for atomization therein; producing an auxiliary air flow substantially parallel to said primary air flow around said primary air flow in the vicinity where the fuel injection is effected; guiding said primary air flow and injected fuel by said auxiliary air flow towards a riser portion of said air intake manifold for evaporating the injected fuel and for creating a uniform air/fuel mixture, said riser portion having a floor surface in contact with an exhaust passage; and adjusting the auxiliary air flow corresponding to the load condition on the engine for increasing said auxiliary air flow under substantially high load condition.

Claim 3

A method for supplying fuel to a single point injection internal combustion engine comprising: producing an adjustable primary air flow through an intake manifold; creating an air/fuel mixture by injecting fuel directly into and substantially parallel to the general direction of flow of said primary air flow at the point of injection and in synchronism with engine revolution; producing an auxiliary air flow which is coaxial with at least a portion of the primary air flow and which flows around the primary air flow; guiding said air/fuel mixture with said auxiliary coaxial air flow to minimize any tendency of the fuel to attach to inner wall surface of the intake manifold; and adjusting the ratio of primary to auxiliary air flow so that the amount of auxiliary air flow is substantially smaller than the amount of the primary air flow when the amount of primary air flow is smaller than a predetermined value and so that the amount of auxiliary air flow is rapidly increased when the amount of primary air flow becomes greater than the predetermined value.

Claim 4

A method for supplying fuel to a single point injection internal combustion engine comprising: producing an adjustable primary air flow through an intake manifold; creating an air/fuel mixture by injecting fuel directly into and substantially parallel to the general direction of flow of said primary air flow at the point of injection and in synchronism with engine revolution; producing an auxiliary air flow which is coaxial with at least a portion of the primary air flow and which flows around the primary air flow; guiding said air/fuel mixture with said auxiliary coaxial air flow to minimize any tendency of the fuel to attach to inner wall surface of the intake manifold; and adjusting the ratio of primary to auxiliary air flow so that the amount of auxiliary air flow is substantially smaller than the amount of the primary air flow when the amount of primary air flow is smaller than a predetermined value and so that the amount of auxiliary air flow is rapidly increased when the amount of primary air flow becomes greater than the predetermined value.