Check valve central metering injection system

Claim 1

A fuel system for supplying fuel to an internal combustion engine having at least one fuel injector, a control unit for generating control signals in timed relation to the combustion processes therein, and a source of pressurized fuel, the system comprising: fuel rail means having a first and a second end for receiving pressurized fuel and having means for delivering said fuel to the at least one fuel injector; bi-level means in fluid communication with the source of pressurized fuel for selectively maintaining the pressure within said fuel rail means at a first and second level of pressure, said bi-level means further including a first and a second pressure regulator connected in series, said series combination having an input, an output and common node; a check valve means in fluid communication with said second end of said fuel rail means for permitting fluid to flow from said common node into said fuel rail means; a three-way valve means having first, second and third orifices in fluid communication with said bi-level means and said fuel rail means, for selectively communicating, in response to external control signals, fuel at said first and at said second pressure levels to said fuel rail means; a first conduit means for providing fluid communication between said first orifice and the inlet of said bi-level means; a second conduit means for providing fluid communication between said second orifice and the first end of said fuel rail; a third conduit means for providing fluid communication between said third orifice and the outlet of said bi-level means; and exit conduit means in fluid communication with said third orifice and said outlet of said bi-level means for permitting fuel to exit therefrom.

Claim 6

A method of metering fuel to an internal combustion engine from a fuel injector in fluid communication with the engine and a fuel rail of a fuel system having an injection and non-injection mode of operation; the steps of which comprise: causing pressurized fuel at a first determinable pressure level to flow within the fuel rail; operating said fuel system in the fuel recirculating configuration during times not involving fuel injection; changing the configuration of said system to a dead ended configuration during times involving fuel injection; causing fuel to flow from said fuel injector while said fuel system is in said dead ended configuration; returning the configuration of said fuel system, after a determinable length of time to said fuel recirculating configuration; and reversing the direction of fuel flow through said fuel rail.

Claim 7

A method of metering fuel to an internal combustion engine from a fuel injector in fluid communication with the engine and a fuel rail of a fuel system having an injection and non-injection mode of operation; the steps of which comprise: causing pressurized fuel at a first determinable pressure level to flow within the fuel rail; operating said fuel system in the fuel recirculating configuration during times not involving fuel injection; changing the configuration of said system to a dead ended configuration during times involving fuel injection; causing fuel to flow from said fuel injector while said fuel system is in said dead ended configuration; returning the configuration of said fuel system, after a determinable length of time to said fuel recirculating configuration; and reversing the direction of fuel flow through said fuel rail.