Patent ID: 7634986

Claim:
A fuel supply system for an accumulator fuel injection system designed to inject fuel, as stored in an accumulator, into an internal combustion engine through a fuel injector comprising: a feed pump working to pump fuel out of a fuel tank through a first fuel path and feed the fuel to a second fuel path; a high-pressure pump working to pressurize and supply the fuel, as fed from said feed pump through the second fuel path, to an accumulator; a priming pump disposed between the fuel tank and said feed pump, said priming pump working to pump the fuel out of the fuel tank to feed the fuel through the first fuel path; a fuel filter disposed in the second fuel path between said feed pump and the high-pressure pump to filter the fuel, as delivered from said feed pump to said high-pressure pump; a return path extending from between said feed pump and said fuel filter in the second fuel path to between said priming pump and said feed pump in the first fuel path; and a return valve working to open and close said return path selectively, when a fuel feeding pressure that is a pressure of the fuel in the second fuel path between said feed pump and said fuel filter exceeds a first set pressure, said return valve being placed in a first open position to open said return path to return the fuel from downstream to upstream of said feed pump, when a fuel priming pressure that is a pressure of the fuel, as fed by said priming pump, exceeds a second set pressure, said return valve being placed in a second open position to open said return path to direct the fuel, as fed by the priming pump, to between said feed pump and said fuel filter.