Patent ID: 7874284

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 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 flow rate control valve disposed in the second fuel path between said fuel filter and said high-pressure pump, said flow rate control valve working to control a flow rate of the fuel delivered to said high-pressure pump; a return path extending from between said feed pump and said fuel filter to the first fuel path which is upstream of said feed pump; and a control valve working to open and close said return path selectively, when a pressure of the fuel in the second fuel path between said fuel filter and said flow rate control valve exceeds a first set pressure, said control valve being placed in an open position to open said return path to return the fuel from downstream to upstream of said feed pump to keep the pressure of fuel between said fuel filter and said flow rate control valve below the first set pressure.