Fuel feed apparatus and accumulator fuel injection system having the same

An accumulator fuel injection system for injecting high-pressure fuel into a combustion chamber of an internal combustion engine, the accumulator fuel injection system comprising:

• a common rail for accumulating high-pressure fuel;
• an injector for injecting high-pressure from the common rail into the combustion chamber;
• and
• a fuel feed apparatus for supplying high-pressure fuel to the common rail;
• wherein the fuel feed apparatus comprising:
• a high-pressure pump for pressurizing fuel and press-feeding the fuel to the common rail;
• a feed pump for pumping fuel from a fuel tank to the high-pressure pump;
• a fuel filter provided downstream the feed pump for filtering fuel pumped from the feed pump;
• a return passage for returning fuel from a downstream of the feed pump to an upstream of the feed pump;
• and
• a return flow control unit for controlling flow of fuel retuning through the return passage.