Low fuel vapor emissions fuel system

Abstract

A low fuel vapor emissions fuel system which reduces the need for FVCS and further obviates both the fuel pump and its return fuel line, composed generally of a rigid tank, a flexible fuel bladder within the tank, a filler pipe connecting between the fuel bladder and an exterior body location, a filler cap which removably seals the filler pipe, a fuel line from the fuel bladder to the engine, an air compression system for selectively pressurizing the cavity between the fuel bladder and the tank, and a fuel level sensor. In operation, when the ignition key is turned on, the air pump pressurizes the cavity between the tank and the fuel bladder. A program of the vehicle computer monitors the air pressure to provide a nominal fuel pressure for the engine. The air pump system further includes a vent valve, which also includes an over pressure relief valve. The filler door is interfaced with a sensor switch which is connected to a vent valve actuator; when the filler door is opened the vent valve opens to thereby relieve the pressure in the cavity. The filler cap is coupled with a cap actuator which prevents filler cap removal from the filler pipe unless fuel pressure in the fuel bladder has dropped to atmospheric pressure.

Dependencies are inferred from the claim text.