A FUEL SUPPLY APPARATUS AND A FUEL SUPPLY CONTROL METHOD FOR COMMON RAIL TYPE FUEL INJECTION SYSTEM

摘要

A fuel supply apparatus (100) and a fuel supply control method for a common rail type fuel injection system are disclosed. The fuel supply apparatus (100) comprises a low-pressure pump (2) which supplies a fuel from a tank (4) to a high-pressure pump (6) such as a port-controlled reciprocating pump (6) through a filter (8) and a metering unit (10). A unidirectional valve (14) is provided between an outlet of the metering unit (10) and an inlet of the high-pressure pump (6). The unidirectional valve (14) selectively supplies the fuel from the output of the metering unit (10) to the high-pressure pump (6) based on the fuel pressure at the output of the metering unit (10). A return line (16) connects the output of the metering unit (10) to the tank (4). A throttle (18) in the return line (16) selectively supplies a part of the fuel from the output of the metering unit (10) to the tank (4).