Fuel injector having dual flow rate capabilities and engine using same

摘要

The present invention relates to fuel injectors having the ability to inject fuel at multiple pressures during an injection event. Traditional fuel injectors used in common rail fuel injection systems and unit pump fuel injection systems typically did not have the ability to inject fuel at multiple pressures during an injection event. However, engineers have learned that increased control over an injection event can lead to improved emissions by the fuel injectors. Therefore, the present invention utilizes an electronically controlled valve member that can direct. the flow of fuel through a fuel injector during an injection event between a relatively restricted passageway and a relatively unrestricted passageway. The present invention finds particular application in both common rail fuel injection systems and electronic unit pump fuel injection systems used in diesel engines.