Patent ID: 8443780
Filing Date: 2013-05-21
Classification: F02M

Abstract:
1. A method of operating a fuel system for an internal combustion engine comprising the steps of: injecting fuel into an engine cylinder at a medium pressure level at least in part by fluidly connecting a nozzle outlet of a fuel injector with a common rail containing the fuel at the medium pressure level; increasing a pressure of fuel in a plunger cavity of the fuel injector from a low pressure level existing in the plunger cavity during the medium pressure injection to the medium pressure level by fluidly connecting the plunger cavity with the common rail; increasing a pressure of fuel in the plunger cavity from the medium pressure level to a high pressure level by moving a tappet of a mechanically actuated pressure intensifier in response to rotation of a cam; injecting fuel at the high pressure level into the engine cylinder at least in part by fluidly connecting the nozzle outlet with the plunger cavity; and operating the fuel system in a low leakage mode subsequent to the injection of fuel at the high pressure level at least in part via a step of returning a pressure of fuel in the plunger cavity from the high pressure level to the low pressure level.