Patent ID: 6227175
Filing Date: 2001-05-08
Classification: F02M

Abstract:
A fuel injector body for an internal combustion engine, comprising:an injector body in fluid communication with a source of fuel;a nozzle assembly through which fuel in dispersed from said fuel injector assembly during an injection event;a high pressure fuel delivery system providing high pressure fuel to said nozzle assembly;a combined initial injector and peak injection pressure regulator operable to control said nozzle assembly to regulate the rate of fuel injection at the beginning of an injection event and further operable to limit the maximum pressure of the fuel dispersed from said nozzle assembly; said injection pressure regulator movably between a closed position and a first open position which reduces the rate of fuel injection at the beginning of the injection event as well as a second open position which limits the maximum pressure of the fuel dispersed by the nozzle assembly; said injection pressure regulator including a housing having a valve bore in fluid communication with said fuel delivery system; said valve bore defining a first, larger diameter; said housing including an inlet defining a second, smaller diameter for fluid communication between said fuel system and said valve bore; said injection pressure regulator further including a rate shaping valve including a body complimentarily received within and movably supported within said valve bore; a pintle head adapted to be received in said inlet so as to define a predetermined annular clearance therebetween, and a annular shoulder formed between said body and said pintle head and defining a valve chamber between said annular shoulder and said valve bore; said regulator movable between a closed position and an open position which reduces the rate of fuel injected at the beginning of the injection event and a waste gate valve movably supported within said fuel injector assembly between a closed position and an open position to allow fuel to flow into said valve chamber which limits the maximum pressure of the fuel injected at the end of the injection event by reducing the pressure of the fuel at the beginning of the injection event;a biasing member supported within said fuel injector assembly which biases said injection pressure regulator to its closed position with a predetermined force such that injection pressure regulator moves to its first open position only after the pressure in said fuel delivery system has reached a predetermined first opening pressure and such that said injection pressure regulator moves to its second open position only after the pressure in said fuel delivery system has reached a predetermined second opening pressure; anda solenoid and armature control valve assembly to control timing and fuel quantity during each fuel injection event.