Hydraulic piston and two way valve (TWV), solenoid valve, have been added to the conventional nozzle. Receiving signals from the engine control module (ECM), the TWV opens and closes to change the pressure in the pressure adjustment chamber on top of the hydraulic piston so that the hydraulic piston works thereby to inject the fuel from the nozzle.
Action of Injector
Non-Injection
When there is no continuity to the TWV with the outer valve down, or the outer seat closed, the command piston is pushing the nozzle downward to close the injection hole as fuel pressure does not escape from the control room.
Injection Start
When there is continuity to the TWV with the outer valve up, or the outer seat open, the command piston is moving the nozzle upward to open the injection hose as fuel pressure escapes from the control room.
Injection is conducted twice, the first injecting a small amount of fuel, the pilot injection, and the second injection, the main injection, injecting when ignited.
Injection Finish
When there is no continuity to the TWV with the outer valve down, the outer seal closed, the command piston is pushed down to push the nozzle further downward to close the injection hold as the fuel pressure does not escape from the control room.
