Begin Injection 10 Injection begins when current is applied from the ECM to open the two-way valve (10). With valve open, fuel from the control chamber (14) flows through orifice 1 (12) out of the injector to the fuel leak-off line (18). The fuel is then routed back to the fuel tank. As the fuel from the control chamber exits the injector, the force is removed from the hydraulic piston (15), allowing fuel through the nozzle (17) to start the injection process.
11 18 3 12 3—Electronic Injector 10—Two-Way Valve 11—Fuel Inlet 12—Orifice 1 13—Orifice 2 14—Control Chamber 15—Hydraulic Piston 16—Valve Spring 17—Nozzle 18—Fuel Leak-Off 13 14 15 16 TX1003034 –UN–25JAN06 17 Begin Injection Continued on next page JC89288,0000037 –19–30JAN06–4/5 TM2361 (24JUN08) 9010-05-6 450DLC Excavator Operation and Tests 062608 PN=254 Theory of Operation No Injection 10 Fuel from the high pressure common rail enters the electronic injector at the fuel inlet (11).
When no current is supplied to the two-way valve (10), the valve spring (16) and hydraulic pressure of the fuel in the control chamber 11 18 (14) cause the hydraulic piston (15) to push down and close the nozzle (17). High pressure fuel is held inside the nozzle until injection. 3 12 3—Electronic Injector 10—Two-Way Valve 13 14 11—Fuel Inlet 12—Orifice 1 13—Orifice 2 15 14—Control Chamber 9010 15—Hydraulic Piston 05 16—Valve Spring 16 6 17—Nozzle 18—Fuel Leak-Off –UN–25JAN06 TX1003033 17 No Injection JC89288,0000037 –19–30JAN06–3/5 Theory of Operation No Injection 10 Fuel from the high pressure common rail enters the electronic injector at the fuel inlet (11).
When no current is supplied to the two-way valve (10), the valve spring (16) and hydraulic pressure of the fuel in the control chamber 11 18 (14) cause the hydraulic piston (15) to push down and close the nozzle (17). High pressure fuel is held inside the nozzle until injection. 3 12 3—Electronic Injector 10—Two-Way Valve 13 14 11—Fuel Inlet 12—Orifice 1 13—Orifice 2 15 14—Control Chamber 15—Hydraulic Piston 16—Valve Spring 16 17—Nozzle 18—Fuel Leak-Off –UN–25JAN06 TX1003033 17 No Injection JC89288,0000037 –19–30JAN06–3/5 9010 05 6