Diesel distributor fuel-injection pumps VE - K-Jet.org

Closed control loops (Fig. 5)Injected fuel quantityThe injected fuel quantity has a decisiveinfluence upon the vehicle’s starting,idling, power output and driveabilitycharacteristics, as well as upon its particulateemissions. For this reason, thecorresponding maps for start quantity,idle, full load, accelerator-pedal characteristic,smoke limitation, and pumpcharacteristic, are programmed into theECU. The driver inputs his or her requirementsregarding torque or enginespeed through the accelerator sensor.Taking into account the stored mapdata, and the actual input values fromthe sensors, a setpoint is calculated forthe setting of the rotary actuator in thepump. This rotary actuator is equippedFig. 5with a check-back signalling unit andensures that the control collar is correctlyset.Start of injectionThe start of injection has a decisive influenceupon starting, noise, fuel consumption,and exhaust emissions. Startof-injectionmaps programmed into theECU take these interdependencies intoaccount. A closed control loop is usedto guarantee the high accuracy of thestart-of-injection point. A needle-motionsensor (NBF) registers the actual start ofinjection directly at the nozzle andcompares it with the programmed startof injection (Figs. 2 and 3). Deviationsresult in a change to the on/off ratio ofthe timing-device solenoid valve, whichcontinues until deviation reaches zero.Closed control loop of the electronic diesel control (EDC)Q Air-flow quantity, n act Engine speed (actual), p A Atmospheric pressure, s set Control-collar signal(setpoint), s act Control-collar position (actual), s v set Timing-device signal (setpoint), t K Fuel temperature,t L Intake-air temperature, t M Engine temperature, t i act Start of injection (actual).FuelAcceleratorpedalOperator’spanelAirElectroniccontrol fordistributorpumpsELABOn/OffECUCruisecontrolVEpumps setpointt Ks actualStartquantitycontrolEGRcontrolp As v setpointStart-ofinjectioncontrolInjectedfuel-quantitycontrolt LQ lVehiclespeedsensorInjectionnozzlet i actualtMn actualExhaustemissionsEGR valveEngine and vehicleUMK0465E57