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

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Axial-pistondistributorpumps,VE-MVSolenoid-valve-controlledaxial-piston distributorfuel-injection pumps VE-MV60ProspectsOn the electronically-controlled distributorpumps of the future, the electricalactuator mechanism with control collarfor fuel metering will be superseded by ahigh-pressure solenoid valve. This willpermit an even higher degree of flexibilityin the fuel metering and in the variabilityof the start of injection.Design and constructionThis pump is of modular design. The fieldprovendistributor injection pump can thusbe combined with a new electronicallycontrolled fuel-metering system (Fig. 1).Basically speaking, the solenoid-valvecontrolleddistributor pump’s dimensions,installation conditions, and drivetrain includingthe pump’s cam drive, are identicalto those of the conventional distributorpump. The most important new componentsare:– Angle-of-rotation sensor (in the formof an incremental angle/time system[IWZ]) which is located in the injectionpump on the driveshaft between thevane-type supply pump and the rollerring,– Electronic pump ECU, which is mountedas a compact unit on the top side ofthe pump and connected to the engineECU,– High-pressure solenoid valve, installedin the center of the distributor head.With regard to its installation and hydrauliccontrol, the timing device with pulsevalve is identical to the one in the previouselectronically-controlled distributorpump.ComponentsAngle-of-rotation sensorAngle-of-rotation detection uses thefollowing components: Sensor, sensorretaining ring on the driveshaft, and thetrigger wheel with a given tooth pitch.Detection is based upon the signalsgenerated by the sensor.The pulses generated by the sensor areinputted to the ECU where they are processedby an evaluation circuit. The factthat the sensor is coupled to the pump’sroller ring ensures the correct assignmentof the angular increment to theposition of the cam when the roller ring isrotated by the timing device.Pump ECUThe pump ECU is mounted on the upperside of the pump and uses hybrid techniques.In addition to the mechanicalloading with which it is confronted inthe vehicle's under-hood environment,the pump must also fulfill the followingassignments:– Data exchange with the separatelymounted engine ECU via the serialbus system,– Evaluation of the signal from theangle-of-rotation sensor (IWZ),– Triggering of the high-pressure solenoidvalve,– Triggering of the timing device.Maps are stored in the pump ECU whichnot only take into account the settingpoints for the particular vehicle applicationand certain engine characteristics,but also permit the plausibility of the receivedsignals to be checked. In addition,they form the basis for defining a numberof different computational values.
High-pressure solenoid valveThe high-pressure solenoid valve mustfulfill the following assignments:– Large valve cross-section for efficientfilling of the high-pressure chamber,even at very high rotational speeds,– Low weight (low moving masses), tokeep the loading of the parts to a minimum,– Short switching times to guaranteehigh-precision fuel metering, and– Magnetic forces which are powerfulenough to cope with the high pressures.The high-pressure solenoid valve is comprisedof:– The valve body,– The valve needle, and– The electromagnet with electricalconnection to the pump ECU.The magnetic circuit is concentric to thevalve. This fact permits a compact assemblycomprising high-pressure solenoidvalve and distributor head.Method of operationPrinciplePressure generation in the solenoidvalve-controlleddistributor injectionpump is based on the same principle asthat in the conventional electronicallycontrolledVE pump.Fig. 1Fuel supply and deliveryVia the distributor head and the openedhigh-pressure solenoid valve, the vanetypesupply pump delivers fuel to thehigh-pressure chamber at a pressure ofapprox. 12 bar.No fuel is delivered when the high-pressuresolenoid valve is de-energized(open). The valve’s instant of closingdefines the injection pump’s start ofdelivery. This can be located at thebottom dead center (BDC) of the cam oron the rise portion of the cam slope.Similarly, the valve’s instant of openingdefines the pump’s end of delivery. Thelength of time the valve is closed determinesthe injected fuel quantity.The high pressure generated in the highpressurechamber (the fuel from thesupply pump is compressed by the axialpiston when this is forced up by the camplate riding over the rollers of the rollerring) opens the delivery valve and thefuel is forced through the pressure lineto the injection nozzle in the nozzleholder. Injection pressure at the nozzleis 1400 bar. Excess fuel is directed backto the tank through return lines.Since there are no additional intake portsavailable, if the high-pressure solenoidvalve should fail, fuel injection stops.This prevents uncontrolled “racing” of theengine.Solenoid-valve-controlled axial-piston distributor fuel-injection pump (section)Electroniccontrol fordistributorpumpsUMK1205Y61
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Dieseldistributor fuel-injection pu
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(prechamber engines and direct-inje
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Diesel fuelinjectionsystems:An over
Page 10 and 11:
Axial-pistondistributorpumpsMechani
Page 12: Axial-pistondistributorpumpsSubasse
Page 17 and 18: contaminants in the fuel can lead t
Page 19 and 20: Pump assembly with distributor head
Page 21 and 22: Fig. 10Distributor plunger with str
Page 23 and 24: Delivery valve with return-flowrest
Page 25 and 26: - Maximum-speed governing: With the
Page 27 and 28: start-quantity position by the ball
Page 29 and 30: Overrun (engine braking)During down
Page 31 and 32: Injection timingIn order to compens
Page 33 and 34: through a sliding block and a pin s
Page 35 and 36: Fig. 2Schematic of the VE distribut
Page 37 and 38: the torque-control lever tilts arou
Page 39 and 40: Power and torque comparison, natura
Page 41 and 42: Load-dependentcompensationDepending
Page 43 and 44: Cold-start compensationThe diesel e
Page 45 and 46: Design and constructionThe hydrauli
Page 47 and 48: Testing and calibrationInjection-pu
Page 49 and 50: Throttling pintle nozzleThe throttl
Page 51 and 52: Sac-hole nozzle with cylindrical sa
Page 53 and 54: The nozzle-holder body contains the
Page 55 and 56: This necessitates a nozzle holder w
Page 57 and 58: formation in accordance with specif
Page 59 and 60: Closed control loops (Fig. 5)Inject
Page 61: Table 1. ECU reactionsFailure Monit
Page 65 and 66: Sheathed-element glow plugs:Tempera
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Diesel distributor fuel-injection pumps VE - K-Jet.org

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