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

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Axial-pistondistributorpumpsSeat-hole nozzleIn order to minimise the residual volume– and therefore the HC emissions – thestart of the spray hole is located in theseat taper, and with the nozzle closed it iscovered almost completely by the nozzleneedle. This means that there is no directconnection between the sac hole and thecombustion chamber (Figs. 7 and 8). Thesac-hole volume here is much lower thanthat of the sac-hole nozzle. Compared tosac-hole nozzles, seat-hole nozzles havea much lower loading limit and are thereforeonly manufactured as Size P with aspray-hole length of 1 mm.For reasons of strength, the nozzle tip isconically shaped. The spray holes arealways formed using e.c.m. methods.Fig. 7Seat-hole nozzleStandard nozzle holdersAssignments and designsNozzle holders with hole-type nozzles incombination with a radial-piston distributorinjection pump are used on DIengines.With regard to the nozzle holders, onedifferentiates between– Standard nozzle holders (singlespringnozzle holders) with and withoutneedle-motion sensor, and– Two-spring nozzle holders, with andwithout needle-motion sensor.ApplicationThe nozzle holders described here havethe following characteristics:– Cylindrical external shape with diametersbetween 17 and 21 mm,– Bottom-mounted springs (leads to lowmoving masses),– Pin-located nozzles for direct-injectionengines, and– Standardised components (springs,pressure pin, nozzle-retaining nut)make combinations an easy matter.50Fig. 8Seat-hole nozzle: Tip shapeUMK1408Y UMK1407YDesignThe nozzle-and-holder assembly is composedof the injection nozzle and thenozzle holder.The nozzle holder comprises the followingcomponents (Fig. 9):– Nozzle-holder body,– Intermediate element,– Nozzle-retaining nut,– Pressure pin,– Spring,– Shim, and– Locating pins.The nozzle is centered in the nozzle bodyand fastened using the nozzle-retainingnut. When nozzle body and retaining nutare screwed together, the intermediateelement is forced up against the sealingsurfaces of nozzle body and retainingnut. The intermediate element serves asthe needle-lift stop and with its locatingpins centers the nozzle in the nozzleholderbody.
The nozzle-holder body contains the– Pressure pin,– Spring, and– Shim.The spring is centered in position by thepressure pin, whereby the pressure pin isguided by the nozzle-needle’s pressureshaft.The nozzle is connected to the injectionpump’s high-pressure line via the nozzleholderfeed passage, the intermediateelement, and the nozzle-body feed passage.If required, an edge-type filter canbe installed in the nozzle holder.Fig. 9Standard nozzle holder1 Edge-type filter, 2 Inlet passage,3 Pressure pin, 4 Intermediate element,5 Nozzle-retaining nut, 6 Wall thickness,7 Nozzle, 8 Locating pins, 9 Spring,10 Shim, 11 Leak-fuel passage,12 Leak-fuel connection thread,13 Nozzle-holder body, 14 Connection thread,15 Sealing cone.1151413Nozzlesand nozzleholdersMethod of operationThe nozzle-holder spring applies pressureto the nozzle needle through thepressure pin. The spring’s initial tensiondefines the nozzle’s opening pressurewhich can be adjusted using a shim.On its way to the nozzle seat, the fuel passesthrough the nozzle-holder inlet passage,the intermediate element, and thenozzle nody. When injection takes place,the nozzle needle is lifted by the injectionpressure and fuel is injected through theinjection orifices into the combustionchamber. Injection terminates as soon asthe injection pressure drops far enough forthe nozzle spring to force the nozzleneedle back onto its seat.21211109Two-spring nozzle holdersApplicationThe two-spring nozzle holder is a furtherdevelopment of the standard nozzleholder, and serves to reduce combustionnoise particularly in the idle and part-loadranges.DesignThe two-spring nozzle holder featurestwo springs located one behind the other.At first, only one of these springs has aninfluence on the nozzle needle and assuch defines the initial opening pressure.The second spring is in contact with astop sleeve which limits the needle’sinitial stroke.345876UMK1413Y51
Page 3 and 4: Dieseldistributor fuel-injection pu
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Page 8 and 9: 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: Sac-hole nozzle with cylindrical sa
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 and 62: Table 1. ECU reactionsFailure Monit
Page 63 and 64: High-pressure solenoid valveThe hig
Page 65 and 66: Sheathed-element glow plugs:Tempera

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

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