HISTORY OF FUEL INJECTION - DISA

1 HISTORY OFFUEL INJECTION By FRANK DeLUCA, Chief fuel INJECTION Engineer, of American Bosch Arma Corporation HISTORY of FuelInjectionWhenRudolphDiesel contracted withAugsburg and Krupp ofGermany in1893 to deve-lop a moreefficientinternalcombustion engine, one of hisobjectiveswas to use a s fuel themountainouspiles of powdered coalwhich had beenaccumulatingthroughout firstexperimentalcoaldust burning engine was built thatyearusing a i r toblast thefuelinto method i sshownschematically inFig. 1,which powderedcoalwas contained inhopperBprovidedwithrotaryvalve D,and the compressed air wasstored intank INJECTION valve Ewas lifted, the highpressure airflowedintothe combustion chamberCthroughorificeFcarryingwith it thecoaldischargedthrough the a t-tempting tostartthe engine it exploded, and allsubsequentefforts tooperate theengine oncoaldustfailed, sothat oil wasfinallyadopted a s the firstexperimentswithoil, itwas mechanically injected into the engine.

2 The resultswereunsatisfactory,probablybecaus e of thecrudeinjection equipment withlargedead fuel volume, sothat tousing the compressed airequipmentavailablefrom hiscoal dustexperiments. His firsttestswith a i rinjectionproved sosuccessfulthatthisbecame theaccceptedmethod of INJECTION for ,early inthe development ofthis newengine the importance of the fuelinjectionprocess onenginecombustion was emphasized,and subsequentprogress indiesel enginedevelopment has beenlargelydependentuponimprovements INJECTION system INJECTION (After 54286 of 1895.)The operating principle ofmost airinjectionsystemshas been similar to the onefirstused was metered anddelivered by apump to the atomizer,which was incommunicationwith ahighpressure air storagetank supplied by an aircompressor,and injectionoccurredwhen theinjectorvalve was opened by a airthenflowedintothe engine cylindercarryingalongwith it themeteredfuelas a construction ofDiesel'sfuelatomizer has notbeenfullyestablished, but most ofthe earlydesigns ofatomizers had aseries of1 8 inchdiameterholesthroughwhich the a i rand fuelpassedbeforeentering the perforateddiscatomizer,shown (seefollowingpage),cameinto use about the consisted of amechanicallyoperatedvalvesurrounded by astack of drilleddiscs, orpulverizerrings, on 1 HISTORY of fuel Injectionwhich an aspirating valve atomizer wich becamepopularforsmall air INJECTION engines.

3 As shown in ,the meteredoil was of the first satisfactory airlessinjectionsystem wasappliedto an enginein1910byJamesMcKechnieofVickers, As shown in (seefollowingpage),oilwasdeliveredbyamet eringpumptoaspringloadedplunger, beinjected into theenginecylinder asthespringreturned theplunger annularspaceabovethevalveseat, andwhen the valve wasliftedanaspiratingeffectwasproducedon theoiltodischargeitalongwiththeairflowin gpastinto ,butwithlittleor no commercial ,and it was attempted byThornycroftofEnglandin1903,buttheIn191 3 Vickers, which atomizer of K. ( No. 910534 of 1909.) fuel toanaccumulatorand headeroflargecapacity withthefuel pressuremaintainedatabout5000psibyarelie fvalve,andthefuel Oakland, & Sons ofEnglandused jerkpumpsin1891andRuston,Proctor & Co.,alsoofEngland,used asimilar 1914 De La VergneCompany of Philadelphia usedajerk pumpthatdeliveredfuelataveryhighrate(ful lloaddeliveryin about 12 crankshaftdegrees)totwosinglehole,swirlt ypenozzleslocatedoppositeeachotherinthec ombustionchamber.

4 2 HISTORY of fuel InjectionINJECTION PUMPSThe one feature common toallinjectionpumpsfromtheearliesttothep resenthasbeentheuseofplungerstocreatethe requiredinjection pressure. Earlypumpsrelieduponpackedglandstominimi zetheleakageofhigh pressure 4. The McKechnie solid INJECTION systemreference to closefitting of the plunger and barrel for elimination of the packing gland appearsin a patentfiled in 1912 by Otto F. Persson of the United States. In 1919 Philip L. Scott,also an American,described a method of fitting a plunger to a barrel with an estimatedclearance of MethodsThe earliest known , , , of , duration of the plunger stroke during wichthe by-pass valve D was closed was lenghtenedor reduced by moving the wedge K in or out, thusincreasing or decreasing the fuel quantitydelivered by the metering control by means of a helix on plunger was introduced by Carl Pieper ofGermany in 1892.

5 According to his German patent ,057 and as shown in Fig. 6 (see following page), a suction port was controlled by Fig. 5. 's metering pump with spill valvea top beveled plunger, and by rotating the plungercontrolledby a wedge.( patent of1900)a variation of thePort closure time was effected tochange the fuel quantity delivered by the No. 9403 was granted toWilliam in 1895 for a double port helixcontrol for varying both the beginning and ending of INJECTION . 3 HISTORY of fuel InjectionControlofthefuelquantitybysucti onvalvetiming was Lanster . ,613issuedin1903, a governorcontrolledlinkageconnectedtothep umpingplungerwouldholdthespringloaded suctionvalveopenfor a longer or shorter timetodecrease or , ,fuelataregulatedhighpressurewasdelivere dtochamberAfromwhich , fuewas distributedtothevariousoutletsDbymeans ofslotBuncoveringtheductsE. Thefuel quantitywasincreasedor decreased byloweringorraisingthedistributortovaryt heeffectivewidthofslotB.

6 TheBritishmotorship"Selandia,"launchedin 1913, usedaFig. (AfterCarldistributortypeinjectionsystem onitsfirstPieper'sGermanpatent No. 66057of1892.) Valves Oneoftheproblemsencounteredwithearlyjerk pump INJECTION system was the drippingor after ,increasedfuelconsumption,andnozzlecar-b onization, ,HerbertKempton,proposedadeliveryvalveha vingaholeinitthroughwhichthehighpressure fuelwasrelievedwhentheplungerreturnedon , device.(After he wasgrantedU. S. ,235,611On itFrancoisFeyens'Britishpatent In1920 VanAmstellofHollandde-scribedanon-return valvehavingacylindricalpistondirectlybel owthevalveseattowithdrawaportionoftheLiq uidbeforethevalve Swedenintroduced a retractiontypedeliveryvalveforwhichhewas granted patent ,589,515in1926. It embodied theonefeaturehispredecessorshadbeenstriv ingfor: automatic (see followingpage),thevalvehadaclosefittingp istonbeneathitsseat, seat of the valve.)

7 4 HISTORY of fuel InjectionTheduplexdeliveryvalvewasfirstp roposedbyEugeneTartraisofFrancein1921, ,492,111on inside ,whenfueldeliveryfromthepumpceasedandthe mainvalveseated,thehighpressureinthe discharge tubingwasrelievedthroughthesmallvalveunt ilitsclosingpressurewas , ,2,090, ,increasinginwidthfromtoptobottom, ( ' ,589,515of1926.) SPRAY NOZZLESF uelinfectionwasfirs used inottocyleenginesbeforethe inventionof the DieselEngine. The objectivewastoobtain betteratomizationofthepressurizedfuelthr oughspraynozzles than was possible , , ,000onanengineaccessory,includingapoppet nozzle,whichhe claimedwould burn keroseneandheavycrudepetroleumsaswellast helighternapthascommonly used for fuelinavaporizer, ,583was granted to A. H. Goldinghamforapoppetnozzlewith anorifice plate below ,patentNo, in 1890 on thefirstnozzleof thistype. ,thevalvewasliftedoffits seat by fuelpressure actingonthe piston in oppositionto thespring.

8 In commonwithother earlydesigns,thiswasalowpressurenozzle. A lip projectionwasaddedbelowtheorificesothatt he ,differentialvalvetypenozzle,whichisthem ostpopularnozzletoday, (see followingpage), ,20,582onasimilarnozzlewithtangentialfue lchannelsfor the fuelenteringat the seattoproduceadiffusedspray. 5 HISTORY of fuel InjectionPintleValveIn1910,PeterBowmanof DenmarkappliedforapatentinEnglandonwhatm aybetheearliestformofaninwardlyopening, ,thepintle,orvalveextension,protrudedthr oughthesprayholetoproduceanannularorific e,and theseatfortheflatbottomvalvewasclosetoth eorificesothatthenozzle , ,017, ,Guy Bell, ,585,277 on anaccumu-latornozzlewhichinjectedattheen dofthepumpstroke,ratherthanduringit. As shown inFig. 12(seefollowingpage),fuelfromthepumpwasd eliveredtoaspaceFig. 10 Inwardly opening differential nozzle of nozzlevalveremainedseated,becausethepres sureof abovethevalvedroppedtoalowpressure, andthe pressure of thefuelstoredinthe accumulatorandaroundthevalvethenactedon the differentialareaofthevalvetoliftitagains tthespring.

9 Thestoredfuelthendischargedthroughthenoz zleorificeuntilits pressuredroppedtothenozzlevalveclosing ,701,089 was granted in 1929 toEdwardVonSalisof Switzerland for a nozzlewithaspringoperted accumulator plunger, andothermodifications were made later byRobertBroege in 1931 and Gustav wasfirstsuggested byanAmerican, , openingpintle ,059,604 on such a (afterPetcr Bowman's )nozzleforeach enginecylinderwith fuel suppliedfromaconstantpressureaccumulator charged Kennedy was granted ,092,956 on anovelconstruction ofan electro-magnetic nozzle valve in 1933, andtheAtlas-ImperialDieselEngineCompanyo fCalifornia about that time announced acommercialinjectionsystemwiththis typeof theearliestdaysofthediesel engine,troubles were encountered with the fuel 6 HISTORY of fuel toeliminatethetubing by , periodofsuctionvalveBpassedthroughcheck valve inusetoday. (seefollowingpage), Accumulator nozzle( ' ,585,277of 1926.)

10 C on ,thedifferentialvalveD was , ,981,913ontheunitinjectordesignadoptedfo rtheGeneralMotorstwo-cycle diesel INJECTION EQUIPMENTF romthefirstsuccessfuldieselengineto1926, ,precisionpartsrequiringclosetolerances, (AfterCnrlWeidmstn' ,932of1905.) 7 HISTORY of fuel Injectionrailfuelinjectionsystems were usedexclusivelyontheratherlargeenginesof thatAperiod. Smallengines,especiallyoftheautomotivety pe,werenotparticularlysuccessful,primari lybecauseofthelackofsuitable December, 1922theRobertBoschCompanyofStuttgart,Ger manydecidedtomanufacturefuelinjectionequ ipment, and afteryearsofdevelopmentitspopularjerkpum pwithhelixcontrol, ,831,649was grantedtoOttmarBauerin1931,was thesame time precisionnozzleassembliesofthepintleandh oletypewereintroduced,andsubsequently other items such as supplypumps,governors,andfilters were (AfterFrederickLamplough' ,517equipmentthehighspeeddieselenginecam eof 1911.)