US2159360A - Fuel injection mechanism - Google Patents

Description

May O. L. STARR ET AL FUEL INJECTION uEcHANIsM Filed layls. 1936 2 sheets-sheet 1 -mmh E. J/ /7//// v///- i fllll/l//M May 23,y 1939.

O.. L. STARR Er AL FUEL INJECTION MEcHANIsM Filed lay 19, 1936 2 Sheets-Sheet 2 INVENTORS 05cm? L. STARR GEORGE W. Ew/s ATTORNEY /l 'Patented May 23, 1939 FUEL INJECTION M'Ecnamsn'r Oscar L. Starr, Mission SanJose, and George W. Lewis, San Leandro, Calif., assignors to Caterlilla: Tractor Co., Sa'n Leandro, Calif., a voor poration of California T Application-May 1s, 193s, lscroll No. 80,566

'f 7 claims'. (c1. 1oz- 41) Our invention relates to fuelinjection mechanism, and more particularly fuel Ainjection mec of the type having parts which are mounted for relative angular adjustment to control fuel injection- .li'uel injection mechanism of the character described is very common and is Y lower face of guide member 32.

being employed in numerous forms.

Atype of such fuel injection mechanism. inthe form ofa fuel'injection pump, is disclosed in ln Fig'. 1, and comprises a body memberor pump f casing Il having rigidly positioned therein pump barrel or sleeve Il in which a-pumpplunger I2' is closely iltted forboth angular adjustment and axial reciprocation. with an aperture or orifice Il connected by suit- A able pagage means (not shown) with fuel supply manifoldV Il in turn connected-to a suitable source of fuel supply. Thus, fuel can pass into sleevev I I when the upper edge of plunger I2 is below orifice Il. When the plunger is'moved upwardlyfflt is apparent that oriijlce I3 can be cl'osed to force fuel under pressure into a conduit (not shown) j connected with a cylinder of the engine.

Means, which maybe broadly considered as valve means, is provided to control the quantity oi' fuel injected. An annular groove lItis formed in the plunger below the upper edge thereof,l anda slot lfleads from such groove toA the upper edge of the plunger. From adjacent the top at' one 3o' side of slot Il is forx'ned'a by-pass ledge or edge 'Il whiclrhas a constant angle slant downwardly to groove I6. By-pass edge Il is adapted to'cooperate with orifice I3 to establish communicationbetween the above the upper edge of 35' the pllmger andgroove It, through slot I1. 'Be'- lcauseof the angular position of edge il, rit is apparent that the time of such by-pessing may be controlled by angular ent of plunger I2, to thereby control the quantity of fuel which 40 the pump can inject. The`mechanism whereb theA plunger can be angmsrly adjusted as, it

-reciprocated comprises sleeve 1I' journalled for 4 .rotation about barrel Il, and which is provided adjacent -its upper end with gear teeth 2l. and

l adjacent its lowerV end with axially'extending and aligned slots 2| (onlyvone of which appears in Fig. 1). outwardly extending arms 22 secured to pump plungercil, alidably engage in said slots 2| dm'lngreciprocation of the pump. Sleeve Il 59 is held in'fposition by cup-shaped retaining mein,

Pump barrel Ii is provided i2 in a downward direction; asuitable guide cup J2 being provided to take up sidethrust andV limit downward movement when it engages retainer ring I3.. Plunger I2 is axially reciprocated by anysuitable cam and tappet means (not shown) g operated by the engine and which contacts the Control means 35 'including a rack is slidnbly mounted for axial reciprocation in casing il, and has gear teeth for engagement with gear teeth 2l 1 on sleeve I9. Thus, it is seen that any axial movement of control means 35 effects, through gear teeth 2l, rotation or angular. adjustment of sleeve if about `plunger barrel Il, and consequently angular adjustment of plunger I2 through ll the sliding connection between slots 2i in sleeve 1|! and arms 22. The control means 3l isusually connected to the governor of the engine so that the injection of fuel is controlled automatically; and for a. multiple cylinder engine a plurality gg of such controlmeans is connected for simultaneous operation.' In the type of fuel injection mechanism to which the invention relates, manufacturing tolerances are Jvery small, and all parts are machined mi 'with exact precision in an effort to produce pumps having exactly the same. characteristics with reference to theirl timing and fuel metering, so th'at when plurality of pumps are employed on' a multiple cylinder engine, the engine will operate 30 smoothly and eiciently.' In this respect.- it is I necessary for all of the pump plungers to have exactly the' same eif'ective angular position for any given phase of fuelindection, so that no one pump meters more 'or less fuel than another pump 35 Y for such phase. Although 1t might be possible by individual hand work to manufacture al plurality of pumps with dimensions so identical as /to enable all the pumps to have exactly the same timing at any-given angular position; of the 40 plungers thereof when the pumpalare installed on the engine, there exists quite a problem in producing or obtaining this result in the commercial production of pumps in large quantities.

' With respect to multiplecylinder engines, Tit 45 is also desirable to enable the pumps Ito be interchangeably mounted on the engine, so that in assembling` the pumps thereon they can be positioned `in any order and still give synchronous 1 timing without further adjustment Also, it is desirable that in case of replacement of any given pump, by a new pump, the new pump can be mounted on the engine and be in Proper tim- Cing position without further timing adjustment.

'I'he inability to manufacture commercially 65 pumps having exactly the same dimensions,

presented a problem in this connection.

Our invention is designed to overcome the problems discussed, and has as its objects, among others, the provision of. improved-z (1) Simple means enabling adjustment to secure corresponding and accurate timing for all, of a plurality of fuel injection mechanisms'of the character described;

(2) M of the character related, permitting complete' interchangeability of the fuel injection mechanism, thus enabling any1-of such mechanism to be' replaced without aecting the timing:

enable such'adjustment of themechanism to be made easily and conveniently before 'assembly` thereof on the engine, and\ (4) Means, of the character related, which is of simple'and economical construction. v

Other objects of the invention will become apparent from a perusal of the following description thereof In general terms, the construction of our in- V vention comprises control mechanism having relatively n iovable'parts which can be adjusted without altering the overall length of such control mechanism, to thereby adjust the relative V angular position of the fuel metering parts' in a that the lengthA or the rack; the adjustable means being of predetermined length and extending beyond both. ends of the control rack v.thereby determining the" overall length qof the entire control mechanism. "I'hus, by virtue of'` the motion connection, movement of the control rack can be effected to adjust the angular Yposition of the plunger when the adjustable means is restainedcagainst axial movement. At the same time, the overall length of-the con- 5g trol mechanism Awill net be changed.' In -a plu- 7. ment of the control mechanisms will he eifected rality of pumps, the overall length of each of the 'described controlm is made exactly thesame.

f The pumps are adapted ior mounting on .the

engine with the described control mechanisms l of the several pumps in free end \to end abutting or contacting relationship, and allin axial alignment. An operating member for connection with the 'governor of the engine is provided and 'has spacedmeans engaging the outer ends of the outermost control m Such operating 'member is movable to eiIect simultaneous movement of all of the control mechanisms. The combined length oi' the control nicchanisms is exactly equal tothe length or distance.

between the spaced *means of -th'e operating mein. ber; no Jclearance existing between the abutting ends;l of the control mechanisms. Hence, moveas a unit 'together solely by virtue of surface to surface contact therebetween, and all pumps can be simultaneously controlled. no play can develop to alter timing ofthe pumps, as occurs in heretofore employed -link and pin connections.

l 75 As a result ofthe described'arrang'ment, it is (a) Meander thecimdcter related'wmch will Fig. 7 is,a more 'or less'schematic vview, in which parts of a pump are: shown in apparentthat each pump can be timed before-| hand without effecting a change in the overall length of the control mechanism for the plunger, to cause each pump to have exactly the same timing relationship as the other, pumps. Inasv much as the overall length of the control mechanism is not changed by such adjustment and since all the control mechanisms are-of exactly the' same length, the pumps can be `mounted on the' engine in any'order, and any pump can be, removed and replaced by another pump'without" the necessity of making any timing adjustment on the engine. Thll sintrghangeability of the 4 pumps obtains. 4

Reference' will. now be made tothe drawings for a more detailed descriptionof the invention.

In the drawings: v

Fig. 1 is a vertical section, partly in elevation. of a type of pump ,in`which our invention may be employed, parts being broken away to disclose clearly the construction., The view also illustrates the preferred manner of .mounting and aligning the pump on an engine.

Fig. 2 is a plan view, illustrating the pump mounting and aligning meansmlooking in -the direction of arrow 2 in Fig. 1.

Fig. 3.- is an enlarged longitudinal sectional view, partly in elevation, of a preferred form of control mechanism for Iangularly pump plunger.

. Fig. 4 is a vertical section `taken in a plane indicated by the line Min-Fig. 3.

Fig. 5 is a longitudinal section, partly in eieadjustingA the vation, through a pump housing on whichv the pumps are mounted, and illustrates-the relation of the pumps to each other and-to the operating member therefor.

Fig. 6 is an enlarged longitudinal' sectional view of a modified form of control mechanism,

sectionillustrating a preferred type of appa-. ratus fortiming the pumps beforehand.

Fig. 8 is a view. similar to Fig. 7,'illustrating the apparatus having parts thereof in a difierent position from that shown in Fig. 7. Fig. 9y is a fragmentary vertical section, on a reduced scale, taken in a plane indicated 'by line 9-9 in Fig. 7. ,f Y

The preferred control mechanism 35, for angularly adjustingjshe plunger (Figs. l and 3), is

mounted forl axial reciprocation infpump body or casing 10, and includes rack element 36 which is hollow lto ,provide an axially extending passage therethrough and which has teeth 3l formed thereon for engagement with teeth 20 of sleeve I9, so that. any axial 'movement'of the control mechanisms is transmitted by;sle'eve I9. in themanner previously related, to thereby effect angular adjustment of the pump plunger `I2 with-referenceto orice |3 in pump barrel Il.

:Also included in' the control mechanism 35, is adjustable means inthe form of pin member 3.8 e

mounted within raclt element 36. Pinfmember 38 has a motion imparting threaded connection 39, with rack element adjacentone end thereof, and projects beyond 'both` ends of the rack ele.-v ment to thus 13x` the overall'length of control mechanism 35. All of the pin members 38,111 a plurality of pumps, are made of exactly the same predetermined length.

Adjacent one end thereof,

New. -M

elevational vpin as is lmrnied l Ywith ailat 4I for engagement by anysuitable tool to effect adjustment relative to rack element 'l5 rack element II is formed with axially extending slots 46 (Figs. 3 and 4) whereby, after rack` 36 has been properly adjusted with relation to pin 3l to effect the correct timing of the pump, a clamping ring Il maybe press-fitted over the threaded end portion ol'l rack 36 to wedge the threads and hold the parts in proper adjustment. This provides a simple and economical method of securing rack 36 in .correct relation to pin Il, andalso provides a means for preventing an' unskilled workman from tampering with the timing of the pump after it has been correctly timed by any suitable method'. An ordinary lock nut could be `employed. for this purpose but is objectionable because it can be readily' tampered with. Both ends 48 oi' the pin Il arel accurately machined or ground to provide perfectly flat surfaces normal to the axis of reciprocation of the control mechanism, to4 enable accurate end to end abutting relationship of the various pump control mechanisms when the pumps are assembled on the engine in a manner to be subsequently described.-

From the preceding description, itfis apparent that if pin 38 is constrained against axial movement, for example by abutting an end 4l thereof against a suitable fixed abutment, and rotated,

the rack 36 will be moved axially of the pin l! to vthereby angularly adjust, pump plunger J2. Thus,`the angular relation of plunger I2 with relation to orifice i3, can be delicately adjusted beforehand, so that all of a plurality of pumps will have exactly the sametiming for any given phase of fuel injection. overall length of the control mechanism will not be changed; lsuch length being made exactly thesame for all pimps, as was previously related.'

` A plurality of pumps, which have previously been adjusted so that all of the pumps have the' same timed relation fora given phase of fuel iny jection, are, mounted on the engine and controlled simultaneously, by means illustrated in 'Figa l,v 2 and 5. Pump housing 4l, on the enabutting relationship, asis illustrated in Fig. 5.v

`troli'mechanism 35 is indicated Vby refe' gine, is provided `with an accurately machined` top 5l having aperturesl 5l to receive thepump caslngs Il. Such top has pump aligning dowel pins 52 accurately positioned adjacent each aperture l I, and which areA adapted to center properly and x each pump by engagement in dowel pin apertures 53 formed accurately in horizontal -flange 454 on pump casing Il. Cap screws' il serve vto fasten each punip which cannot become misaligned upon tightening of, suchjscrews because of the centering effected by the dowel pins.

The positioning of dowel pins l2 for the various pumps and the length of pump` ,control mechanisms 35 is `such that each pum-p can be individually mounted, and when all of the 'pumps are so mounted the adjacent ends 4l of all the control mechanisms 35 will be in exact end to end throttle control andthe engine governor (not shown), and mounted for axial reciprocation At the same time, the

B, such distance being the saine as- 3 along an axis parallel to the .axls'of .control mechanisms 35. Member B1 is slidably mounted in the opposite end walls 5l of pump housing n,

and has spaced ears or projections Il. The'inner surfaces of such ears l-are accuratelymachined to engage the outer ends of the outermost control 'mechanisms I5, and are spacedapart a distance C exactly equal to the combined lengths A of the control mechanisms. The individual pump control mechanisms!! are, in effect, locked together between ears of control member 51,

and any movement of member 51 must necessarily eect simultaneous'movement of all of the control.. mechanisms an equal amount. Thus, operation of the control member I1 effects simultaneous operation of' control mechanisms' 3l. without play, to adjust synchronously all the pumps simultaneously, during operation of .the engine.

In the modified illustrated in Fig. 6, the rack'element 1I ishalso tubular and has suitable teeth 1i for engagement with teeth 2l on sleeve I9 in the pump. I'hreaded into the internally threadedends of rack Il are cap screws T2 whichengage, at their inner ends, the ends 'of `a pin 'I5 which is slidably mounted 'in the axial passage in rack 1l.

form of control mechanism- The combined length of cap screws 'I1 and pin 1I, which together form the means adjustable relative to rack 1l, is made'the same for all the control mechanisms. By merely loosening one cap screw. 12 and tightening the other cap screw 12, the relative podtion of the'teeth on rac): fill can' be varied with relation to the flat ends 'I3 -of cap screws 12,- to thereby effect adjustment or the timing of the pump without varying the overall length of the control mechanism, in'the manner previously related with reference to the J preferred construction.

The pumps may bel adjusted beforehand in any suitable manner to effect` synchronous timing for all the pumps. Preferably, the pumps `are calibrated or standardized before assembly, in apparatus similar to that disclosed-in our assignee's copending application, Serial No.'6il8,960,

filed November 7,1933, by Carl G. A. Rosen and resulting' in U. S. Patent No. 2,106,932, granted February l, 1938. This enables all of the pumps. v

e the pump plungers, when the pumps are installed on the engine.

Briey, such preferred calibrating apparatus (Figs. 'z a'nd ci comprises a vertical frame or nxture Illprovided at its upper edge with a horizontal flange lll' having aperture Il! to receive centering properly the' pump, as that employed on the engine; and screw ill'is so adjusted as to provide the same distance-.D betweenithe inner endtliereof and the axis of the pump rimer as exists fbetween the end of each'control mechanism 35 of a pump and the axisf the plunger of the adjacent pump when assembled on the.

engine.

by the same type olf/means, including dowels for J'ournalled and slidably mounted inxbosses 'IIS 'l5 jacent the hori'zontalilange IIII, isa fuel tank.

"35, to eect relative adjustment between the pin and the rack 36 upon turning of wheel II3. Secured at one'side-of the vertical frame |00 ad- I'I`4 provided with acontrol valve' IIS and a supplyconduit I ll'adapted for connection with the pump to supply fuel through pump orifice I3.

.Slidably mounted'beneath horizontal ange III in suitable guideways II8,is a plate H9, having axially aligned horizontally positioned spaced bosses I2I`inwhich horizontal shafty |22 is jour.-

nalled. AShaft' |22 has secured for rotation there with cam |23 upon which rests a vertical pinfl24 slidably mounted in boss `'|26 positioned above spaeedubosses' I2I, and adapted to engage the lower face of guide cup 32. It is thus seen that.

grotation of shaft |22 will eii'ect lifting of pin |24 ,a predetermined distance xed by the high point and the low point of cam |23, to" thereby elevatefpump. plunger VI2 the same distance. In

Fig. 7,7the lower end of .pin |24 is show'n resting on the low point of the'cam, and in Fig. 8 on the nigh point. f

Rotation of cam |21 havingspringg-pressed pin |28 adapted to be held in eitherof elongated 'apertures |29 in plate' I3I secured'to the side of fixture IIN.t Plate I3I is, alsoV provided with elongated aperture |32 through which shaft |22 projects. Although' apthrough pin |29 and'shaft |22, respectively, it

' win be 'noted (Fig. 9) .that their width is the by adjustable'screw |33 having adjusting 'wheelsame as that of pin |28 and shaft |22, respectively. slidable plate, I I9 can be adjusted in a vertical direction; and in any adusted positionthereof, apertures I'29 in cooperation with pin I29,\will hold cam |23 in proper4 highandl llo'w positions. r

Vertical adjustmentlof plate I I9 and the mechanism mountedfor adjustment therewith, for a purpose to be explained hereinafter, is effected |34. -Screwv |33 is th'readedin boss |36 ilxedly secured to frame |90, and bears against .pin |31 'ilxedly mounted in boss |33 which is iixedly mounted non ,slide 'plate' II9 below spaced bosses I2I. 0

The preferred method of calibrating'afuel injec'tion` pump in the described apparatus toobtain synchronous timing of all pumps manufactured, will now be described.:y In the manu- 1 I `facturetliereoif,allwpumps are made to have exactlythe same length from the Y upper edge of plunger I2;to the lower face or surface of guide cup 32, by any suitable method. Our assignees previouslyreferred to patent ,to Carl G. A. Rosen:

No. 2,106,932, disclose va simple way of obtaining this result;V Y

` Eachcomplete pump including control mech-` anism v35,thereomisffixedly mounted `onihorizontal flange v III to project through aperture |32 therein; theldowel pins serving to center accurately allvthe'pumps in the manner previously expnined. mamut end u'br pm n (111g. 'n of contrormechanism 35 is held in contact against the' inner end of adjusted screw |03 by spring -III"vwhich VurgesJ'shaft III inwardly. Shaft I-22on s1idable plate ||9 is in a position that vertlcallyvslidable pin |24 rests on the low point of cam |23; and the lower adjusting I23 can be 'effected by handle arrangement for vobtaining synchronous I 'aisaseo and |34 is a shaft III urged inwardly by spring plunger just closes orifice I3 completely and the fuel ow vis consequently shut oil. The operator can accurately obtain .this exact position forall 'pumps because when it is reached, fuel will cease to ow, through opening |39. Such posiv tion corresponds to. a xed point for all pumps for commencement vof'fuel injection when the pumps .are installed on the engine.

After such point is reached, handle I2Ii s next turned to' raise cam I 23, without plate I|9 being lmoved, to present-'its high pointto pin |24 and thereby "ei'ieetv lifting of plunger I2 a predetermined distance. Fig. 8. At such position. adjusting wheel 'II3 is turned to adjust angularly pump plunger I2, in the manner previously related, so that slanting This position, thus, determines a cut-off or bypass point for a fixed distance oiaXial travel of the pump plunger; 1and in such position p in .38 -and rack 36 are 4securely 7locked together by the means previously described. The pump is then the same 'manner.A Y

Inasmuch as all pumps will have Afor a given travel at a predetermined angular position of the plunger, the same points of commencement and termination of fuel injection, they will all bel synchronously timed for any travel of the plunger. and any angular position thereof inasmuch as slanting edge`-|8 is of constant angle..l Further- ;more, because of the fact that-all control mecha- "nisms 35 are of exactly the same length vwhich Thisposition is illustrated in `edge I9 on the plunger just opens orifice I3 to allow-fuel to fiowagain out through opening |39.

- removed, and'suceeeding pumps are calibrated in erturesf|29 and |32Y are larger than the sections u 35 From the" preceding description', itwill vbe seen A that the control mechanism of our invention is simple 'to manufacture as it embodies a comparatively few number of parts which can be accurately machined, and 'at the same timesuch control mechanism. provides an accurate and simple timing of the pumps. A

We, therefore, claim as our invention: '|11 Control mechanismvfora fuel injection device adapted to be detachably mounted on an en- .'gine with otherslmilar detachably mounted deand of. the type having members relatively V'adjustableto Acontrol fuel injection, comprising an4` element having an axially extending passage therethrough, and ,means extending through said passage beyond both of the opposite ends of said element and having a threaded connection with j said element to effect relative axial lac ljnstment with respect thereto, saidmeans being of a predetermined length and having its ends formed for freely disengageable surface contact withI corresponding means of similar devices. 'f 2. An interchangeable fuel injection device comprising members relatively adjustable to conf 'j strol fuel injection, and control mechanism therefor, said control mechanism being of a predemembersi'said rack axially an engine. and including means relatively adl justable axially to'v time said members without` changing the overall length of saidL control mechanism 3. A'jfuel injecties device comprising members relatively adjustable to control'iuel injection, and

10 control mechanism 4therefor having its. ends formed for freely disengageable end to en d abutting contact with slmilaroontrol m of similar devices when mounted on anengine;. said control mechanismincluding an element mounted 15. for movement Pon said device'and connected with one of said members, and means extending be-,x yond both of the opposite ends of said element' and relatively adjustable axially with respect thereto. Y 4. An interchangeble fuel Vinjection pump adaptedrfor detachable mounting on an engine iminterconnected relationship vwith other simi- -lar detachably mounted pumps and comprising a plunger member and -a cylinder member mounted for relative angular adjustment and having cooperating valve means of'thetype including a slanti'ng edge which controlsel injection upon `relative angular adjustment ofv said' members; and control mechanism for saidmembers comprising an element connectedioone of-said members -and mounted on said pump for axial reciprocation and having a e therethrough. and j means of lpredetermineds length extending passage'ubeyond both of the opposite ends of said element and imparting connection with said element to pro` vide for relative axialadiustment ofJ- said element withjlespecttowuch means ofv predetermined length and thereby enable adjustment of'.

u un member connected witnma 'eianent without-.chemins the overall length 'of said control l mechanism; said means of predetermined length being formed for vfreeiyiiisengageable contact I,with `similar means yof said similar pumps' s whereby said angular adjustmgt can`be ellected Without proper in between millilil 5.. An interchangeable fuel' berscomprisingarackmoimtedonsaidpnmpfor axialreciprocationaaziconnectedtooneofsaid 'Nimm therethrough. and means of ,predeteryondbothoftheobpoliteendsofsa'id.rac!and havingsmotion-impartingthreadedconnection :u of similarV devices when mounted 0n f a lmotion g'ag'eable end'to end engagement.

with said rack to provide'for relative axial adjustment o! said rack with respect tosuch means of pre'ltermined length and thereby enable adjustment of the/member connected with said rack without changing the overall length Jr-.seid 1 derenglne of the compression' ignition type comprising a plurality of similar interchangeable fuel vinjection devices each of which is preadjusted to a dennite standard and has members relatively adjustable to control fuel injection and includesA` control mechanism for eiiecting relative adjustment betweenv s aid members, said control mech- `anismsbeing in freely disengageable end to end' '20 engagement with adjacent end portions of adja- `cent control m under all operating conditions ofsaid assembly toeprovide for movement of all of vsaid control m simultaneously in either endwise directionandjto allow for ready removal or insertion of any of said devices; each control mechanism comprising an axially reciprocable element, and means ot prev determined length extending beyond both of the opposite ends of said element and adjustable axially relative to said element without changing the overall length of said control mechanism;

and means enablingall ofv said control. mechanisms to be held together in saidj freely disen- 'L Avfuel injection assembly for a multider engine of the compression ignition type comprising a plurality` of similar interchangeable fuel iniection devices each oi' which is preadjusted to a definite standard and has members relatively vsdjustable'to control fuel injectionA and includes control mechanism for effecting relative adjust'- ment 'between sai'd members, said controlfmechanisms beingin freely disensas'eable end to end engagement with adjscentend portions ot adjacent control m under all operating conditions ot said assembly to provide for movement ofall of said control mechanisms simultaneously in either endwise directionandto allow for ready removal or insertion of any of'said devices: each an axially' reciprocable element. and means ofapredetermined ektendin'g beyond both oi' the opposite ends of said ement and adjustable axially relative to said element without the overall length of said control mechanism: and a movable member having spacedpart means for cooperat-v ing with the outermost of said control mechanism to hold them together and effect simultaneous movement'of all of said control -unit in eitherdlreotion. 1

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