US1697952A - Fuel-injection-contkol mechanism - Google Patents

Description

lan.l 8, 1929 L.4 O. 'FRENCH FUE-'IJ INJECTION CONTROL MECHANISM Filed Jan'. l, 1927 Patented an. 8., 1929.

)PATENT oF'FicE.'

VLouis arnnncmor MILWAUKEE, wisconsin.

` FUEL-INIECTIoN-CONTROL MECHANISM.

. Appueation ined January 1o, 1927. serial No. 160,177.

The invention relates to internal combus;

tion engines and more articularly to a}- paratus 4forcontrolling uel fed to the cyimpractical to meter thel fuelby a mec anithrough a wide range o f engine speed and' cally-controlledand-operated pump.. A system wherein the fuel under pressure in a supply line. is metered'to the cylinder by va con'- trol `valve offers one field ofsolution of this problem and one of the objects of this invention is to provide in such a system an .irnproved metering valve which permits the `accurate-metering of the fuel in very small amounts.-

A further object ofthe invention is to pro- .vide a fuel control valve wherein the amount of lift of the metering control valve is controlled by micrometrically adjustable stop mechanism'obviatin the use of'a stuffing box.

A furtherobject o the invention is to provide a fuel control valve wherein the use of "a smiling-box associated with the valve-liftin'gmechanism is obviated.

Afurther objectof the invention is to provide a fuel injection system wherein the same charge amounts per .cycle may be furnished then-reduced above a predetermined speed l and shut olf at the desired-maximum speed.

The invention further consistsin the several features hereinafter set forth and more' 'particularlfv defined by claims at the conclusionhereo In the drawin -Fig. 1 is a vertical sec.-

' tional viewof a uel injector embodyinggthe invention;

Fig. 2 isa detail sectional view taken o n the line 2-2 of Fig..1; Y l

Fig. 3 is a detail sectional view taken on the line3-3 of Fig.'1;.

Fig. 4 is a detail plan view of an actuating cam;

`part of the valve-operating mechanism.`

Fig. 6 is a vertical view of an alternative form of rocker arm mechanism to replace that Fig. 5 is a vertical sectional vview through shown on the outside of the fuel chamber in Fior. 1.

Tn the drawingsl the numeral designates the cylinder -of an internal combustion engine ofeither the two or four 'cycle type, 8 the c yllnder'head secured thereto, 9 the piston working therein, and 10 a shaft, such as a cam shaft or otherlay shaft,vdriven by the i engine.

The f uelcontrol valve, here shown as -a fuel injector valve, embodies a casing 11 pro' vided with lugs 12 through which studs 13 project and receive nuts 14 to clamp the invjector'to the lhead 8, thelower tapered end 'of plaid1 casing having a fluid-tight fit with said ea l 1 A control valve 15 works in a bore 16 of the casing and seats against a member l 17, clamped to the end of the casing by. a flange nut 17f,"provided with a discharge passage or spray orifice 18. The enlarged upper'end' 'of the valve stem is slidably mounted in the bore 16 and provided with grooves 19 to estab `sh communication betweena chamber 20 an the lower end of the bore 16.. A fuel supply pipe 21 connects with a passageV 22l in a detachable plug 23 and delivers fuel-to i the chamber 20. v

The upper end of the stem ofthe valve 15 has threaded engagement with a cap-nut 24 adjustably secured thereto. by a locknut 25, the -nut 25 serving to lockthe nu't 24'in ad'- justed position, said nut 25 providing an annular shoulder with .which the forked end 29 of a lever 30 is adapted toengage. The -varlve` is normally'held in it's closed position by a spring 31 and when associated with a pres- Aur fuell supply system by the .pressure of the The lever 30 vworks. in the space provided by th'e chamber 20, a passage 32 and a chamber 33 and 1s pivotally mounted on al shaft 34 mounted in almed bores 3 5 in thecasing, the

o enbore35 being closed off Iby a -screvwv against the'central portion of a iexible metal diaphragm 40, formed of one or more laminati-ons, which is clamped at its outer portion against .an annular shoulder 41 by a nut-42 in threaded engagement with the casing and.'

havingja centrally disposed bore. vThe diaphragme 40 areclampedto the rod 39, so as to produce movement thereof when they are ieXed, by means of an exteriorly dis-- posed yoke43 and rods 44and 45 associated therewith and alined with said rod. The rod 44. engages the central portion of the lower .diaphragm at its inner .end and has a nut -46 of the yoke 43 is apertured to receive the endmounted on the reduced threaded end thereof forming an adjustable abutment secured by a locknut 47 whch may engage the nut 42 to forma stop, said nuts being adjustable to v limit the clearance 'position of the freeend of the`lever 30. Thelower central portion 'of the rod 44 and abuts againstl the nut 46` The rod 45 is in the form of a bolt .en aging the central portion of the upper diap iragm raising its other end 29 .so that it engages at its inner end and -having threaded engage4 ment at the upper portion of its shankwith a -threaded opening in the upper central portion, of the yoke so that the bolt forms the movable jaw of a clamp and screwingthis Y bolt inwardly serves to clamp the parts to gether and when so clamped the yoke is se cured in this position by a locknut 49. While the natural resiliency of the diaphragms tends to hold the parts and the lever 30 in a central position, a spring 48 interposed between the lower diaphragmand a shoulder` in the lower nut 42 insures the return'movement of these parts. to a clearance position of the lever 30, which position is" limited by the ad-' justment ofthe nuts 46 and 47.

With this construction a downward pres .sure exerted upon the-upper end of the yoke,

as by the engagement of a tappet lever therewith, causes the yoke, together with the rods 39, 44 and 45 and the central portions of the diaphragms, to move downwardly thereby depressing the end 37 of the lever 30 and the lower face of the nut 25 and lifts the valve oil its seat to allow fuel to pass into 'the engine cylinder. the use of a stuiling-box and produces a balanced arrangement since the pressure exerted on one diaphragm is balanced lby that exerted on the other and inorder to keep the 31' may be rela-tively light'. The clearance' This .construction obviatesv the plug 23. On larger-engines if -larger between the' lever and the nut 25 may be ad;v justed by'adjusting the lever from outside of the casing, as previously described, or the nuts '24and 25 ma be adjusted-while the valve is in assemble position upon the removal of lifts are necessary the diaphragms 40 may,

of course, bemade larger.

Where the valve 15is used to -meterthe fuel 'y supplied to the engine, I prefer to provide means independent of the valve actuator for varying or adjusting the lift of the valve and for this purpose I have shown a stop rod 50 'slidably' mounted and guided' in ablock 51 and having 'its upper end held firmly against aJdiaphragm 52 by a spring 53 interposed besov tween said end and the block 51.' The block 51 is clamped to the easing 11 bythe inward ly`extending lange54 of a tubular casing*- member 55 having threaded engagement with the casing and forcing the block against the shoulder 56 in the -cas'ing'or against a plurality of annularshims 5 7 resting thereon which provide a means for initially determin- -ing the position of the lower end ofthe stoprod .whenth'e diaphragm 52 is'in a normal positio'nand fors'ubsequent adjustment in case the nut 24 is shifted from its initial posi-l tion. The-block being tightly lclamped between the 'shoulder 56l and .the shoulder formed by the lower'face'ofthe flange54 forms a fluid-tight connection therewith. The'valve-closing spring 31' engages the block 5l at one end and the nut 24 at its other en'd.

The outer portion ofthe diaphragm 52'is clamped against an annular shoulder 58 by a nut 59'in threaded engagement with the member 55 and having a central bore 60. The

outer upper end portion of the' member 55 is threaded to adjustably receive a .cap-nut member 61 which has a 4pin 62 projecting therefrom and extending through the bore 60 into engagement with. the diaphragm so that as the 4nut 61 is screwed down the pin 62 depresses the central portionoi the diaphragm and hence movesthe rod 50 downwardly. Theicasing 55, or'a. partthereof, is preferably provided with an index line 63 and the-nut with index lines 64 graduated to read"in'thousandths or-subdivi'sions there# of so that when the rod 5 0 is moved down -until it engages the nut 24 on the upper end ofthe valve 1n a closed position, the nut 61 maybe turned back 'a.t1itle, determined by the-scale, to give the desired clearance between the rod 50 and the valve to determine the lift of the valve. The index line 68 may be on a splitcollar 63 mounted in a recess in and rotatable relativeto the casing andl settable to a zero position lwhen the valve is closed and clamped in this position by a screw64. The nut may be rotated by hand -1 and looked in adjusted positionby a screw 65 or an arm 66 on the memberdlmay be suitably connected for remote control operashown in Figs. .-fornrof la cam tiqn either manually orunder the action of the engines governor, if such is provided.

permitted 'to liftthe amount determined by With this construction it will be noted that as the yoke is depressed the valve'15 is only the position of the stop 50 whose adjustment permits very and may be made while the engine is running."

As a means for acuatingthe valve I have 1 and 5' an actuator in the 67 mounted on a Ashaft 10 driven by the engine.' vThe connections between said cam 'andthe valve include a roller` 68 on a tappet 69 operatively connected by a rod 7 0 with'a lever 71 pivoted at 71- and carrving an adjustable screw tappet. mem-.

I f ber 72 en'gageable with the head of the bolt -The part 74 is secured at one end to rod -70 m v 4.5.- Thetappet 69 is formed by the parts 7 3,

A74,- 75, a spring 76 and nut 77. The partA "73, suitably gulded i`n apart of the engine crank case, has a central bore' '7 8 and a flange 79 and carries the roller 68 at its lower end.

'and .hasa plunger portion 80 working the b ore 78 and a` threaded portion 81. The

- part 7 is in the -form -of a sleeve-nut ad;

u the flange 79. The spring 7 6 is mounted' justably engaging -the portion 81,-towhich it is locked by the nut 77 and has an inwardly-extending flange'82 engageable with in the bore 7 8` and acts to move the parts 7 3 and 74 to an outer position and forms a yielding drive connection therebetween which p'ermits .the parts ofthe tappet to b e moved as a unit by the cam 67 until Athe valve 15 has been lifted- 'and stopped .and thereafterl coin-4 l presses sothatthe part 73 moves while the by the' stop 50 and during the remainder of its lift the drive connection yields. This perpart 74 and the linkage'connected therewith remains-'stationary duringthe remainder of the lift of .the-cam 67. The weight of the tappet and its associated parts may maintain the roller 68 against the cam or a spring v. 'may alsobe used as, for example, the ten- 45,

sion spring 83. t

With this yielding drive .construction the lift ofthe Cain irsttakesup the clearancebetween the 4screw 72 and the head of the `rod 45, then moves the yoke downwardly and lifts the valve 15 the amount' permitted mits the cam to have a lift which will notv cause-the valve to be lifted becauseof expansion of the linkage with increase in the temperature. and because of small inaccuracies in the cam surface and which at the same time permits thevalve to be Ilifted through 'the range of lift `within the ex- `tent of ad'ustment of the stop 50. However,

Afor small ore engines this lift is preferably made a 'small amount in order to furnish the engine with the very small amounts o'f fuel required and particularly on starting when the duration of lift is relatively longer accurate control of the valve with the cam 67 rotating slowly. .The amount i of fuel metered to the engine'depends upon the amount and durationofthe lift .of the valve. The duration of lift is determined by the profile of the camv 67 whose lift portion 84 isv preferably tapered, as shown in Fig. 5', so. that the duration of liftbecomes a-function of the speed of .the engine which, 'depending uponithe taper, may increase or de `crease .the amount of -uel supplied to the in, the cam has oppositely disposed slots 86 therein of varying angularity and 'a collary SAO 87 is mounted on the cam and carriesl a.'

pinA 88passing through the slots. 85 and 86,"

with the result that when the collar is moved -by a forked arm l(not shown) operatively connected with the annulargrooveS' in said collar, said c'ollar advances the pin 88 lengthwise along the shaft -10 and by reason of the slots 86 this motion 1 is translated into an angular and longitudinal movement ofthe cam. By a proper shaping of the slots 86 the cam is advanced' or retarded to best suit the powerV characteristicszof the engine and vits -shape may-be obtained by trial runs at different. speeds and different timings.

Under some conditions vof service it is desirable to furnish constant quantity fuel charges through a wide range of engine speed. While a tapered cam can be used for constant quantity regulation for a small range of speed, the' extent of movement of. such a cam for a wide range is too great to be satisfactorily handled by an. enginev governor. ATo meet these conditions I have shown in Fig. 6. a hammer member or tappet 90 associated with a cam 91 mounted on an overhead cam shaft 92 ,driven by the engine. This cam has a projeetion 93 with anabrupt descent engageable' with a toothed projection 94 on the member 90 pivoted to a support 95 at 96 so that-when the lever V-or hammer 9 0 is raised b y the-interactionolf the projections', 93 and 94 energy is Astoredup in'a spring 97 interposedbetween Jsaid lever and support 95 and when these projections pass eachother this energy "is expended and causes 'the member 90 to deliver a blow upon: the head of the bolt 45 of sufficient strength to move the parts associated therewith,` as' previously described, to lift. the valve 15 to the extent determined by the step'. Since the lever 90 delivers afree blow the 'du- -ration of the opening movement of the valve {15 is independent of the enginespeed so thatj' the same amount of fuel will be furnished the This construction also providesa 4yieldable lost motion vconnection between the' 'actuating camand the Valve 15. To prevent the enginev exceeding a maximumspeed after-theengine* has passed through the predetermined range ofs eed mentioned above,',the cap member may e turnedunder the action ofthegovernorto decrease the lift of the valve, or the ampli'- tude of movementof the lever 90 may be decreased by an adjustable screw stop 98 mounted in the support 95 andturnable under the action of the governor to a position to engage and limit the free movement of the lever 90, and in eithercase the decrease of lift of the valve cuts down the fuel supply and finally,V when maximum speed has beenreached, the valve is not liftedsothat the fuel supply .is cut off. -F 1 1 I have shown the control valve. 15 as the control valve lof the 'fuel injector and this is the preferred construction', but it may -be used as a `metering control valvein the fuel discharge line to control the action ofa spray .valve opened automatically by. the pressure of the fuel. Where the valve is used as ametering valve the' fue, introduced in the Supply line'2l by ainy-#suitblepumping mechanism, may be maintainedtleazeinwat constantpressure by a suitablepressure valve or accumulator in said line, or it maybe built up to the desired pressure by.- suitable pumping mechanism during the timeof the available injec-y tion-period. The Valve, however, is not to be limited to a metering control valve unless specified,.and I further desire it to be understood that this invention is not to be limited to"any particularl form- 0r arrangment of parts @accept in so far as such limitations are included in the claims or necessitated by the -prior art.

What I claim as myinvention is:

1. Ina fuel injection system, the combination with a fuel meterin control valve, of operating meansiffir` sai valve .including a spring hammer operating in cyclic synchronism with the engine to impart substantially7 equal' va1veopening impulses of'substantially7 equal duration -independent of the engine speed to cause said valve to supply the engine with substantially constant quantity fuel lco charges. through a wide range of speed,l and means, independent of'said operatingmeans, to positively limit the lift of -said valve.

2. In a fuel injection system, the combination with a fuel metering control fvalve, of operating means for said valve including a spring-hammer to impart substantially equal valve-opening iin ulses of substantially equal duration in ependent of the -engine speed -to cause said valve to -supply the en'- j gine'with substantially constant quantity of `fuel chargesthrough a predetermined speed range, and means operating above said speed rangeto reduce the lift of said valveand,

chamber, means connecting said diaphragms interiorly and eXteriorly whereby bothdiaphragms are flexed on the application of pressure applied thereto outside of saidvcasing, and means operativelyconnecting the interior connection between said diaphragms to said valve to open the-same when the diaphragms are flexed, v

4. In a fuel controlvalve, the combination' with a casing having acharnber and an outlet passage, of a valve mounted therein and controlling the passage. of fuel through said outlet, apair of oppositely disposed, flexible,

metal diaphragms closing off a part of said chamber, means connecting the central portions of ,the diaphragms to move together including a member in said chamber clamped to and disposed between the diaphragms, and

a lever pivotally connected to said member and operatively Aconnected to said. valve for opening the same when pressure is applied to said diaphragms exteriorly of said casing.

5. Ina fuel control valve, the combination with a casing having a chamber and an outletpassage, of a'4 valve mounted therein and' controlling the passage of fuel through said outlet passage, a pair of oppositely disposed lexible, metal diaphragms closing olf a part of said chamber, a member abuttin against the interior central portions of said diaphragms, an exteriorly disposed clamp engageable with said diaphragms and clamping 'them to said member, and means operatively connecting said member with'said valve to lil( open the same when the diaphragms arer flexed. .4

6. 'In a fuel control valve, the combination with a casing havingan`out`let passage, of,

valve working in said casing and controlling the passage of fuel through said outlet passage, 'A a pair of statically balanced diaphragms operatively .connected to said valve,

means outside said casing foriexing saidA diaphragms to lift said valve, and means for limiting the lift of said valvecomprising a 'stop member within saidcasing, a diaphragm, and an eXteriorly-disposed adjustable member for flexing said last named diadiaphragms associated with said level', means phragm. for flexing said diaphi'agms to move said 10 l8. In a fuel control-valve, theeombination levell to open said valve, means to move said with a casing` having an outlet; passage, of lever to a clearance position, and adjustable 5 a valve Working in said Casing and eontrolstop means to determine the clearance posiling the passage of fuel through said outlet tion of saidlever. passage, a lever Within said casing associated In testimony whereof, I aiX my signature. AWith said valve, a pair of oppositely disposed LOUIS O. FRENCH.

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