US1705665A - Fuel-injection system - Google Patents

Description

M arch19,192 9. Lo, FRENCH 1,705,665

\ FUEL INJECTION SYSTEM Filed Dec. 31, 1925 I 97 .Efi I1 I 95 99 E/V l/VE Ell EN INVENTOR.

. Patented Mar. 19,1929

-' i, UNITED -sTATEs LOU IS O. FRENCH, OF,MI l'JWAUKEE, WISCONSIN.

Application filed December engine, when the engine is stopped the con ply passages to the, engine cylinder are ele-i tacts of the switch mechanism may be engaged so that should the operator turn on the fuel control switch previous to turnlng over the engine one of the injector Valves may be opened before the engine is started, and while the fuel is not then under pumping pressure some of the fuel ma dribble into the engine cylinder if'parts 0 the fuel supvated. To obviate this difficulty one of the objects of this invention is to prevent the operation of the electromagnetically-operated i alves until the engine is being started or turned over.

In some instances it is desirable to make.

. FUEL-INJECTION sysrnim.

a1, 1925. Serial NT). 78,641.

Fig. 5 is a diagrammatic View of a fuel in ection system embodying 1 the invention,

parts being broken away and parts being.

shown in section.

, Referring to I Fig. 5, the fuel'injection system includes 'a fuel supply tank 6 connected by a pipe 7 with a fuel pump 8 ,o f any suitable construction, which is generally driven by the engine and is of a ty e to insure a relativelyconstant supply of to a pressure pipe 9 in iwhi the fuel is maintained, while the pump is operating, at substantially constant pressure by means of fuel a pressure valve mechanismof any suitable construction. As shown, pressure valve mechanism 10 includes a' casin parts 11 and 12 with a diapl ra'gm 13 secured between them, a valve 14 working in a slotted guide tube 14 and being normally urged; by a spring 15 acting on thediaphragm to close off communication between the presexcess fuel to the tank'fiythe tension of the .the engine directly reversible, and another spring 15 being adjustableby means of a object of this invention is to'provide a fuel injection system wherein direct reversal by preignitionmay be obtained through sw1tch mechanism associated with the control circuit ofthe electrically-controlled fuel injection system. A A further object of the invention is to provide, in connection with a governor-controlled switch mechanism for fuelinjection systems of the type above referred to, a timing cam which at starting accommodates for the relatively slow speed of the engine that inayrezgist during this period, and prevents excessive charges of fuel being introduced into the engine cylinder during starting.

The invention further consists in the several features hereinafter set forth and. more particularly defined by claims at the conclusion hereof. Inthe drawings, Fig.1 is a vertical sectional view through control switch mechanism embodyingthe invention, parts being broken way;

Fig.

. 3-3 of Fig. 1;

, Fig. 4 is a detail. sectional view of switch mechanism used in the system;

slide-block 18 associated with a bolt 19 in threaded engagement with the part 12 of the casing. From the pipe .9 branch pipes.

20 respectivelydead to the electromagnet made up of y .75- sure pipe 9' and the,chambe r 16 which communicates with a pipe 17 that returns the ically-o'perated fuel injector valves 21 which include a control valve 22 having an arma ture' 23 associated with an electromagnet 24 and controlling passa e of 'fuel from its supply pipe 20 through the valve casin and the fuel nozzle 25 into the cylinder of t e engine in the head 26 of which the injector valve is.

- mounted, a

spring 27 normally tending to close theva ve which is opened by the electroma net a the desired time and for the desire period. Asan'y suitable construction of electromagnetic valve may be used in the system, further description thereof is deemed unnecessary.

shown in Figs. 1 and 2, and includes a shaft 28 driven by the engine, a switch including The switch mechanism for controlling the operation of the electnomagnetic valves is va fixed contact 29 and a movable contact 30,; a timing cam 31 mounted onv the shaft 28 and cooperating with the contact 30 to open and close the control circuit, and in the case of a multi-cylinder engine distributor mechanism includinga brush 31 mounted on the shaft 28 and cooperating with contacts 32 res ectively associated with the engine cylin ers. y r r The means for preventing the operation of the injection valves until the engine is turned section 38 of a twopart casing 39 having 41 in the pipe 9, the parts 38 and 39 being by bolts 38, plunger 37 being normally urged to open Thus, when the swltches 54 and 33 are connected together" and to a diaphragm 42 to prevent possible leakage, the

fore the engine is started and the switch mechanism 33 not used, it is apparent that if one of the electromagnets is then receiving current through the distributor contact 32, with the result that its control valve is open, the engine cylinder. However, with the switch mechanism 33 included, the control circuit to the electromagnets cannot be completed until the engine has been turned over to such an extent that the pump 8, driven thereby, has established a pressure head of fuel in the pipe '9 whichtheri acts upon the diaphragm 42 to move the plunger 37 and the bridging contact 36 so as to close! the circuit through the contacts 35 and 34.

circuit. position by a spring 44 interposed closed and t e contacts 47 is in contact with between it and the section 38. Thus when the contacts 45 and' 46, current W'lll flow fuel pressure builds up in the pipe 9 the diaphragm 42is flexed outwardly thereby and ence the plunger 37 is moved outwardly,

I and thus the contact 36 is moved into ennected by a bridgin' gagement with the contacts and 35 to.

close the control circuit.

, The switch" mechanism 44, for use in reversing the engine, includes a. pair of contacts and 46'suitably insulated from each other and supported upon a block 44 ofainsulating material and adapted to be concontact 4T carried by a manually-operate plun er 48 which is normally moved to-ficlose position by a s ring 49. This switch is associated with t e control switch. mechanism so that it operable simultaneously with the shifting o the contacti30 angularly, relative-to the cam and is here shown as mounted on the lever 50 secured .to the angularly adjustablecasing 51 of the control switch, though it will be understood that it may be associated with linkage for operating said lever 50 ,I from a distant point.

The circuit connections for the various units of the system are shown in Fig. 5, wherein the numeral 5% designates a battery and-53 a conductor connecting one side i of the battery with the contact 35 and includinga manual cut-out switch 54. A conductor 55- connects the contact 34 with the,

. contact 45'and a conductor 56 connects the X 7 connection 59.

contact .46 with the fixed contact 29. The

. contact 30 is grounded at 57 "and a condenser.

58 is connected across the-contacts 29 and 30 to reduce arcing. One terminal of thecoil of each eleotromagnet has a round The other side of tile battery 52is connected by a conductor 60 to the brush 31 and each of the contacts 32 isconnctd to the other terminal of the etil of each, electromagne't by a conductor 61* whlch may include a resistance 62 to reduce the time constantof the -magnet circuit.

If the switch 54 is closed by the operator and the contact 30 is in closed position befrom one side of the battery 52 through conductor 53, contacts 35, 36 and 34, conductor 55, contacts 45, 47 and 46, conductor 56, contacts 29 and 30 (assuming the cam 31 has permitted thecontact 30 to move to closed position) to ground 57. At this time is passes through the nozzle 25 into the cylinder of the engine at the desired time and by reason of the cam 31, hereinafter described, in the desired amount. Then as-the engine continues, to rotate the contact-30 will again move into circuit-closing relation with the contact 29 when the brush 31 has moved into engagement with the other distributor contact so that the other cylinder of the engine will receive its fuel charge at the proper time in the cycle.

In case it is desired to reverse theengine, shifting the lever 5% and thereby rotatin the case 51- will cause the contacts 30 an 29 to be moved angularly relative tothe cam 31 andthis will necessarily change the cyclic timing of the "charge. Thus, for a two cycle engine of the port scavenging type, if we assume that the fuel is being injected near the, end of the compression stroke and the engine is running in one direction, throwing out the engine clutch and pressing on the plunger' 48 to separate the contact 47 from the contacts 45 and 46 cuts oil the supply of fuel and allowsthe engine to slowdown. When'the engine has slowed down sufiicie'ntly the lever 50, with the switch 44 still held open, is turned so as to advance the time of closing of the contacts 30 and 29 to the beginning of the compression stroke and the switch 44 is then allowed to close so that the control circuit is rendered operative to inject a charge of fuel at the beginning of the compression stroke, with the result that before the'piston completes its compression stroke a preignition will occurvvhich will drive the piston down-' wardly and thus turn the engine over in the opposite direction. As soon as this reversaltakes place the operator opens switch 44: and moves the lever back to a running position which will again cause the fuel to be delivered near the end of the compres sion stroke with the engine rnnning regularly in the reverse direction. Thus, by providing the switch 44 f r operation in conjunction with the means for changing the timing of the control switch the fuel injection period may be changed to reversethe direction of the engine. In the case of a four cycle engine itwill, of course, be understood that the timing of the inlet and exhaust valves for eflecting a reversal by well-known mechanisms for this purpose which are commonly used on Diesel type engmes would be used in conjunctiomwitlrthe changing" of "the time of fuel injectionto effect a reversal of the engine, but as the 1 present invention is directed to the fuel injection system alone no special form of valve-operating mechanism for .four cycle engines has been shown. W

Referring to Figs. 1 and 2, wherein a control switch mechanism is shown in detail,

the numeral 63 designates a two-part. casing, and-51 a switch casing mounted on the casing 63 for angular adjustment frelativethereto, as by means of screws 64 in casing 51, having pm projections extending into an annular groove 65 in the casing 63, and 66 a cover secured to saidswitch casing by clips 67.

- The shaft 28 has a tight fit in the inner race of the ball-bearin 68, with a shoulder 69 adjacent said ring,a d the otherrace ring is fitted to the casing 63, whereby the shaft is journalled in the casing and prevented from moving upwardly. Y

rotate with the shaft 28 by screws 74 andhas a bore 75 in which the sleeve 72 is, free to move within the limits determined by a lonv gitudinal slot 76 in said sleeve, and a pin 77 on the ,hub of the spider 73. The sleeve movement'is effected by any suitable governor associatedwith the spider-'7 3. As shown keyway 'formed 7 the oppositely disposed arms of the spider have, levers 78 pivotally mounted thereon,

their forked ends 79 being provided with pins 80, mounted in an annular groove 81 formed in the upper part ofthe sleeve,

their outer ends carrying the weights 82. A spring 83, acting in opposition to the govepnor weights, is interposed between the upper end of the sleeve 72 and a manually-con- .trolledcollar 84 slidably mounted on the shaft 28. The collar is moved manually by alever 85' pivotally mounted on the casing and having forked ends 86, provided with pin projections engaging in the groove of said collar, and an e'xteriorly disposed operating arm.

- A ball-bearing .87 is located between the hub of the spider and thecasing' 63.

The cam 31 has one or more, the number dependingupon the number of engine cylinders, tapered reliefs 88 formed thereincwithone side, the advancing side, preferably parallel withQthe axis of the cam so thatfor any given angular adjustment of the casing 51 the circuit closing' period will begin at the same time. The contact 30 is suitably pivoted at 89 and is normally urged against the cam by a spring 90 and base spherical projection 91 engaging said cam. ,It will be noted from the drawings that the reliefs 88 gradually taper outwardly from the upper end 92 to an intermediate point and then taper toward a point 93 at their lower ends.

These tapered reliefs permit the contact 30.

to remain in engagement with the contact 29 for longer or shorter relative periods of time, depending upon the position of the cam 31, and hence the duration of current flow in the control circuit or ircuits may be varied with the .result that the electromagnets are energized for varying periods of time/so that the valves are held open for corresponding periods and thus varying amounts .of fuel are delivered to the engine cylinders in proper'cyclic sequence through the connection of this switch mechanism with the brush 31 and contacts 32. As

lated from, the shaftr28, and is urged'by a spring 92 againstthe commutator track 93 having the contacts 32 inset therein, and the shown the brush 31 is mounted on, but insu- I brush receives its current from'a brush 941' urged by a spring 95against the brush 31 and mounted in a member 96 provided with terminal connections 97. The contacts 32 have studs98 secured thereto provided with terminal connections 99. The current to the contact 29 is led 'in through 'theterminal support 100 insulated from the case 51 and .gonnected with the conductor 56. i

As the speed of the engine increases the cam 31 Will ,be moyed longitudinally of the shaft 28 by the action of the governor weightsswinging outwardly and the sleeve 72 moving upwardly so that different por-' tions of the tapered [reliefs 88 will be brought into operative relation with the eam As the upper end 92 of the relief of the cam is relatively short, the engine may be turned over slowly, as in starting by hand, without furnishing-excessive amounts of fuel to the engine. Furthermore, it willJoenoted, that the'cam may be designed'so that greater quantities of fuel are furnished at intermediate speeds than at the hi her speeds where the cam is operated .by t e governor, and this is desirable for/certain kinds of power W0rk. v t

Fro'm'the "foregoing description it will be noted'that I have provided means for preventing feeding of fuel to the engine cylinder until the engine is'actually being started; means for preventing an excessive charge when the engine is turned over slowly during. starting; and nfeans permitting of the ready reversal of the engine by preignition.

I- desire it to be'understood that this invenution is not to be li' 'tedto any specific form orarrangement of parts except in 'so far as such limitations are specified in the claimsornecessitated by the prior art. 7

What I claim as my invention is: 1. In a fuel injection system, the combination of a fuel injector valve, an electromagnet controlling the operation of said 'valve, a control ,circuit for said, electromagnet .inc uding circuit control mechanism controlled by the engine, means forsupplying fuel to said injector, and automatically-op crating switch means for preventing opera? nor takes up its action.

-tion of the control ci being started. 1

2. In a fuel injection system wherein the rcuit until the engine is w a 1,705,666 r livered to said valve from a pressure system including a pump, the combination with such switch mechanism in said control circuit to render said circuit inoperative .until the fuelpressure builds up in said system during the starting of the engine. 3

-3. In a .fuel 'njection system, the coinbination with a fuel-metering device for controlling the supply of fuel delivered to y 60. system, of fuel-pressure,-controlle"d the engine, of an electromagnet controlling the operation of device, -a control circuit for said electromagnet including circuit control means and a manually-operated member for ,varying the timing of said circuit control means, and switch means in said control circuit mechanically associatedwith' said manually-operated member ,whereby the operator may open "said control cir-- cuit as he moveslsaid manually-operated member to permit reversal of the engine by the injection of a preigniting charge of fuel into the engine cylinder.

4. In a fuel injection system; circuit control mechanism fora metering control electromagnet, comprising a switch including a movable contact, an engine-driven cam for operating said cont-act, a governor, means operated by said governor for adjusting'th'e .came and switch 'relative to each other to vary the duration of the circuit-closing periods of said switch, said cam havinga reliefsurface controlling the closing of the switch contacts and preventing excessive quantities of fuel being delivered tothe engine during starting and before the gover- In-testimony whereof, I aflix my signa-

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