US911345A - Internal-combustion engine. - Google Patents

Description

. G.- M. s.' T AIT se o. ELLIS.

` INTERNAL OOMBSTION ENGINE.

' AAPPLIOAflION IILED FEB. B, 1906.

Petem-,ed Feb.2,19o9.

s SHEETS-SHEET 2.

INVENTOR ATTORNE -G. M. S. TAIT & ELLIS.

INTERNAL GOMBUSI-ION ENGINE.

APPLIGATION FILED rma. a

Patented Feb. 2, 1909.

SHEETS-SHEET 3.

iNVENTORS ATTRNEY entre y L srairns 'fr enrich;

eopFREY M. s'. 'rArrfoF MONTLAIB, NEW JERSEY, AND oARLEToN ELLIS, OE'WHITEPLAINS,

i NEW YORK'.

INTERNAL-COMBUSTIONENGINE.

No. mns/i5.v

v Specication of Letters Patent. Appneaaon sled February 8,1996. serial Nn. acoso?.

renteareb. a, i909.

To all whom it fmay concern:

Be it known that We', Gournay M. S. TAIT,

a British subject, residing in Montclair, Esf

sex county, New Jersey, and CARLnToN EL- Lis, residlng in White Plains, Vrestchester county, New York, have invented certain.

newand useful mprovements'in'internal- Combustion Engines, of which the following is a specification. ,y w f Our invention relates to improvements in internal -combustion l engines, and involves features particularly valuable in engines intended to 'be operated by producer gas and similar gas `of lov;r or Avariable thermal value or comprising gaseous ingredients havin quite different properties as regards seltignition, flame-propagation etc. The engine herein described carries out the process of re ulating the development of power in interna combustion engines, forming the subject matter of the application for Letters Patent, 4filed by us on' November 14th, i905, Sr. No. 287,240.- f

Ourinvention consists in novel means for regulating the operation of internal confibust-ion engines; in improvements in the value gear and igniting gear, and in means.

for automatically ,y adjusting the same in accordance withvariation of speed of the engine, and in other features of invention, all as hereinafter described and particularly pointed out in the claims. y

The methods heretofore employed for regulating the operation of internal combustion engines have all proved unsatisfactory. The liit-andmiss method of` regulation produces excessive speed fluctuations, so that it is entirely im ract'ica-ble in many cases, and in many of it forms is extremelyl waste. -ful of' fuel. All jm'ethods of regulating in'-v volving variation in the quantity of gas and air taken into the cylinder, suchl as' throtf tling andA variable opening or closing of the admission valve (the latter-methodsomey times termed variable'cuto) 4produce extreme variation in the compression pressure, suchv pressure increasing at'fdifferent rates according-to- ,the quantity of gasand air taken into the cylinder. i Such variation in compression is extremely detrimental as regards economy,'for it is well known that for highest efficiency high `,compression is necessary, and obviously an engine which at light loads compresses only to relatively low pressures, is uneconomical at suchlight loads andI low compression pressures. Variation of theV compression is particularly detrimental, however, in the case of. engines eperating on producer gas, or similar gas of 'low or variable thermal-value. Such gases require high compression to insure thorough and prompt ignition, or even to insure ignition at all.` If the fengine hel regulated by varying the amount of fluid taken into thej cylinder, it may eas/ily, and frequentlyl does, happen, that at light loads and 10Wv compression pressures, ignition is uncertain o r fail saltoge t'her. .It is of course substantially impracticable to supply a richer mixture to an'enjgine when operating at light load than when operating at heavy load, and todo so Would stillfurtherdecrease the efficiency at light loads. The extreme ofvtliis l also, .the gas from thelproducer is apt to be of especiallylow thermal value, and since the engine is then wilthoutload, usually, and its valve gear is a-dJusted so that the. compression is low it is often diiiicultito ,start 'an engine operating-on producer gas.v All of these difficulties We bbviate `by taking 'into -thezcylindersubstantially the same quantit :of fluid' at' all times, regulation being`e 4fected by varying the richness of the charge by automaticallyvaryingl the amount ofair admitted, or 4by admitting and similarly regulating a neutral diluent gas, such as products of combustion. The compression is then substantially the same at all loads. 'To compensate for thevariation in the rate of fiaine propagation With-varying amounts ofair .or-'neutral dilnent gas-in? the charge,

I l u .E c n c. We automatically vary the point ci ignition to correspond with the variation in the amount of diluent. ln this way we are able to employ very high compression pressure atall loads, with resulting gain in economy,

`and to realize nearly the same economy at light loads as at full load.

ln the specication of,`A an application for Letters Patent tiled by G., M. S. rtait on Get. 31, 1905, Sr. No. 285,245, the difficulties experienced in the use, in high compression engines, of fuels which are not homogeneous as to combustible constituents, are pointed out, particularly the difficulties attending the use in high compression engines of as con: taining a considerable percentage't hydrogen; the hydrogen being apt to ignite auto- Ajmatically during the compression stroke,

`thus producing excessive back. pressure against the piston, causing the engine to do negative work and greatly lowering the etl'icieney of the engine. Such trouble is termed ,preignition When using a fuel containing ingredients, such asv hydrogen, Which tend to cause preignition, or irregular combustion (as when one or more ingredi- .ents burn largely or entirely before the loads, to avoid variation in the compression with variation in load or speed, to prevent pre-ignition, to insure complete ignition, and to permi. the use of fuel of low and variable thermal value, and to make the mechanism by which the above objects are accomplished,

A simple, compact and efficient.

We 'will now proceed todescribe our invention with reference to the accompanying drawings, illustrating one form of internal combustion engine embodying our invention.

' In the said drawings: Figure 1 shows a central vertical section of the ene-ine on a plane transverse to the crank shaft; Fig. 2 shows a side view of the engine, a portion of the governor mechanism and associated parts being shown in section; Fig. 3 shows a front view of the governor; Fig. l shows a detail view of the eccentric, Fig. 5 shows a detail View of the governor and eccentric looking from the left of Fig. 2; Fig; 6 shows a detail topview of the bell crank and associated parts 'of the governor mechanism; Figs;4 'l

and 8 show the application of our invention toa multi-cylinder engine, Fig. 7 showing a 9 if. l 984:5

side view of a` three cylinder engine jnovided with` our improved valve gear and regulatin mechanism.

in the said draw-ings 1 designates the engine cylinder, and 2` the cooling jacket thereof, 3 the piston, 4.- the connecting rod, 5 the crank and (S the crank shaft; these parts being` all of substantially common const rui tion.

7 designates an admission valve and 8 an exhaust valve. These valves are operated by a` rocker 9 pivoted at 10 and vibratied by means of a valve rod 11 connected to said rocker 9 at 12 and itself actuated by a spring 13 and by a cam 14- on a counter shaft, 1.3, said shaft 15 being driven in the construe` tion shown from the crank shaft (i, by means of suitable gearing and a shaft 1G. rlhe particular 'engine shown, is supposed to be of the so called four cycle type, and there` for@ the gearing by which shaft 15 is -driven is of such ratio that shaftI 15 revolves at half the speed `of the crank shaft. The rocker 9 alternately presses in first one ot' the said valves and` then the other. and is adjustable longitudinally at its pivotal point. l0 .for varying thejtime of opening and closing of the valves. lts two ends are furher provided with adjustment' screws 1T by means of which a certain adjustment of the operation of the ,valves may also be obtained. As will be obvious from inspection of the drawings, the operation of this valve gear is as follows: In Fig. 1 the parts of the valve gear are shown in the position occu` pied near the beginning of the admission stroke, piston 3 descending and admission valve 7 being open, the lowest portion ot the cam 14 being opposite the end of the valve rod 11. lWhen the piston nears the end of its downward stroke, the rise '18 of the cam lll liftsrod 11 somewhat, moving rocker 9 sutiiciently to permit the valve to close. At the beginning of the exhaust:I stroke the rise 19 of the cam moves the valve rod 11 androcker still farther, causing valve 8 to open and at about the end of the exhaust stroke, the valve rod 11 slips oi'i' from,

rise 19 to the lowest portion of the cam. causing valve S to close and falve 7 to open. By adjusting the rocker 9 longitudinally the relative periods of opening and closing of the two valves maybe varied, and by means of the screws 17 the time of opening and degree of opening of said valves may also be varied.

Fuel is supplied to the engine through a pipe 20, which may be provided with suitable regulating means 21 as indicated in Fig. 2. This pipe may be considered to be a pipe connected to a gas producer.

22 designates a pipe for supplying air for combustion and also for the dilution of the charge for the purpose of automatic regula` tion. Pipe 22 may also have some custom i ary regulating device 23: 22 terminates in a collar 24v surrounding pipe 20, the

' 27, indicated in dotted lines in Fig. 2, which -port may be understood to be connected toa source ofsupplyof products of combustion,

such, for example, as the exhaust pipe of the engine. The governor 26 not only adjusts Vvalve 2,5, but also controls the operation of the. igniting device, varying the time of ignition to correspond with g variation in the quality of thegas or the amount of diluent admitted. We may, of course use any suitable igniting device, and for purposes of illustration .have indicateda touch" spark igj niter 31, voperated byga'n -eccentric .28 on counter shaft 15. and an eccentric rod 29 and bellcrank 30. To 'vary the time `of ignition, we vary the lead of the eccentric 28 by the direct action of the governor. Without 'limiting ourselves vto any kparticular type of governor for thepurpose we' have indicated a well known combined inertia and centrifu-A gal governor. This governor may be caused to vary the lead of the eccentricvby any suitable mechanism. InFigs. 1`to"6incl'i isive, we have illustrated one mechanism for .the purpose, applicable principally to single cylinder engines and comprisinga link v.32 connecting the governor weight with an arm. 28a projecting from the eccentric 28. Asv

will be seen, whenY theposition of the'goy;

ernor weight changes, theY angular position of the eccentric 28 with reference to the Shaft` 15, will be changed. In the case of a multi-1 ple cylinder engine, we ordinarilyemploy" somewhat different mechanism to vary the advance of the eccentric'sby the .action-.of the governor. The same governor 2,6, which controls the' time of ignition, also operated' the valve 24. For this purpose the governor.

weight is connected by me'ans of' a link 33 with a bell cran-k '3,4 revolving with thev governor and connected atthe center of rotation to a link 35, itself connected to 'a bell crank 36 and thence b a rod 37 tovalve-25.

In the case of a multi-cylinder engine, we customarily employ means whereby, by the action of a single governor andthe movement of a single operating membe'nthe angular'advance of all of the igniter `eccentries is varied simultaneously 4and to the same extent.4 'One convenient.. means for doing this 1s shown` in Fig- 7. As'there shown, the vgovernor is4 .arranged` to4 move videawah Spiral key ways as-,ffwhiehfthe therefore that longitudinal motien of they shaft. varies the angular advance of all eccentrics simultaneously and to the same extent. In this constriction the carrying wheel of the governor and the several valve operating cams 1e are connected to the shaft 15.` .through straight 'key ways 39 andy run be-. tween `stationary stops 40 which prevent them from moving endwise with the shaft.

Themethod of regulating the development of pw'er is as follows: Supposing the'engineto beoperating. under maximum load, valve n 2,5 vwill be substantiallv half open as regardspassage of air from pipe 22 to pipe 2Q, and a charo'eof maximum richness will 8o erite'r'the engine cylinder during each ad-A` missiolrstroke, and will there be compressed,

ignited, and caused t expand, in the ordi-r .y nary Way. If now the load on the engine' be reduced, the centrifugal governor 26 will" 85 open VAvalve 25- still farther, admitting more -fairfrompipe 22 to pipe 20, and also opening port 27 `'and admitting products of combustion, which mingle with the air and gas, dilutingthelatteraind retarding the combustion of hydrogen similar substances until the final ignition ofthe charge. The total amount of fluid'taken into the' cylinder remainslthesame it will be seen, whatever thev` load, and therefore the compression is sub- 95 stantially thesame at all loads; but the richness of the charge will be decreased. The rate of combustion"being thereby changed, the governor 26 automatically advances" the poi-nt of ignition to compensate for the" de-V 10c creased speed of combustion. Conversely, when the load ou the engine is again incre ed,l thefv automatic governor willrednce puntfjo'f dil'uent admitted and will v p'sed: rateg ,of combustion of the charge. "The 'governor `2 6 also varies the point of Oinitio'n .to Ycorrespond with the change in ra e of yflame propagation through the mixture dife to dilutionfof the charge, varyfing the angular advance ofthe eccentric or eccentritzs28. 'It will beseen therefore, `that bythe action o f the two automatic governing device/s the character of the charge and the point ofignition will be varied to suit the load on the engine and to maintain constant speed, without ivarying the compression.A vWe 'are enabled, therefore, -to em' ploy very high compressionl at light loads as `well as at intermediate and heavy loads,and

to employ fuelv of low thermal value at all loads, the ignition of such fuel being rela- -tively certainbecause of the very high compression employed. This compressionweh prefer to befrom say 91% to 16 atmosph eres,`"l25 preferably not below 11 atmospheres'. At `this .high compression mixtures which can not `be depended upon to ignite at lower `pressures ignite readily.

Producer. gas such as we especiallycori-.130

ignition-5to Acorrespond with the in- 105v eine@ template using has for its principal comlI proportions and are thoroughly mixed voith bustible constituent, caibon monoxid; but

. many types 4of producers or generators of fuel gas produce large quantities of hydrogen as Well, giving rise to the preignition trouble above mentionedwhen the engine operates' with high compression. iVhen the gas used contains little or no hydrogen, 'we

- commonly einply air' alone as the diluent, it

being understood that any excess of air mixed With the gas above that required for coinbustion is a mere diluentand is substantially neutial. When thel gas used contains considerablequantities of hydrogen or other readily igniting gases which 4tend to give rise to preignition troubles, We preferably mix more or less products of combustion with the air. Such products of combustion may be drawn from theexliau'st pipe of the engine, or from thestaclr of any convenient furnace orthe like, and are preferably cooled before -being mixed With the air and gas, von account ot' the greater density at low temperature. The specilicheat, by volume, of products of combustion is relatively high, ascompared' with air, and such products. exert a marked influence tending to hold back the ignition of hydrogen and like constituents which tend to ignite prematurely under the conditions cylinder during compression; such holding back being due, probably, in great measure to the Vpresence of considerable quantities/ of carbon dioxid inthe products of combustion. By properly diluting the cliai'ge to correspond With the load on the engine, Without varying the amount of the charge, by correspondingly varying the point of ignition,

and when necessary holding back theigni tion by employing greater or less quantities of products of combustion in the charge, we are able to insure proper ignition, Without so much combustion before the piston reaches the end ofits compression stroke as results in excessive bacl pressure on the piston and the doing of negative Work; and thereby we are enabled to'use, at all loads, very cheap fuel gas of low thermal value,l or containing considerable proportions of -ingredients havingwidely different rates of combustion, and are thus enabled to obtain very high coinmercial and thermo-dynamic economy.

Hitherto itlias been generally considered that the effect of products of combustion in I the chargey ofaii explosion engine is highly preiudicial, as tending to make ignition irregular oi' to prevent it altogether, and very often elaborate measures have'been taken to produce very complete scavenging of the cylinder; but We have fou-nd" that the. ob-

jections'heretofore found to be unavoidable or the unintentional retention of a portion of the products of combustion Within the cylinder do not apply when the products of;

combustionare used in carefully regulated the entering air and gas, but that to the contrary very decided advantages result from the proper mixing of suitably regulated proportions of products of combustion with the charge, as before stated.

ln the case of engines which operate by the injection of fuel into the cylinder or combustion chamber of the engine, the products of combustion for diluting the mixture and retarding combustion will'he introduced, orordinarily, With the entering charge of air.

that we claim. is

l. ln an internal combustion engine, the combination of a combustion chamber, means for supplying thereto a combustible charge and a dilueiit gas, and regulating means controlling botli the supply of dilucnt and ignition, and arranged to vary the point of ignition and supply of diluent; correspondingly.

2. ln an internal combustion engine, the combination of a combustion chamber, means for supplying thereto a con'ibustible charge and a dilueiit andv automatic governing means cbntrolling both the supply of diluent and ignition, and arranged to vary the point.

spondingly.

3. In an internal combustion engine, the combination of a combustion chamber, means for supplying thereto a combustible charge and a diluent gas, and aii automatic speed governor controlling both the supply of dilu cnt and ignition, and arranged to vary the point of ignition and supply of diluent correspondingly.

et. In. an interna-l combustion engine the combination of a, combustion chamber, means for supplying thereto a coinbustilile charge and products of combustion, and regulating` means controlling both the supply of products of combustion and ignition, and arranged to vary the point of ignition and lsupply of products of combustion correspondingly. s

5. ln an internal cbmbustion engine, the combination `of a combustion chamber, means for supplyingthereto a combustible charge and products. of combustion, and au- -toniatic governing means controlling both the supply of -products of ,combustion and ignition, and arranged to vary the point of ignition and supply of products of'coin- `bustion correspondingly. l

6. ln an ,internal combustion engine, the combination of ay combustion chamber, means for supplying thereto a eon'ibustible charge and products of con'ibustion, and an automatic speed governor controlling both the supply of products of combustion and ignition, and arranged to vary the point of ignition and supply of-pioducts of combusion correspondingly.

in an internal combustion engine, the combination of a combustion chamber,

Crt

mixture and alsovamancla dierent-dilut-j ing gas, and regulating means controlling? means for supplying thereto a combustible the supply of both. n

means for supplying theneto'a combustible mixture .and also air amil a different diluting gas a Valve controlling both the latter, 4ernor for 'adjusting said waive;

the supply of 10. In an internal combustion engine, the

combination .of means ifm' :supplylng a comof combustion to en,

trolling such supply yof mr products of combustion, `anni an automatic governor for adjusting-said valve.

bustibleV mixture and also air an dioxid to the engine, a -valy such supplyof air and carbondioxid, an

span automatic governor for valve. Y v. v

1.2. In an internal combustion engine, the combination of means for supplying a comi',bustible mixture and a diluent gas .to' the 3 5 engine, a valve controlling such supply Vof -diluent gas, igniting means, andautomatic governing means controlling sa'ilvalve and Y ignlting means correspondingly. j

13. In an internal'combustion'engine, the 40 combination of .means 'for supplying a combustible mixture and'a-jdiluent lgas to the engine, a `Valve controlling?suchsuppl)1 of diluent gas, speed goifernor acljustingxbothtsaid va Ve 'and the Apoint of igmtion correspondingly.

V14. In an'internal combustion engine, the

combination'of means for` supplying a combustible mixture and a 'diluent gas to the en ine, ignlting means, a shifting eccentric 50 or 'operating the same,V regulating means which shifts saldeccentricto Vary the point r of ignition, vantmeans' operated by said regulating means for varying the supplyof diluent harmo and an :auitaamatic lspeeol govbust-ible miXtureand also aiirjan vproducts a' valve can; f

,- 'ignition accordingly.- all. In an internal the combination of meansfor'suppl a comigniting means, `antifa sin 1eof ignition. v f

1 5; In an internal combustion engine, the combination of a -combustion chamber,

ywith the change in point meansor supplying a combustiblemixture land thereto a combustible mixture and air and a further diluent gas and for varying the proportion of diluent while maintaining substantially, constant the `,total amount of gas,'and means for compressingthe gas in 'saidfchamber Ato between 9% fand 16'atmospheres, approximately, and causing combus tion thereof. j,

'16. In an internal combustion engine, the

combination of a combustion chamber,v

means forfsupplying thereto La combustible :mixture and air and a further-diluent gas,

means for compressing the gasin said chamber 'to between :and 16 atmospheres :1pv 'proximately, and for causin combustion thereof, andl automatic regu ating means tcomprlsing means for Vvarying the propor- 'tion of diluent and for 'varying the point of 17.111 an internal combustion engine, the

combinationV of a combustion chamber,

means for supplying thereto fuel and combastion-supporting 'gas- 'and lproducts of combustion, means for cempressng the contentsA of `the chamber, vand for causing the ofalln'oductsA of combustion and tion thereo,-. and automatic gmeans comprising means for va rmportin for varying. sponolingly;l

18. In K an internal combustin engine, k the e 'point of ignition corre- 'combination of a combustion' "chamber,

mea/ns for. supplying thereto fuel and comlbus'tion supportingl gas and carbon dioxid,

means for com'ressing the contents of the chambenfanfl or causing 'lgmtlon thereof, and automatlc regulatmg means compus- '95 ing means-for- Varying'the proportion of I carbon dioxid and for varying'the point of ignitio'n correspondingly. l

In testlmony 4whereof-,We hereunto ,atix

our'signaturesin the'presence of two wit- GODFREY-M. SuTAIT.

, CARLETON ELLIS.

Witnesses:

I-I.v M. MARBLE, FLETGHEn P. SCOFInLp.

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