US2319858A - Method and means for controlling combustion engines - Google Patents

Description

May 25, 1943. H; B. GRow 2,319,858

METHOD AND MEANS FOR CONTROLLING COMBUSTION ENGINES I Filled Feb. 24, 1941 5.Sheets'-Sheet l BY a May 25 1943 H. B. GRow 2,319,858

METHOD AND MEANS FOR CONTROLLINGCOMBUSTION ENGINES Filed Feb. 24, 1941 Y s sheets-sheet 2 1N VENT OR. /arZan/. vranf BYv I May 425, 1943. H B', GROW 2,318,858

METHOD AND MEANS FOR coNTRoLLINGN'coMBUsT-ION ENGINES Filed Feb. 24, 1941 3 sheets-sheet s ,lgen

Patented May 25, 1943 METHOD AND BIEANS FOR CONTROLLING COMBUSTION ENGINES Harlow B. Grow, Freeport, N. Y.

Application February 24, 1941, Serial No. 380,094

(Cl. 12S-106) 20 Claims.

The present invention broadly relates to internal combustion engines and especially to engines of the fuel injection type,` such-as Diesel motors, and to the method and means whereby their operation, speed or power may be controlled.

In present-day practice injection type internal combustion engines, especially in Diesel engines, the speed and power output control of such engines is being accomplished by changes in volumes of fuel charges introduced into the engines. In Diesel engines, wherein the ignition or combustion of the fuel charge is predicated upon the rise in temperature of compressed air within the engine cylinder, fuel of a relatively high flash point is used, such as fuel oil or so-called Diesel oil, the flash point of which should be in the neighborhood of 150 degrees Fahrenheit or more, as compared with the far lower flash point of gasoline used in other types of combustion engines. Due to the high flash point of the fuel, it is essential, in order to facilitate ignition of the fuel without undue lag, that the fuel be atomized into a very fine spray or mist. Obviously in order to promote proper atomization and uniformity of a given fuel charge, the volume and density of the fuel injected and the pressure at which it is introduced, must not appreciably change.

In controlling the operating speed and power of present-day engines, and especially of highspeed Diesel engines employed in aircraft, diiculty is encountered in running the engine at low speed and in idling it down, in the way it is possible with gasoline engines. Attempts of 10W- ering the number of revolutions of high-speed Diesel engines, say to between one fourth to one eighth of the normal speed, usually cause an uneven running of the engine and often result in a complete stoppage, for the reason that the quantity of injected fuel becomes so small that usually employed injection pumps can no longer handle the fuel or bring it under a sufficient pressure for proper atomization. The fuel injection systems used at the present time in Diesel engines may be divided into three representative classes:

l. A system using self-metering, high pressure pumps, known as jerk pumps, individually connected with their respective engine cylinders, which pumps meter and compress the fuel charges, and in conjunction with which fuel injectors are employed for atomizing and admitting the fuel. charge into the engine cylinder.

2. A system employing high-pressure, plungertype pumps, serving a plurality of engine cylinders, and adapted to maintain fuel in a container at constant pressure, from which container the fuel is conveyed to the individual engine cylinders, each equipped with a mechanically operated injector.

3. An individual compressor system in which small compressors or injector cylinders and pistons are used to compress a fuel-rich charge of fuel and air prior to injecting such charge lthrough an automatic valve into the engine cylinder.

Pumps or compressors employed in the rst and third systems mentioned, are rather complicated in their arrangement and often fail to properly function, and sometimes break down completely.

The pumps or compressors of all three systems enumerated may be classed as constant-stroke devices. In addition to these, many engine designers equip motors with variable-stroke pumps, wherein the stroke distanceof the piston may be altered during operation. The mechanism for changing the piston stroke considerably adds, to the already complex construction, another cause for a possible breakdown. Moreover, present-day systems employing either variablestroke pumps, or constant-stroke pumps, involve a further serious disadvantage, in that they do not provide for satisfactory atomization Qf the fuel charges, when the volume of the latter varies. y As has been stated before, it is necessary, in order to assure instantaneous combustion of high flash point fuel, that the latter be thoroughly broken up or atomized into a very fine spray, otherwise an undesirable lag in ignition, or even a total ignition failure will be experienced.

Correct atomization depends upon two major factors, i. e. pressure and volume, and in a lesser measure upon the density of thecharge. Injectors employed in high-speed Diesel engines are therefore designed to produce the desired fuel spray for a given volume introduced at a given pressure. When either the volume or the pressure or both are altered, the character of the spray will materially change, unless the adjustment of the injector is changed accordingly.

Obviously such adjustment of injectors in an operating engine could be made only by still further complicating the engine control mechanism, and While attempts in that direction have been made, so far no practical solution has been found. Thus in present-day practice the setting of injectors is necessarily xed for best atomization values Within a relatively narrow range of pressures and volumes at which fuel is introduced.

From the above explanation it will become quite clear that when the engine is to be throttled down, present-day pumps or compressors of the metering type, or pumps with variable stroke, Will deliver to the injector a fuel charge of lesser volume. By the same token, when the throttle is opened, a correspondingly greater volume of fuel will be injected. These charges in fuel volume cause a considerable fluctuation of injection pressure.

In order to maintain uniform and positive operation of a high-speed engine at any speed, correct and positive ignition of each successive fuel charge introduced into the engine must be assured.

The herebefore enumerated systems and devices do not meet this requirement, sinceV they do not effect at all engine speed, the essential uniformity in volume and pressure, and consequently do not provide uniformity of the successive fuel charges injected into the engine, when its speed or ypower varies. This lack of fuel charge uniformity causes uneven engine operation, poor acceleration and possible engine stop- Pag.

From the foregoing explanatory matter the numerous disadvantages of present-day control devices for compression-ignition engines, and the lack of satisfactory speed and power control of such engines becomes readily apparent.

The present invention has for its principal purpose theelimination of these disadvantages and to provide positive and dependable speed and power control for high-speed injection-'type o-i Diesel engines, whereby it is made possible to assure accurate injection and ignition timing, to regulate the rate and effective power .output of fuel charge injections, and to maintain vsuch injections at a constant, predetermined volume and atan approximately uniform pressure, thereby facilitating great flexibility in varying the power outputof an engine. Y

One of the objects of the present invention is the method of controlling the operation of internal combustion engines kby varying the combustibility or power effect of the successive fuel charges introduced. into the engine, without changingthe volume of such fuel charges, nor materially varying the pressure at which they are introduced, and wherein these fuel charges comprise, at the moment of their injection into theengine, liquid matter only, containing neither gases nor air, thus virtually constituting what is known as fsolid liquid fuel injections, which I shall hereinafter term solid injections.

AAnother object of the present invention is the method' of controlling the operation of highspeed internal combustion engines by changing, at will, from .normal engine fuel to a mixture of such normal engine fuel Vwith another liquid agent, or vice versa, and by altering the composition of suchmixture without changing the volume of, or 4the pressure at which fuel charges of either `norn'ial 'engine fuel or of such mixture are introduced into the engine.

Another object of the present invention is the methoid'of regulating or varying the speed ant powerxof high-speed injection-type internal combustion engines, consisting of mixing with the .normal engine fuel, having certain combustion characteristics, van ag .it having diiferent characteristics from that of the normal engine fuel, and injecting fuel charges of either normal engine fuel,.or vof Vthe mixture, at constant volume and without materially changing the pressure at which such fuel charges are introduced, thereby altering the effective power output of the engine.

Still another object of this invention is the method of reducing the speed or power of highspeed Diesel type engines, which method consists of mixing normal engine fuel of a certain heat value with an agent having a lesser heat value than that of the normal fuel, immediately prior to the introduction of a fuel charge into the engine, without changing the normal volume of such fuel charge, nor materially altering the pressure at which such fuel charge is introduced, thereby lowering the effective power of such fuel charge.

Another object of this invention is the method of controlling the operation of Diesel engines by changing the combustibility of the successive fuel charges introduced into the engine, without altering the normal volume of the fuel charges, nor materially altering the pressure at which the fuel charges are introduced, and wherein the fuel charge is composed of normal engine fuel mixed with an inert agent, which mixture is strongly emulsiedprior to the introduction of the fuel 1 charge into the engine, whereby the normal engine fuel becomes nely distributed and diffused within ysuch agent, thereby changing the physical s ructure of the fuel charge.

Still another object of this invention is to provide suitable means, appropriately connected with injection type high-speed engines, which facilitate the introduction into the engine of a fuel charge containing either normal engine fuel, or a fuel charge consisting of a mixture of normal engine fuel and another agent, designed to alter the effective power output of the normal engine fuel, and which means are provided with suitable instrumentalities for operating them so that the proportion of normal fuel to such agent may be readily changed, as desired, while the engine opcrates.

Another object of this invention is to provide suitable mechanical means for putting into effect the aforestated methods, which means consist vof various instrumentalities for controlling the flow of fuel and of another liquid agent, for mixing liquids, for emulsifying or diifusing them, to assure relative uniformity of the mixture prior to its injection into engines in the form of fuel charges, and means for injecting uniform fuel charges of constant volume, and introduced at substantially a constant injection pressure, at any engine speed.

The foregoing and a number of other objects and important advantages of the present invention will become more fully apparent from the ensuing description, in connection with the accompanying drawings, which latter are held in a more or less diagrammatical form. and are intended to serve for explanatory purposes only, and are not designed to limit the present invention to the specific structures illustrated.

As has been explained previously, high-speed injection-type internal combustion engines or Diesel engines, primarily employed for aircraft, possess as their standard equipment various types of injector pumps or compressors, by means of which fuel is introduced into the engine cylinders. All these devices are more or less calculated for certain volumes of fuel charges injected at a certain injection pressure for producing the normal speed or power of the engine. When it is attempted to operate an engine at a lower speed or with less power, by reducing `either the volume of fuel charges or the pressure at which they are introduced, the pumps or compressors can no longer efficiently handle the fuel, and the required atomization by the injectors of the fuel charge, lacking in volume, cannot take place. This results in what is known as missing of the engine, and often causes engine stoppage. Metering pumps or variable stroke pumps designed for regulating speed or power of such engines are unsatisfactory. They are not only costly, but their operating mechanism is lso complicated that they are often subject to eratic operation, precipitating a total breakdown.

The present invention is designed to control the operation'of engines not by changing the volume and density of fuel charges, but by changingtheir combustibility or power effect when injected into an engine cylinder, thus assuring the required volume and pressure for proper atomization of such fuel charge. This change in combustibility or power effect of fuel charges is accomplished by what may be termed dilution or diffusion of the normal engine fuel.

In the ensuing description and in the appended claims certain expressions will be found intended to simplify their wording. For this reason it may be well to elucidate these expressions.

Thus, for instance, under normal or active engine fuel is to beunderstood a fuel which is normally used in the type of engines indicated, such as Diesel fuel oil for Diesel engines.

Under fuel charge will be understood a certain volume of introduced fuel of either normal engine fuel, or a mixturecontaining such normal fuel and an agent having combustion characteristics different from normal fuel.

The words normal fuel charges designate fuel charges containing only active or normal, engine fuel. The .words "normal engine speed define the speed of an engine attained while developing its normal power for which it is designed. For example, an engine is designed to normally produce 1200 H. P. at a normal speed of 2500 R. P. M.

The term diluting agent designates a liquid with which normal engine fuel is either mixable, or with which it may be emulsied; such agent or carrier may either be an inert liquid which is not combustible, or a liquid having cornbustion characteristics or heat values different from that of the normal engine fuel, and which heat values may be either higher or lower than rthat of the normal fuel.

The word dilution does not only4 mean the usual physical dilution, such as is possible with water and alcohol, but rather a mixture, or an emulsion, or a composition of liquids, wherein one of the liquids is normal engine fuel, which is finely and uniformly distributed within a liquid different from the normal engine fuel. The words "diiiusion or diffusing also indicate the uniform distribution of normal engine fuel in the body of another liquid.

The terms controlling or regulating the operation of an engine relates to changes in either the speed, R. P. M., or power, H. P., of an engine.

entexpressions to be employed in this application, reference is now made to the accompanying drawings, wherein Fig. lis a more or less diagrammatical illusthrough a modified valve structure;

Fig. 3 is a cross sectional view taken 0n line 3-3 of Fig. 2;

Figs. 4 and 5 illustrate other forms of valve structures;

Fig. 6 shows a still different embodiment of a valve structure, including an emulsier;

Fig. 7 is a vertical cross section through a partly diagrammatical illustration of an injector pump and injector arrangement;

Fig. 8 is a section taken on line 8 8 of Fig. 7;

Fig. 9 is a diagram showing a chart of an injection.

Fig. 10 is a diagram showing the timing of an injection; and

Fig. 1l represents a partial side elevation in fragmentary section of an engine showing diagrammatically the employment of the present invention.

The underlying principle of the present invention resides in the feature of regulating the speed or power of an engine by changing the physical character, the heat value or the effective power of injected fuel charges, without changing their volume or appreciably altering the pressure at which they are introduced.

Referring to Fig. 1, there is indicated a container l0, representing supply means for normal engine fuel, and another container I I representing supply means for a diluting or diffusing agent, such as water, carbon tetrachloride, or any other inflammable, or non-inflammable, or inert liquid. Both containers are connected by suitable conduits to a valve structure I2, constituting a mixing chamber for both the fuel and the agent. This structure is provided with an opening I3, connected with tank I0, and opening I4, connected with tank II, which openings issue into ports I5 and I6, respectively, and which ports are respectively controlled by threaded rotary valvestems I1 and I8. Ports I5 and I8 connect with a mixing space I9, from which leads a single conduit 20 to fuel injector pump 2|, wherein operates a piston 22. Pump 2| is connected with an engine cylinder indicated at 23. It is to be noted that, while pipe or conduit 20 is shown relatively long, it is essential that the connection between valve structure I2 and pump 2| be as short as practicable. The reason for this statement will become presently evident.

Valve stems II and I8 are provided with gears 24 and 25, respectively, which mesh with one another and are preferably of the same diameter and contain the identical number of teeth. In engagement with one of the gears is an operating gear 26, which may be driven by any suitable mechanism. Thus when gear 26 is moved, its motion is transmitted to gears 24 and 25, whereby the threaded stems |I and I8 will be moved oppositely to one another in longitudinal direction, so that one of the stems will either reduce the passage through, or completely close one port, while the other stem will simultaneously increase the passage through, or completely open the other port. Depending upon the direction of rotation of gear 2E, the se uence of th Having thus clarified the meaning of the differq e reclprocal closmg or opening of the two ports will take place.

From the explanation of the crude arrangement shown in Fig. 1 it will be quite evident nevertheless, that the operation of the valve stems in valve housing I2 are intended to effect the delivery to pump 2| of a fuel charge containing either normal engine fuel, or a mixture of normal fuel with an agent, and that the proportion of normal engine fuel in such mixture may be readily controlled by valves l1 and I8.

`InFigs. .2 and 3 lthere is illustrated another valve or control assembly, consisting of a housing 21-provided-with fuel inlet port 28 and an agent inlet port 29. These ports terminate in relatively ynarrow slots disposed at an angleto one trol 'member 3|. The latter -has slanting edges 32 and 33, adapted to slide over ports 28 and 29,

thereby controlling the amount of liquid passing through these ports. Obviously, port control member 3i `may also completely close or open either of the two ports, as clearly shown in Figs. 2 and 3. The chamber in which sleeve 3|l-operates serves as a mixing compartment, and is provided with a single outlet 3!! for the passage ,of a fuel charge into the-pump. Sleeve 30 may be operated in any suitable manner, forinstance by a gear 34.

Another vvalve arrangement is illustrated -in Fig. 4, 'consisting -of a valve .casing 35, in -which operates a slide valve '35, :provided with :a 'body reduction 31. Slide valve 36is intended =to control elongated port openings .38 and 39, into which lead pipes VIl!) and 4|, connected, respectively, with a fuel container, ysuch Aas tank i5., and .an

- agentcontainer,such as tank I I, shown in Fig. 1.

Below ports 3.8 and .3S 'is shown `a:mixing chamber 42 from which leads aconduit i3 to theinjecticn pump.

Still anot-hcrfmodiiied form of a valve structure is portrayed in Fig. 5, wherein 'is .employed a casing 44 provided with inlet ports 45 .and 45,

Allof I the afored'escribed valve structures, del signed for handling either undiluted normal engine fuel or mixtures of normal .engine fuel with other liquids, `donot provide means for mechanically `mix-ing .or emulsifying such 'fuel mixtures. In the embodiment .illustrated in Fig. 6, mechanical mixing means .are provided. In this device valve housings A54 .and 55 Vare employed, Yin which operate, respectively, control valves 56v and 51, both connected .by means `of actuating lever 58, pivoted 'at 59. is a conduit 60 forconveying a diluting agent to port'GI. Into oneside of valve housing 55 leads to control port 62 a conduit 53, which connects theport with a circulating pump 64. The latter receives through pipe'normalengine fuel vfrom `a fuel tank, such -as container `Hl of'Fig. l. From conduit 6.5 branches `ofl through Ya T-tting 66 another conduit 61 which is controlled by valve 58. From ithe other side of valve port 62 issues a -connecting pipe 69, which leads to a chamber 10', wherein is `mounted a turbine 1|.. Conduit 61 Venters .at 12 the bottom of chamber 10. Driven by turbine -||"isa.sl'1aft '13, provided with a plurality of lpaddles 114, and .operating ina mixing chamber 1.5. VValve 4ports 5| and-62 are connected with chamber 15, `so that when an agent .and normal engine-*fuel enter the'mixing chamber, they become thoroughly intermixed by `:padd1es .1.4,before they can leavethrough .passage Leading into valve housing 54 16, leading to pump-cylinder Tl, connected with fthe engine.

-Inasmuch as normal engine fuel, supplied through pipe 65, is constantly circulated by rotary pump 64 in 'the system including pipe 53, valve housing 55, Vpipe 69 and pipe 61, turbi-ne wheel 1| and paddle shaft 13 will always operate,

Vas long as valve 68 is open. This valve serves stant-volume fuel charge, the pressure at which such .charge is injected will vary but little, even though the speed of the engine may change.

Aside from the employment of a constantstroke pump system, delivering fuel charges .of constant volume at a substantially constant pressure, it is essential, in order to have proper operation of the device, .that the connection between the fuel mixing instrumentality and .the pump be as short as possible. This is necessary in order to preclude any segregation ofthe normal engine fuel from the diluting agent, `while the mixture passes to the pump. Similarly it is also essential that the connection between the inj ection pumps and the engine cylinders be made as short as .practicable in order to eliminate as much as possibleany lag in engine response, due to changes in throttle settings.

It is to be noted, of course, that in the present invention the throttle is intended to control not the volume, but the eifectivenessor power effects of full charges to be injected, and that these power effects vary in direct proportion to the percentage of active or normal engine fuel contained in these charges. Thus when a fuel charge consists of 100% of normal or active engine fuel, its power effect will be at a maximum, while when the fuel charge is composed of say 50% of normal engine fuel and 50% of a diluting or diffusing agent, its power effect will be approximately one half of that maximum.

The term "approximately is chosen with design, since in computing the power effect of a mixed fuel charge, another important factor is to be taken into calculation, which factor may be considered a by-productof the present invention. It concerns what may be called a fuel ionization effects, produced by injecting mixed fuel charges containing water. The latter rapidly changes into vapor and promotes ignition and combustion of the injected fuel charge composition.

Referring again to the statement that the connections between the fuel mixing chamber and the injection pump, and between the latter and the engine cylinder are to be as short as possible, a proposed solution of this problem is illustrated in Figs. 7 and 8, wherein numeral 18 denotes the engine cylinder, with which is closely connected a combination mixing valve and injection pump structure 19. The later comprises a pump cylinder 80 in which reciprocates piston 8|, driven by a grooved cam 82, shown diagrammatically. The cam engages a roller 83, at the end of piston rod 83', which latter is conveniently guided, as at 84.

Pump cylinder 8U has a circumferential ange 84, made either integral with the cylinder body, 01 arranged separately, but conveniently. joined therewith. This flange supports a similarly flanged valve housing 85, which is bolted to the cylinder ange. The contacting surfaces joining the housing with the pump cylinder are sealed, as indicated at 86.

The outer surface of the pump cylinder, above flange 84, is machined, and a machined cylindrical recess 81 is .provided in the valve housing adjacent to the outer machined portion of the pump cylinder. A cylindrical rotary sleeve valve 89, with an elevated extension 90 and a gear ring 9|, is operatively mounted in recess 81, being actuated by gear 92. vThe latter is lodged in enlargement 93 of housing 85, and its drive shaft 94 extends fro-m a bearing depending from cylinder flange 84. Y

Extension 90 of the. rotary valve controls flat, horizontal inlet ports'95 and 96 issuing into the top of cylinder 80. These ports are aligned. with corresponding passages 91 and 98 provided Vin housing 85. Extension 90 is equipped with recesses 99 and |00, adapted to either registerwith their respective ports and passages, or partly reduce their effective areas. The solid portions of extension 90 may close one orthe other passageway, such as shown in the figures at right.

Passages 91, 98 are connected by suitable fittings |0|, |02 to tanks containing normal engine fuel and.- a diluting agent, such as shown at I0 and in Fig. 1. Within each of the two fittings are preferably arranged check valves |03, see Fig. '1, opening towards the cylinder and closing during the compression stroke of piston 8|. Inlet ports 95, 96 are disposed angularly, in the manner sh-own at 28 and 29 in Figs. 2 and 3, for the purpose of automatically intermingling the two components of the fuel charge, as they forcibly enter the pump cylinder. The latter serves in itself as a mixing chamber, whereby a lconnection between a separate mixing chamber and the injection pump, such as indicated at 20 in Fig. `l, is entirely eliminated.

In addition to this marked advantage, the proposed structure includes another improvement, in that the distance between the injection pump and the engine cylinder is shortened to a minimum. This is accomplished by providing a compact injection nozzle structure |04, see Fig. '7, which serves in the place of a close nipple, and which joins the pump and engine cylinders. The nozzle structure includes an exchangeable nozzle tip |05 and a spring-held check valve |06, lthe latter being adapted to open towards the engine cylinder at a predetermined injection pressure, for which the valve spring is adjusted.

The proposed combination mixing `valve and injection pump structure of Figs. 7 and 8, while not intended to have any limiting effect-upon my invention, not only clearly indicates thepossibility of shortening or eliminating f-uel charge transfer passages, but is also designed to facilitate` the explanation of a new injection timing system, believedto have decided advantages over existing injection methods.

All the devices illustrated and described in the foregoing matter are primarily intended' to deliver fuel charges at a constant volume and approximately at a constant pressure. Consequently, in order to change the speed or power of the engine, the only thing required is to change from normal engine fuel to a mixture containing the latter at a desired proportion. By altering such proportion, the power eii'ect of the fuel chargeis controlled. Thuswhenit isrequired to reduce the speed or power of an engine,

the normal engine fuel must be diluted by an agent having a lower combustion value than that of the normal fuel.

Inasmuch as the present invention contemplates the maintenance of injected fuel charges at a constant volume and under substantially a constant pressure, while only the combustibility of the fuel charge is altered for controlling the speed or power of an engine, accurate timing a-nd control of the rate of fuel injection may be readily predetermined and kept constant, irrespective of throttle setting.

The action of a constant-strike injector pump, designed to inject fuel charges of a uniform volume, may be considered to consist of two major phases, i. e. suction and compression, and a minor phase, during the beginning of the compression stroke, which I shall term the starting phase. During this latter phase the piston is brought to a position at which a sharp cut-olf of the fuel charge takes place, whereupon immediately follows the compression of the charge.

The aforesaid sharp fuel cut-oli is facilitated by a bleeder or discharge passage |01 indicated in Fig. 7. This passage is governed by a springinduced, outwardly opening check valve |08. Upon passing and closing bleeder passage |01, the piston lo-cks the desired volume of the fuel charge in the cylinder, wherein it is now brought to the required injection pressure, at which nozzle valve |06 is opened to permit the injection of the compressed fuel charge into the engine cylinder.

When the ,full volume of a fuel charge is wholly injected, in one instance, into the engine cylinder, there occurs, instead of a relatively slow fuel combustion, a sudden, excessive detonation, followed by a sudden rise in pressure, which is highly undesirable, since when such pressure becomes excessive, it will cause engine knocking.

In the lower part of Fig. '7 groove-cam 82 is del signed to operate, in the direction 0f the arrow,

. its broken-line position I, piston 0| is at its inner dead center, practically contacting the cylinder head. As the cam turns through a 180 arc a towards its full-line position II, the piston moves to its outer dead center. position and sucks in a fuel chargev of the required volume. This outward piston movement isA intended to be very rapid. Y

Now commences the inward or fuel charge compression and injection stroke of the piston. During the cams rotation through the first half of arc b, towards the third indicated cam position III, the piston, starting from a point below bleeder passage |01, will, upon passing and closing the passage, immediately start compressing and injectingthe fuel charge. The latter will be under practically the full required injection pressure. As the cam approaches the end of arc b, marked by radial line P, and continues in its movement through short arc c, to radial line P', an initial injection at a, relatively slow rate takes place. As the cam rotation progresses from radial line P through last arc d, the balance of the fuel charge is progressively injected at a relatively rapid rate. The initial fuel charge having been ignited, causes the ignition of the balance of the injected fuel charge.

While the foregoing explanation may leave with the reader a slow-motion impression, the actual time required for one completeworking cycle of the device corresponds to only a very small fraction of a second, and may be consideredfor all practical purposesl an instantaneous action. The small difference between a full-volume, instantaneous fuel charge injection and the modified two-stage injection just described, is brought out clearly in Fig. 9.

In this diagram the volume-or injection rate,'

and the time periods of two comparative types of fuel charge injections are indicated. Both are figured from the timel the injector piston has passed bleeder passage |01 (Fig. 7)-, and has brought the fuel charge-to the'required injection pressure, at which complete atomization of Ythe fuel charge is made possible. For simplicitys sake it is assumed that the injection pressure is the-same for Vboth injection types during their entire injection periods.

The full-line curve X represents a full-volurne, instantaneous fuel chargeinjection, corresponding to the'full and-direct inward movement of the injection pump piston. The injection commences at 0, and endsat the topV of the curve at X. At thatfpoint theentire fuel charge has been transferred to the engine cylinder, and thevpressurein-thepump drops to Zero, as indicated by the vertical-A downward portion of the curve, meeting the lower` horizontal of the diagram nearnumeral 'L The broken-line curve Y denotes a two-stage fuel charge injection, described in connection with Fig. 7. Between time divisions 2 and 3 curve` Y progresses at a slant, indicating the initial injectionA and ignition period, the cutoiff having taken place at time division 2. Curve Y further indicates that an initialfuel charge pcrtionfor the-initial ignition period had taken place `between divisions 2f and'3, and that, starting from `division 3, the remainder of the fuel charge isinjected into the enginecylinder.

The timing of fuel charge injections for the engine,isbestillustrated .in Fig. 10. Assume that a full-volumefuel charge would normally be injected at a point advancedv 10 degrees from the inner dead center of the engine piston. The initial injection and ignition of a. portion of the fuel charge, indicated between points Zand 3 of Figure 9, is preferably advanced in respect to the point of injection-.of themajor fuel charge portion. An advanced pointfor an initial injection and ignition is indicated at aLpoint marked "12 degrees. The light, initial fuel charge will ignite readily, and when the rest of the fuel charge is injected the heat within the cylinder will be sufiicient to assure positive ignition ofthe whole charge.

Rccapitulation Comparing heretofore employed means for .con-

trolling the speed and power of engines with theA injectedifuel charge, whereby a high-speed engine may` be .safelyiidle'd-downto! a lowy spee'd withoutt-he danger lof engine stoppage;

'7; The maintenance ofthe engine at a safe working. temperature, always.

.8.1 The employment of-devicespfor accomplishing the desiredA results; which are simple in construction and, due to their simplicity, are reliable in. their function. andV are inexpensive, being far less' costly than similar unsatisfactory devices usedfheretofore.-r

f Having; thus described the. presentY invention, and having; pointed-'out thev salient advantages thereof, itl istobebornein mind vthatthe illustrations-*are notzintended t0= disclose final structures,

yet are indicativeof the principlesupon whichy the disclosedv method,` and the rdevices accomplishing it,:are basedgand that these :illustrations areto serve purely-forexplanatory purposes, and that the method indicated, as well as the devices shown, may be altered and improved, and I therefore reserve for'myself the right toeffect suchchanges andrimprovements in bothwithin the broad scopeof my invention, asexpressed in theV annexed claims.

I claim:

1. The methodof controlling the operationof compression-ignition type internal combustion enginesconsisting of varying the combustibility, andl therefore the effective power of solid fuel charges introduced into the engine without changing their volume, but by changing the potency of such solid fuel charges.

2. The method of controlling the speed'and power of compression-ignition type internalcombustion engines consisting of changing the effective heat value of introduced solid fuel 'charges without a change in their volume;

3. The method of regulating and varying the speed or power of Diesel engines consisting o f introducing into an engine sol-id fuel charges at a constantvolume and changing theirr combustibilitygbyf mixing,V thel normal engine fuel with liquid agentsA having combustion. characteristics different from ythat'of the lnormal engine fuel.

Ae. The method of varyingv the speed or power of compression-ignition, injection-type internal combustion engines consisting of introducing into an engine fuel charges at constant vvolume and approximately ata constant pressure, and changing their effectiveness by changing their effective,V

heat valuesimmediately prior to their introduction into theengine. i

5. The method 'of Varying the speed or power of compression-ignition, fuel-injection type internal combustion engines-byvarying the combustion characteristics offuel charges introduced into the engineat af. constant volume, the method consisting ofadmixing with the normall engineV fuel .having certaincombustion values ania'gent having ldifferent combustion values, prior`to.' the introduction of the `fuel charge into the engine. i 6. vTheniethod offreducinglthe speed of'. highspeedDi'eseletype engines consistingfof mixin'glther norma1.liquid"'engine fuel with a liquidagent having alessrfheat'value thanthat 'of vthe normal fueLi priori. to: introducing the fresortingfsolidlfuelf charges into the engine, without either substantially altering the normal volume of, nor appreciably reducing the normal pressure at which such fuel charges are normally introduced into the engine. i

'7. rThe method of reducing the speed or power of compression-ignition, injection-type, highspeed internal combustion engines, which consists of mixing the normal liquid engine fuel with a liquid inert agent, and injecting the resulting mixture in the form of solid fuel charges at volumes and pressures substantially equalling normal fuel charges of normal engine fuel during normal engine operation.

8. The method of controlling the operation of high-speed compression-ignition engines, which consists of governing the combustion or power effectiveness of constant volume solid fuel charges, introduced at substantially uniform pressure, by changing the proportion of normal engine fuel in such fuel charges, and injecting and igniting first an initial solid fuel charge portion, followed immediately thereafter by the injection and ignition of the balance of the solid fuel charge.

9. The method of regulating the operation, as to speed or power, of compression-ignition, injection-type, high-speed internal combustion engines, which comprises changing at will from the normal engine fuel to a mixture containing a percentage of such normal engine fuel, and vice versa, and injection and igniting the resorting solid fuel charge in at least two stages.

10. The method, as stated in claim 9, effecting such mixture immediately prior to injecting it into the engine in the form of a solid fuel charge, introducing the latter at substantially the pressure and. of a volume a fuel charge of normal engine fuel is being injected for operating the engine at its normal speed or power.

11. The method, as stated in claim 9, effecting such mixture immediately prior to injecting it into the engine in the form of a fuel charge, introducing the latter at substantially the pressure and of a Volume a fuel charge of normal engine fuel is being injected for operating the engine at its normal speed or power, and changing the composition of the mixture, by altering the percentage of normal engine fuel in said mixture, While the engine operates, to effect changes in speed and power of the engine.

12. The method of regulating the speed or power of compression-ignition injection-type internal combustion engines, which comprises injecting into an engine cylinder and igniting there in consecutive fuel charges of either normal engine fuel or of a liquid mixture containing such normal engine fuel, introducing and igniting such fuel charges in at least two continuous stages within one injection period, while maintaining the total volume and the injection pressure of such fuel charges substantially constant.

13. The method as stated in claim 12, said mixture constituting an emulsion of normal engine `fuel with an inert agent, produced immediately prior to injecting it in the form of a fuel charge.

14. The method as stated in claim 12, said mixture constituting an emulsion of normal engine fuel with water, produced immediately prior to injecting it in the form of a fuel charge.

15. The combination with a Diesel type engine, of supply means containing normal engine fuel and other supply means containing a liquid agent having combustion characteristics different from that of the normal engine fuel, and adjustable means for facilitating the mixing of normal fuel with the agent at any desired proportion to each other, prior to the introduction of a solid fuel charge into the engine.

16. The combination with an compression-ignition, injection-type internal combustion engine having constant volume fuel charge injection means, of supply means containing normal engine fuel and other supply means containing a liquid agent having combustion characteristics different from that of the normal engine fuel, means connected with said injection means for mixing, at any desired proportion to each other, said normal engine fuel with said agent, without affecting the operation of the constant volume injection means.

17. In a device for controlling the operation of high-speed Diesel engines by changing the combustion effects of a solid fuel charge while maintaining the latter at a substantially uniform volume, a mixing chamber having two controlled ports and a single outlet, regulable port control means in the mixing chamber for reducing or fully closing one of the ports, while simultaneously increasing or fully opening the other port, or vice versa, one of the ports being connected with a reservoir containing normal engine fuel, the other port being connected with a reservoir containing an agent having combustion characteristics different from that of the normal fuel.

18. In a device for controlling the operation of high-speed compression-ignition, injection-type engines by uniformly injecting solid fuel charges of constant volume and at a substantially constant injection pressure, but of different power effects, a valve structure having at least two controlled inlet ports, one for normal engine fuel and at least another for a different liquid, control means for said ports, operating means for said port control means adapted to reciprocally and simultaneously effect the closing and opening of the ports, a mixing chamber forming part of the valve structure, a constant-stroke injection pump closely connected and communicating with said chamber, and short connecting means provided with the pump for joining it with an engine cylinder.

19. In a device, as stated in claim 18, and means for agitating or mixing liquid in said mixing chamber.

20. In a device for changing the combustion or power effectiveness of fuel charges in compression-ignition fuel-injection-type engines, the combination with an engine cylinder of fuel charge injection means, adapted to deliver solid fuel charges of constant volume and at a substantially constant pressure, means for governing the combustion or power effectiveness of fuel charges, handled by said injection means, said governing means comprising a valve instrumentality controlling at least two inlet ports connected with normal engine fuel and a liquid agent mixible therewith, and means for operating said injection means and adapted to cause the latter to inject a solid fuel charge during one injection period in at least two immediately consecutive stages, the rst stage being an initial injection and ignition stage.

HARLOW B. GROW.

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