Internal combustion engine
US RE21750 E
Abstract available in
Claims available in
Description (OCR text may contain errors)
March 11, 1941. A M, STARR Re. 21,750
INTERNAL COMBUSTION ENGINE Original Filed Oct. 21; 1932 4 Sheets-Sheet 1 Fig. 1. if
ATTORNEY March 11, 1941. A. M. STARR INTERNAL COMBUSTION ENGINE Original Filed 0cth2l, 1932 4 Sheets-Sheet 2 Fig.5.
ATTORNEY March 11, 1941. STARR Re. 21,750
INTERNAL COMBUSTION ENGINE Original Filed Oct. 21, 1952 4 Sheets-Sheet F5 M Hflfliu 2.1.5 r J 74? m J a g .Lv 5w. 22 A uu m Em: 1 E P Q k IN VEN TOR.
A TTORNEY R-5 ,wmlmT 1 ing:
March 11, 1941. STARR Re. 21,750
INTERNAL COMBUSTION ENGI NE Original Filed Oct. 21, 1932 4 Sheets-Sheet 4 I HM] llll igllll -vza IN VEN TOR.
Reissue d Mar. 11, 1941 UNITED sTATEs PATENT OFFICE INTERNAL COMBUSTION ENGINE Original No. 2,025,362, dated December 24, 1935,
Serial No. 638,866, October 21, 1932. Application for reissue December 17, 1937, Serial No.
This invention relates to improvemen in internal combustion engines and has for o e of its objects an engine construction which utilizes the less volatile hydrocarbon fuels such as Diesel oil,
a substantially constant air intake cycle, wherein the fuel may be throttled at will without restricting the amount of air entering the cylinder at each stroke. This is accomplished by my fuel injecting principle wherein I time the period of injection in accordance with the amount of fuel injected. This timing of the injection is so adjusted that varied amounts of fuel injected for different throttle positions are allowed to mix before ignition with substantially that portion of the-air in the cylinder required to support'the complete combustion of the amount of fuel injected. That is to say, at full throttle when it is desired to utilize all of the oxygen inthe cylinder the injection occurs well in advance of ignition to allow time for turbulent distribution of the fuel with all the air in the cylinder, whereas at reduced throttle the fuel is injected just before ignition so that the small charge of fuel is mixed before ignition with only a small volume of air adjacent tothe spark plug. By this means I obtain a constant air intake cycle and hence a high efliciency throughout the throttle range of the motor.
Another object is to provide an engine wherein the timing of fuel injection with reference to the position of the engine piston and the quantity of fuel injected at each stroke is automatically correlated.
Another object is to provide an engine of the fuel injection type wherein a portion of the residual heated gases of combustion are retained in a chamber adjacent to the cylinder and not exhausted during the scavenging stroke, nor disturbed during the intake stroke of the engine.
The hot gases thus entrapped supply a heated atmosphere through which each succeeding charge of fuel is injected, with the result that the atomized fuel charge is gasified (in part at least) and is thus prepared for explosion by the spark.
A further object is to provide an engine capable of utilizing non-volatile fuel oils as an operating medium and which will, at the same time, possess the advantages of electrical ignition and conse- 12 Claims. (01. 123-32) quently be capable of running at speeds unattainable with engines of the Diesel type.
Another object is to provide an engine of light construction which is capable of running on nonvolatile fuels and which is capable of starting without priming and without the assistance of auxiliary machinery other than the conventional starting mechanism employed on ordinary automotive vehicle engines.
A further object is to provide an engine which, by reason of its peculiar construction, is less inclined to overheat than gasoline engines now in use and which, therefore, may more readily lend itself to air cooling.
Another object is to provide an engine head which is interchangeable with the engine head of any ordinary carburetor type of gasoline engine so that at nominal expense any gasoline operated engine can be converted to operate satisfactorily on a non-volatile flued with a resultant increase in efficiency and economy.
A further object is to provide an engine suitable for automobile, airplane and motor-boat uses wherein the necessity of a highly volatile fuel is entirely eliminated and the great fire risk which prevails particularly in airplane and motor-boat installations is practically eliminated.
Another object is to provide an engine having a. combustion chamber capable of retaining heated .gases therein between the strokes of the engine and in which said chamber is so equipped with a fuel injector and spark plug that atomized fuel is directed past the points of the spark plug and through the entrapped heated gases or hot atmosphere and out the open end 'of the chamber into the cylinder.
Another object is to provide an engine capable of operating at higher compression ratios than carburetor type engines, without detonation.
Another object is to provide an engine construction which eliminates the usual carburetor and its attendant parts and which, therefore, has
' a better volumetric efllciency. Such efliciency is increased by my construction because there are no restricted carburetor passages to hinder the intake air flow and because of the absence of fuel vapor in the intake air charge. By increasing volumetric efllciency more power is obtained from a cylinder of a given size.
Referring to the drawings:
Figure 1 represents a vertical sectional view of a part of the upper portion of an engine embodying one form of my invention together with a Figure 2 isan inverted plan view along the line IIII of Figure 1;
Figure 3 is a vertical sectional view of a portion of an engine of the overhead valve type embodying my invention;
Figure 4 is an inverted plan view along the line IVIV of Figure 3;
Figure 5 is an enlarged view of a fuel injection system used in conjunction with the apparatus shown in the preceding figures;
Figure 6 is a sectional view taken along the line VIVI of Figure 5; and v Figure 7 is a side elevation of an engine assembly wherein'my invention is utilized.
Referring to the details shown in Figure 1, the numeral I indicates a piston which operates in a cylinder block 2, the walls of which are cooled in the customary manner by a water jacket 3. A wrist pin 4 is secured to a connecting rod 5 in the usual manner and this connecting rod is assumed to be associated with the usual engine crank shaft, fly wheel and other par-ts commonly used in internal combustion engines. The valve 6 and its attendant parts are of the conventional construction employed in gasoline engines. One form of my invention, as applied to the conventional L-head motor, is illustrated in detail in the engine head of this figure wherein the head casting in general is identified by the numeral I. Said head is cooled by a water jacket 8 and 3, and is secured to the cylinder block 2 in the usual manner by means of the studs 3 and nuts II provided to draw the engine head tightly against the gasket I2. It will be noted that the'engine head is recessed to form a space I3 which affords communication between the engine cylinder 2 and the exhaust and air intake valves, one of which is indicated by the numeral 6 An important feature of my invention resides in a combustion chamber I4 formed in the engine head I so that it is in open communication with a cylinder bore. A spark plug I5 is mounted in a threaded opening I6 of the head and is provided with points I1 exposed within the chamber I4, and preferably located atthe edge of a spray projected from a nozzle 32 associated with a fuel injector which will be more fully described hereinafter. While the chamber I4 and the space I3 are in open communication with each other it should be'noted that the head casting is provided with a lip I8 which tends to deflect the air rushing into the cylinder through space I3 in a downward direction so that the incoming air produces the least possible disturbance to the hot gases entrapped in the combustion chamber I4.
Surmounting the casting which forms the main head of the engine is a fuel injector comprising a housing preferably of circular cross-sectional shape in its upper end and hexagonal at a portion indicated by the numeral whereby to permit the same to be gripped by a wrench for assembly or removal. The housing I9 is secured in the head casting by the threads 2I', and is hollowed out to receive a helical compression spring 22 which bears against the flattened head 23 of a rod 24. A hexagonal-headed screw 25 serves as a means for adjusting the tension of spring 22 and is held in adjusted position by a lock nut 25.
The housing I3 securely holds an injector unit 21 in the position shown and in such manner that a fuel feed conduit 28 communicates with a groove 25 in the upper portion of said unit to deliver fuel through a conduit 20 into an annular space 3| and from which space the fuel is injected into the combustion chamber I4 and cylinder 2 through the pintle nozzle 32. The-injector unit 21 containsa circular aperture formed along the axis of said unit. This aperture is ground to receive a. plunger 33 which is also ground and lapped to form a sliding fluid-tight fit in said aperture. At the lower end of the injector unit 21 and integral therewith, and extending through the nozzle 32, is a projecting tip or pintle 34 which is preferably flared to take the form of a truncated cone having its large end lowermost. The purpose of this flaring tip is to cause the atomized fuel to discharge as a jet properly disseminatlng the atomized spray to promote distribution thereof in. the cylinder, and at the same time giving the spray such shape and direction that it will not impinge against the walls of the cylinder. The portion 30 of the plunger 33 is ground on its lower surf-ace to fit against a ground seat' at the inner end of the opening of the nozzle 32 and acts as a valve to keep the nozzle closed except during the instant when the plunger 33 is raised by the high pressure of'the fuel oil in the space 3I and which pressure occurs upon opening of the valve I04. The angle of the pintle 34 may be varied to suit the size I comparatively narrow spray, but if the chamber I4 is of low wide construction, then the angle of the pintle 34 is increased to give more spread to the projected spray. In Figure 3 the injector nozzle is represented in action to give, a general idea of the manner in which the fuel is projected into the part of the cylinder traversed by the piston and thoroughly mixed with the air therein. The chamber I4 may be circular or oval in cross section or of other shape to carry out the objects of the invention, the spray nozzle being constructed so as to give a jet conforming to the shape of a ven chamber.
In Figure 1' the fuel for combustion is supplied by means of a pumping and metering system (not shown in this figure) which is assumed to deliver the liquid fuel under high pressure (say about 1,000 lbs. per square inch) to an annular space I03 which surrounds a valve stem I02; said valve stem being a continuation of a larger stem 39 which has a fluid-tight fit with its surrounding wall 4I. At the lower end of the stem 33 is a removable collar 42 which forms a seat for a compression spring I05 which malntains the ground valve I04 against its seat 45. The lower end 46 of the valve stem 33, in its normal position, just clears the surface of a conduit 52, through conduits 20 and 29, and into the annular chamber 3|, whereupon, the high pressure of the oil against the lower end of the plunger 33 overcomes the pressure of the spring 22 thereby causing the plunger 33 to rise slightly to permit a jet of atomized fuel to be very rapidly' and forcibly projected through the nozzle 32. Thus, after the engine has warmed up slightly,
30 are so constructed as to project the fuel ina Figure 2, which is an inverted plan view taken on the line II-II of Figure 1, shows the combustion chamber [4, the spark plug points l1 and the tip of the injector nozzle 34. It also shows the chamber l3 and the lip l8 which deflects the incoming air or gases entering the cylinder; the openings marked 53 in this view being theholes through which the studs 9 pass to secure the head to the cylinder block of the engine. While Figure 2 for convenience represents the head of only one cylinder, it should be understood that ordinarily the casting I would extend the full length of the cylinder block and would be provided with a number of chambers and other parts corresponding with the number of cylinders in the engine.
Referring to Figure 3, this figure represents my invention applied to the ovhead valve type of motor and since the same principles would apply in the overhead valve construction as would be used in the L-head type just described, or in the T-head type of motor, the application of my invention to the overhead valve type of motor will be understood by those skilled .in the art without repeating the description in minute detail. In this figure, as in the foregoing figures, the body of the engine, which may be of conventional type, as well as the exhaust manifold and other parts which have no direct bearing upon the invention, have been omitted. It is clear that the overhead valve construction permits the intake and exhaust valves to be placed closer to the combustion chamber and thus enables areduction in volume of the compression space inherently required in order to extend the head over the valves of an L-head engine. This enables an overhead valve motor to be designed to afford more space for combustion in the chamber l4 than would be practical in an L-head motor of the same size.
The sleeve valve typeof motor lends itself particularly well to my invention since all the compression space may then be utilized for cham-' ber ll, but it has not been deemed necessary to illustrate the sleeve type motor in this application as the principles for applying my invention to the sleeve valve motor would be substantially the same.
In Figure 3, the piston l is represented as being in progress in its upward compression stroke and the fuel is represented as being discharged from the nozzle 3: in a conical jet having diverging sides which form an angle such that the jet clears the walls of the chamber I but fiares outwardly below said walls to enable said fuel to mix thoroughly with the charge of air which is rapidly being compressed. A notable feature of the chamber ii, in the modified form illustrated in this figure, resides in the curved flaring of its walls in the zone where the chamber meets with the space at the top of the cylinder, as indicated at the point 54. I have found that a streamline effect is produced by the curvilinear walls defining chamber I4 and that this has an advantageous effect in that it facilitates turbulent mixture of the injected fuel and the air. It is within the province of my invention to vary the curvature of the walls of the chamber H or to employ any angle of flare for said walls that may be best suited to carry out the objects of my invention.
While in Figure 3, as well as in Figure 2, I l
have illustrated the spark plug in a certain position with reference to the chamber I4, I do not limit myself to the particular position shown and it is within the scope of my ivention to use more than one spark plug within each chamber if desired and to use such modified forms of spark plug or other electrical ignition apparatus as may be desired and to locate them in any position that will produce an explosion of the charge by an electrical spark.
Figure 4 is an inverted plan view of the engine I head represented in Figure 3 taken along the line IV-IV thereof. In this figure, the exhaust valve is designated by the numeral 56 and the intake valve (not shown in Figure 3) by the numeral 51. The spark plug points are represented by the numeral l'| and the nozzle tip by 34.
Figure 5 illustrates a fuel injection system that I may employ in carrying out the objects of my invention. In this figure, Bl represents a fuel supply tank from which a pipe 59 conducts the fuel to a fitting 6!, from whence it passes into a conduit 62, past a ball check 'valve 83 which is held on its seat by a spring 64, through a conduit 05 and into a pump cylinder 66. The fuel is forced from said cylinder by a piston 61, past a 12 is formed by metallic walls possessing sufficient elasticity to act as a cushion and absorb the pulsations induced by reciprocation of the pump piston 61 and maintain a substantially uniform hydraulic pressure a the lower end of the fuel line H. The pump piston 61 is connected to one end of a connecting rod 14 and the opposite end of said rod is connected to a shaft 13 which may be connected with the engine crank shaft (not shown).
In order to maintain the desired pressure in the chamber II, the fuel pump is designed to be capable of pumping such quantity of oil as will meet the maximum fuel requirements of the engine. When the engine is not operating under full load, surplus fuel pumped by the piston 01 is by-pased and is returned to the supply line 59 through a conduit 15, which is controlled by a check valve 16 loaded by the pressure of a compression spring 11 so as to maintain the desired pressure in the chamber 12, the fuel pipe II, and a pipe I8.
The fuel pumped into the pipe 'II passes through a conduit 19 and thence into an annular space 8| formed by reducing the upper end of a valve stem 82 as indicated at 84. The lower portion of the valve stem 82 has a ground and fluidtight sliding fit in a block 83. At the extreme upper end of the valve stem 82 is a valve element 85 which has a face ground to provide a close fit with a conical seat in the block 83. The valve element 85 is actuated by a cam 86 which enages the lower extremity of the valve stem 82. In the present disclosure, a four cylinder engine chamber 89 formed in a block 92. 15
is shown as illustrative and, accordingly, the cam 85 is assumed to have four lobes. one for each cylinder. Two of said lobes are shown in Figure 5 and indicated by the numeral 81. The cam 86 is secured to a cam shaft 88, whereby for one revolution of the cam shaft 88 the valve 85 will be lifted four times by the four lobes 01. Or in other words, once for each charge of fuel required by the respective cylinders of the engine.
In order to control the quantity of fuel delivered to the engine in accordance with variations demanded by changes in load and speed, I provide a fuel governor means (Fig. 5) including a This chamber communicates directly with a bore for a rod 9|, and the rod 9| is ground and lapped to pro-' vide a sliding, fluid-tight fit in said bore. The
rod 9| carries a collar 93 against which a stiff compression spring 94 is seated. From this construction, it will be apparent that the rod 9| is free to move in an upward direction when the fuel enters the chamber 89 under suificient pressure to overcome the pressure of the spring 94. When this occurs, however, the upward travel of the rod M is limited by the position of a slide 95 which acts as a throttle by which the flow of fuel to the engine is governed. This slide is provided with an inclined surface 91 that acts as an abutment against which the upper end 9| of the rod 9| strikes when the pressure in the chamber 59 forces said rod upwards.
When the engine is idling at its slowest speed, the slide 98 is in its forward position, and the inclined surface 91 is spaced slightly from the up- 1 per extremity II of the rod 9| to thereby allow said rod to move vertically this very slight distance against the action of the spring 94. If it is desired to speed up the engine, then the slide 98 is retracted or moved to the left relatively to the block 92, and the rod 9I is permitted a relatively greater movement equal to the distance or clearance then existing between the end 9i and the face of the inclined surface 91. In this manner the volume of fuel, which is allowed to pass thevalve 85 at each contact of the lobes 81 of the cam 85 with the lower end of the stem 82, is definitely regulated by the position of the slide 98, or throttle as it may be called. Thus, when the valve 85 is lifted to admit a charge of fuel into the chamber 89, the rod 9| is caused to rise vertically under the high pressure. of the fuel. Obviously, when the valve 85 is closed the rod 9| will bear against the fuel with a pressure equivalent to the force exerted by the spring 94 divided by the area of the rod 9|. Accordingly, a definite, measured charge of fuel is held under pressure in readiness to be discharged through a given injector nozzle into a, given cylinder of the engine as soon as a given valve controlling the fuel supply to said injector nozzle is opened. When said valve is opened, the spring 94 forces the rod 9i down to the limit of its travel, thereby forcing the oil charge from the chamber 89 into the cylinder, as will be clear from the following.
Leading from the chamber 89, Figure 5, isa conduit IOI which connects said chamber with annular spaces I03 below valves I04, I04, I04 and. I04, respectively. These annular spaces surround the stems associated with said valves and are maintained full of fuel in readiness to be discharged through an associated injector nozzle when one of the valves I04 or I04a, etc. is lifted from its seat. These valves are normally held closed by compression springs I05 and are actuated or opened by cams 98, 98, 90 and 98, re-
- crank shaft.
ferred to. The lobes 81 on the cam 85 are angu.
larly positioned relative to the lobes on the cams 98, 98, 98 and 88 so that when the valve 85 is open the valves I04, I94, I04 and I04 are all closed and remain closed until after the valve 85 is closed. With this arrangement, it will be obvious that as the cams 98, 98', 98 and 98 lift the valves I04, I04, I04 and I04 in their firing order, a charge of fuel is released under suflicient pressure to lift the plunger 33 of an associated injector and thereby cause a forcible injection ofatomized fuel into each cylinder in its turn; it being understood that the compression springs I05 and the oil pressure above the valves are suflicient to hold said valves firmly on their seats until they are lifted in predetermined order by thecams 95, 98*, 98 and 98 'One of the fuel injectors is diagrammatically shown in this figure to illustrate the relationship between the several injectors of an engine and the fuel feed system, it being understood, of course, that the valves I04, I84, Il4 and I04 each control the fuel supply to a different injector.
I may vary the fuel system in many ways. For instance, the valves of the I04 series may be placed radially about a central cam or cams. Also, the springs I05 may be located at the top of the valves instead of below them; or under certain conditions, the springs may be omitted, as when the oil pressure on the top of the valves keeps them seated by virtue of. a differential in pressure on opposite sides of said valves.
The fuel feed system, as a whole, is operated by the shaft I3 which is assumed for the sake of illustration to be connected with the engine A gear I05,- which is fixed to the shaft I3, causes a meshing gear I'I to rotate. The gear I01 is provided with a hollow extended hub I08 and imparts rotary motion to the fuel system injector cam shaft 88 by means of a, pin III fixed in a collar II4 slidably mounted on the hub Ill. The pin III extends radially inwardly from the collar 4; through a helical aperture in the hub I88, and terminates in a straight groove II! cut in the shaft 88. Thus the pin forms a driving connection between the 'hub I08 and shaft 88. With this connection, it is possible to alterthe angular position of the shaft 88 relative to the hub I08 and while both are rotating, by
simply moving the pin III to or fro relative to the grooves III and 3. Since the pin III is secured rigidly in the rotating collar II4, its position in said grooves can'be controlled by shifting the collar .I I4 on the hub I08. Such shifting is achieved through a forked arm carrying trunnions I44 which ride in a groove I45 in the collar II4. With the above mechanism, the timing of the injection of the fuel charges with respect to any angular position of the engine crank shaft can be changed at will while the engine is running. v
The forked arm H5 is pivotally mounted upon a bracket II'Iv by a pin II5. An extension of the arm H5 is connected'to an intermediate portion of a link I I9 by means of a pin II8 which projects from one side of said link. One arm of the link II9 contains a slot I2I which is not cut clear through link II9, but is deep enough to operatively receivea pinl22 carried by the slide 95. A rod I43 is pivotally connected at one end to the link I I 9,by a pin I20 and its opposite end to a lever I 26 by a pin I44. The lever is mounted so that it can be set at any desired position relative to a segment I23 (Fig. 7). Movement of the rod I43 by manipulation of the lever III will rotate the link II! about the axis of the pin H8 and such rotation will change the angle of the slot I2I relative to the horizontal line of travel of the slide 96 and tendto shift the slide 95 bodfly. The force tending to move the slide 96 horizontally has a vertical component which, since the link H9 is held firmly by rod I43, causes the arm II! to rotate about the pin I I6 and thereby move the collar II4 along the hub I68 and alter the injection timing. When the collar H4 is in its right hand position, i. e., nearest to the gear II", the injection begins at the end of the compression stroke (retarded injection) and when the collar H4 is in its extreme left hand position the injection begins at the start of the air intake stroke (advanced injection). Therefore, moving the slide 96 to the right reduces the amount of fuel injected for each charge and retards or delays the beginning of injection; whereas moving said slide to theleft increases the amount of fuel injected for each charge and advances the beginning of injection. When the throttle is in idling position, the slide 96 is in its right hand position; the pin I22 is at the end of the slot I2I adjacent the pin Ill; and the arm H5 is swung to retard the injection period so as to make it practically simultaneous with the timing of the spark. If the rod I43 were moved at this time there would be no consequent movement of the arm H6 because the link II! would merely rotate about its pivot pin I I8 inasmuch as the axis of the pin I22 substantially coincides with the axis of the pin IIB. Therefore, the retarded position of the arm- H5 is not changeable by move- ..ment of the rod I43 when the throttle is in idling position. However, when the pin I22 is moved by the throttle slide 96 so that its axis no longer coincides with that of the pin III! (as shown in Figure 5) there must be a corresponding movement of the arm Hi, the degree of movement depending upon the extent to which the slot I2 I has been inclined. That is to sayjif the slot I2I we're horizontal the fuel injection system would remain-with retarded timing regardless of the throttle position, and if the slot were inclined about as shown in Figure 5 the fuel injection system would be fully advanced at full throttle. Moreover, if the slot l2I were further inclined just a degree or so the timing of the fuel injection system would be advanced a correspondingly small amount at full throttle.
In considering the movement of the link H9 and the arm H6 produced by the pin I22, it should be remembered that when the lever I25 is locked in position relative to the segment I23,
(Fig. '1) the rod in can still pivot about the pin I44 carried at thelower end of said lever. To this extent, rod I43 is always free to move, and it will be noted that it must so move when the arm H5 is actuated by movement of the throttle.
slide 96. a It is within the province of my invention to make the slot I2I or the surface 91 curved instead of straight so that the timing of injection is suitable for any setting of the throttle, which is one object of my invention. In this way, the desired control is obtained and it is possible to make adjustments for various operating conditions so that any change in the throttle position will be accompanied by the most desirable change in the timing of the fuel injection.
The rod I43 is adjusted to give the best motor performance under various operating conditions.
When starting a cold motor, the full throttle po-.
sition is used in which the injections occur slmultaneous with the creation of the ignition spark (slot I2I is here set horizontal). Under these conditions I find that the heat of compression during the cranking or mechanical starting of the engine is sumcient to. enable the spark plug to ignite the charge to create at least a weak explosion, after which the hot gases from the explosion tend to volatilize succeeding charges of fuel and thus the operation continues; With a full throttle and low engine speed (lugging) the time of injection may be advanced to begin during some, part of the compression stroke, while with a full throttle and high engine speed the injection may be advanced to begin during the air intake stroke. The type of fuel as well as the construction and compression ratio of the motor are also factors which determine the setting of the rod I43. In general, the more volatile the '-fuel, or the less its tendency to detonate, the
The viscosity of the fuel also determines the extent to which speed changes alter the amount of fuel injected; and since fuels may vary in vis cosity it is within the province of my invention to provide a. needle valve (not shown) in the line II to regulate the resistance which the system oifers to fuel flow and thus maintain the proper relation for the change in the amount of fuel injected as a result of changes in speed. Such a valve may be linked to the throttle mechanism or controlled by a governor for purposes of varying the resistance in the fuel line to meet special operating conditions.
It should be understood that the advance of the timing of the injector mechanism, which results in the advance of the timing of the actual injection, as heretofore referred to, has a dual purpose; one is to adjust the timing of the injector to compensate for time lag, especially at high speed, and the other is actually to advance the period of injection with reference to the crank angle.
Referring to Figure '7, a conventional engine block I26 is illustrated equipped with the head mechanism and fuel system which form the subject-matter of this invention. A sufficient number of the parts shown in the figures heretofore described have been here correspondingly marked with reference numerals to enable the parts to be readily identified. Figure '1 assumes the engine to be installed in an automotive vehicle wherein the throttle slide 96 is connected by a rod I21 to a lever I28 which is controlled by a foot pedal I29, a spring I30 acting to return the throttle slide to the idling position whenever the foot pressure on the pedal 29 is released. Said figure illustrates a feature of my invention which I have found advantageous under cert in conditions, namely, that of diverting a portionof the exhaust gases back into the cylinders during idling of the engine. I have found that under some conditions, when the engine is idling very slowly, the engine block tends to cool off to a greater extent than is desirable and that operating conditions are improved by letting some of the exhaust gases return to the cylinders to be introduced with the cold air in lieu of introducing cold air alone.
I accomplish this object by providing a branch desirable to introduce some of the heated gases in the cylinders while idling at slow speeds, it is not desirable to admit such gases when the engine is carrying appreciable load. I have, therefore, arranged the mechanism shown so that, as soon as the throttle is slightly opened, and the engine is given an increased fuel charge, the inflow or exhaust gases to the cylinder is automatically shut off. This is-accomplished by means of a butterfly valve I38 which is here shown in open position. This valve is carried by a shaft to which is secured a ball crank I39 having an upwardly extending arm which is caused to bear against a collar Ill by means of a spring 2. The collar Ill is secured to the rod I21 and as the pedal I29 is pushed downwards to open the throttle the rod I21 is moved toward the left and the tension on the spring I42 is relieved whereby to close the butterfly valve I38. When it is desired to obtain the quietest and smoothest possible operation at idling speeds, a butterfly valve may be placed in the air intake manifold I and operated in conjunction with the throttle lever, similar to the manner shown in connection with the butterfly valve I38. By this means the vibrations caused by full compression at idling speeds is eliminated.
The perfect operation of my engine is attained by a combination of various related devices. The cylinder head construction provides the entrapped hot atmosphere through which each charge of fuel is sprayed beforeit is ignited and burned. It is by this construction that my engine is capable of using the less volatile fuels successfully. The method of feeding fuel-to the engine provides for correlation of the amount of each charge of fuel sprayed into the cylinder with the extent of the engine's piston travel during which the fuel is injected. It is by this method of feeding fuel in combination with my cylinder head construction that it is possible to attain the extensive'speed range and high engine speed as well as the economy of the constant air intake cycle of my engine. a
When the engine is to develop its full power, the fuel is sprayed into the cylinder as the air is rushing in during the intake stroke and consequently all this air is uniformly mixed with the proper amount of fuel so that complete combustion of the fuel is obtained. Thus, prior to compression, an explosive mixture completely fills the engine cylinder. When the engine is to run at reduced throttle it is clear that there is more air in the cylinder than is required to combust the small fuel charge injected, and if this small amount of fuel were to mix with all this air the consequent mixture would be so lean that it could not explode. The fuel injection system of my engine is so designed that by the time ignition is to occur the-reduced fuel charge has mixed or is mixing with substantially that portion of the air in the cylinder required for the complete combustion of the particular quantity of fuel injected.
My fuel injecting system accomplishes this by injecting the small fuel charge at a time which just precedes, or is simultaneous with, its time for ignition. For any throttle position, the injection period is properly timed to allow the fuel to mix with the amount of air before combustion. While I have illustrated one means of correlating the fuel throttle 96 with the cam shaft 8.8 controlling the injection timing, I do not limit myself to the arrangement shown, for the same object may be carried out by various other arrangements of levers and cams, or by an arrangement of planetary gears to take the place of the helical slot H3 and its attendant parts.
It should be especially noted that my engine is capable of operating to advantage on gasoline or the like as well as the non-volatile fuel oils.
I do not limit myself to the precise construction of cylinder heads shown in the accompanying drawings inasmuch as the central axis of the chamber I 4 may or may not be on the extended central axis of the cylinder bore as shown. Moreover, the chamber Il may be placed on one side of the top of the cylinder bore and inclined so that the fuel charge may be directed toward the center of the piston head. The chamber I4 may be given any shape conforming with the shape of the spray from any injector nozzle. I prefer to have the volume of the chamber l4 equal to at least one-third of the total volume of the compression space. Y
The fuel nozzle used may be of any construction that will atomize oil by the use of compressed air as well as the solid injecting principle shown. The spark plug may be of the present design illustrated or any modification thereof and I may combine the injector and properly arranged electrodes as a unit. If desired, the electrodes may be arranged at the mouth of the fuel nozzle in such a way that the electric discharge passes directly through the fuel jet issuing from the injector. I may provide means outside the engine to adjust the position of the electrodes within the chamber I4, and it is within the province of my invention to provide such adjustment.
I am aware that various forms of antechambers or combustion chambers have been used in connection with Diesel engines but the use of such chambers has been for purposes other than those herein described, and not for the purpose of entrapping therein heated residual gases to be utilizedfor heating an atomized spray of fuel during the unrestricted passage of such spray through the chamber into the displacement space of the engine well in advance of ignition by a spark.
I also am aware that whatever may be the shape of the compression space adjacent to an engine cylinder, such space contains hot gases not removed at the 'end of the exhaust stroke and also contains gases heated by compression at the end ofeach compression stroke, but the presence of these hot gases has no bearing upon the present invention. In the first place, residual exhaust gases in an ordinary compression space are dissipated by and intermixed with the intake air, rendering them ineffective for the purpose herein described. heated by compression alone become hot only toward the very end of the compression stroke and hence are ineffective for carrying out the objectives of my invention. With my cylinder head construction, a hot atmosphere is continually present in chamber I4. ,Even when the engine is running with alight load and the exhaust is relatively cool it should be noted that the ex- In the second place, gases jection begins.
plosionsare localized in chamber I4 and the hot gases from each explosion tend to remain in this chamber while the cooler intake and ex-' haust gases flow in and out of the cylinder. Hence, if a heavy load is suddenly placed upon the engine, this hot atmosphere is present to heat the consequent larger charge of fuel regardless of the engine pistons position when the in- Since the gases in chamber II are hotter than the gases in an ordinary cylinder head before compression occurs, it is obvious that after-compression and ignition, the gases in the upper end of chamber ll will attain a temperature considerably higher than in an ordinary cylinder head. It is the presence of gases at this high temperature in the upper part of chamber H which enables the ordinary electrical ignition system to emciently ignite fuel oil for all operating conditions of the engine.
In Figures 1 and 3 it will be noted that the fuel injecting nozzle 32 and its attendant parts project to a certain extent into the chamber II. This tends to cause considerable heat from the burning gases to be transferred to the nozzle casing I9 and the fuel oil which it contains, thus facilitating more complete vaporization of the fuel oil when it is sprayed into intimate contact with the hot gases in the chamber ll. It is within the province of my invention to extend this nozzle into chamber II to any desired ex-. tent, in fact, I may so extend the nozzle casing into the chamber ll that it will be jacketed by hot gases to a considerable extent. Whatever length or shape of injection nozzle I may employ I have found that it is always desirable to direct the nozzle toward the interior of the displacement part of the cylinder and not against the walls of the cylinder and its associated parts.
I reserve the right to apply the principles herein described to any type of motor to which they are applicable, such as the V type and the radial or rotary types etc., whether of the two cycle or four cycle design.
Where the term "throttle is used in this specification it is intended to mean any device for varying the quantity of fuel fed to the engine and is not necessarily limited to the particular means herein set forth.
Where. I use the term hot gas chamber 1 refer to a special chamber designed to entrap a portion of the hot gases of combustion and retain the same in such manner that they are not exhausted during the scavenging stroke of the engine nor mixed to any great extent with the air which rushes into the cylinder during the intake stroke of the engine.
Where I use the term compression space I refer particularly to the space in the cylinder head adjacent to the engine cylinder wherein gases are fully compressed when the piston is at the top of its stroke.
By "displacement part-of a cylinder I mean that part of a cylinder which is traversed by the piston as distinguished from any space in the upper portion of the cylinder that is not reached by the piston in its normal travel.
When I use the term non-volatile fuel I mean a fuel that does not evaporate rapidly at normal atmospheric temperatures, as distinguished from volatile fuels such as gasoline or alcohol. I
Where I use the term electrical ignition I mean ignition from periodic electric discharges such as those which cause sparks and in no way do I mean ignition from a wire'heated by a continuous electrical flow.
What I claim is:'
1. An internal combustion engine including a cylinder head, a cylinder and piston, an elongated combustion chamber in said cylinder head,
an inlet passage in said head leading downwardly and directly into said cylinder, said inlet passage being adjacent said combustion chamber and separated therefrom bya partition member constructed with a deflecting lip to direct the incoming air charge into the engine cylinder and away from the combustion chamber, said combustion chamber having communication with said cylinder and having. a quiescent zone in the end remote from said cylinder wherein aelongated combustion chamber in said cylindenzs head, a quiescent zone formed in the portion of said combustion chamber most remote from said cylinder, a fuel injection nozzle in said chamber located to' direct a spray of fuel through said quiescent zone and chamber and substantiallytoward said cylinder, a spark-mechanism in said chamber having a spark gap adjacent the opening in said nozzle, a downwardly-leading air intake passage formed in said cylinder head-adjacent said combustion chamber, a partition member in said cylinder head between said combustion chamber and said air intake passage having a portion which serves to deflect the incoming air away from said combustion chamber and toward said cylinder.
3. An internal combustion engine construction comprising a cylinder and a cylinder head,
combustion chamber in said head, said chamber being of reduced cross-sectional area at the end most remote from said cylinder and gradually increasing in cross-sectional area toward said cylinder, an injector nozzle located to direct a spray of fuel through said combustion chamber toward said cylinder, a spark plug in said chamber having a spark gap adjacent the outlet of said nomle, a downwardly-leading air intake passage in said cylinder head adjacent said combustion chamber, a downwardly opening air valve to control 'said passage, a partition member in said cylinder head between said combustion chamber andsaid air intake passage having a portion which serves to deflect the incoming air away from said combustion chamber and toward said cylinder.
4. An internal combustion engine including a cylinder head, a cylinder and piston, a combustion chamber in said cylinder head, said combustion chamber being elongated upwardly and having its walls converging toward the end most remote from said cylinder to produce a quiescent zone of comparatively little turbulence at the end of said chamber most remote from said cylinder, a fuel injection nozzle in said quiescent zone located to direct a spray of fuel through said quiescent zone and combustion chamber substantially toward said cylinder, a spark gap in said quiescent zone adjacent said nozzle, a
downwardly-leading air intake passageway in said cylinder head. separating means between said air intake passageway and said combustion chamber, said separating means including a lip member acting to deflect the intake air downwardly into said cylinder and prevent said intake air from directly entering into said combustion chamber.
5. An internal combustion engine including a cylinder head a cylinder and piston, intake and exhaust passageways in said cylinder head, engine-timed valves mounted in said cylinder head to control said passageways, a combustion chamber in said cylinder head, said chamber being elongated upwardly to provide a quiescent zone in the endthereof most remote from said cylinder, a fuel injection nozzle in said quiescent zone located to direct a spray through said quiescent zone and combustion chamber substantially to-- ward said cylinder, a spark gap in said quiescent zone adjacent said nozzle, the said air intake passageway leading downwardly through said cylinder-head into said cylinder, and being separated from said quiescent zone and said combustion chamber by a wall having a deflecting lip which deflects the incoming air downwardly into said cylinder and prevents direct entrance thereof into said combustion chamber and said quiescent zone.
a 6. An internal combustion engine construction comprising a cylinder and a cylinder head, an elongated combustion chamber in. said head, said chamber being of reduced cross-sectional area at the end most remote from said cylinder, an injector nozzle located to direct .a spray of fuel through said combustion chamber toward said cylinder, a spark plug in said chamber having a spark gap adjacent the outlet or said nozzle, a downwardly leading air intake passage in said cylinder head adjacent said combustion chamber, a downwardly opening air valve to control said passage, a partition member in said cylinder head between said combustion chamber and said air intake passage having a portion which serves to deflect the incoming air away from said combustion chamber and toward sai cylinder. 4
7. An internal combustion engine including a cylinder head, a cylinder connected to, said cylinder head, a piston in said cylinder, said cylinder head having an elongated combustion chamber formed therein, an air inlet passage operatively arranged with respect to said combustion chamber and in communication with said cylinder, said cylinder head being provided with an 'air deflecting lip to direct incoming'air downwardly into'said cylinder, said combustion chamber having communication with said cylinder and having a quiescent zone in the end thereof remote from said cylinder wherein a minimum of turbulence is produced, and an injector and electric ignition means in said quiescent zone,
said injector nozzle being positioned to direct its spray adjacent said ignition means and substantially toward said cylinder and piston.
8. An internal combustion engine construction comprising a cylinder and a cylinder head, an elongated combustion chamber in said head, said chamber being of reduced cross-sectional area at the end most remote from said cylinder and .being arranged and constructed so that gaseous material can enter said chamber only through its end adjacent said cylinder, whereby to provide a quiescent zone in said chamber, an injector nozzle located to direct a spray of fuel through said combustion chamber toward said cylinder, a spark plug in said chamber having .a spark gap adjace nt the outlet of said nozzle, downwardly opening air intake passage in said cylinder head adjacent said combustion chamber, an air valve to control said passage, a partition member in said cylinder head between said combustion chamber and said air intake passage, one side of said partition member forming a wall of the combustion chamber and the other side a wall of the air intake passage and serving to deflect the incoming air away from said combustion chamber and being arranged and constructed so that gaseous material can enter said chamber only through the end thereof communicating with said cylinder, said combustion chamber also having a portion of the walls defining the same converging in a direction away from said cylinder to form a quiescent zone, an injector nozzle having an outlet in said combustion chamber arranged to direct a spray of fuel through said quiescent zone and combustion chamber toward said cylinder, a spark plug carried by said cylinder head having a spark gap adjacent the outlet of said nozzle, an air intake passage operatively arranged relative to said combustion chamber for admitting charges of air into said cylinder, an air valve controlling the admission of said charges of air, and an air deflecting wall interposed between said combustion chamber and said air intake passage for deflecting the incoming air downwardly into said cylinder, said wall having at least a portion of a seat for said air valve formed thereon.
10. An internal combustion engine construction comprising a cylinder and a cylinder head, an elongated combustion chamber in said head, said combustion chamber being in direct communication with said cylinder and being arranged and constructed so that gaseous material can enter said chamber only through the end thereof communicating with said cylinder, whereby to pro- ..vide a quiescent zone in said chamber, an injector nozzle having an outlet in said combustion chamber located so as to direct a spray of fuel through said combustion chamber toward said cylinder, a spark plug carried by said cylinder head having a spark gap in said combustion chamber adjacent the outlet of said nozzle, an air intake passage operatively arranged relative to said combustion chamber, an air valve controlling the egress of air from said air passage,
and a wall in said cylinder head, said wall being arranged and constructed to serve the dual purpose of deflecting incoming air and fuel into said cylinder.
11. An internal combustion engine including a cylinder head, a cylinder connected to said cylinder head, a piston in said cylinder, said cylinder head having an elongated combustion chamber formed therein arranged and constructed so that gaseous material can enter said chamber only through its end adjacent said cylinder, a downwardly leading air inlet passage operatively arranged with respect to said combustion chamber and adjacent thereto and in communication with said cylinder, said cylinder head being provided with a partition member between said intake passage and said combustion chamber, adownwardly opening valve to control said passage, a seat for f said valve a portion of which is located upon said partition, the portion of said valve seat which is located upon said partition being formed at an angle to direct incoming air directly into said cylinder, said combustion chamber having a quiescent zone in the end thereof remote frommote from said cylinder and being arranged and constructed so that gaseous material can enter said chamber only through its end adjacent saidv cylinder. whereby to provide aquiescent zone in said chamber; an injector nozzle in said chamber positioned to direct a spray of fuel through said chamber toward said cylinder; a spark plug in said chamber having a spark gap adjacent the outlet of said nozzle; a downwardly leading air intake passage in said cylinder head adjacent said combustion chamber; a downwardly opening air valve to control said passageway; and means in said cylinder head separating said combustion chamber from said air intake passage arranged and constructed to direct the incoming air downwardly into said cylinder.
, ALLAN M. STARR.