This invention was first disclosed with the United States of America Patent and Trademark Office in the following applica ions: Serial Number 06/107,338 filed December 26, 1979 and Serial Number 06Λ15,677, filed as continuation in part on September 7, 1982. The inventor, Mr. Horacio Andre ^' s Trucco, is a citizen of the USA, residing at 13 Saddler Court, Huntington Station, New York 117^6, USA.

SUMMARY

The intermittent internal combustion engine, as known today, can be divided into two basic categories: a) the spark ignited, or gasoline en- gine and b) the compression ignition, or diesel engine. Each type of engine requires a different fuel whose properties are very specific; The spark ignited engine calls, among others, for a fuel with relatively high volatility and high "octane number," while the diesel engine requires fuel with relatively low viscosity and high "cetane number." Because of these rather narrow and precise required fuel properties, the percentage of motor fuel obtainable from crude oil is relatively low. Today engine designers are looking for new ways that will make it possible to utilize lower quality fuels in these engines, because that will increase the yield of useful motor fuel obtainable from petroleum. In addition, if we consider the vast resources of non-petroleum liquid fuels available to us, plus the possibilities to produce inexpensive synthetic liquid fuels and coal-liquid slurries that cannot be util ized in present types of internal combustion engines, it is obvious that a new type of engine that could efficiently accept these low grade fuels will immediately find it way into the motor vehicle and power plant market, reducing the nation's de¬ pendence on imported crude oil while creating the need for domestic pro¬ duced alternate fuels and utilizing our immense coal resources.

This invention can easily be incorporated into any type of inter¬ mittent internal combustion engine as known today and can immediately be utilized in automobile and transportation engines effecting a drastic reduction in the nation's petroleum consumption.

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SPECIFICATION

It is the object of this invention to provide intermittent internal combustion engines with means to vaporize a liquid fuel or slurry fuel prior to its mixing with the combustion air. It is a further object of this invention to append a vaporizer chamber interconnected to the con¬ ventional combustion chamber of said engine through a valve that can be opened and closed as required. It is a further object of this invention to provide said vaporizer and combustion chambers with a multiplicity of fuel injectors and spark plugs such as to obtain a controllable and de¬ pendable combustion with most liquid fuels and slurry fuels regardless of its octane or cetane rating, its volatility, its viscosity and simi¬ lar properties required by the spark ignited and/or diesel engine. It is still a further object of this invention to achieve combustion inside said engines resulting in low and acceptable emission indexes for carbon monoxide (CO), oxides of nitrogen (N0 _χ ) , unburned hydrocarbons (UHC) particulate matter and soot.

Other objects, advantages and features will further become appar¬ ent hereinafter in the drawings in which:

Figure (l) is a cross-sectional view of a four-stroke internal com¬ bustion engine constructed in accordance with this invention;

Figures (2,3 and 4) show pressure-volume diagrams corresponding to engines constructed in accordance with this invention;

Figure (5) is a cross-sectional view of a rotary piston internal combustion engine constructed in accordance with this invention;

Figure (6) is a cross-sectional view of a two-stroke internal combustion engine constructed in accordance with this invention;

(Figure (7) is a cross-sectional view of a four-stroke internal combustion engine constructed in accordance with this invention utiliz¬ ing a pneumatically actuated valve;

Figure (8) shows a cross-sectional view of a pneumatically actu¬ ated valve in open position;

Figure (9) shows a pressure crank-angle diagram corresponding to an engine constructed in accordance with this invention;

Figures (10 and 11) show the pneumatically actuated valve when assisted by electro-magnetic means;

Figure (12) shows the effect on valve opening timing when assisted

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by electro-magne ic forces;

Figure (13) shows a pneumatically actuated valve assisted by exter¬ nal control pressure;

Figure (14) shows a pneumatically actuated valve with self contain¬ ed pressure equilizer passage and assisted by a spring;

Figure (15) shows the effect on valve opening timing when assisted by a spring and/or external control pressure.

In describing the embodiments of this invention illustrated in the drawings, specific terminology will be used for the sake of clarity. However, it is not intended to be limited to the specific terms so selected and is to be understood that each specific term includes all technical equivalents _t wh i ch operated in a similar manner to accomplish a similar purpose.

In the preferred embodiment of this invention illustrated in Figure (1), an internal combustion engine, partially shown, is seen to consist of a piston 1, shown near to its top dead center (TDC) , connecting rod 2, cylinder 3, piston rings 4, intake valve 5, exhaust valve not shown, camshaft 6, a multiplicity of cams 7, a multiplicity of valve tappets 8, acting on push rods 9 that cause rocker arms 10 to actuate said intake and exhaust valves in accordance with a four-stroke cycle, a convention¬ al combustion chamber 11, a vaporizer chamber 12 interconnected to said conventional combustion chamber through passage 13, a vaporizer valve 14, shown in the open position, valve stems 15, valve guide 16, vaporizer rocker arm 17, mechanically contacting valve locks 18, spring retainer 19, valve spring 20, spring bracket 21, attached to cylinder head 22 through a multiplicity of points 23, a push rod 2k, actuated by said camshaft and said valve tappet such as to open or close said vaporizer valve by the combined action of rocker arm 17 and valve spring 20, a spark or glow plug 25 reaching said vaporizer chamber, a spark or glow plug 26 reachi ng sa i d conventional combustion chamber, a fuel injector 27 penetrating into said vaporizer chamber, a secondary fuel injector 28 penetrating into said conventional combustion chamber, a leak collecting plenum 29, a passage 30 connecting said plenum to intake duct through orifice 31 -

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ln operation, a fresh charge of air or gaseous oxidizer contain¬ ing no fuel is drawn, without throttling, Into cylinder 3 during the downstroke of piston 1 while intake valve is open but exhaust value and vaporizer valve 14 are closed, during the following upstroke of piston 1 the charge of air is compressed, all valves are closed, thus increasing its temperature and pressure. Before piston 1 reaches its TDC vaporizer valve 14 opens. Assume the vaporizer chamber 12 is filled with vapor¬ ized fuel whose temperature and pressure is "higher" than the levels for the compressed charge of air, when vaporizer valve 14 opens, the fuel vapors will transfer from vaporizer chamber 12 into conventional combus¬ tion chamber 11 mixing with the compressed air in a gaseous phase. At this point, spark plug 26 delivers a spark that ignites the vaporized fuel -compressed air mixture establishing a diffusion flame. It is im¬ portant to realize that because the fuel is vaporized and it is at a temperature sufficiently high for autoignitioπ there Is no ignition delay involved in the initiation of the chemical reaction, and in addi¬ tion because the gaseous state of the fuel the flame front is only controlled by its mixing rate. The important advantage of this new type of internal combustion engine is that any type of liquid fuel or slurry fuel, regardless of its cetane index will instantly ignite and thereafter sustain a vigorous and smooth combustion characterized by a noise-free operation of the engine. An added advantage is that a diffu¬ sion flame from gaseous mixtures cannot detonate thus eliminating the need for octane rated fuel . The combustion phase continues while piston 1 reaches its TDC and during a part of the following downstroke that delivers mechanical power to the engine crankshaft. At a point during this expansion phase of the cycle, the vaporizer valve 14 closes en¬ trapping inside vaporizer chamber 12 hot combustion product gases. After vaporizer valve 14 closes, piston 1 continues the expansion phase of the cycle, followed by the opening of the exhaust valve and the exhausting ^~ f ^~ combust ion products during the next upstroke of piston 1 completing a four-stroke cycle. Notice that after the vaporizer valve 14 closes, the entrapped combustion products cannot expand, so they maintain its high level of pressure and temperature. At a desired point after vapor¬ izer valve 14 is closed, fuel injector 27 sprays liquid fuel or slurry fuel into vaporizer chamber 12. The fuel spray absorbs heat by direct mixing with the entrapped combustion products vaporizing at a finiterate. Now the vaporizer chamber contains a mixture of combustion products and

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vaporized fuel . Notice that the entrapped combustion products contain insignificant amounts of oxygen or oxidizer, consequently the injected fuel cannot burn inside vaporizer chamber 12. The vaporized fuel is now ready to be transferred into conventional combustion chamber 11 at the opportune time to repeat the cycle described above. Small amounts of vaporized fuel that will leak through valve stem 15 are collected in chamber 29 from where it is recirculated back into the cylinder via pas¬ sage 30 and orifice 31 during an intake phase of a cycle.

Figure (2) is a pressure-volume diagram of the cycle described above, solid lines represent the pressure variation inside combustion chamber 11 and dashed lines represent the pressure variation inside vaporizer chamber 12. Arrows indicate the event direction as cycle progresses. From point "a" to point "b" the ynthrottled induction of a fresh charge of air takes place, from point "b" to point "c", the air is compressed while all valves are closed, at point "c" vaporizer valve 14 opens allowing to vent the con¬ tents of vaporizer chamber 12 into conventional combustion chamber 11 through orifice 13. Immediately after, at point "d" a spark supplied by spark plug 26 ignites the mixture of vaporized fuel and compressed air. The pressure inside combustion chamber 11 rapidly increases due to the combustion and the moving of piston 1 travelling toward its TDC. The pres¬ sure inside vaporizer chamber 12 initially decreases due to the venting, at point "e" it is approximately equal to the pressure level i ns i de combus¬ tion chamber H. Because the volume of combustion chamber continues to decrease, but the volume of vaporizer chamber 12 is fixed, the flame front establ ished inside combustion chamber 11 will move back into vaporized chamber with a reverse or inverted diffusion flame. After piston 1 reaches its TDC the common pressure inside combustion and vaporizer chambers peaks at point "f". During the expansion phase from point "f" to point "h",the vaporizer valve 14 closes at an intermedial point "g" entrapping hot com¬ bustion products inside vaporized chamber 12. Notice that while the engine cycle evolves from point "e" through point "g", vaporizer chamber 12 and conventional combustion chamber 11 both in combination determine the bound¬ aries of the "actual" combustion chamber. The bulk of the combustion pro¬ ducts continues the cycle dictated by the displacement of piston 1 , from point "h" to point "a" the exhaust phase completes the fourth stroke of the cycle. Going back to point "g" notice that the relatively high pres- pressure and temperature prevailing inside vaporizer chamber remains approx¬ imately constant until when at point "j" liquid fuel or slurry fuel is injected inside the vaporizer chamber 12. STITUTE SHEET

the liquid fuel droplets and particles absorb heat by direct mixing with the entrapped hot combustion products. As a result the injected fuel vaporizes and superheats. Notice that the residence time available for vaporization includes the evolution time: from point "j" through points "k", "m", "n" and finally to point "c" when vaporizer valve 14 opens. Point "j" was selected to emphasize the relative long residence time available for the injected fuel to vaporize. Depending on the partic¬ ular fuel utilized, point "j" can be shifted to a later time before point "c" is reached. Notice that the combustion process described above occurs in the presence of some inert combustion product from the previous cycle; its chemistry is similar to the one in exhaust gas re- circulation, a technique widely used for N0χ reduction of internal com¬ bustion engines. Furthermore, a fully vaporized fuel, below overall stoichiometri c fuel-air ratio combusts with minimum emission of UHC, CO, soot and smoke.

Figure (3) is a pressure-vol ume diagram obtainable with the present invention that differs from the one shown in Figure (2) as described below. At point "c" when vaporizer valve 14 opens, the pressure prevail¬ ing inside vaporizer chamber 12 is "lower" than the pressure inside conventional combustion chamber 11 ; consequently fresh compressed air or oxidizer is transferred into vaporizer chamber 12. At point "d", spark plug 25 supplies a spark that ignites the air-vaporized fuel mixture establishing a reverse diffusion flame. Notice that spark plug 25 does not contribute to the vaporization process that takes place while the cycle evolves from point "j" though point "c" . At point "f" when most of the vaporized fuel has been consumed, a secondary amount of liquid fuel or slurry fuel is sprayed by secondary fuel injector 28 inside com¬ bustion chamber 11 where a fraction of the initial fresh charqe of air is still available. Since i s temperature at this point is much higher than the one normally obtainable in a diesel engine, the additional secondary fuel injected will easily ignite and burn with a diffusion flame much like in a diesel engine regardless of i s cetane rating.

The flexibility of secondary fuel injection utilizing secondary fuel injector 28 also applies to the case of the cycle described by Figure (2) . The effect of secondary fuel injection is better shown in Figure (4) where the dashed line indicates the effect of such secondary

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fuel injection.

Power is controlled, like in a diesel engine, by metering the total amount of fuel injected to each cycle when the aspirated amount of fresh air is non-throttled.

Cold starting this engine can be achieved in various manners depend¬ ing upon the properties of the fuel utilized. Fuel with light viscosity and high volativity can be initially injected into the vaporizer chamber 12 to obtain ignition with assistance of a spark, after the engine has warmed up, usually a few seconds; a much heavier fuel can be utilized for injection into vaporizer chamber 12 and thus achieve the vaporization described above. A second alternative is to externally preheat the walls of the vaporizer chamber 12; with this technique the engine will cold start utilizing heavier fuels. A third alternative is to temporarily mix fuel with the intaking air alike in a spark ignited engine and to run the engine in this mode until it warms up and then initiate the fuel injection into vaporizer chamber 12.

Figure (5) is an embodiment showing a cross-sectional view of a rotary piston engine constructed in accordance with this invention, seen to consist of a rotor 32, a casing 33, an intake port 3 , an exhaust port 35, a conventional combustion chamber 11 , vaporizer chamber 12 inter¬ connected to said conventional combustion chamber through a passage 13, a vaporizer valve 14, vaporizer rocker arm 17, valve spring 20, spring bracket 21 attached to said engine casing (not shown) , a push rod 24, actuated by a cam and tappet mechanism not shown, a spark plug 26 reach¬ ing said conventional combustion chamber, a fuel injector 27 penetrating into said vaporizer chamber, a secondary fuel injector 28 penetrating into said combustion chamber.

In operation, a fresh charge of air is drawn through intake part 3 and a four-stroke cycle as described in Figures (2 or 4) takes place ex¬ hausting its combustion products through port 35.

Figure (6) is an embodiment showing in cross-sectional view a two- stroke piston engine constructed in accordance to this invention, seen to

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consist of a piston 1, cylinder 3, provided with intake transfer port 36 and exhaust port 37, a conventional combustion chamber 11 , a vaporizer chamber 12 interconnected to said conventional combustion chamber through passage 13, a vaporizer valve 14, vaporizer rocker arm 17, valve spring 20, spring bracket 21 attached to cylinder heat at a multiplici¬ ty of points 23, a cam 38 acting on said vaporizer rocker arm, a spark plug 26 reaching said conventional combustion chamber, a fuel injector 27 penetrating into said vaporizer chamber.

In operation, fresh charge of air is drawn through intake trans¬ fer port 36, while exhausting the combustion products from previous cycle through port 37. It is easier to realize that a pressure-vol ume diagram similar to the one shown in Figure (2) applies to this two- stroke engine.

Notice that in both cases of Figure (5) and Figure (6), only one spark plug is necessary to obtain controllable combustion, and that said spark plug 26 is placed "outside" vaporizer chamber 12. The embodiment of Figure (1), which has two spark plugs, can operate either pressure- volume diagram as shown in Figure (2) or Figure (3) .

Figure (7) shows an embodiment of this invention utilizing a pneu¬ matically actuated vaporizer valve 14, shown in the closed position, hfere valve guide 16 is hermetically closed at one end to form stem chamber 39, passage 4θ interconnects vaporizer chamber 12 to stem chamber 39 through orifice 39.

In operation, a fresh charge of air or gaseous oxidizer is drawn into cyclinder 3 during the downstroke of piston 1 while intake valve 5 is open but exhaust valve and vaporizer valve 14 are closed. During the following upstroke of piston 1 , the charge of air is compressed while all valves are closed. Before piston 1 reaches its TDC, the pressure inside combustion chamber 11 will surpass the pressure level prevailing inside vaporizer chamber 12. As a result of this pressure differential across valve 14, a force represented by vector 42 will act upon valve 14, forcing it to open. Assume the vaporizer chamber 12 is filled with vaporized fuel whose temperature is higher than the levels for the

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compressed charge of air. When vaporizer valve 14 opens, the fresh charge of air will transfer from conventional combustion chamber 11 into vaporizer chamber 12 mixing with the vaporized fuel in all gaseous phase. At this point, spark plug 25 delivers a spark that ignites the vaporized fuel -compressed air mixture establishing a reverse diffusion flame. The combustion phase continues while piston 1 reaches its TDC and during a part of the following downstroke that delivers mechanical power to the engine crankshaft. As soon as valve 14 moves away from its seat by the initial impulse of force 42, the pressure inside vaporizer chamber 12 equals the level of pressure inside combustion chamber 11 ; thus force 42 is reduced in magnitude because the effective area for the pressure differential to act is decreased from the area of valve passage 13 to the cross-sectional area of stem 15- However, valve 14 continues to translate by the action of this reduced force 42 and by its kineti c energy . During the translation of valve 14, the volume of stem chamber 39 dimin¬ ishes and the gases entrapped inside it a re compressed because orifice 41 was covered during the initial translation of valve 14 away from its seat. Pressure- inside stem chamber 39 will increase exceeding the pressure level inside vaporizer chamber 12 and thus generate a force represented by vector 43 in Figure (8) . This new force 43 will stop the initial trans¬ lation of valve 14 and cause it to reverse its movement until valve 14 closes entrapping inside vaporizer chamber 12 hot combustion product gases. After vaporizer valve 14 closes, piston 1 continues the expan¬ sion phase of the cycle. Notice that after vaporizer valve 14 closes, the entrapped combustion products cannot expand so they maintain its relative high level of pressure and temperature. At a desired point after vaporizer valve 14 is closed, fuel injector 27 sprays liquid fuel or slurry fuel into vaporizer chamber 12. The fuel spray absorbs heat by direct mixing with the entrapped combustion products vaporizing at a finite rate. Now vaporizer chamber 12 contains a mixture of combustion products and vaporized fuel . Notice that the entrapped combustion pro¬ ducts contain insignificant amounts of oxygen; consequently, the injected fuel cannot burn inside vaporizer chamber 12. The vaporized fuel is now ready to be mixed with the next charge of compressed air contained in¬ side conventional combustion chamber 11 when valve 14 opens to repeat the cycle described above.

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Passage 40 interconnects vaporizer chamber 12 and stem chamber 39 when valve 14 is closed and orifice 41 is uncovered. This permits the pressure in both chambers to equalize assuring that stem chamber 39 is always filled with gases required to generate force 43. Figure (9) shows in dotted line the pressure variation inside stem chamber 39; notice that this pressure is equal to the level prevailing inside vapor¬ izer chamber 12 as long as vaporizer valve 14 is closed, because then orifice 41 is uncovered. After point "c", when vaporizer valve 14 starts to open and orifice 41 is covered, the pressure inside stem chamber 39 will rise; when the valve reverses its translation, the pressure will decrease to reach the level prevailing inside vaporizer chamber 12 just after vaporizer valve 14 closes. The variation in position of vapori¬ zer valve 14 is graphically shown on the upper part of Figure (9) . At point "x", the valve starts to open due to the action of force 42; at point "p", the valve reaches its maximum opening and the pressure inside stem chamber 39 reaches its peak level at point "r". The action of force 43 will force the valve to close at point "q" . The timing of points x, p, and q is affected by the area of valve opening 13, the cross-sectional area of valve stem 15, the valve total mass, the volume of stem chamber ]39, the engine load and engine rpm. Consequently, a variable timing will occur when the engine operates through a range of load and rpm. This variable timing may not be acceptable for certain engine applications demanding optimum performance through a broad range of load and rpm. This variable timing can be diminished or eliminated by imposing upon valve stem an electromagnetic force with a device as shown in Figures (10 and 11) . Both figures show the same vaporizer valve 14 in cross-sectional view, a hollow stem 15 reduces valve inertia. Valve stem 15 is made of a non-magnetic material except for its end portion 44 that is made of a ferro-magneti c material; in addition valve guide 16 and stem chamber 39 are also made of non-magnetic material .

Coils 45 and 46 fitted around valve guide 16 act as electromagnets when energized with an electric current. Referring to Figure (10), that shows vaporizer valve 14 closed, notice that electromagnet 45 is capable of generating upon magnetic mass 44 a force 47 that can be utilized to anticipate the normal opening of valve 14 or to delay its normal closing time. Figure (12)shows in solid line a hypothetical nor¬ mal opening history for valve 14. In dashed line is shown the effect on

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valve opening history when electromagnet 46 is first energized from point "s" to point "t", then electromagnet 45 is energized from point "t" to point "u" and again electromagnet 46 is energized from point "v" to point "w". By combining the action of both electromagnets, it is possible to substantially alter the timing for opening and closing vaporizer valve 14.

Figure (13) shows an additional approach to vary vaporization valve 14 opening and closing time. External gas pressure is supplied through check valve 4 into stem chamber 39 in order to generate force 50 acting upon vaporizer valve 14. By adjusting the magnitude of force 50, the valve opening and closing timing is changed. When valve 14 opens and translates the gas pressure inside, stem chamber 39 increases because check valve 49 prevents ^" flow back into external gas supply line. The increased stem chamber pressure acts as a cushion, causing valve 14 to stop

Figure (14) shows vaporizer valve 14 when assisted by a spring 51 to vary .its normal opening-closing time. Spring 51 exerts force 52 upon valve 14 that alters the valve timing. Notice that valve stem 15 in¬ corporates a passage 53 and check valve 54. This combination is equiva¬ lent and i nterchangable with passage 40 and orifice 41 shown in Figures (7, 8, 10 and 11) . Passage 53 through check valve 4 permits the pressure inside vaporizer chamber 12 to equalize into stem chamber 39- When valve 14 opens and translates, the gas pressure inside plenum chamber 39 increases because check valve 5 prevents flow back into vaporizer chamber

Figure (15), upper graph, shows variation of spring force 52 as a function of crank angle, the lower graph shows effect of forces 50 and 52 on altering vaporizer valve 14 opening and closing time.

It will be obvious to those skilled in this art that the invention described above is applicable to any type of intermittent internal com ^¬ bustion engine, four-stroke or two-stroke cycle, reciprocating piston, rotary piston, free piston gas generator, etc. Various changes and vari ^¬ ations may be made without departing from the spirit of this invention and the scope thereof as defined in the following claims:

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