CA1133337A - Method and apparatus for control of pressure in internal combustion engines - Google Patents
Method and apparatus for control of pressure in internal combustion enginesInfo
- Publication number
- CA1133337A CA1133337A CA288,703A CA288703A CA1133337A CA 1133337 A CA1133337 A CA 1133337A CA 288703 A CA288703 A CA 288703A CA 1133337 A CA1133337 A CA 1133337A
- Authority
- CA
- Canada
- Prior art keywords
- air
- chamber
- fuel
- combustion
- combustion chamber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B55/00—Internal-combustion aspects of rotary pistons; Outer members for co-operation with rotary pistons
- F02B55/02—Pistons
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B41/00—Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F3/00—Pistons
- F02F3/28—Other pistons with specially-shaped head
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B1/00—Engines characterised by fuel-air mixture compression
- F02B1/02—Engines characterised by fuel-air mixture compression with positive ignition
- F02B1/04—Engines characterised by fuel-air mixture compression with positive ignition with fuel-air mixture admission into cylinder
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/30—Controlling fuel injection
- F02D41/3011—Controlling fuel injection according to or using specific or several modes of combustion
- F02D41/3017—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used
- F02D41/3023—Controlling fuel injection according to or using specific or several modes of combustion characterised by the mode(s) being used a mode being the stratified charge spark-ignited mode
Abstract
ABSTRACT OF THE DISCLOSURE
A piston type internal combustion engine is arranged to use, in a time dependent process, the shock compression and expansion waves generated by the com-bustion of the fuel to pump highly energized compressed air from a reservoir chamber adjacent the combustion chamber and in communication with the latter through a restricted passageway into the combustion zone during the entire combustion process. The combustion chamber, reservoir chamber and passageway are configured to pro-mote controlled pumping of air from the reservoir into the combustion chamber throughout combustion due to the interaction of the compression and expansion waves. The air in the reservoir is fuel-free and is preferably placed in the reservoir during an aspirated intake event by controlling the timing of fuel flow during intake and the mixture of the charge at the intake port. The pre-ferred embodiment provides the reservoir chamber in the piston near its working face and the passageway is an annular gap between a radial lip of an annular member supported above the piston and the cylinder wall.
A piston type internal combustion engine is arranged to use, in a time dependent process, the shock compression and expansion waves generated by the com-bustion of the fuel to pump highly energized compressed air from a reservoir chamber adjacent the combustion chamber and in communication with the latter through a restricted passageway into the combustion zone during the entire combustion process. The combustion chamber, reservoir chamber and passageway are configured to pro-mote controlled pumping of air from the reservoir into the combustion chamber throughout combustion due to the interaction of the compression and expansion waves. The air in the reservoir is fuel-free and is preferably placed in the reservoir during an aspirated intake event by controlling the timing of fuel flow during intake and the mixture of the charge at the intake port. The pre-ferred embodiment provides the reservoir chamber in the piston near its working face and the passageway is an annular gap between a radial lip of an annular member supported above the piston and the cylinder wall.
Description
il;~3337 The present invention relates to an apparatus and technique for increasing the efficiency of operation of an internal combustion engine and more particularly to an improved apparatus and technique that permits control of generated pressures and temperatures during combustion of fuel in the combustion cham~er of an internal combustion engine for ~6~H~} predetermined parameters of pressure and temperature within the combustion zone~ in order to~ decrease the amount of pollutants exhausted by the engine during operation.
Efficient conversion of energy into useful work has been the goal of engine designers since the creation of internal combustion engines utilizing the Otto cycle, i.e., - reciprocating~rotary, diesel engines and the like. In view of the scarcity and high cost of engine fuels, engineers and engine designers have been grappling with the fundamental problems of exhaust emission pollutants and increased fuel economy, yet striving to improve performance in these areas without sacrificing engine performance and efficiency. This has produced internal combustion engines that are operating in a critical compromise of fuel/air mixture composition, pressure and temperature that results in the engine generating and discharging harmful pollutants (CO, NOX and HC) in order to achieve adequate performance.
To deal with the NOX emissions designers have retarded spark and employed such devices as exhaust gas recirculation systems, each which decreases overall engine performance, with a resultant decrease in engine performance i:l33337 and which further cause increases in HC and CO emissions.
These increased HC and CO emissions must be eleared up by expensive catalytic converters which in turn require unleaded fuels.
Continued distortion of the eombustion proeess in internal combustion engines ean only result in a hodge-podge of engine eontrol devices that inerease engine manu-faeturing eost and result in low engine performance with low fuel economy.
Realization in both industry and the government that internal combustion engines will require drastie design changes to aehieve permissible government pollution standards has resulted in eonsiderable developmental efforts to inves-tigate the combustion proeess. These efforts have resulted in various teehniques such as ehanging the size and shape of the eombustion chamber, relocation of the spark within the eombus-tion ehamber, the use of multiple-source ignition sehemes and the use of stratified eharge designed eombustion ehambers.
Various modifieations of a eombustion ehamber shape into a hemispherieal ehambers with ehanges in eonventional spark loeations by designing spark plugs with extended gap designs has reduced HC emissions but this design has mechanieal manufacturing difficulties that far outweigh the amount of reduced emissions obtained.
Another technique presently being utilized is the use of a multiple-souree ignition configuration to eause ereation of a torch-like flame to shoot into a homogeneous-~1333;~
lean air/fuel mixture within the combustion chamber with the torch fueled by the same fuel as the main chamber. The torch ignition mixture is mechanically separated from the main chamber by an antechamber constructed in the engine head to open into the main combustion chamber.
Another popular scheme is the stratified charge engine (SC) configuration which can have numerous varia-tions. The basic idea of the SC engine involves introduction of a rich, easily ignitable mixture in the vicinity of the spark plug and a very lean mixture throughout the rest of the chamber, so as to have a differing air/fuel ratio in various areas within the cylinder chamber, rich in some lean in others, with the resulting overall air/fuel ratio considerably leaner than stoichiometric. The burning takes place in stages with a srnall volume of rich air/fuel mixture being ignited first to create a flame that spreads out into the cornbustion chamber charged with very lean air/fuel ; mixture causing ignition of these areas more thoroughly and burning them more completely than in conventional internal combustion engines.
The above are a few of the rnore pertinent de~ices of the numerous proposals that have been set forth to reduce pollution and increase engine and fuel performance. Each has some distinct disadvantage because of its interaction with other engine parameters inherent in the Otto cycle or diesel cycle engine. In view of this there has been created a need in the industry of an internal combustion engine operating on a gas cycle that has the characteristics of the Otto cycle but which has a process of combustion that is time controlled and will operate with the advan-tage of high compression ratio and fuel rich air ratios with the efficiency and total fuel oxidation of the diesel without its disadvantages of high pressure, high temperature and knock tendency.
Accordingly, the present invention has been developed to overcome the specific shortcomings of the above known and similar techniques and to provide an improved apparatus and technique for generating a heat balanced cycle for internal combustion engines with per-formance, pollution characteristics, and a multifuel burning capability that is not present nor possible with conventional Otto or diesel cycle engines.
The present invention, in its broadest aspect, comprises a time dependent process for carrying out an energy conversion cycle involving converting chemical energy into thermal potential by utilizing the pressure waves generated during the rapid reaction of a combus-tible fuel in the presence of oxygen and using the ther-mal potential for producing useful work in the combustion chamber of a piston type internal combustion engine oper-ating over periodic cycles that each include an intake, compression, expansion (work producing) and exhaust event.
The process further comprises, for each operating cycle of the engine, the steps of:
a) supplying air alone into a combustion chamber of the engine during the initial portion of the intake event.whil~ the volume o~ t~e combustio~ cha~ber is increasingi b) .addin.g.~uel intQ.the combustion chamber during a later part of the charge intake an.d compression eYent, the total quan.tity o~ fubl bein~ selected to provide a reaction that will rapidl~ produce a predetexmined thermal potential and a predetermined maximum pressure in the combustion~ chamber;
c) increasing the temperature o~ the total ~uantity of air and fuel admitted durin.g the c~cle by compressing at least the air during.the c.ompression eventi d) partially isolating a portion of the initially supplied air ~rom substantially all of the later supplied fuel during the charge intake:and compression event by placing a portion of the initially supplied air in a reservoir chamber located adjacent the combustion chamber, said reservoir chamber communicating with the combustion chamber through a narrow gap that permits controlled transmittal of pressure gradients between ~the combustion and reservoir chambers, and maintaining the isolated portion of air in the reservoir chamber free from substantiai contamination with fuel throughout the c~ycle;
e) igniting the fuel in the c~mbustion chamber to initiate its rapid reaction with immediately available oxygen near the end of the compression event, and thereby generating a continuous series of pressure shock ~
,, . .. _ . , , . ,.. _ .. _ . , .. . _ _ _ . .. . . _ .. _ 33~7 and expansion waves that traverse the combustion chamber and intersect the gap to produce pressure differentials between the combustion and reservoir chambers indepen- -dently of the total pressure in the combustion chamber and continuing throughout the reaction;
f) permitting and promoting by combustion and reservoir chamber geometry, and gap configuration, the cyclic rapid rebound and reentry of the shock waves across and through the gap at a rate to cause controlled pumping of oxygen into the combustion chamber from the reservoir chamber due to the said pressure differentials between the chambers throughout the combustion event;
g) permitting expansion of the combustion chamber during the expansion (work producing) event;
h) exhausting the combustion chamber near the end of-.the expansion event.
The invention also comprises, as an apparatus, an internal combustion engine including a variable vol-ume combustion chamber into which is admitted a fuel air charge during at least part of an intake and compression event forming part of the operating cycle of the engine, such charge being compressed during at least part of the intake and compression event, reacted during a combustion expansion event, and discharged during an exhaust event;
a piston means movable within a cylinder to vary its volume between the piston means and the head of the cyl-inder, the combustion chamber disposed between the piston means and the head of the cylinder; apparatus for ~ .
-4b-"
11~3337 independently supplying air and fuel to the combustion chamber in timed relationship with the movement of the piston, and inlet and exhaust valves for controlling admission of air and fuel into the combustion chamber through an intake port and discharging of combustion products from the combustion chamber through an exhaust port; apparatus for supplying substantially fuel-free air alone to the combustion chamber through the intake port during the initial part of each charge intake and compression event; apparatus for supplying fuel into the combustion chamber during a later part of each charge intake and compression event, whereby the proportion of fuel to air of each charge varies from excess fuel near the intake port to substantially fuel-free air near the piston at the beginning of the compression event; an air reservoir chamber; and a passageway between the combus-tion chamber and air reservoir chamber, said passageway providing restricted communication between said reser-voir chamber and combustion chamber, the combustion cham-ber, reservoir chamber and passageway having geometricconfigurations that permit transmittal through the pas-sageway of pressure shock waves incidental to a combus-tion event in the combustion chamber, and controlled pumping of air compressed by said shock waves from the reservoir chamber into the combustion chamber throughout the combustion event independently of total pressure in the combustion chamber or piston position due to the interaction of shock compression and expansion waves in the vicinity of the passageway.
-4c-~133337 The general purpose of the invention is to pro-vide a technique and apparatus to refine the Otto cycle of present internal combustion engines to operate on a heat balanced with pressure exchange cycle that has a time dependent process of combustion for improving engine per-formance and eliminating exhaust pollutants. A balancing chamber or air reservoir is provided that is in communica-tion with the combustion chamber of the internal combus-tion engine through a carefully designed gap; this chamber and gap allows pressure exchange operation on the compres-sion and power stroke of the piston independently of average pressure in the combustion chamber, and through-out the combustion reaction. On the admission or intake stroke, air and fuel are sequentially directly admitted via a valving arrangement into the combustion chamber.
The decrease in pressure caused by atmospheric pressure and the receding piston draws the air and fuel into the combustion chamber with a non-homogeneous charge of fuel and air, that is fuel rich at the top and virtually air at the bottom.
As compression starts,the air, with slight possible fuel contamination, is forced into the balancing chamber via the gap, increasing the pressure within the balancing chamber or reservoir as the pressure increases in the combustion chamber by the piston moving toward TDC. At ignition and burning of the locally fuel-rich mixture the reaction rate is so fast as to drive at quasi con-stant volume (compression) shock wave across the combus-tion chamber and through the gap into the balancing cham-ber or reservoir. Simultaneously, expansion waves from the reflected shock waves propagate back across the com-bustion chamber causing a pressure imbalance between thecombustion and reservoir chambers. The air in the reservoir chamber flows out into the combustion chamber through the gap for replenishing the air within the com-bustion chamber for sustaining complete combustion of the fuel. These expansion-compression waves interact through-out the combustion event and act in an oscillatory manner to draw or pump air from the reservoir chamber into the combustion chamber a substantial number of times. An additional effect of the alternating expansion-compres-sion waves is to cause stirring at the combustion zoneat supersonic through sonic speeds. Passage of weak shock waves into the combustion chamber will fractionate the fuel particles, effectively atomizing them for rapid _~
i~33337 combustion and thus eliminates the need of atomization of fuel by carburetors or like devicse as fuel -6a-is drawn in the combustion chamber.
The reservoir in the combustion chamber is formed by providing a radially extending lip centrally supported on the piston at a predetermined distance from the piston top surface. The peripheral dimension of the lip is slightly less than the diameter of the cylinder in which the piston is disposed so as to form a narrow spaced gap or passageway between the peripheral edge of the lip and the cylinder wall surface. The lip is heated by the burn-ing gases during the combustion cycle and acts as a heatexchanger to provide heating of gases in the combustion chamber during the compression cycle. Fuel is fed into the combustion chamber by means of a carburetor like or an injection like system of fuel supply via an intake manifold and intake valve arrangement. An air inlet is provided to permit atmospheric air to flow directly into the combu~stion chamber whenever the intake valve opens preceding delivery of the fuel to the combustion chamber to cause substantially fuel free air to be drawn into the combustion chamber ahead of the fuel charge.
For a complete understanding of the nature and features of an embodiment of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings wherein:
Figure 1 shows a pressure-volume diagram of the Otto cycle.
Figure 2 shows a pressure-volume diagram of the Diesel cycle.
Figure 3 shows a pressure-volume diagram of the heat balanced cycle.
Figure 4 is a diagrammatic representation of the -7a-1~33337 inventive appara~us installed in an internal combustion engine.
Figures 4a and 4b are diagrammatic representa-tions of pressure exchange cap shape.
Figure 5 (A-G) are illustrations of the sequence of operation of a heat balanced pressure exchange engine cycle.
Figure 6 is a diagrammatic representation of the inventive apparatus installed in a rotating internal combustion engine.
Figure 7 is a partial cross-sectional view of the rotor showing construction features of the balancing chamber or reservoir.
A comparison of the three ideal gas cycles, Otto -15 cycle, Diesel cycle and heat balanced cycle, follows to provide a better understanding of the heat balanced cycle technique utilized in operation of an internal combustion engine.
Referring now to the graph of Figure 1, that illustrates a simplified ideal pressure volume diagram of an internal combustion cycle known in the art as the constant volume or Otto cycle. Starting at point a, air at atmospheric pressure is compressed adiabatically in a cylinder to point b, heated at constant volume to point c, allowed to expand adiabatically to point d, and cooled at constant volume to a point a, after which the cycle is repeated. Line ab corresponds, e.g., to the compression stroke, bc to the chamical heat input by conversion of -8'~
~133337 chemical energy to thermal potential, cd to the working stroke, and da to the exhaust of an internal combustion engine. Vl and V2, are respectively the maximum and minimum volumes of air in the cylinder. The ratio of Vl/V2 is -8a-1~333;~7 compression r~tio of the internal combustion engine.
The heat input Q to the cycle is the quantity of heat supplied at constant volume along the line bc. The LQ exhaust heat, representing the quantity of loss of heat, is removed along da. The following simplified ~Gf~6Sf~ I
~ equations r~e~cn~ the efficiency of the Otto cycle:
(1) Q = heat added at constant volume LQ = rejected heat
Efficient conversion of energy into useful work has been the goal of engine designers since the creation of internal combustion engines utilizing the Otto cycle, i.e., - reciprocating~rotary, diesel engines and the like. In view of the scarcity and high cost of engine fuels, engineers and engine designers have been grappling with the fundamental problems of exhaust emission pollutants and increased fuel economy, yet striving to improve performance in these areas without sacrificing engine performance and efficiency. This has produced internal combustion engines that are operating in a critical compromise of fuel/air mixture composition, pressure and temperature that results in the engine generating and discharging harmful pollutants (CO, NOX and HC) in order to achieve adequate performance.
To deal with the NOX emissions designers have retarded spark and employed such devices as exhaust gas recirculation systems, each which decreases overall engine performance, with a resultant decrease in engine performance i:l33337 and which further cause increases in HC and CO emissions.
These increased HC and CO emissions must be eleared up by expensive catalytic converters which in turn require unleaded fuels.
Continued distortion of the eombustion proeess in internal combustion engines ean only result in a hodge-podge of engine eontrol devices that inerease engine manu-faeturing eost and result in low engine performance with low fuel economy.
Realization in both industry and the government that internal combustion engines will require drastie design changes to aehieve permissible government pollution standards has resulted in eonsiderable developmental efforts to inves-tigate the combustion proeess. These efforts have resulted in various teehniques such as ehanging the size and shape of the eombustion chamber, relocation of the spark within the eombus-tion ehamber, the use of multiple-source ignition sehemes and the use of stratified eharge designed eombustion ehambers.
Various modifieations of a eombustion ehamber shape into a hemispherieal ehambers with ehanges in eonventional spark loeations by designing spark plugs with extended gap designs has reduced HC emissions but this design has mechanieal manufacturing difficulties that far outweigh the amount of reduced emissions obtained.
Another technique presently being utilized is the use of a multiple-souree ignition configuration to eause ereation of a torch-like flame to shoot into a homogeneous-~1333;~
lean air/fuel mixture within the combustion chamber with the torch fueled by the same fuel as the main chamber. The torch ignition mixture is mechanically separated from the main chamber by an antechamber constructed in the engine head to open into the main combustion chamber.
Another popular scheme is the stratified charge engine (SC) configuration which can have numerous varia-tions. The basic idea of the SC engine involves introduction of a rich, easily ignitable mixture in the vicinity of the spark plug and a very lean mixture throughout the rest of the chamber, so as to have a differing air/fuel ratio in various areas within the cylinder chamber, rich in some lean in others, with the resulting overall air/fuel ratio considerably leaner than stoichiometric. The burning takes place in stages with a srnall volume of rich air/fuel mixture being ignited first to create a flame that spreads out into the cornbustion chamber charged with very lean air/fuel ; mixture causing ignition of these areas more thoroughly and burning them more completely than in conventional internal combustion engines.
The above are a few of the rnore pertinent de~ices of the numerous proposals that have been set forth to reduce pollution and increase engine and fuel performance. Each has some distinct disadvantage because of its interaction with other engine parameters inherent in the Otto cycle or diesel cycle engine. In view of this there has been created a need in the industry of an internal combustion engine operating on a gas cycle that has the characteristics of the Otto cycle but which has a process of combustion that is time controlled and will operate with the advan-tage of high compression ratio and fuel rich air ratios with the efficiency and total fuel oxidation of the diesel without its disadvantages of high pressure, high temperature and knock tendency.
Accordingly, the present invention has been developed to overcome the specific shortcomings of the above known and similar techniques and to provide an improved apparatus and technique for generating a heat balanced cycle for internal combustion engines with per-formance, pollution characteristics, and a multifuel burning capability that is not present nor possible with conventional Otto or diesel cycle engines.
The present invention, in its broadest aspect, comprises a time dependent process for carrying out an energy conversion cycle involving converting chemical energy into thermal potential by utilizing the pressure waves generated during the rapid reaction of a combus-tible fuel in the presence of oxygen and using the ther-mal potential for producing useful work in the combustion chamber of a piston type internal combustion engine oper-ating over periodic cycles that each include an intake, compression, expansion (work producing) and exhaust event.
The process further comprises, for each operating cycle of the engine, the steps of:
a) supplying air alone into a combustion chamber of the engine during the initial portion of the intake event.whil~ the volume o~ t~e combustio~ cha~ber is increasingi b) .addin.g.~uel intQ.the combustion chamber during a later part of the charge intake an.d compression eYent, the total quan.tity o~ fubl bein~ selected to provide a reaction that will rapidl~ produce a predetexmined thermal potential and a predetermined maximum pressure in the combustion~ chamber;
c) increasing the temperature o~ the total ~uantity of air and fuel admitted durin.g the c~cle by compressing at least the air during.the c.ompression eventi d) partially isolating a portion of the initially supplied air ~rom substantially all of the later supplied fuel during the charge intake:and compression event by placing a portion of the initially supplied air in a reservoir chamber located adjacent the combustion chamber, said reservoir chamber communicating with the combustion chamber through a narrow gap that permits controlled transmittal of pressure gradients between ~the combustion and reservoir chambers, and maintaining the isolated portion of air in the reservoir chamber free from substantiai contamination with fuel throughout the c~ycle;
e) igniting the fuel in the c~mbustion chamber to initiate its rapid reaction with immediately available oxygen near the end of the compression event, and thereby generating a continuous series of pressure shock ~
,, . .. _ . , , . ,.. _ .. _ . , .. . _ _ _ . .. . . _ .. _ 33~7 and expansion waves that traverse the combustion chamber and intersect the gap to produce pressure differentials between the combustion and reservoir chambers indepen- -dently of the total pressure in the combustion chamber and continuing throughout the reaction;
f) permitting and promoting by combustion and reservoir chamber geometry, and gap configuration, the cyclic rapid rebound and reentry of the shock waves across and through the gap at a rate to cause controlled pumping of oxygen into the combustion chamber from the reservoir chamber due to the said pressure differentials between the chambers throughout the combustion event;
g) permitting expansion of the combustion chamber during the expansion (work producing) event;
h) exhausting the combustion chamber near the end of-.the expansion event.
The invention also comprises, as an apparatus, an internal combustion engine including a variable vol-ume combustion chamber into which is admitted a fuel air charge during at least part of an intake and compression event forming part of the operating cycle of the engine, such charge being compressed during at least part of the intake and compression event, reacted during a combustion expansion event, and discharged during an exhaust event;
a piston means movable within a cylinder to vary its volume between the piston means and the head of the cyl-inder, the combustion chamber disposed between the piston means and the head of the cylinder; apparatus for ~ .
-4b-"
11~3337 independently supplying air and fuel to the combustion chamber in timed relationship with the movement of the piston, and inlet and exhaust valves for controlling admission of air and fuel into the combustion chamber through an intake port and discharging of combustion products from the combustion chamber through an exhaust port; apparatus for supplying substantially fuel-free air alone to the combustion chamber through the intake port during the initial part of each charge intake and compression event; apparatus for supplying fuel into the combustion chamber during a later part of each charge intake and compression event, whereby the proportion of fuel to air of each charge varies from excess fuel near the intake port to substantially fuel-free air near the piston at the beginning of the compression event; an air reservoir chamber; and a passageway between the combus-tion chamber and air reservoir chamber, said passageway providing restricted communication between said reser-voir chamber and combustion chamber, the combustion cham-ber, reservoir chamber and passageway having geometricconfigurations that permit transmittal through the pas-sageway of pressure shock waves incidental to a combus-tion event in the combustion chamber, and controlled pumping of air compressed by said shock waves from the reservoir chamber into the combustion chamber throughout the combustion event independently of total pressure in the combustion chamber or piston position due to the interaction of shock compression and expansion waves in the vicinity of the passageway.
-4c-~133337 The general purpose of the invention is to pro-vide a technique and apparatus to refine the Otto cycle of present internal combustion engines to operate on a heat balanced with pressure exchange cycle that has a time dependent process of combustion for improving engine per-formance and eliminating exhaust pollutants. A balancing chamber or air reservoir is provided that is in communica-tion with the combustion chamber of the internal combus-tion engine through a carefully designed gap; this chamber and gap allows pressure exchange operation on the compres-sion and power stroke of the piston independently of average pressure in the combustion chamber, and through-out the combustion reaction. On the admission or intake stroke, air and fuel are sequentially directly admitted via a valving arrangement into the combustion chamber.
The decrease in pressure caused by atmospheric pressure and the receding piston draws the air and fuel into the combustion chamber with a non-homogeneous charge of fuel and air, that is fuel rich at the top and virtually air at the bottom.
As compression starts,the air, with slight possible fuel contamination, is forced into the balancing chamber via the gap, increasing the pressure within the balancing chamber or reservoir as the pressure increases in the combustion chamber by the piston moving toward TDC. At ignition and burning of the locally fuel-rich mixture the reaction rate is so fast as to drive at quasi con-stant volume (compression) shock wave across the combus-tion chamber and through the gap into the balancing cham-ber or reservoir. Simultaneously, expansion waves from the reflected shock waves propagate back across the com-bustion chamber causing a pressure imbalance between thecombustion and reservoir chambers. The air in the reservoir chamber flows out into the combustion chamber through the gap for replenishing the air within the com-bustion chamber for sustaining complete combustion of the fuel. These expansion-compression waves interact through-out the combustion event and act in an oscillatory manner to draw or pump air from the reservoir chamber into the combustion chamber a substantial number of times. An additional effect of the alternating expansion-compres-sion waves is to cause stirring at the combustion zoneat supersonic through sonic speeds. Passage of weak shock waves into the combustion chamber will fractionate the fuel particles, effectively atomizing them for rapid _~
i~33337 combustion and thus eliminates the need of atomization of fuel by carburetors or like devicse as fuel -6a-is drawn in the combustion chamber.
The reservoir in the combustion chamber is formed by providing a radially extending lip centrally supported on the piston at a predetermined distance from the piston top surface. The peripheral dimension of the lip is slightly less than the diameter of the cylinder in which the piston is disposed so as to form a narrow spaced gap or passageway between the peripheral edge of the lip and the cylinder wall surface. The lip is heated by the burn-ing gases during the combustion cycle and acts as a heatexchanger to provide heating of gases in the combustion chamber during the compression cycle. Fuel is fed into the combustion chamber by means of a carburetor like or an injection like system of fuel supply via an intake manifold and intake valve arrangement. An air inlet is provided to permit atmospheric air to flow directly into the combu~stion chamber whenever the intake valve opens preceding delivery of the fuel to the combustion chamber to cause substantially fuel free air to be drawn into the combustion chamber ahead of the fuel charge.
For a complete understanding of the nature and features of an embodiment of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings wherein:
Figure 1 shows a pressure-volume diagram of the Otto cycle.
Figure 2 shows a pressure-volume diagram of the Diesel cycle.
Figure 3 shows a pressure-volume diagram of the heat balanced cycle.
Figure 4 is a diagrammatic representation of the -7a-1~33337 inventive appara~us installed in an internal combustion engine.
Figures 4a and 4b are diagrammatic representa-tions of pressure exchange cap shape.
Figure 5 (A-G) are illustrations of the sequence of operation of a heat balanced pressure exchange engine cycle.
Figure 6 is a diagrammatic representation of the inventive apparatus installed in a rotating internal combustion engine.
Figure 7 is a partial cross-sectional view of the rotor showing construction features of the balancing chamber or reservoir.
A comparison of the three ideal gas cycles, Otto -15 cycle, Diesel cycle and heat balanced cycle, follows to provide a better understanding of the heat balanced cycle technique utilized in operation of an internal combustion engine.
Referring now to the graph of Figure 1, that illustrates a simplified ideal pressure volume diagram of an internal combustion cycle known in the art as the constant volume or Otto cycle. Starting at point a, air at atmospheric pressure is compressed adiabatically in a cylinder to point b, heated at constant volume to point c, allowed to expand adiabatically to point d, and cooled at constant volume to a point a, after which the cycle is repeated. Line ab corresponds, e.g., to the compression stroke, bc to the chamical heat input by conversion of -8'~
~133337 chemical energy to thermal potential, cd to the working stroke, and da to the exhaust of an internal combustion engine. Vl and V2, are respectively the maximum and minimum volumes of air in the cylinder. The ratio of Vl/V2 is -8a-1~333;~7 compression r~tio of the internal combustion engine.
The heat input Q to the cycle is the quantity of heat supplied at constant volume along the line bc. The LQ exhaust heat, representing the quantity of loss of heat, is removed along da. The following simplified ~Gf~6Sf~ I
~ equations r~e~cn~ the efficiency of the Otto cycle:
(1) Q = heat added at constant volume LQ = rejected heat
(2) ~Otto = AQ ~ LQ
~Otto = efficiency Reference should now be made to Figure 2 which illus-trates a Diesel cycle of an internal combustion engine for an understanding of its operation with respect to the operation of the Otto cycle explained above. The idealized air-Diesel cycle starting at point a, air is compressed adiabatically to point b, heated at constant pressure to point c, expanded adiabatically to point d, and cooled at constant volume to point a. Since there is no fuel in the cylinder of a Diesel engine on the compression stroke, preignition cannot occur and the compression ratios may be much higher than that of an internal combustion engine operating on the Otto cycle. Therefore, somewhat higher efficiencies can be obtained than those obtained for the Otto cycle. The following simplified equations define the various parameters of the Diesel engine cycle:
~Otto = efficiency Reference should now be made to Figure 2 which illus-trates a Diesel cycle of an internal combustion engine for an understanding of its operation with respect to the operation of the Otto cycle explained above. The idealized air-Diesel cycle starting at point a, air is compressed adiabatically to point b, heated at constant pressure to point c, expanded adiabatically to point d, and cooled at constant volume to point a. Since there is no fuel in the cylinder of a Diesel engine on the compression stroke, preignition cannot occur and the compression ratios may be much higher than that of an internal combustion engine operating on the Otto cycle. Therefore, somewhat higher efficiencies can be obtained than those obtained for the Otto cycle. The following simplified equations define the various parameters of the Diesel engine cycle:
(3) Q = heat added at a constant pressure LQ = heat rejected ` - 1133337 B~ - LQ
~4) ~Diesel = ~Q
~Diesel = efficiency The heat balanced cycle is illustrated by the pressure-volume diagram of Figure 3 drawn from the same heat input Q. Line ab corresponds to the adiabatic compression bcc' shows the addition of heat with bc correspondin~ to the part of the heat added at constant volume and cc' to the remaining heat at constant pressure, c'd is the adiabatic expansion and da the exhaust. Reference to the diagram shows, the quantity of heat Q, added is now divided into two heat quantities, AQ at a constant volume and BQ at a constant pressure, thus maintaining the same quantity of heat Q except that this parameter is divided into two events.
The following simplified equations set forth the relationship of the operating parameters of the heat balanced cycle:
i (5) AQ + BQ = Q
AQ is heat added at a constant volume BQ is heat added at a constant pressure Therefore:
(6) A + B = 1 The balancing ratio is defined as (7) ~ = A-therefore, ~ ) A = ~ and ~3 = ~-~-F
The Otto cycle is the limit when A is 1 and the Diesel cycle is the limit when A = O. The variation of ~ will combine the Otto and Diesel cycles. The efficiency of the ~i33337 heat balanced cycle is expressed as:
Q - LQ AQ+BQ-L[AQ]-I,[BQ]
( 9 ) n ~ = Q = ~:
n - AQ - L[AQ] BQ _ L~BQ3 Q Q
n~ ~ A AQ - L_QA] _ BQ - LlBQ]
n = AQ - L[AQ] + BQ - L~QB]
(10) n = A AQ L[QA] + B Q BQ
Referring to the efficiency of the cycles, n~ AnV + snp;
nV = 1 - (1) ; n = 1 _ (1 ) k ~ i ~P3~ 1 Calling v = ~p J k and rB = v.r.
The efficiency of the Controlled heat balanced cycle is :
(11) n = 1 _ (l)k 1 1 ~ (1) k-l a~ - 1 ]
The efficiency limits of the heat balanced cycle are those of the Otto and Diesel cycles with the same design compression ratio, or:
fi~ k-l ~
n~ r-) when ~ or A > 1, Otto cycle (1) k-l k 1) ~ whent~ or A O,Diesel cycle 11333~7 Referring now to the drawing of Figure 4, that shows a diagrammatic representation of an embodiment of a balancin~ chamber or reservoir formed on a piston for refining the Otto cycle of an internal combustion engine to function on a heat balanced with pressure exchange four stroke cycle. An engine housing or block 10 forms a cham-ber for a reciprocating piston 14 that is attached by means of wrist pin 13 to connecting rod 11. A crankshaft 12 is coupled to connecting rod 11 by means of a journal 1 10 bearing to permit reciprocating motion of piston 14 to be transformed into rotating mechanical energy that may be utilized to drive machinery,an automobile or like - device, for providing work output.
The inner wall of engine housing 10, adjacent the wall of piston 14, forms a cylinder wall 36 that is in contact with rings 15 to provide a gas pressure tight seal between moving piston 14 and cylinder wall 36 to prevent the escape of high pressure gases generated by burning fuel in variable volume combustion chamber 38.
Attached to engine housing 10 is cylinder head 37 form-ing a closed combustion chamber between the uppermost portion of housing 10 and the inner recessed portions of the head. Cylinder head 37 has two ports, exhaust and intake, that open and close by means of operation of exhaust valve 23 and intake valve 28 arrangements, respectively. These valves are opened and closed in time sequence with the reciprocating movement of piston 14 by means of valve lifters, push rods, camshafts, and the -1~
. --~133337 like, not shown, to allow the internal combustion engine to operate on a four stroke Otto cycle.
.
-12a-~i33337 Attached to cylinder head 37 is an intake manifold 27 that forms a closed passageway for allowing the flo~
of fuel and atmospheric air to combustion chamber 38. An air filter 33 is provided to filter air entering a carburetor like device 29 through venturi 35, that has nozzle or port 41 attached to fuel container 32 via a valve and fuel line 31. Air flowing through venturi 35 creates a vacuum to draw fuel from fuel container 32 into combustion chamber 38. Carburetor like device 29 may be replaced by other fuel delivery devices, such as fuel injectors or like devices, known to those skilled in the art. A throttle plate 34 attached to a linkage arrangement, not shown, controls the amount of vacuum through venturi 35 by restricting air flow through the venturi for controlling the amount of fuel delivered to the engine. An additional linkage arrangement, now shown, may be coupled to control air flow through air inlet 26 to further control the amount of atmospheric air delivered to the engine during its operation. Air inlet 2S, open to atmospheric air, permits 2G a large volume of air to be delivered to combustion chamber 38 on the intake stroke of the engine prior to delivery of any fuel laden air charge. This air vent is positioned adjacent intake valve 28, as shown, but may be located at any position between carburetor device 29, a fuel ~ or other fuel deliverying device, and the intake valve port of intake valve 28.
A spark plug 24 is attached in cylinder head 37 in a conventional manner, and operates to deliver an electric ,. . .
li33337 volta~e to create a spark in combustion chamber 38 in proper timing sequence with other engine elements to ig-nite fuel within combustion chamber 38, for creating power to drive piston 1~.
A cap like element 19 is centrally attached to piston 14 at its surface face by means of a rivet, bolt or like fastening device. This cap like portion 19 is of mushroom-like shape with a thickened cylindrical stalk-like center portion that has one of its circular face sur-faces in contact with the circular surface of piston-14.
Integral with the other circular surface of stem-like portion 17 is a relatively thin, radially extending cylin-- drical lip 20 having a periphery that is spaced a pre-determined distance from cylinder wall 36 to form a gap 18. The remaining exposed surface of piston 14, the dimensional height of the stem-like portion 17, and inner surface of lip 20, form a chamber 16 open to the combus-tion chamber by the clearance gap or passageway 18, de-fined by the inner cylinder wall surface and the edge of lip 20 which may extend the entire outer peripheral distance of top 20 or some predetermined portion, thereof.
Chamber 16 is sealed on its lower side by means of piston rings 15. The reservoir 16 is thus formed by a portion of the top surface of piston 1~, an inner surface portion of lip 20, the cylinder sidewall, and the cylindrical wall of stem element 17, and communicates with the combustion chamber through the gap 18.
Although cap like element 19 is described as f fastened to the piston it is to be understood that cap 19 may be integral with piston 19 and the chamber may be machined or shaped in the piston in the same manner as piston ring grooves. Additionally, it is to be under-stood that although -14a-' 11333~7 chamber 16 is shown as formed with parallel sides, the underside of the lip 20 may be sloped towards the piston top as shown in Figure 4A or constructed with diametri-cally opposing sides to form a balancing chamber or reser-voir 16 without departing from the spirit of the invention.Figures 4A and 4B show cap configurations and combustion chamber geometries, as well as volumes A and B of the combustion chamber at minimum volume and reservoir cham-ber volume, respectively.
The principle of operation of an internal combus-tion engine on the heat balanced-pressure exchange cycle may be best understood by reference to Figure 3 which shows a p-v diagram of the idealtheoretical heat balanced-pressure exchange cycle and Figure 5 (A through G) that illustrates the operating sequence of an embodiment of a heat balanced-pressure exchange engine cycle during its four stroke op~eration. Figure 5A illustrates piston 14 completing an exhaust stroke with the exhaust valve 23 about to close, with piston 14 moving upward forcing the flow of the burned gases, depicted by arrows, out through the exhaust valve port through a passageway in exhaust manifold 22. At this point intake valve 28 is closed and no air or fuel is flowing through intake manifold passage-way 27. Air vent 26 located adjacent the inlet valve port has allowed a charge of fuel free air at atmospheric pres-~ sure to fill the entire volume of the intake passageway - . in the intake manifold up to and through venturi 35. As intake valve 28 opens, best shown with reference to Figure -15 ~
1~33337 5B, piston 14 positioned near top dead center (TDC) moves~
downwardly enlarging the space at the top of the cylinder ; atmospheric air pressure and a decrease in air pressure due to the receding piston draws an inflow of air filling the space in the cylinder. The inflow of air first enter-ing the combustion chamber 38 is the charge of air within the -15a-intake manifold passageway that is replenished somewhat by air vent 26 before sufficient vacuum is generated in venturi 35 to next draw a charge of rich fuel laden air into the cylinder chamber, after the air has first been admitted. As the piston reaches its lowest position, bottom dead center (BDC), the cylinder space has been filled with a charge varying from rich in fuel near the top to substantially fuel-free near the cap 19 and with-in reservoir 16 As piston 14 reaches its lowermost point of travel within the cylinder, (BDC), the pressure inside the cylinder is still less than atmospheric pressure and additional air and fuel can enter the cylinder, even after the cylinder begins to move upward. Therefore, the intake valve 26 does not close until the crankshaft arm ll-is a predetermined amount of travel past BDC; this is best shown by the illustration of Figure ~C.
After the intake stroke, best shown by reference ~, to Figure 5D, both valves (23,28) are closed and piston 14 moves upward on the compression stroke. Piston 14 ! compresses and heats the air and fuel in the combustion and reservoir chambers. Throughout the upward movement of piston 14, an accumulation of air with possible slight fuel content occurs in reservoir 16 due to slight dif-fusion of fuel through the charge. The air in reservoir 16, however, is still maintained substantially fuel-free and outside flammability limits throughout the cycle.
During operation of the engine, the burning gases heat l~or~
il33337 cap 19 which acts as a heat exchanger and causes heating of the --16a-1~3333~
air and fuel charge during compression as the charge flows' over and around it, thus providing additional heating of the gases.
Figure 5E illustrates the initiation of combus-tion with piston 14 near TDC and both valves closed.
Piston 14 has compressed the air/fuel charge to give greater force to the expanding gases when combustion (ignition of the fuel) takes place. At this point, a spark ignites the fuel of the charge and it reacts with immediately available oxygen with an explosive force tending to drive piston 14 downward and expand the com-bustion chamber as the pressure in the combustion chamber increases. The pressure increase at quasi-constant volume (combustion) shown as line bc in Figure 3, generates and drives compression (pressure) shock waves across the com-bustion chamber and into reservoir 16, via passageway 18, momentarily co~mpressing the air in the reservoir 16 against its internal walls. Simultaneously, the expansion - waves created by interaction of reflected shock waves and the combustion front propagate in a reverse direction into the space between the top of cap 19 and cylinder head 37 momentarily decreasing the pressure in combustion chamber 38, particularly near the gap. A pressure imbalance in the gap area occurs due to the shock compression of the very lean substantially fuel free air in reservoir 16 to pressures greater than local pressure in combustion chamber 38, causing the air within chamber 16 to flow out via passageway 18 into combustion chamber 38, in which a ! `- -17- ~
pressure imbalance has occurred. This condition is illustrated with reference to Figure 5F which shows outflow of the heated shock compressed air from reser-voir 16 via passageway 18 into combustion chamber 38 during the compression event. The pressure imbalance condition occurs as a time dependent process and even though the average pressure in the combustion chamber may be higher than the average pressure in the reservoir chamber. The nature of the interaction of shock and expansion waves is such that the pressure imbalance is expected to be localized along the gap area 18.
-17a-113333~
The interaction of the reservoir and the com-bustion chamber is crucially important for proper heat balanced-pressure exchange engine operation. To provide the necessary oscillating action of the compression and expansion waves during combustion of the fuel as they successively interact within the combustion zone and to provide a pumping action to force substantially fuel free air from chamber 16 requires certain dimensional interrelationship of combustion chamber volume A (at mir.imum volume), reservoir chamber volume B and passage-way 18 (Figures 4A and 4B) for a particular engine con-figuration. In an internal combustion engine the volu-metric balancing ratio of B/A is normally in a range of from .20 to 3. The passageway opening 18 should be .05 to .200 in. (1.27-5.08 mm) measured across its narrow-dimension. The lower value typical for standard size cylinder of automobile engines, the higher value typical for compression ignition engines. The gap, however, must be capable of permitting controlled pas-sage of the oscillating shock waves into and out of thereservoir, to permit controlled pressure imbalances to occur across the gap, and to control the rate of flow of oxygen through the gap from the reservoir chamber in response to the fluctuating pressure imbalances, so that oxygen will be supplied to the combustion chamber in controlled amounts entirely throughout the combustion event, quite independently of overall average pressure conditions in the combustion chamber, or piston position, in the manner of a pumping action.
-18 ~ -Table ] se-ts forth the pressures and tempera-tures present at designated points on the pressure-volume ; curves of Figures 1 and 3 in comparison of two identical engines; one operating on a heat balanced cycle and the other on an Otto cycle. The compression ratio selected ~y ) was 8 to 1.
-18a-Otto Cycle : Heat Balanced Cycle = 8 ~ = 0 : ~ = 8 ~ = .43 . _ -- ---- -- - :
State : Psia : T R . Psia : T R State a 14.7 600 14.7 600 a a 240 1200 : 240 1200 b c 1000 4980 670 2800 c 670 3070 c' .~
A two-stroke engine cycle that has a similar ' 10 combustion cycle as the four stroke but that requires only one revolution of the crankshaft can also be modi-fied to operate on a heat balanced cycle.
The compr~ssion stroke of the working piston draws a fresh supply of air into the crankcase. On the next compression stroke this air is compressed in the combustion chamber-and fuel is later injected into the combustion cha~mber. A cap structurally similar to the one described above operates in the same manner to sustain combustion during the burning of fuel-air charge in the - 20 combustion chamber to cause the engine cycle to be refined to a heat balanced cycle.
The described apparatus used to modify recipro-cating internal combustion engines, that is, to produce power by pistons moving up and down in cylinders for driving a crankshaft which changes the up-and-down motion to rotary motion, may also be used to improve performance of rotary engines; that is, engines in which power is produced by the action of a rotor turning inside an oval shaped combustion chamber, e.g. the WANKLE engine.
The conventional piston is replaced with a three-- sided rotor 60, best shown with reference to Figure 6.
Rotor combustion pockets are rotated pas~t an intake port 51, a spark plug 61 and an exhaust port 67 to cause rotating combustion. The combustion cycle follows the familiar pattern of the conventional four-stroke-cycle, Otto cycle, of an internal combustion engine in the sequence of events-intake, compression, power and exhaust, as shown in the pressure-volume graph illustrated in Figure 1. Modification of the engine with reservoirs will refine its cycle so that it operates on a heat balanced pressure exchange cycle, illustrated in Figure 3, in a similar manner as the explana-tion above with respect to the reciprocating engine.
Figure 6 illustrates a rotary engine 50 having a rotor 60 that has been modified with a reservoir 66. The reservoir 66 is formed by partial closing of the normal depressions 68 in the rotor 60 with a shaped plate like member 63, or cap, that extends across depression 68, best shown with reference to Figure 7. An opening or passageway 64 is formed by a surface of the cup-like depression and an elongated lip-like, projection 71 formed on one edge of closure element 71. hip-like portion projects inwardly toward the depression to form a tapered restricted ope~ing defining a passageway at the mouth of balancing chamber 66.
A substantially smaller opening 65 is located at the rear ~of reservoir 66 so that the reservoir 66 has a half circle segmental cross-sectional area that tapers gradually in extending from lip 71 to opening 65. It is to be understood ~i33337 that other shaped chambers may be used as long as the balancing ratio of the volumes, formula 7, is considered, Although only a single reservoir is shown on rotor 60, it is to be understood that a reservoir of similar design is positioned on each of the other two rotor lobes shown.
A shaft 62 with appropriate internal and external gearing is connected to rotor 60 for transmission of power to an external load.
Rotary engine 50 has two ported openings, intake 51 and exhaust 67 r for intake and exhaust of gases, respectively.
An intake tubular passage 49 formed with a venturi section 48 is attached to the housing of engine 50 and has its other end open to atmospheric air by means of a filter 43. A fuel supply tank 44 attached by means of fuel line 45 to extend adjacent to venturi 48 draws fuel into engine 50 by a lowered pressure area caused by air flow through venturi 48. An additional air vent 47, closed by filter 46 is positioned between the inlet port 51 and fuel port for supply of atmospheric air to passageway 49. It is to be understood that other fuel supply means such as fuel ejectors or like fuel delivery devices may be used for supplying fuel to rotary engine 50. ~
~-~ In operation, rotor ~ revolves around its own geometric center; at the same time, internal gears 62, 6~) within rotor 5~, move its center in an eccentric path.
The result is all three corners of the rotor lobes are in ~0 constant contact with the housing walls. As rotor ~
re~olves, the three rotor lobes form three moving combustion ~i33337 chambers that are constantly changing in volume. This action in each of the three combustion chambers brings about the intake, compression, power and exhaust effect that is similar to the four-stroke cycle of the recipro-cating engine.
Figure 6 illustrates the rotor 60 at intake stroke in the combustion chamber of the rotor lobes equipped with balancing chamber 66. The intake port 51 has been uncovered by moving rotor and the combustion chamber begins to fill with air in passageway 49 and additional atmospheric air supplied by air vent 47.
Immediately thereafter, a fuel rich charge is supplied by means of venturi 48, fuel line 45 and air flowing through air filter 43. The first lean air in the com-bustion chamber flows in reservoir 66 and as the air-fuel charge continues to fill the combustion chamber the fuel rich air extends in a rich to lean mixture from the combustion housing to the rotor surface. As - rotor 50 continues it closes the intake port 51 and the combustion chamber contains the maximum air-fuel charge.
Continued rotation of the rotor decreases the volume of the combustion chamber, compressing the air-fuel charge and forcing air into the reservoir 66. A spark plug 61 ignites the compressed charge of gas causing expansion of the gases. Compression shock waves are driven into balancing chamber 66 across gap 18. At the same time the expansion waves created by interaction of reflected shock waves and the combustion front propagate into the -2 ~
1~33337 combustion chamber. Because a pressure imbalancing occurs due to the shock waves the -22a-air within balancing chamber will flow through the gap in a regulated manner into the combustion chamber to supply air to sustain more complete burning. This oscillating action of compression-expansion continues S a multiplicity of times throughout the combustion cycle and thus supplies air during the entire combustion cycle in timed sequential relationship with the turning of rotor 60 dependent on ratio of-the volume of the combus-tion chamber with respect to the volume of the reservoir and the size of passageway 64. The action of the bal-ancing is to supply air and this air is such a lean mixture that no combustion of gases takes place in reservoir 66.
As can be seen from the above description, the present invention provides an apparatus and techniques for providing control of pressure and temperature in the operation of an internal combustion engine either reci-procating or rotary of spark or compression ignition and two or four stroke configuration in a refined thermo-dynamic cycle by providing a balancing chamber and pas-sageway or gap parameters that have a relationship with the combustion chamber volume of the engine. Variation of these parameters within certain limits will allow an engine to operate on a balanced heat cycle that has many of the advantages of both the Otto and Diesel cycles with few or none of their disadvantages. In particular an engine operating on a balanced cycle has better oper-ating engine performance, overall engine speed and load ~' , ~1333~7 conditions, better fuel economy and less emission of - pollutants. These are some of the advantages not found in the prior art technique and devices mentioned -23a-11~3337 above.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
~4) ~Diesel = ~Q
~Diesel = efficiency The heat balanced cycle is illustrated by the pressure-volume diagram of Figure 3 drawn from the same heat input Q. Line ab corresponds to the adiabatic compression bcc' shows the addition of heat with bc correspondin~ to the part of the heat added at constant volume and cc' to the remaining heat at constant pressure, c'd is the adiabatic expansion and da the exhaust. Reference to the diagram shows, the quantity of heat Q, added is now divided into two heat quantities, AQ at a constant volume and BQ at a constant pressure, thus maintaining the same quantity of heat Q except that this parameter is divided into two events.
The following simplified equations set forth the relationship of the operating parameters of the heat balanced cycle:
i (5) AQ + BQ = Q
AQ is heat added at a constant volume BQ is heat added at a constant pressure Therefore:
(6) A + B = 1 The balancing ratio is defined as (7) ~ = A-therefore, ~ ) A = ~ and ~3 = ~-~-F
The Otto cycle is the limit when A is 1 and the Diesel cycle is the limit when A = O. The variation of ~ will combine the Otto and Diesel cycles. The efficiency of the ~i33337 heat balanced cycle is expressed as:
Q - LQ AQ+BQ-L[AQ]-I,[BQ]
( 9 ) n ~ = Q = ~:
n - AQ - L[AQ] BQ _ L~BQ3 Q Q
n~ ~ A AQ - L_QA] _ BQ - LlBQ]
n = AQ - L[AQ] + BQ - L~QB]
(10) n = A AQ L[QA] + B Q BQ
Referring to the efficiency of the cycles, n~ AnV + snp;
nV = 1 - (1) ; n = 1 _ (1 ) k ~ i ~P3~ 1 Calling v = ~p J k and rB = v.r.
The efficiency of the Controlled heat balanced cycle is :
(11) n = 1 _ (l)k 1 1 ~ (1) k-l a~ - 1 ]
The efficiency limits of the heat balanced cycle are those of the Otto and Diesel cycles with the same design compression ratio, or:
fi~ k-l ~
n~ r-) when ~ or A > 1, Otto cycle (1) k-l k 1) ~ whent~ or A O,Diesel cycle 11333~7 Referring now to the drawing of Figure 4, that shows a diagrammatic representation of an embodiment of a balancin~ chamber or reservoir formed on a piston for refining the Otto cycle of an internal combustion engine to function on a heat balanced with pressure exchange four stroke cycle. An engine housing or block 10 forms a cham-ber for a reciprocating piston 14 that is attached by means of wrist pin 13 to connecting rod 11. A crankshaft 12 is coupled to connecting rod 11 by means of a journal 1 10 bearing to permit reciprocating motion of piston 14 to be transformed into rotating mechanical energy that may be utilized to drive machinery,an automobile or like - device, for providing work output.
The inner wall of engine housing 10, adjacent the wall of piston 14, forms a cylinder wall 36 that is in contact with rings 15 to provide a gas pressure tight seal between moving piston 14 and cylinder wall 36 to prevent the escape of high pressure gases generated by burning fuel in variable volume combustion chamber 38.
Attached to engine housing 10 is cylinder head 37 form-ing a closed combustion chamber between the uppermost portion of housing 10 and the inner recessed portions of the head. Cylinder head 37 has two ports, exhaust and intake, that open and close by means of operation of exhaust valve 23 and intake valve 28 arrangements, respectively. These valves are opened and closed in time sequence with the reciprocating movement of piston 14 by means of valve lifters, push rods, camshafts, and the -1~
. --~133337 like, not shown, to allow the internal combustion engine to operate on a four stroke Otto cycle.
.
-12a-~i33337 Attached to cylinder head 37 is an intake manifold 27 that forms a closed passageway for allowing the flo~
of fuel and atmospheric air to combustion chamber 38. An air filter 33 is provided to filter air entering a carburetor like device 29 through venturi 35, that has nozzle or port 41 attached to fuel container 32 via a valve and fuel line 31. Air flowing through venturi 35 creates a vacuum to draw fuel from fuel container 32 into combustion chamber 38. Carburetor like device 29 may be replaced by other fuel delivery devices, such as fuel injectors or like devices, known to those skilled in the art. A throttle plate 34 attached to a linkage arrangement, not shown, controls the amount of vacuum through venturi 35 by restricting air flow through the venturi for controlling the amount of fuel delivered to the engine. An additional linkage arrangement, now shown, may be coupled to control air flow through air inlet 26 to further control the amount of atmospheric air delivered to the engine during its operation. Air inlet 2S, open to atmospheric air, permits 2G a large volume of air to be delivered to combustion chamber 38 on the intake stroke of the engine prior to delivery of any fuel laden air charge. This air vent is positioned adjacent intake valve 28, as shown, but may be located at any position between carburetor device 29, a fuel ~ or other fuel deliverying device, and the intake valve port of intake valve 28.
A spark plug 24 is attached in cylinder head 37 in a conventional manner, and operates to deliver an electric ,. . .
li33337 volta~e to create a spark in combustion chamber 38 in proper timing sequence with other engine elements to ig-nite fuel within combustion chamber 38, for creating power to drive piston 1~.
A cap like element 19 is centrally attached to piston 14 at its surface face by means of a rivet, bolt or like fastening device. This cap like portion 19 is of mushroom-like shape with a thickened cylindrical stalk-like center portion that has one of its circular face sur-faces in contact with the circular surface of piston-14.
Integral with the other circular surface of stem-like portion 17 is a relatively thin, radially extending cylin-- drical lip 20 having a periphery that is spaced a pre-determined distance from cylinder wall 36 to form a gap 18. The remaining exposed surface of piston 14, the dimensional height of the stem-like portion 17, and inner surface of lip 20, form a chamber 16 open to the combus-tion chamber by the clearance gap or passageway 18, de-fined by the inner cylinder wall surface and the edge of lip 20 which may extend the entire outer peripheral distance of top 20 or some predetermined portion, thereof.
Chamber 16 is sealed on its lower side by means of piston rings 15. The reservoir 16 is thus formed by a portion of the top surface of piston 1~, an inner surface portion of lip 20, the cylinder sidewall, and the cylindrical wall of stem element 17, and communicates with the combustion chamber through the gap 18.
Although cap like element 19 is described as f fastened to the piston it is to be understood that cap 19 may be integral with piston 19 and the chamber may be machined or shaped in the piston in the same manner as piston ring grooves. Additionally, it is to be under-stood that although -14a-' 11333~7 chamber 16 is shown as formed with parallel sides, the underside of the lip 20 may be sloped towards the piston top as shown in Figure 4A or constructed with diametri-cally opposing sides to form a balancing chamber or reser-voir 16 without departing from the spirit of the invention.Figures 4A and 4B show cap configurations and combustion chamber geometries, as well as volumes A and B of the combustion chamber at minimum volume and reservoir cham-ber volume, respectively.
The principle of operation of an internal combus-tion engine on the heat balanced-pressure exchange cycle may be best understood by reference to Figure 3 which shows a p-v diagram of the idealtheoretical heat balanced-pressure exchange cycle and Figure 5 (A through G) that illustrates the operating sequence of an embodiment of a heat balanced-pressure exchange engine cycle during its four stroke op~eration. Figure 5A illustrates piston 14 completing an exhaust stroke with the exhaust valve 23 about to close, with piston 14 moving upward forcing the flow of the burned gases, depicted by arrows, out through the exhaust valve port through a passageway in exhaust manifold 22. At this point intake valve 28 is closed and no air or fuel is flowing through intake manifold passage-way 27. Air vent 26 located adjacent the inlet valve port has allowed a charge of fuel free air at atmospheric pres-~ sure to fill the entire volume of the intake passageway - . in the intake manifold up to and through venturi 35. As intake valve 28 opens, best shown with reference to Figure -15 ~
1~33337 5B, piston 14 positioned near top dead center (TDC) moves~
downwardly enlarging the space at the top of the cylinder ; atmospheric air pressure and a decrease in air pressure due to the receding piston draws an inflow of air filling the space in the cylinder. The inflow of air first enter-ing the combustion chamber 38 is the charge of air within the -15a-intake manifold passageway that is replenished somewhat by air vent 26 before sufficient vacuum is generated in venturi 35 to next draw a charge of rich fuel laden air into the cylinder chamber, after the air has first been admitted. As the piston reaches its lowest position, bottom dead center (BDC), the cylinder space has been filled with a charge varying from rich in fuel near the top to substantially fuel-free near the cap 19 and with-in reservoir 16 As piston 14 reaches its lowermost point of travel within the cylinder, (BDC), the pressure inside the cylinder is still less than atmospheric pressure and additional air and fuel can enter the cylinder, even after the cylinder begins to move upward. Therefore, the intake valve 26 does not close until the crankshaft arm ll-is a predetermined amount of travel past BDC; this is best shown by the illustration of Figure ~C.
After the intake stroke, best shown by reference ~, to Figure 5D, both valves (23,28) are closed and piston 14 moves upward on the compression stroke. Piston 14 ! compresses and heats the air and fuel in the combustion and reservoir chambers. Throughout the upward movement of piston 14, an accumulation of air with possible slight fuel content occurs in reservoir 16 due to slight dif-fusion of fuel through the charge. The air in reservoir 16, however, is still maintained substantially fuel-free and outside flammability limits throughout the cycle.
During operation of the engine, the burning gases heat l~or~
il33337 cap 19 which acts as a heat exchanger and causes heating of the --16a-1~3333~
air and fuel charge during compression as the charge flows' over and around it, thus providing additional heating of the gases.
Figure 5E illustrates the initiation of combus-tion with piston 14 near TDC and both valves closed.
Piston 14 has compressed the air/fuel charge to give greater force to the expanding gases when combustion (ignition of the fuel) takes place. At this point, a spark ignites the fuel of the charge and it reacts with immediately available oxygen with an explosive force tending to drive piston 14 downward and expand the com-bustion chamber as the pressure in the combustion chamber increases. The pressure increase at quasi-constant volume (combustion) shown as line bc in Figure 3, generates and drives compression (pressure) shock waves across the com-bustion chamber and into reservoir 16, via passageway 18, momentarily co~mpressing the air in the reservoir 16 against its internal walls. Simultaneously, the expansion - waves created by interaction of reflected shock waves and the combustion front propagate in a reverse direction into the space between the top of cap 19 and cylinder head 37 momentarily decreasing the pressure in combustion chamber 38, particularly near the gap. A pressure imbalance in the gap area occurs due to the shock compression of the very lean substantially fuel free air in reservoir 16 to pressures greater than local pressure in combustion chamber 38, causing the air within chamber 16 to flow out via passageway 18 into combustion chamber 38, in which a ! `- -17- ~
pressure imbalance has occurred. This condition is illustrated with reference to Figure 5F which shows outflow of the heated shock compressed air from reser-voir 16 via passageway 18 into combustion chamber 38 during the compression event. The pressure imbalance condition occurs as a time dependent process and even though the average pressure in the combustion chamber may be higher than the average pressure in the reservoir chamber. The nature of the interaction of shock and expansion waves is such that the pressure imbalance is expected to be localized along the gap area 18.
-17a-113333~
The interaction of the reservoir and the com-bustion chamber is crucially important for proper heat balanced-pressure exchange engine operation. To provide the necessary oscillating action of the compression and expansion waves during combustion of the fuel as they successively interact within the combustion zone and to provide a pumping action to force substantially fuel free air from chamber 16 requires certain dimensional interrelationship of combustion chamber volume A (at mir.imum volume), reservoir chamber volume B and passage-way 18 (Figures 4A and 4B) for a particular engine con-figuration. In an internal combustion engine the volu-metric balancing ratio of B/A is normally in a range of from .20 to 3. The passageway opening 18 should be .05 to .200 in. (1.27-5.08 mm) measured across its narrow-dimension. The lower value typical for standard size cylinder of automobile engines, the higher value typical for compression ignition engines. The gap, however, must be capable of permitting controlled pas-sage of the oscillating shock waves into and out of thereservoir, to permit controlled pressure imbalances to occur across the gap, and to control the rate of flow of oxygen through the gap from the reservoir chamber in response to the fluctuating pressure imbalances, so that oxygen will be supplied to the combustion chamber in controlled amounts entirely throughout the combustion event, quite independently of overall average pressure conditions in the combustion chamber, or piston position, in the manner of a pumping action.
-18 ~ -Table ] se-ts forth the pressures and tempera-tures present at designated points on the pressure-volume ; curves of Figures 1 and 3 in comparison of two identical engines; one operating on a heat balanced cycle and the other on an Otto cycle. The compression ratio selected ~y ) was 8 to 1.
-18a-Otto Cycle : Heat Balanced Cycle = 8 ~ = 0 : ~ = 8 ~ = .43 . _ -- ---- -- - :
State : Psia : T R . Psia : T R State a 14.7 600 14.7 600 a a 240 1200 : 240 1200 b c 1000 4980 670 2800 c 670 3070 c' .~
A two-stroke engine cycle that has a similar ' 10 combustion cycle as the four stroke but that requires only one revolution of the crankshaft can also be modi-fied to operate on a heat balanced cycle.
The compr~ssion stroke of the working piston draws a fresh supply of air into the crankcase. On the next compression stroke this air is compressed in the combustion chamber-and fuel is later injected into the combustion cha~mber. A cap structurally similar to the one described above operates in the same manner to sustain combustion during the burning of fuel-air charge in the - 20 combustion chamber to cause the engine cycle to be refined to a heat balanced cycle.
The described apparatus used to modify recipro-cating internal combustion engines, that is, to produce power by pistons moving up and down in cylinders for driving a crankshaft which changes the up-and-down motion to rotary motion, may also be used to improve performance of rotary engines; that is, engines in which power is produced by the action of a rotor turning inside an oval shaped combustion chamber, e.g. the WANKLE engine.
The conventional piston is replaced with a three-- sided rotor 60, best shown with reference to Figure 6.
Rotor combustion pockets are rotated pas~t an intake port 51, a spark plug 61 and an exhaust port 67 to cause rotating combustion. The combustion cycle follows the familiar pattern of the conventional four-stroke-cycle, Otto cycle, of an internal combustion engine in the sequence of events-intake, compression, power and exhaust, as shown in the pressure-volume graph illustrated in Figure 1. Modification of the engine with reservoirs will refine its cycle so that it operates on a heat balanced pressure exchange cycle, illustrated in Figure 3, in a similar manner as the explana-tion above with respect to the reciprocating engine.
Figure 6 illustrates a rotary engine 50 having a rotor 60 that has been modified with a reservoir 66. The reservoir 66 is formed by partial closing of the normal depressions 68 in the rotor 60 with a shaped plate like member 63, or cap, that extends across depression 68, best shown with reference to Figure 7. An opening or passageway 64 is formed by a surface of the cup-like depression and an elongated lip-like, projection 71 formed on one edge of closure element 71. hip-like portion projects inwardly toward the depression to form a tapered restricted ope~ing defining a passageway at the mouth of balancing chamber 66.
A substantially smaller opening 65 is located at the rear ~of reservoir 66 so that the reservoir 66 has a half circle segmental cross-sectional area that tapers gradually in extending from lip 71 to opening 65. It is to be understood ~i33337 that other shaped chambers may be used as long as the balancing ratio of the volumes, formula 7, is considered, Although only a single reservoir is shown on rotor 60, it is to be understood that a reservoir of similar design is positioned on each of the other two rotor lobes shown.
A shaft 62 with appropriate internal and external gearing is connected to rotor 60 for transmission of power to an external load.
Rotary engine 50 has two ported openings, intake 51 and exhaust 67 r for intake and exhaust of gases, respectively.
An intake tubular passage 49 formed with a venturi section 48 is attached to the housing of engine 50 and has its other end open to atmospheric air by means of a filter 43. A fuel supply tank 44 attached by means of fuel line 45 to extend adjacent to venturi 48 draws fuel into engine 50 by a lowered pressure area caused by air flow through venturi 48. An additional air vent 47, closed by filter 46 is positioned between the inlet port 51 and fuel port for supply of atmospheric air to passageway 49. It is to be understood that other fuel supply means such as fuel ejectors or like fuel delivery devices may be used for supplying fuel to rotary engine 50. ~
~-~ In operation, rotor ~ revolves around its own geometric center; at the same time, internal gears 62, 6~) within rotor 5~, move its center in an eccentric path.
The result is all three corners of the rotor lobes are in ~0 constant contact with the housing walls. As rotor ~
re~olves, the three rotor lobes form three moving combustion ~i33337 chambers that are constantly changing in volume. This action in each of the three combustion chambers brings about the intake, compression, power and exhaust effect that is similar to the four-stroke cycle of the recipro-cating engine.
Figure 6 illustrates the rotor 60 at intake stroke in the combustion chamber of the rotor lobes equipped with balancing chamber 66. The intake port 51 has been uncovered by moving rotor and the combustion chamber begins to fill with air in passageway 49 and additional atmospheric air supplied by air vent 47.
Immediately thereafter, a fuel rich charge is supplied by means of venturi 48, fuel line 45 and air flowing through air filter 43. The first lean air in the com-bustion chamber flows in reservoir 66 and as the air-fuel charge continues to fill the combustion chamber the fuel rich air extends in a rich to lean mixture from the combustion housing to the rotor surface. As - rotor 50 continues it closes the intake port 51 and the combustion chamber contains the maximum air-fuel charge.
Continued rotation of the rotor decreases the volume of the combustion chamber, compressing the air-fuel charge and forcing air into the reservoir 66. A spark plug 61 ignites the compressed charge of gas causing expansion of the gases. Compression shock waves are driven into balancing chamber 66 across gap 18. At the same time the expansion waves created by interaction of reflected shock waves and the combustion front propagate into the -2 ~
1~33337 combustion chamber. Because a pressure imbalancing occurs due to the shock waves the -22a-air within balancing chamber will flow through the gap in a regulated manner into the combustion chamber to supply air to sustain more complete burning. This oscillating action of compression-expansion continues S a multiplicity of times throughout the combustion cycle and thus supplies air during the entire combustion cycle in timed sequential relationship with the turning of rotor 60 dependent on ratio of-the volume of the combus-tion chamber with respect to the volume of the reservoir and the size of passageway 64. The action of the bal-ancing is to supply air and this air is such a lean mixture that no combustion of gases takes place in reservoir 66.
As can be seen from the above description, the present invention provides an apparatus and techniques for providing control of pressure and temperature in the operation of an internal combustion engine either reci-procating or rotary of spark or compression ignition and two or four stroke configuration in a refined thermo-dynamic cycle by providing a balancing chamber and pas-sageway or gap parameters that have a relationship with the combustion chamber volume of the engine. Variation of these parameters within certain limits will allow an engine to operate on a balanced heat cycle that has many of the advantages of both the Otto and Diesel cycles with few or none of their disadvantages. In particular an engine operating on a balanced cycle has better oper-ating engine performance, overall engine speed and load ~' , ~1333~7 conditions, better fuel economy and less emission of - pollutants. These are some of the advantages not found in the prior art technique and devices mentioned -23a-11~3337 above.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
Claims (11)
1. A time dependent process for carrying out an energy conversion cycle involving converting chemical energy into thermal potential by utilizing the pressure waves generated during the rapid reaction of a combustible fuel in the presence of oxygen and using the thermal potential for producing useful work in the combustion chamber of a piston type internal com-bustion engine operating over periodic cycles that each include an intake, compression, expansion (work producing) and exhaust event, characterized by, for each cycle:
a) supplying air alone into a combustion chamber of the engine during the initial portion of the intake event while the volume of the combustion. chamber is increasing;
b) adding fuel into the combustion chamber during a later part of the-charge intake and compression event, the total quantity of fuel being selected to provide a reaction that will rapidly produce a predetermined thermal potential and a predetermined maximum pressure in the combustion chamber;
c) increasing the temperature of the total quantity of air and fuel admitted during the cycle by compressing at least the air during the compression event;
d) partially isolating a portion of the initially supplied air from substantially all of the later supplied fuel during the charge intake and compression event, by placing a portion of the initially supplied air in a reservoir chamber located adjacent the combustion chamber, said reservoir chamber communicating with the combustion chamber through a narrow gap that permits transmittal of pressure gradients between the combustion and reservoir chambers, and maintain-ing the isolated portion of air in the reservoir chamber free from substantial contamination with fuel throughout the cycle;
e) igniting the fuel in the combustion chamber to initiate its rapid reaction with immediately available oxygen near the end of the compression event, thereby gen-erating a continuous series of pressure shock and expansion waves that traverse the combustion chamber and intersect the gap to produce pressure differentials between the combustion and reservoir chambers by a pressure exchange process independently of the total pressure in the com-bustion chamber or piston and continuing throughout the reaction;
f) permitting and promoting by combustion and reservoir chamber geometry, and gap configuration the cyclic rapid rebound and reentry of the shock waves across and through the gap at a rate to cause controlled pumping of oxygen into the combustion chamber from the reservoir chamber resulting from the pressure exchange process throughout the combustion event;
g) permitting expansion of the combustion chamber during the expansion (work producing) event;
h) exhausting the combustion chamber near the end of the expansion event.
a) supplying air alone into a combustion chamber of the engine during the initial portion of the intake event while the volume of the combustion. chamber is increasing;
b) adding fuel into the combustion chamber during a later part of the-charge intake and compression event, the total quantity of fuel being selected to provide a reaction that will rapidly produce a predetermined thermal potential and a predetermined maximum pressure in the combustion chamber;
c) increasing the temperature of the total quantity of air and fuel admitted during the cycle by compressing at least the air during the compression event;
d) partially isolating a portion of the initially supplied air from substantially all of the later supplied fuel during the charge intake and compression event, by placing a portion of the initially supplied air in a reservoir chamber located adjacent the combustion chamber, said reservoir chamber communicating with the combustion chamber through a narrow gap that permits transmittal of pressure gradients between the combustion and reservoir chambers, and maintain-ing the isolated portion of air in the reservoir chamber free from substantial contamination with fuel throughout the cycle;
e) igniting the fuel in the combustion chamber to initiate its rapid reaction with immediately available oxygen near the end of the compression event, thereby gen-erating a continuous series of pressure shock and expansion waves that traverse the combustion chamber and intersect the gap to produce pressure differentials between the combustion and reservoir chambers by a pressure exchange process independently of the total pressure in the com-bustion chamber or piston and continuing throughout the reaction;
f) permitting and promoting by combustion and reservoir chamber geometry, and gap configuration the cyclic rapid rebound and reentry of the shock waves across and through the gap at a rate to cause controlled pumping of oxygen into the combustion chamber from the reservoir chamber resulting from the pressure exchange process throughout the combustion event;
g) permitting expansion of the combustion chamber during the expansion (work producing) event;
h) exhausting the combustion chamber near the end of the expansion event.
2. A process according to Claim 1, wherein fuel is added into the combustion chamber during the intake event by adding same to air aspirated into the combustion chamber during said intake event after air alone has first been aspirated and wherein the temperature of the fuel is increased by compressing the fuel as well as the air during the compression event.
3. The process according the Claim 2, wherein the ratio between the volume of the reservoir chamber and the combustion chamber at minimum volume is between .2 and 3Ø
4. The process according to Claim 3, wherein the gap size measured across its narrow dimension is between .05 and .2 in. (1.27 and 5.08 mm).
5. The process according to Claims 1 or 2, wherein the reservoir chamber is located in the piston of the engine adjacent its working face, said step of placing a portion of the initially supplied air in the reservoir chamber occurring by moving the piston towards a combustion chamber wall during a compression event after the air alone has been supplied into the combus-tion chamber.
6. An internal combustion engine including a variable volume combustion chamber into which is admitted a fuel air charge during at least part of an intake and compression event forming part of the operating cycle of the engine,such charge being compressed during at least part of the intake and compression event, reacted during a combustion/expansion event, and discharged during an exhaust event; a piston movable within a cylinder to vary its volume between the piston and the head of the cylinder, said combustion chamber disposed between the piston and the head of the cylinder; means for independently supplying air and fuel to the combus-tion chamber in timed relationship with the movement of the piston, and inlet and exhaust valves for controlling admission of air and fuel into the combustion chamber through an intake port and discharging of combustion pro-ducts from the combustion chamber through an exhaust port, respectively, characterized by:
a) apparatus for supplying substantially fuel-free air alone to the combustion chamber through the intake port during the initial part of each charge intake and compression event;
b) apparatus for supplying fuel into the com-bustion chamber during a later part of each charge intake and compression event, whereby the proportion of fuel to air of each charge varies from excess fuel near the in-take port to substantially fuel-free air near the piston at the beginning of the compression event;
c) an air reservoir chamber adjacent the com-bustion chamber;
d) a passageway between the combustion chamber and air reservoir chamber, said passageway providing restricted communication between said reservoir chamber and combustion chamber, the combustion chamber, reser-voir chamber and passageway having geometric configura-tions that permit transmittal through the passageway of pressure shock waves incidental to a combustion event in the combustion chamber to cause compression of fluid in the air reservoir chamber by pressure exchange, and con-trolled pumping of air compressed by said shock waves from the reservoir chamber into the combustion chamber throughout the combustion event as a result of such pres-sure exchange independently of total pressure in the com-bustion chamber or piston position, and manifested by the interaction of shock compression and expansion waves in the vicinity of the passageway.
a) apparatus for supplying substantially fuel-free air alone to the combustion chamber through the intake port during the initial part of each charge intake and compression event;
b) apparatus for supplying fuel into the com-bustion chamber during a later part of each charge intake and compression event, whereby the proportion of fuel to air of each charge varies from excess fuel near the in-take port to substantially fuel-free air near the piston at the beginning of the compression event;
c) an air reservoir chamber adjacent the com-bustion chamber;
d) a passageway between the combustion chamber and air reservoir chamber, said passageway providing restricted communication between said reservoir chamber and combustion chamber, the combustion chamber, reser-voir chamber and passageway having geometric configura-tions that permit transmittal through the passageway of pressure shock waves incidental to a combustion event in the combustion chamber to cause compression of fluid in the air reservoir chamber by pressure exchange, and con-trolled pumping of air compressed by said shock waves from the reservoir chamber into the combustion chamber throughout the combustion event as a result of such pres-sure exchange independently of total pressure in the com-bustion chamber or piston position, and manifested by the interaction of shock compression and expansion waves in the vicinity of the passageway.
7. An internal combustion engine as claimed in Claim 6, said piston including a reciprocating piston element and a member on the top of the piston element extending towards the cylinder head, said member includ-ing a radially extending lip portion spaced from and extending along the wall of the cylinder, and spaced above the piston element; said reservoir chamber occupy-ing the area between said lip and the top of the piston element; said passageway having a width and length de-fined respectively as the distance between the lip and the cylinder wall, and the circumferential distance along the cylinder wall over which the lip extends; said pas-sageway width being between .05 and .20 inches (1.27 and 5.08 mm).
8. An internal combustion engine as claimed in Claim 7, said passageway having a uniform width and a length extending over the major portion of the periphery of the piston element.
9. An internal combustion engine as claimed in Claim 7, the ratio between the combustion chamber minimum volume and the reservoir chamber volume being between .2 and 3Ø
10. An internal combustion engine as claimed in Claim 6, including a charge intake manifold located up-stream of the intake port, said air supply apparatus in cluding an air supply valve located in said manifold up-stream of and closely adjacent said inlet valve, and a control for controlling said supply valve for enabling air to be admitted into the intake manifold adjacent the inlet valve between inlet valve openings.
11. An internal combustion engine as claimed in Claim 10, said air and fuel charge being admitted by aspiration through said intake port, and including exter-nally energized ignition means in the combustion chamber for initiating combustion of the charge.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US73396276A | 1976-10-19 | 1976-10-19 | |
| US733,962 | 1976-10-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1133337A true CA1133337A (en) | 1982-10-12 |
Family
ID=24949785
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA288,708A Expired CA1096256A (en) | 1976-10-19 | 1977-10-13 | Method and apparatus for control of pressure in internal combustion engines |
| CA288,703A Expired CA1133337A (en) | 1976-10-19 | 1977-10-13 | Method and apparatus for control of pressure in internal combustion engines |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA288,708A Expired CA1096256A (en) | 1976-10-19 | 1977-10-13 | Method and apparatus for control of pressure in internal combustion engines |
Country Status (9)
| Country | Link |
|---|---|
| JP (2) | JPS5351319A (en) |
| BR (2) | BR7706997A (en) |
| CA (2) | CA1096256A (en) |
| DE (2) | DE2745923A1 (en) |
| ES (2) | ES463353A1 (en) |
| FR (2) | FR2368610A1 (en) |
| GB (2) | GB1591125A (en) |
| IT (2) | IT1090515B (en) |
| SE (2) | SE435412B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4465033A (en) * | 1978-10-25 | 1984-08-14 | Blaser Richard Florencio | Energy conversion cycle for internal combustion engine and apparatus for carrying out the cycle |
| DE2908756C3 (en) * | 1979-03-06 | 1984-08-09 | Spurk, Joseph H., Prof. Dr.-Ing., 6123 Bad König | Externally ignited reciprocating internal combustion engine with a main combustion chamber and a secondary combustion chamber |
| US4485779A (en) * | 1982-12-20 | 1984-12-04 | Spurk Joseph H | Internal combustion piston engine including a cylinder having a main combustion chamber and at least one secondary combustion chamber |
| US4592331A (en) * | 1983-09-23 | 1986-06-03 | Sonex Research Inc. | Combustion process for I.C. engine using a resonating air chamber in a reciprocating piston to induce closed organ pipe resonance in the combustion chamber |
| US4788942A (en) * | 1986-06-30 | 1988-12-06 | Sonex Research, Inc. | Internal combustion engine using dynamic resonating air chamber |
| GB2294976A (en) * | 1994-11-08 | 1996-05-15 | Centrad Marketing Pte Ltd | Rotary internal combustion engine |
| RU2160373C2 (en) * | 1999-01-11 | 2000-12-10 | Яримов Марат Отеллович | Internal combustion engine operation method |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR645974A (en) * | 1927-12-20 | 1928-11-06 | Improvements to pistons and sealing rings | |
| US2187724A (en) * | 1936-11-30 | 1940-01-23 | Herman Howie Uhli | Piston and ring assembly |
| DE2114901A1 (en) * | 1971-03-27 | 1972-09-28 | Hentsch, Erwin, 2800 Bremen | Internal combustion engine with air storage space and fuel injection |
| DE2828749C2 (en) * | 1978-06-30 | 1983-10-20 | M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8500 Nürnberg | Pistons for internal combustion engines |
-
1977
- 1977-10-11 GB GB4223377A patent/GB1591125A/en not_active Expired
- 1977-10-11 GB GB4222577A patent/GB1591124A/en not_active Expired
- 1977-10-12 DE DE19772745923 patent/DE2745923A1/en active Granted
- 1977-10-12 DE DE19772745902 patent/DE2745902A1/en active Granted
- 1977-10-13 CA CA288,708A patent/CA1096256A/en not_active Expired
- 1977-10-13 CA CA288,703A patent/CA1133337A/en not_active Expired
- 1977-10-17 IT IT5143877A patent/IT1090515B/en active
- 1977-10-17 SE SE7711645A patent/SE435412B/en not_active IP Right Cessation
- 1977-10-17 SE SE7711646A patent/SE435413B/en not_active IP Right Cessation
- 1977-10-17 IT IT5143977A patent/IT1090516B/en active
- 1977-10-18 BR BR7706997A patent/BR7706997A/en unknown
- 1977-10-18 FR FR7731364A patent/FR2368610A1/en active Granted
- 1977-10-18 FR FR7731363A patent/FR2368609A1/en active Granted
- 1977-10-19 ES ES463353A patent/ES463353A1/en not_active Expired
- 1977-10-19 JP JP12563277A patent/JPS5351319A/en active Granted
- 1977-10-19 ES ES463354A patent/ES463354A1/en not_active Expired
- 1977-10-19 JP JP12563177A patent/JPS5351318A/en active Granted
- 1977-10-19 BR BR7706996A patent/BR7706996A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE2745902A1 (en) | 1978-04-20 |
| BR7706996A (en) | 1978-06-27 |
| FR2368609A1 (en) | 1978-05-19 |
| ES463353A1 (en) | 1978-07-01 |
| SE435413B (en) | 1984-09-24 |
| IT1090515B (en) | 1985-06-26 |
| FR2368609B3 (en) | 1980-06-27 |
| JPS5351319A (en) | 1978-05-10 |
| SE7711645L (en) | 1978-04-20 |
| FR2368610B3 (en) | 1980-06-27 |
| DE2745923C2 (en) | 1987-10-29 |
| JPS5351318A (en) | 1978-05-10 |
| GB1591124A (en) | 1981-06-17 |
| BR7706997A (en) | 1978-06-27 |
| GB1591125A (en) | 1981-06-17 |
| FR2368610A1 (en) | 1978-05-19 |
| JPS6110649B2 (en) | 1986-03-31 |
| CA1096256A (en) | 1981-02-24 |
| ES463354A1 (en) | 1978-07-16 |
| JPS6110650B2 (en) | 1986-03-31 |
| DE2745902C2 (en) | 1987-01-29 |
| SE435412B (en) | 1984-09-24 |
| DE2745923A1 (en) | 1978-04-20 |
| IT1090516B (en) | 1985-06-26 |
| SE7711646L (en) | 1978-04-20 |
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