Abstract:
A pressure spike modulator for engagement to the cylinders of an internal combustion engine. The device provides for adjustment of engine cylinder pressures using a reciprocating piston which provides a temporary increase in engine combustion chamber volume. Pressure from combustion chamber gases is communicated by the device back into the combustion chamber during the downstroke of the engine piston. Engine compression and peak combustion pressure may be modulated by adjusting pressure supplied to the device to resist incoming engine gases. Fuels for the attached engine may thereby be varied or substituted by adjusting the engine peak pressure and compression to one adequate for the chosen fuel.

Description:
[0001]    This application is a continuation-in-part to and claims the benefit of U.S. Provisional Application No. 60/842,498 filed Sep. 5, 2006 and incorporated herein in its entirety by reference. The disclosed device relates to internal combustion engines. More particularly it relates to an apparatus and method engageable either during OEM manufacture or as a retrofit, which provides a secondary pressure chamber as a means to infinitely vary the compression ratio of a communicating engine cylinder and thereby concurrently vary the fuel required to run the engine. Further, the device and method provide a means to modulate the pressure spike occurring during cylinder combustion and particularly during combustion of diesel fuel in an internal combustion engine. Further, when engaged to a gasoline engine, the device and method herein will allow burning of diesel type fuels without reinforcement to the engine structure. 
     
     FIELD OF THE INVENTION 
     Background of the Invention  
       [0002]    Internal combustion engines function by cylinder pressure that is generated by the expansion of the air mixture including nitrogen (⅘ of the air) caused by the fuel combining with the oxygen (⅕) of the air and igniting. This ignition generally produces heat causing the expansion of gasses and the nitrogen portion of the mixture remaining after the combustion. Proper mixture ignition and burning requires the flame propagation to be progressive providing a controlled pressure increase inside the cylinder to avoid destructive pressures that can damage the engine structure. 
         [0003]    When seen on a pressure/volume diagram, this internal pressure at near top dead center of the piston in the cylinder is seen as a spike. This peak or spike then trails off as the piston descends in the cylinder expanding the total volume area containing the pressure, thereby lowering it. This progressive flame propagation requires a slower burning fuel which in the case of gasoline is described as the octane rating. In the case of diesel and jet type fuels, which have inherently low octane characteristics and which operate to ignite the fuel with pressure generated in the cylinder, instead of an igniter, a very heavy engine structure is required to accommodate the extreme forces of the “spike” occurring at the start of the combustion process of the in the cylinder. However, in the extreme pressures produced in engines employed in racing conditions (such as tractor pulling contests), such engines are seriously damaged, regardless of the costly heavy duty components employed in the engine to accommodate the pressures anticipated. 
         [0004]    Additionally, the high combustion pressures and temperatures in all internal combustion engines conventionally cause air pollution through generation of nitrous oxide created by the ignition process of the fuel and oxygen. Subsequent to ignition, the Nox is exhausted to the atmosphere. 
         [0005]    The device and method herein disclosed and described teaches a pressure spike modulator apparatus and method of employment thereof yielding highly improved modulation and control of the compression ratio of an internal combustion engine. It concurrently provides a means to vary the fuel employed to run such engines, enabling the use of lower octane fuels and even pressure ignited diesel fuel in internal combustion piston driven engines. 
         [0006]    The device is engageable to existing engines by adapting it to engage in a conventional spark plug, fuel injector, or other port communicating into the cylinder. Or, it may be designed into the engine at manufacture with the device in communication with the cylinder through the cylinder head or wall surface. It is particularly suited to adapt existing gasoline engines to run on diesel, or to adapt piston driven airplane engines using aviation fuel known as “avagas” and having an octane rating of at least 100, to run on diesel, jet fuel, or similar lower octane rated gasoline or fuels thereby increasing the supply of fuels available to such engines. 
         [0007]    In this respect, before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction and to the arrangement, of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
         [0008]    As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for designing of other methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent construction insofar as they do not depart from the spirit and scope of the present invention. 
         [0009]    An object of this invention is the provision of a pressure spike modulating device and method that may be included in new internal combustion engines. 
         [0010]    An additional object of this invention is the provision of the pressure spike modulation device and method which may be engaged to existing internal combustion engines. 
         [0011]    Yet another object of this invention is the provision of the pressure spike modulation device adapted for engagement to aviation engines to allow their operation on diesel fuel, jet fuel, or diesel fuel. 
         [0012]    Another object of this invention is to provide such a pressure spike modulation device that may be easily incorporated into current and future internal combustion engines and manufacturing techniques therefor. 
         [0013]    An additional object of this invention is to provide such a pressure spike modulation device and method that will allow internal combustion engines to operate on a wide variety of fuels of varying octane or burn ratings, by providing an infinite adaption of the compression ratio in cylinders of internal combustion engines. 
         [0014]    Yet an additional object of this invention is the prevention of pollution of the atmosphere by decreasing the formation of and exhaust of nitrous oxide in internal combustion engines. 
         [0015]    These together with other objects and advantages which will become subsequently apparent reside in the details of the construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part thereof, wherein like numerals refer to like parts throughout. 
       SUMMARY OF THE INVENTION 
       [0016]    The free piston spike modulator and method of use on internal combustion engines herein described and disclosed may be employed to reduce the high pressure spike which occurs upon the ignition of fuel and oxidizer in the cylinder of a conventional internal combustion engine. Those skilled in the art will realized that such a peak or spike in pressure is conventionally graphically depicted in a Pressure/Volume (p/v) diagram. The device herein when engaged in a sealed communication with the upper end of an engine cylinder, absorbs and stores peak pressure and spreads the pressure increase in the engaged cylinder over a wider range, eliminating the need for heavy components such as reinforced pistons, heavy connecting rods, and strengthened crank-shafts and crankcases. The device when engaged thereto provides an “elastic” or virtual combustion chamber for gas expansion, without sacrificing performance. When in sealed engagement with engine cylinders, it will allow gasoline engines (such as aircraft requiring high octane fuel) to use diesel fuels, or “Jet A” (commonly available worldwide) in place of gasoline in engine structures of conventional gasoline design using conventionally employed lower weight components. The device and method will also allow higher turbo charging boosts in internal combustion engines using a boosted fuel and oxidizer intake, without exceeding ordinary gasoline cylinder pressures during combustion. This allows for higher boost of the engine output without the extra engine reinforcement normally required. 
         [0017]    Still further, the device may be employed as a means to reduce greenhouse gases and air pollution by reducing the Nitrous Oxide formed during conventional cylinder high combustion pressures which conventionally cause more pollution in the atmosphere. When operatively engaged to any cylinder of an internal combustion engine, the device prevents formation of NOX through reduction of the peak cylinder pressures which cause NOX formation. Since Nitrous Oxide is reduced or does not form in the first place during the more even pressures of combustion, there is a resulting significant reduction of Nitrous Oxide in the engine exhaust communicated to the atmosphere. As both a means for fuel adaptation in the engine and a Nox reduction apparatus, the device herein disclosed may be retrofitted on existing engines or installed as a stock component in new engine manufacture. 
         [0018]    Further, the device herein also serves to provide a means for an infinitely variable compression ratio when engaged to engine cylinders which is an attribute long sought after by engine designers, especially on throttled spark ignition engines. In such engines, only at full throttle does a throttled spark ignition operate at full efficiency. The device and method herein disclosed provides a means to vary the compression ratio on the engaged engine cylinder by varying the back pressure providing resistance to cylinder pressure communicated to a lower or venting chamber in the disclosed device. By varying the pressure resisting expansion in the venting chamber, a resulting variance of the peak pressure ratio in the communicating combustion chamber occurs. 
         [0019]    Details such as the workings of a pressure regulator, fittings, and other items are not shown in order to simplify the general drawings of this invention. However, such components are well known to those skilled in the art to provide a pressurized environment to the high pressure chamber of a reciprocating piston thereby providing resistance to that piston of the device from translating. This effectively increases the venting chamber dimension under pressure from the engaged combustion chamber of the engine cylinder. The pressure in the high pressure chamber of the device provides both resistance and resulting pressure levels in the venting chamber and also a cushion zone preventing the piston of the device from impacting a back wall. Lubrication would also be provided to the device by conventional means such as communication with the engine pressurized oil conduits. 
         [0020]    With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. Therefore, the foregoing description and following detailed description are considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  shows the device engaged and in communication with a cylinder of an internal combustion engine as an addition or OEM. 
           [0022]      FIG. 2  depicts the device in sealed engagement to a cylinder through the spark plug hole thereby enabling a gasoline engine to operate on diesel fuel in a pressure induced combustion. Also shown are means for communication of high pressure to the high pressure area of the device to change peak pressure. 
           [0023]      FIG. 3  depicts a mode of the device showing venting of the two portions of the device cylinder. 
           [0024]      FIG. 3   a  is a top view of the venting that may be employed around the external wall of the cylinder. 
           [0025]      FIG. 4  depicts a particularly preferred mode of the device having a domed head allowing for better clearances of sealing rings and higher compression in the lower cylinder portion. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    Referring now to the drawings in  FIGS. 1-4 , wherein similar parts are identified by like reference numerals, there is seen in  FIG. 1 , a mode of the device integral in design and as it might be incorporated in a new engine during manufacture. In  FIG. 2  the device  10  as it might be employed as a retrofit engaged to the engine cylinder  11  through the spark plug aperture  13  in the cylinder head  15  is depicted. In all modes of the device  10  it will function to modulate the peak engine cylinder  11  pressure to which it is engaged by absorbing and storing cylinder pressure during portions of the engine cylinder stroke, and communicating that pressure back into the cylinder  11  of the engine during each stroke of the engine piston  17 . 
         [0027]    Combustion commences generally at a time when a lower wall  12   a  of the piston  12  of the device  10  is in a lower position. A biasing is provided by back pressure communicated to the upper wall  12   b  of the piston  12  in the upper chamber  18  of the device  10  from a pump or steam generator, or other means for generation of pressure  20 . The upper chamber  18  and lower chamber  19  are separated by a center wall  24  which allows translation of a rod portion  14  of the piston  12 . This force maintains the piston  12  at a substantially lower position closest to the engine cylinder  11  until the pressure in the communicating combustion chamber  21  formed by the engine cylinder  11  above the engine piston  17 , exceeds the pressure within the upper chamber  18 . At this point, the piston  12  translates inside the device cylinder  22  bisected by a center wall  24  toward the upper chamber  18  and provides a means to temporarily increase the volume of the combustion chamber  21  by communicating expanding gases in the combustion chamber  21  for a time period. This temporary expansion of the combustion chamber  21  provides means to control the pressure spike in the combustion chamber  21  at the point of the ignition of fuel and air. Temporarily lowering the compression or pressure at the pressure peak, by temporarily increasing combustion chamber size, thereby eliminates high octane requirements in gasoline engines which currently must match the octane of the fuel to the compression ratio yielding the peak pressure in the combustion chamber  21  to avoid pre-ignition. 
         [0028]    Further, such engines as they increase the power and compression of the fuel and air combusted in the combustion chamber  21  must have increasingly heavy and sturdier structural components to communicate that power to the vehicle without damage to moving structural components of the engine. This is particularly true in high compression racing gasoline engines with blowers or other means for pressurized fuel mixture input, and as required by diesel engines which employ a very high compression of the fuel mixture in the combustion chamber to increase temperatures therein sufficiently to ignite the fuel mixture. 
         [0029]    When engaged to a gasoline engine through the spark plug hole, or a fuel injector aperture, or as original equipment with formed engine block or head passages, the device  10  will allow the use of diesel fuel in the engaged cylinder  11  thereby converting it to a diesel engine without the conventional requirement for a heavy and strengthened engine structure. This is accomplished from the temporary relief of peak pressure at the pressure spike point of ignition and subsequent communication of stored pressure and energy back to the expanding compression chamber  21  as the engine piston  17  moves away from the device  10 . 
         [0030]    In operation engaged to the combustion chamber  21  portion of the cylinder  11  of any gas or diesel engine, once a peak pressure in the combustion chamber  21  is reached, which is substantially equal to that of the upper chamber  18  of the device, the communicated gas and pressure in the lower chamber  19  is forced back into the combustion chamber  21 . This is caused when the piston  12  in the device  10  moves downward away from the pressurized upper chamber  18  by the higher force of pressure in that chamber caused when the piston  12  is driven toward the upper chamber  18  by gasses from the engine combustion chamber  21 . 
         [0031]    Subsequently the gases stored under pressure in the lower chamber  19  is forced by the higher pressure in the upper chamber  18 , back into the combustion chamber  21 . This particularly enhances performance since it provides continued even pressure and force to the engine piston  17  of the communicating cylinder  11  to continue to drive the engine piston  17  downward. This is unlike conventional operation where pressure in the combustion chamber peaks and then drops dramatically as the size of the combustion chamber increases. 
         [0032]    In operation the pressure of gasses in the upper chamber  18  provides means to resist movement of the piston  12  and a resulting increase in the volume into which exploding fuel mixtures in the combustion chamber  21  may expand. Thus, a unique and novel ability is provided through the increasing and decreasing of the pressure in the upper chamber  18 . Increasing the pressure in the upper chamber  18  will cause the piston  12  to begin to translate toward the upper chamber  18  at a higher pressure and raise the resulting peak pressure in the cylinder combustion chamber  21 . Conversely, lowering the pressure of the upper chamber will cause an earlier piston  12  translation resulting in an earlier expansion of the effective volume of the combustion chamber  21 , and lowering the peak pressure in the combustion chamber  21 . Thus, by regulating the pressure of the upper chamber  18 , the compression ratio and volume of the combustion chamber  21  available to expanding gasses may also be adjusted. Pressure to the upper chamber  18  is provided by means for pressure generation such as an air pump engaged to the engine, or steam produced using engine exhaust heat and water. The resulting pressurized gas is fed to the upper chamber  18 . A regulator  30  operatively engaged to a means for control such as an electronic control  32  that operates the regulator  30  to maintain a desired pressure in the upper chamber  18  to yield the peak pressure in the combustion chamber  21  desired. 
         [0033]    The device  10  and method of employment thus provides a means to make an internal combustion engine operate on any octane gasoline without pre-ignition by adjusting the upper chamber  18  pressure to yield a correct peak pressure for the fuel. Infinite adjustability of the peak pressure and compression ratio of the engine combustion chambers  21  may be obtained by varying the pressure of the upper chamber  18 . 
         [0034]    The device  10  thus also provides a means for increasing the volume for expansion of exploding fuel mixtures in the compression chamber  21  and means to store the energy thereof by compressing the gas stored in the upper chamber  18  to thereafter expand and force the piston  12  to communicate the gas back into the combustion chamber  21  under force during the stroke of the piston  17  therein. This variable expansion of the combustion chamber  21  by the translating piston  12  of the engaged device  10 , and the storage of energy from the exploding fuel mixture by compression in the high pressure upper chamber  18 , and communication thereof back to the combustion chamber  21 , also provides means for control of or elimination of the pressure spike which exists in all such internal combustion engines close to the time of detention of the fuel and air mixture in the combustion chamber  21 . As such, a much smoother power stroke of the engine piston  17  is yielded by more constant communication of an even force over time from the stored energy in the device  10 , back into the combustion chamber  21  as it is increasing in volume. 
         [0035]    The use of a means for pressure generation and means to regulate the pressure in the upper chamber  18  allows the user to adjust the device to accommodate many types of fuel in the engine to which it is engaged. For instance, a piston driven airplane that runs on high quality aviation gas could use jet fuel or other fuels if needed by adjusting the pressure in the upper chamber  18  and thereby the peak pressure in the engine combustion chamber  21 . Vents  23  communicate with the chambers  18  and  19  for venting of gas during their reciprocation. 
         [0036]    While all of the fundamental characteristics and features of the method and apparatus for modulation of the pressure spike occurring in internal combustion engine cylinders has been described herein, with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be apparent that in some instance, some features of the invention will be employed without a corresponding use of other features without departing from the scope of the invention as set forth. It should be understood that such substitutions, modifications, and variations may be made by those skilled in the art without departing from the spirit or scope of the invention. Consequently, all such modifications and variations are included within the scope of the invention as defined herein.