Abstract:
A universal fuel injection system for liquid and gaseous fuels and mixes thereof the universal fuel injection system having a universal fuel injection module interposed between a liquid fuel injector nozzle the universal fuel injection module having a spring-biased gaseous fuel valve connected to a pressurized gaseous fuel source and to a conical poppet mixing valve in the fuel injector nozzle where liquid fuel from the liquid fuel actuator unit and gaseous fuel selectively admitted through the spring-biased gaseous fuel valve mix for discharge through a fuel nozzle discharge orifice.

Description:
[0001]    This application claims the benefit of provisional application for Total Energy General Optimized Engine Cycle, Ser. No. 60/190,303 filed Mar. 17, 2000 and provisional application for Universal Fuel Injector System, Ser. No. 60/186,967 filed Mar. 6, 2000, and the subject matter relates to the co-pending application for Total Energy General Optimized Engine Cycle, Ser. No. 90/590,156 filed Jun. 7, 2000 and U.S. Pat. No. 5,862,792. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to general categories of a fuel injection system which have common configurations and structural arrangements for internal combustion engines. In particular, this invention relates to injector systems which are able to operate using the “self injection” concept, and/or the “common rail” concept, and includes the “multiple injection per cycle” concept, particularly using the concept of “self-induced pulsations.” These concepts have been the subject of our prior patented technology. The universal fuel injection system improves upon the prior patented technology and is the main subject of this new invention.  
           [0003]    A general attribute that is characteristic of one embodiment using the “universal fuel injection system” and “self-induced multiple injections” is the ability to be associated with and incorporated into any existing or new injection systems.  
           [0004]    The general attribute is further enhanced by the modular structure of the preferred implementation which can be flexibly configured for different injection systems, depending on a particular application.  
           [0005]    For land transportation, cars, busses, trucks, naval propulsion, locomotives, the main sources of fuel have been liquids, including diesel fuels, kerosene and gasoline, all of them based on petroleum resources.  
           [0006]    Natural gas was not sufficiently available to the commercial market for existing vehicles, including more than 600 million, spark ignited and diesel powered vehicles. The conventional, conversion technology, from liquid fuels to natural gas, results in a severe degradation in the performance, resulting in a lower power density and reduced efficiency.  
           [0007]    The typical technology, based on the intake of the natural gas and air in a common admission, diminishes the air volume by the gas volume, typically resulting in a 50% reduction of the effective power and thermal efficiency, caused, for example, by the reduction of the compression ratios in a diesel engine from an original 18-20/1 to a resultant 10-11/1.  
           [0008]    In contrast, direct injection of the liquid and gas fuels conserves the air capacity and the high compression ratio of the engine for a retained maximum power density and thermal efficiency.  
           [0009]    A first objective of this invention is the general and universal capability to directly inject all the liquid fuels, and all the gaseous fuels, like natural gas, compressed natural gas (CNG), or liquefied natural gas (LNG), hydrogen, hydroammonia, etc.  
           [0010]    A second objective of this invention is the capability that the transition from one fuel to any other can be manual or automatic, or commanded or programmed.  
           [0011]    A third objective of this invention is that the universal injector can inject blended fuels from different categories and in different proportions mixing of liquids with liquids, or liquids and gases.  
           [0012]    A fourth objective of this invention is the capability to be modularized, integrated and associated on conventional injection systems, on conventional common rails, and in any self-injection system, having the Common Universal Fuel Injector.  
           [0013]    A fifth objective of this invention is the universal applicability, with practically insignificant or no modification at all, to any and all categories of engines, whether two stroke, four stroke spark-ignited or four stroke diesel.  
           [0014]    A sixth objective of this invention is a constant pressure, direct natural gas injection, using constant pressure natural gas containers, pressurized by liquid fuel injection, with equal volume in accordance with the gas volume injected in the cylinder.  
         SUMMARY OF THE INVENTION  
         [0015]    All the existing injection systems whether conventional, or new, electronically controlled or mechanically actuated, can be fundamentally improved by the association and integration of the universal fuel injector of this invention.  
           [0016]    A first embodiment of the “universal fuel injector” is in a working injection system, as described in the referenced patent, where a “self injection system” related to a fuel injection system suitable for any internal combustion engines, wherein the developed pressure within the compression and combustion chamber is utilized to generate the amplified fuel injection pressure.  
           [0017]    The new improvement introduces a number of novel features and advantages over and above those already described in the referenced patent for a “self injection system”.  
           [0018]    The most important feature introduced by these improvements is the “universal fuel injector,” which can directly inject any “liquid fuels,” of any nature, can directly inject any combination of “liquids with liquid,” for example alcohols with petroleum fluids, without the necessity of using surfacents, water and any liquid or gaseous fuels, alternatively can automatically switch to high pressure natural gas CNG and/or LNG, direct injection, as long as the high pressure of the gas is available. Automatically is switched back to liquid fuel injection when or if the high pressure gas is not available, which is permitting the vehicles a continuous operation without any interruption. All these features and advantages are part of the definition of the “universal fuel injection system.” 
           [0019]    Another essential advantage introduced is the separation between the universal fuel injector module and all the associated injection systems permitting a simple replacement of the existing injector of any engine with the new universal fuel injector module.  
           [0020]    A new and specific embodiment of the referenced invention of the “self injection system” is the inclusion of the “universal fuel injector module” in a preferred embodiment of this invention forming a universal fuel, self injection system. The most important advantage introduced by these improvements is the modular separation between all the functional components, like the actuating module, the high pressure injection module and the universal fuel injector module.  
           [0021]    This system enables independent control of all the parameters of the injection mixture formation and a perfect clean combustion. The modular system allows flexible structural variations depending on specific applications. Features of the improved injection system, originating in the referenced patent, include a hydraulic cylinder actuating module, with a slidable amplifier piston that is provided with an electronic/hydraulic control valve system, having a commanding plunger that is “hydraulically unbalanced.” 
           [0022]    This control module controls the access to the source of pressurized actuation fluid over the “hydraulically unbalanced plunger” and is able to control the opening to the source of the pressurized fluid at the start of the injection. The high pressure injection module is provided with an electro hydraulic valve, which controls the general pressurization, and the timing of the “sharp cut” of the end of injection. The same high pressure injection module is preferably provided with the self-induced multiple injection sub-module. Finally, individual modules of the modularized self-injection system described above, or any existing or new injectors, can be associated with the “universal fuel injector module, which is the main object of this invention.  
           [0023]    In the type of injection systems featuring the self-injection concept, the compression and the combustion pressure of the gases in the combustion chamber of the engine, on which the injector is mounted, provide the driving pressure for pressurizing the actuation fluid (engine oil or fuel) . In this manner, the pressure of the liquid injection fuel, as amplified 10-15 times by the hydraulic actuator, profiles the pressure developed in the combustion chamber. The newly formed injection system directly utilizes the effect of the pressure evolution in the thermal cycle to induce in the fuel injection process a proportional, triangular evolutive pressure, This profile is absolutely ideal for the formation of an air-fuel mixture for a perfect, clean combustion process.  
           [0024]    A second embodiment of the invention of this injection system comprises a working injection system, based on the common rail concept, in which the hydraulic pressure source is a medium pressure fuel pump (approx. 4000 psi). This configuration is provided with a balanced electro-hydraulic valve and a common by-pass discharge communication between the hydraulic actuator module and the high pressure injection module.  
           [0025]    The new modularized injection system is preferably associated with the described “universal injector module,” which is able to direct inject all the categories of liquids and gaseous fuels, individually or combined in any and all proportions, simultaneous or alternatively.  
           [0026]    The injection nozzle is provided with a new popped injection valve, which generates a conic shaped injection spray, equivalent to a nozzle with an infinite number of holes and a high speed vortex generator for spinning the fuel, which generates high intensity centrifugal accelerations of the fuel molecules, producing an explosive dispersion of the fuel and air mixture. This type of fuel injector generates a total homogenization of the fuel air mixture, and is a complete total departure from the non-homogenous fuel mixture of the typical diesel, which is responsible for the usual emission of all the pollutants including NOx and particulate matter.  
           [0027]    The universal fuel injector module, which is one of the main features of this invention, is provided with a switch valve for alternately commuting the operation between pure liquid and high pressure gas-liquid, In the direct, high pressure, gas-liquid operation mode, the poppet valve is provided with a central channel for liquid fuel, and a pilot liquid fuel injection holes concentric with the vortex of high speed, high pressure gas directly injected in the combustion chamber. The combined fuels generate a homogenous gas-liquid super mixture, ignited by the liquid-fuel pilot injection.  
           [0028]    The universal fuel injector module of this invention can be individually associated and integrated in any and all type of injection systems existing or new, including those with in line injection pumps mechanically driven by the engine, or conventional electronic hydraulic common rail injection systems, which is a “universal characteristic” of this new injection system.  
           [0029]    A special category for highly supercharged engines, represented in an alternate embodiment of the self injection system described above, is designed to enable a very large quantity of fuel to be injected in a very short time.  
           [0030]    All of these injection systems can be electronically controlled based on an optimized map of operation for all the regimes of power, torque, rotation and level of supercharging. The electronically controlled system utilized modern smart sensors for diagnosing, and continuously comparing the optimized and the real time cycle parameters, cycle by cycle. Such system is controlled by a central electronic module which enables cycle corrections for all potential deviations from the map of optimum conditions.  
           [0031]    Since the regulation of any and all the cycle parameters is automatic, the control function of the electronic control module is easily extended over all conditions for each injector. The capability of individual self-control of the injection process for each cylinder enables the system to self-diagnose and to equalize all the factors in an absolute regime of cooperative operation. This result is a self-regulating system for uniform operation of each injector in the entire engine system.  
           [0032]    By appropriate modification, the design of the self-injection system can be extended to spark ignited engines for operating lean and ultra lean and clean combustion without departing from the spirit of this invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0033]    [0033]FIG. 1 is a schematic view, partially in cross-sections, of the first embodiment of the universal fuel injection system, having a module structure, utilizing the self-injection concept, with an alternate common rail, multiple injection capability, and the universal fuel injector module.  
         [0034]    [0034]FIG. 2 is a schematic of different injection system alternatives, including new conventional mechanical driven in line injection pump, and existing or new common rail injection systems, which can associate and integrate the “universal fuel injector,” and the constant pressure natural gas direct injection system, including a constant pressure container pressurized by liquid fuel injection.  
         [0035]    [0035]FIG. 3 is an enlarged view of the universal fuel injector, with functional convertibility, from any to any alternative fuels, and operational capability.  
         [0036]    [0036]FIG. 3. 1  is a schematic view of the liquid fuel alternative operation.  
         [0037]    [0037]FIG. 3. 2  is a schematic view of the gas-liquid alternative operation.  
         [0038]    [0038]FIG. 4 is a schematic view of an alternate embodiment of the universal injection system of FIG. 1 provided with a self activated by-pass for an increased actuating fuel supply. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0039]    The preferred embodiment of the universal fuel injection system of this invention is shown in FIG. 1, designated generally by the reference numeral  10 , includes a fuel injector  12 , operating alternately on self-injection or common rail, both of which include the sub-module for multiple induced injections. The fuel injection system  10  is mounted on an internal combustion engine  14 , a portion of which is shown schematically in FIGS. 1 and 4.  
         [0040]    The internal combustion engine  14  is modified to provide a communication passage  16  with the combustion chamber  18  of the engine  14 , to provide pressure pulse for the self-injection feature.  
         [0041]    In FIGS. 1 and 4 the alternative utilizing the self injection concept has an actuator module  60  with a spool valve  64  having dimensional differential in its diameter (D2/D1) as indicated. The gas communication passage  16  from the combustion chamber  18 , to the gas/hydraulic cylinder  80  provides access to the drive medium to displace a free piston  81 . The piston displaces against the return bias of a spring  82 , to pressurize the actuator fluid that is filled in the cylinder  80 , on the top side of the piston. The actuator fluid is in communication with the hydraulic conduit  40  and the supply port  66 .  
         [0042]    The supply port module  60  of the fuel injection cylinder  22  arranged in conjunction with an actuating cylinder  24 . A high pressure injector piston  26  is slidable in the fuel injection cylinder  22 , against the bias of a compression spring  28 . The injector piston  26  has an end  30  coupled to an enlarged amplifier piston  32  that is slidably engaged in the actuating cylinder  24  against the bias of the compression spring  28 . Hydraulic fluid from a hydraulic supply  36  protected by a check valve  38  is fed into the fuel injector  12  through hydraulic conduit  40 . It is to be understood that the fuel injector system may be utilized in gasoline and diesel engines. In the case of diesel engines, the hydraulic supply is connected with the fuel supply such that the diesel fuel comprises the hydraulic fluid necessary to actuate the injector  12 .  
         [0043]    The fuel injector body includes a central body (actuating module)  44  housing the necessary hydraulic actuator components and is connected with the high pressure injection module  50  housing the fuel supply components that include a fuel intake port  46  controlled by an electro hydraulic valve  48  that is biased to be open by an internal compression spring  53 , and closed when attracted by a magnetic plate  51  on the solenoid  52 .  
         [0044]    Fuel from a source (not shown) is pumped in the injector  12  in a conventional manner during the time of the recharging stroke of the injector piston  26  together with the amplifier piston  24  under the retracting force of the spring  28  and the pressure of the supply source.  
         [0045]    During the time of recharging, the injector solenoid  52  is de-energized maintaining the electro hydraulic valve  48  open. In this time fuel fills the passage  54  in the central body of the fuel injector  12  and the chamber  56  defined by the fuel injector cylinder  22  and the injector piston  26  as it retracts.  
         [0046]    On starting of the injection time, the solenoid  52  is energized attracting the magnetic plate  51 , which displaces the attached valve  48  to seal the plenum  56  and  54 . The starting of injection can be decided by the proper compression pressure for the optimum combustion time based on the indication of the pressure transducer  101 , to energize the solenoid  52  and  61  which actuate the electro hydraulic valves  48 - 64  of the injector.  
         [0047]    Controlling the injection by the real condition of the thermal cycle is the best way to optimize the regimes of power and rotation. This is the advantage of a self regulated and optimized injection system.  
         [0048]    The effective start of the injection is determined by the action of the supply module  60  upon energizing the solenoid  61  which attract the magnetic plate  62  against the biased compression spring  63  displacing the spool valve  64 . The valve port  65  will be open giving the incoming fluid access to the actuating cylinder through the channel  67 . The pressure of the actuating fluid coming from the conduit  40  through the port  66  is equal to the actual pressure in the engine compression chamber at the moment the injection starts.  
         [0049]    The injection pressure evolution multiplied by the factor of amplification of the 10-15 times in the injection cylinder  22 , equivalent to the ratio of the area of the amplifier piston  32  and the area of the injection piston  26 .  
         [0050]    The end of the injection process is initiated by de-energizing the solenoid  61  which releases the spool valve  64 . Because the differential relationship of the diameters in the spool valve  64 , where D2/D1, the port  65 , remains open during the pressure drop in the conduit  40 , resulting from the pressure reduction during the expansion time, as transmitted by the gas hydraulic piston  80 , which is returned to its initial position at the beginning of the compression by the spring  81 . In this way, all the accumulated energy in the actuating system, including the energy in the springs  28  and  82 , will be returned back to the engine cycle during expansion.  
         [0051]    Simultaneously with de-energizing solenoid  61 , solenoid  52  is de-energized which releases the electro hydraulic valve  48 , opening the port  46  to the fuel supply (not shown) producing the actual termination of the injection process in a sharp cut-off manner. No shock wave, no pressure oscillation, no post injection release; only a clean injection and clean combustion results from the process.  
         [0052]    The multiple pulse injection claimed in the referenced patent is integrated in the actual invention in cooperation with the universal fuel injection concept producing a major synergetic effect for a perfect combustion without delay of ignition and reduced emission, especially the reduction of Nox. Depicted in FIG. 2 is the universal adaptability and capability of the universal fuel injector  120  to be associated with any conventional mechanical in-line injection pump, generically indicated by numeral  160 , by simply replacing the conventional existing injector with the “universal fuel injector”  120 . Instantly, without any structural modification, the engine can run on any fuels, including natural gas CNG and LNG, conserving and improving all the performances of the original engine.  
         [0053]    In a similar example, the capability of the universal fuel injector  120  to be associated with any conventional existing common rail injection system, generically indicated by the numeral  180  is demonstrated by using a generic electro-hydraulic valve  170  for triggering the injection process.  
         [0054]    For dual fuel operation on direct injection of natural gas that is ignited by a “pilot liquid fuel,” a constant pressure natural gas, is pressurized by a parallel injection of an equal volume VL of liquid fuel in the gas container  190 , with the same volume VG of the natural gas CNG directly injected in the engine cylinder. The distributor device  191  commutes only liquid fuel for direct injection by the universal injector  120 , or diverts a “pilot fuel injection” to be directly injected in the cylinder together with the high pressure natural gas by the universal fuel injector  120 .  
         [0055]    In a similar operation of the common rail system  180 , that can directly inject all the liquid fuel, controlled by the generic electro hydraulic valve  170 , and the distributor  191 , by the universal fuel injector  120 ; or can divert a VL volume of liquid fuel toward the container  190 , and a “pilot injected fuel” through the universal fuel injector  120 , and the main volume of gas VG, equal with the volume VL of liquid fuel, is directly injected together by the universal fuel injector  120 .  
         [0056]    By permanent equality of the volume of the gas VG=VL with the volume of liquid fuel, the pressure in the gas container is maintained constant creating permanent conditions for direct injection of the natural gas and the pilot fuel in the engine combustion chamber.  
         [0057]    In FIGS.  3 - 3 . 1  there is depicted the embodiment of the universal fuel injector module  120 , operating on liquid fuel, and the included injector  10 , has a main body  121 , and a nozzle section  122 . The main body  121  connects to the injector module  50  at one end and to the nozzle section  122  at the other end. Within the injector nozzle  122  is a poppet valve  123  with the valve stem  124  being provided with a central channel  123 . 1  and pilot holes  123 . 2  located on the seat of the conical poppet head  125  of the poppet valve  123  at one end, and, at the other end, an enlarged piston head  126 , capturing lock  126 . 1  of the stem head. The valve stem  124  is displaceable in a stem guide  127  having radial slots  128  to allow fuel to flow from a supply conduit  129  to a nozzle plenum  130 . The poppet valve  123  is biased to close by the compression spring  131  seated on the stem guide  127  and retained by a spring retainer  132  fixed to the valve stem  124 . The conical poppet valve  123  has a conical seating shoulder  139  that seats on the conical seat  140  with the angle of the conical shoulder matching the angle of the conical seat.  
         [0058]    Hydraulic actuator fluid (in this instance liquid fuel) contained in the central conduit  133  contacts the piston head  126  in a piston chamber  134  and, upon sufficient pressurization, displaces the poppet valve  123  as limited by the contact of the retainer  132  with the stem guide  127 . When displaced as shown in FIG. 3. 1 , the poppet head  125  allows fluid to pass from the injector  120  through the uniform flared gap  141 . A fluted vortex guide  136  attached to the poppet valve  123  at the end of the nozzle section  122  of the injector imparts a strong directional rotation to the emitted conical spray.  
         [0059]    As centrifuged by the vortex guide  136 , the high velocity emitted spray appears to generate millions of rotations of the injected fuel inducing enormous centrifugal dispersing forces on the fuel molecules for total homogenization of the fuel mixture. Because this process is repeated by the multiple induce pulsation injection described in the referenced patent, the super dispersion of the fuel molecules creates the supreme mixture possible for any fuel, and by definition a perfection in clean homogenization of the combustion.  
         [0060]    This liquid fuel operation is created by the double access of the liquid fuel through the central conduit  133  and the main conduit  129  that is permitted by the upper position of the switch valve  142  and the open passage  143 . In this upper position the poppet head  144  closes the conduit  145  inside of the connector  146 . This upper positioning of the switch valve  142  results from the bias of the spring  148 . Through the connection  147  the universal fuel injector is connected with the source of the high pressure fuel.  
         [0061]    In FIGS.  3 - 3 . 2  there is depicted the universal fuel injector module  120  operating in the “gas-liquid mode” by the pushed down position of the switch valve  142  by the high pressure of the natural gas coming from the source CNG which opens the conduit  145 , and closes the passage  143 . The result is the access of the CNG in the conduit  129  and the liquid fuel is restricted to the central passage for supplying the “pilot injection” through the central conduit  133  and  123 . 1  and the pilot holes  123 . 2 . The direct injection of the high pressure gas CNG and the high pressure liquid fuel pilot in the seat and vortex channel produces a perfect gas-liquid mixed spray and a supreme final air-fuel mixture.  
         [0062]    In FIG. 4, an alternate embodiment of the injector system is shown. Here the actuator module  60  includes the components as previously described with the addition of a by-pass channel  144  protected by a poppet valve  146 , with a seating end  147  urged toward the valve orifice  148  by a compression spring  150 . The supply port  66  initially provides access to the valve  65  through an enlarged section  152  of the poppet valve cylinder  154 . When the electronically controlled spool valve  64  is opened allowing pressurized actuating fluid to flow to the actuating cylinder  24 , back pressure against the sitting end  147  of poppet valve  146  then displaces the valve against the seating end  147  of poppet valve  146 , displacing the valve against the spring  150  and opening the large orifice  148 . The surge of pressurized actuating fluid acts on the amplifier piston  32  to generate a forceful and instantaneous driving pulse for actuating the injection.  
         [0063]    To facilitate a rapid cut-off at the end of injection, an enlarged cut-off valve  158  is provided to match the high flow system described for a rapid response system utilizing the by-pass valve  146 .  
         [0064]    While, in the foregoing, embodiments of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those of skill in the art that numerous changes may be made in such detail without departing from the spirit and principles of the invention.