Abstract:
A continuous combustion system for an internal combustion engine includes a reaction vessel external to the engine cylinders. The reaction vessel contains a combustion chamber for sustaining continuous combustion of an air fuel mixture during the operation of the associated engine. The reaction vessel contains an incoming air chamber and an exhaust gas chamber that are each in communication with the combustion chamber. Injected fuel vapor is mixed with scavenged exhaust gas for pre-heating and with compressed air from each cylinder provided during the compression stroke of each piston. The compressed air and fuel vapor mixture sustains the ignited combustion continuously, while exhaust gas is fed to the cylinders to provide working fluid to the engine during the power stroke of each piston. A valve mechanism is provided to control the flow of air from and working fluid to the cylinders at the appropriate times in order to sustain operation of the engine.

Description:
RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. provisional application Ser. No. 61/011580 filed on Jan. 17, 2008. 
     
    
     BACKGROUND  
       [0002]    1. Field of the Invention 
         [0003]    The invention is directed to the field of internal combustion engines and more specifically to the area of utilizing continuous combustion for powering such engines. 
         [0004]    2. Description of the Prior Art 
         [0005]    It is well known that two and four stroke internal combustion engines are configured to have a variable combustion chamber as part of the cylinder in which the associated piston reciprocates. In the case of the “Internal Combustion Engine With a Single Crankshaft and Having Opposing Cylinders and Opposing Pistons in Each Cylinder” described in my U.S. Pat. No. 6,170,443 and incorporated herein by reference (“OPOC engine”), each working chamber is a combustion chamber associated with a pair of opposing pistons in a cylinder to provide direct power expansion forces to the faces of the pistons. In each case, combustion is ignited at critical points of the engine stroke cycle resulting in intermittent and individual combustions for each piston cycle. For instance, in a conventional Diesel- or Otto-engine operating at 5000 rpm the total combustion in each cycle has to be initiated, controlled and finalized in only one millisecond. While such high speed combustions are manageable from an engine control standpoint, there is room for improvement in terms of simplification, efficiencies and especially emissions. 
       SUMMARY OF THE INVENTION  
       [0006]    The present invention achieves the goal of simplifying internal combustion engine construction, operation, and maintenance by providing a reaction vessel which contains a central chamber where combustion takes place on a continuous and controlled basis external of the cylinders of the engine. 
         [0007]    The present invention provides continuous internal combustion but intermittent application of hot gases to the moving parts of the engine. Air within the cylinder is initially compressed by the pistons during their compression cycle. The compressed air is transferred to a separate combustion chamber where it is combined with a fuel to support a controlled continuous combustion. The combustion product is a hot pressurized working fluid which is transferred to the same cylinder after the pistons reach TDC for conversion to work by expansion in the cylinder. The cylinder of the OPOC engine contains reciprocating pistons which define, with the cylinder, the working chamber. The pistons are movable with cyclic motions which cause alternate expansion and contraction of the working chamber. The combustion chamber is separate from the working chamber and contains means for burning a fuel utilizing the compressed air at substantially constant pressure to produce a hot pressurized working fluid. 
         [0008]    During operation of the continuous combustion engine, the intake port is opened to admit air into the working chamber. In the case of a 2-cycle OPOC engine, the air is forced into the chamber under pressure, such as by the use of a turbocharger or air pump. This air is then compressed during subsequent contraction of the working chamber during the compression stroke of the pistons. During this compression, and before TDC, a valving mechanism is opened to allow transfer the compressed air to the combustion chamber. In the combustion chamber air is combined with fuel to sustain combustion at a substantially constant pressure to produce a hot pressurized working fluid. Working fluid is then transferred to the same cylinder through the valving mechanism after the pistons reach their TDC positions to undergo expansion in the working chamber and drive the pistons in their cyclic motion. After expansion, the spent working fluid is exhausted through the exhaust port. 
         [0009]    Combustion gasses produced in the reaction vessel are conducted through passages to each cylinder and allowed to enter each cylinder by a control valving mechanism. Each valving mechanism is controlled to coordinate the entry of combustion gasses (working fluid) into the cylinder at or after the reciprocating piston reaches its top dead center position at the end of its compression stroke in order to provide the expansion forces necessary to drive the piston in the opposite direction during its power stroke. In the case of an OPOC engine, where the opposing pistons are asymmetric in their travel within the cylinder and reach TDC at slightly different times, the working fluid is introduced to the cylinder just after both opposing pistons have reached their TDC positions. 
         [0010]    The combustion chamber within the reaction vessel is connected to receive air from each cylinder near the end of the compression stroke of each piston to provide the air necessary to sustain the combustion in the combustion chamber. 
         [0011]    The reaction vessel is configured to scavenge and recirculate a portion of the exhaust gas within the reaction vessel to preheat and carry the injected fuel vapor into the combustion chamber where it adds to the combusted mixture. 
         [0012]    The continuous combustion provided by the present invention allows for a reduction in components and improved operation and maintenance. For instance, a single fuel injector and a single ignition device are utilized as opposed to a plurality of unique devices for each cylinder in conventional intermittent combustion engines. Additionally, a less complicated control and injection driver system is required, since only a single fuel injector is utilized for a plurality of cylinders. 
         [0013]    Other advantages are also realized. For instance, an engine utilizing the constant or continuous combustion will produce less noise than an engine utilizing a conventional intermittent combustion which produces a series of explosions. Another advantage is a reduction in polluting by-products, do to more complete combustion in a controlled and continuous environment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0014]      FIG. 1  is an overall depiction of the present invention installed on an OPOC engine. 
           [0015]      FIG. 2  is cut-away perspective view of the electromechanical valving mechanism applied to a cylinder of an internal combustion engine. 
           [0016]      FIG. 3  is a cut-away perspective enlargement of the valving mechanism shown in  FIG. 2 . 
           [0017]      FIG. 4  is a cross-sectional plan view of the mechanism shown in  FIGS. 2 and 3 . 
           [0018]      FIG. 5  is a more detailed and enlarged view of the reaction vessel shown in  FIG. 1 . 
           [0019]      FIG. 6  is a cross-sectional view of the swirl chamber of the reaction vessel shown in  FIGS. 1 and 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]    An embodiment of the internal continuous combustion engine system of the present invention is depicted in  FIG. 1 . In this embodiment, the system is installed in an OPOC engine of the type referenced above. However, it is noted that this invention is also suited as an improvement for all internal combustion engines of both four and two stroke types, as well as those that employ either diesel or spark ignition systems. 
         [0021]    In  FIG. 1 , an external, remote reactor vessel  100  is shown that provides the continuous combustion of working fluid that is supplied to the cylinders of the engine. Cylinders  200  and  300  are similar in configuration; and as is typical in an OPOC engine, each cylinder contains a pair of opposing pistons (not shown) that operate in opposite phases with respect to the pair of pistons in the opposing cylinder. That is, when the opposing pistons of cylinder  200  each reach their top-dead-center (“TDC”) positions, the pistons of the opposing cylinder  300  are at their approximate bottom-dead-center (“BDC”) positions. 
         [0022]    Electro-mechanical valving mechanisms  210 / 220  and  310 / 320  are attached to respective cylinders  200  and  300  at the ports that would normally be designated for fuel injection near the TDC volume defined in each cylinder. The valving mechanisms are electrically controlled to provide delivery of combustion gases (working fluid) from reactor vessel  100  to the cylinders when the pistons have each reached their TDC positions and provide the expansion energy required to complete the power stroke of the piston(s) in each cylinder. 
         [0023]    With reference to  FIGS. 1 ,  5  and  6 , the reactor vessel  100  is configured to have a combustion chamber  110 , an air supply chamber  120  and an exhaust gas chamber  102 . Air supply chamber  120  has a plurality of supply ports  150  and  152  that are connected via high pressure tubing or hoses  154  and  156  respectively, to receive compressed air from each cylinder. (It should be noted that the representation of the reaction chamber being outside the structure of the engine and high pressure tubing or hoses could conceivably be integrated as a structural part of the engine with high pressure passages formed therein.) Air supply chamber  120  also has an outlet port  122  that supplies compressed air freely into combustion chamber  110 . A swirl chamber  142  is located between the air supply chamber  120  and the combustion chamber  110  and provides an air/fuel mixture to the combustion chamber via its injection nozzle  162 . The exhaust gas chamber  102  is located at the opposite end of the combustion chamber  110  and is in communication with the combustion chamber via exit port  116 . The exhaust gas chamber  102  has a plurality of exhaust ports  140  and  141  that are connected via high pressure tubing or hoses  144  and  146  respectively, to provide the high pressure and heated exhaust gas working fluid to each cylinder. In addition, a feedback passage  112  is provided to allow a small portion of exhaust gas to be scavenged via scavenging port  109  from the reaction vessel and provided to the fuel entry passage  132  adjacent the fuel injector  130 . Combustion chamber  110  supports the continuous combustion of a vaporized fuel, exhaust gas and air mixture that exits the chamber as pressurized and heated exhaust gas through exit port  116  in end wall  114 . A fuel injector  130  provides the atomized fuel vapor spray  134  and is supplied to the combustion chamber via a swirl chamber  142  and an injection nozzle  162 . A venturi effect is produced by the compressed air entering combustion chamber  110  through port  122 . Since the port  122  is surrounded by injection nozzle  162 , this effect produces a vacuum in swirl chamber  142  which draws scavenged exhaust gas from feedback passage  112  mixed with the fuel vapor spray  134  provided by fuel injector  130 . The scavenged exhaust gas provides preheating of the fuel vapor prior to becoming mixed with the compressed air in the combustion chamber  110 . 
         [0024]    Any conventional ignition device  107  can be employed. Ignition sources typically could include a spark plug, glow plug, or spark discharge device to establish the initial ignition. However, once combustion is commenced, there is no need to provide further ignition, since the system will feed the combustion chamber with a fuel air mixture that is continually sustained until the fuel supply is shut off or combustion air supply is terminated. 
         [0025]    Once combustion is commenced, the combustion gasses are under high pressure and exit through exhaust port  116 , into exhaust chamber  102 . From there, the exhaust gasses are routed into each cylinder when the corresponding pistons have reached their TDC positions by the electromechanical valving mechanisms  210 / 220  and  310 / 320 . In order to avoid redundant descriptions, the following discussion will focus on valving mechanism  210 / 220 . The electro-mechanical valving mechanisms  210 / 220  and  310 / 320  are identical in construction, function and operation, and only differ by being operated in different phases. 
         [0026]    In  FIGS. 2 ,  3  and  4 , the electromechanical valving mechanisms  210 / 220  are depicted as mounted in a common housing  211 . The valving mechanism  220  contains a spool valve  222  which is linearly movable to open exhaust gas port  148  to supply combusted exhaust gas working fluid under pressure to the cylinder  200  during the power stroke phase following the pistons reaching TDC. The spool valve  222  also is linearly movable to close off that supply and open up the compressed air port  158 . The valving mechanism  210  drives a seated valve  212  that is in direct communication with the cylinder  200 . At predetermined times, valve  212  is opened to allow the compressing air from the cylinder to feed reactor vessel  100  and then to allow the high pressure exhaust gas working fluid to enter the cylinder. 
         [0027]    In this embodiment, valving mechanism  220  includes a solenoid which includes a pair of electromagnetic coils  228  which are used to drive a ferrous plate  226  mounted on a rod  227  that is connected to spool valve  222 . In this embodiment, rod  227  extends through an aperture  221  in the housing of valve mechanism  220 . A biasing spring  224  is provided to position the spool valve  222  in the position shown in  FIGS. 2 ,  3  and  4 . 
         [0028]    Valving mechanism  210  includes a solenoid having a pair of electromagnetic coils  218 a and  218 b which are used to drive a ferrous plate  216  mounted on a rod  219  that is connected to seated valve  212 . A biasing spring  214  is provided to position the seated valve  212  in a half open condition by interacting with a plate  217  mounted on rod  219  when the coils  218   a  and  218   b  are not energized. In this embodiment, rod  219  is shown as extending through an aperture  215  in the housing of valve mechanism  210 . When coils  218   a  and  218   b  are energized, valve  212  is held in the closed position, as shown in  FIGS. 2 ,  3  and  4 . 
         [0029]    Swirl chamber  142  is depicted in  FIG. 6 . Swirl chamber  142  has an internal spiral cavity formed with a fuel injection entry passage  132  on the outer portion of the spiral cavity. A plurality of mixing vanes  145  are positioned in a circular pattern to cause disturbance and mixing of the fuel vapor with the scavenged exhaust gas prior to being forced through port  122  and into combustion chamber  110 . Fuel injector  130  is mounted on entry passage  132  so that atomized fuel vapor spray  134  is evaporated into the hot and pressurized exhaust gas scavenged via scavenging port  109  and delivered through feedback passage  112 . The vaporized fuel and exhaust mixture is then drawn into the internal swirl chamber  142  by the venturi effect of compressed air being jetted out through port  122 . The vaporized fuel and exhaust mixture is mixed with the compressed air from the cylinder(s) and combusted in combustion chamber  110 . 
         [0030]    In operation, as the piston (or pistons in the case of an OPOC engine) in cylinder  200  starts its compression stroke, coils  218   a  and  218   b  of the valve mechanism  210  are energized to move plate  216  and rod  219  upwards a distance X-X ( FIG. 4 ) to close the valve  212 . Prior to the piston reaching its TDC position, coils  218   a  and  218   b  are de-energized and the force of biasing spring  214  causes seated valve  212  to open. Coils  228   a  and  228   b  of valve mechanism  220  are energized to open compressed air port  158  as the piston approaches TDC. The force applied to plate  226  by the energized coils  228   a  and  228   b  is sufficient to overcome the force of biasing spring  224  and draw the spool valve  212  to the right and close exhaust gas port  148  while opening compressed air port  158 . At TDC, the coils  228  of valve mechanism  220  are de-energized and the spring  224  forces plate  226  and rod  227  to the left a distance Y-Y ( FIG. 4 ) to close the compressed air port  158  and open the exhaust gas (working fluid) port  148 . 
         [0031]    During and near the end of the compression stroke of the piston, compressed air is supplied through conduit  154  to compressed air chamber  120  where it is allowed free passage into combustion chamber  110  via nozzle  122 . 
         [0032]    By cycling the valve mechanisms in synchronism with the stroke cycle of the pistons, compressed air is supplied to and working fluid, in the form of exhaust gases, are released from the combustion chamber to support continuous combustion therein. 
         [0033]    When one considers that another cylinder  300  is working in opposite phase with cylinder  200 , it can be seen that there may be a pulsated backpressure, but essentially continuous delivery of compressed air to the combustion chamber; and a pulsated but essentially corresponding continuous release of working fluid from the combustion chambers. With an increased number of cylinders connected to the combustion chamber backpressure effects will be reduced. 
         [0034]    Before TDC in cylinder  200  and when compressed air is entering air supply chamber  120  from conduit  154 , combustion is continuously supported in combustion chamber  110  and after TDC the combustion gasses are being supplied to cylinder  300  through valving mechanisms  310 / 320  after the piston(s) in that cylinder reached TDC. 
         [0035]    Shortly after the piston(s) in cylinder  200  reach TDC, valving mechanism  220  is de-energized to allow spring  224  to move spool valve  222  to the left in order to both close compressed air port  158  and open exhaust gas port  148 . Valving mechanism  210  opens seated valve  212  to allow exhaust gases to enter cylinder  200  and provide the necessary energy to drive the piston(s) during its power stroke. Valve  212  is then closed before the piston reaches its BDC position and remains closed until the piston enters its compression stroke. 
         [0036]    Combustion is substantially continuous, even though fuel injection may be controlled with pulse width modulation (“PWM”) to regulate the intensity and power generated by the combustion, the result is less components and improved operation and maintenance. 
         [0037]    The fact that there are no more pulsating explosions occurring in each cylinder, the noise generated due to such explosions is eliminated. In addition, NOX emissions are substantially reduced with an extremely high exhaust recirculation rate, while fuel economy is also enhanced. 
         [0038]    As can be seen by the drawings and accompanying explanation, the present invention is a unique improvement over conventional engines. And while the embodiment shown here is the preferred embodiment, it shall not be considered to be a restriction on the scope of the claims set forth below.