Abstract:
An internal combustion engine employing a valve regulating the passage of a fluid between the hollow interior of the combustion chamber and the atmosphere. The valve includes a valve body having a valve opening and a blade track passing around the valve opening. A guillotine blade slides linearly along the blade track between an open position in which said fluid may pass through the valve opening and a closed position in which the fluid is restricted from passing through the valve opening. A reciprocating driver moves the guillotine blade along the blade track when actuated by an electronic control signal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to the field of internal combustion engines. More particularly, the present invention comprises an internal combustion engine having a sliding guillotine valve. 
         [0003]    2. Description of the Related Art 
         [0004]    Most modern internal combustion engines operating on the Otto cycle (or close derivatives such as the Miller cycle) utilize intake and exhaust valves (1) to allow air to fill the combustion chamber during the intake stroke, (2) to trap air in the combustion chamber during the compression stroke and power stroke, and (3) to evacuate the products of combustion from the combustion chamber during the exhaust stroke. The timing, lift, and duration of valve opening is most commonly controlled by the rotation of a camshaft. The camshaft is mechanically linked to the output shaft of the engine such that each valve operates in synchronization with the engine&#39;s combustion cycle. 
         [0005]    In order to change the timing or duration of valve opening, one must replace the existing camshaft with a camshaft having a different cam geometry (or utilize complex mechanisms to vary the distance between the camshaft center and the valve stems). Because engines are generally equipped with camshafts having nearly optimal cam geometries, this is not much of a concern in conventional vehicle applications. When one wishes to employ a more aggressive tuning (such as in racing applications) or when one wants to improve fuel economy, having the ability to vary the timing, lift, or duration of valve opening is desirable. 
         [0006]    Optimal timing, lift, and duration are functions of engine speed and load. Thus, in order to operate at optimal volumetric efficiency, it is necessary to vary timing, lift, and duration throughout an engine&#39;s powerband. It has become increasingly common to utilize multiple intake or exhaust valves on a single combustion chamber or to utilize multiple camshafts or cams to control a single valve. These systems improve volumetric efficiency, but do so at the expense of additional weight, cost, and complexity. Thus, it would be desirable to provide an intake and exhaust valve design which is highly variable such that different timing, lift, and duration may be employed throughout the engine&#39;s powerband. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention is an internal combustion engine employing a guillotine sliding valve regulating the passage of a fluid between the hollow interior of the combustion chamber and the atmosphere. The valve includes a valve body having a valve opening and a blade track passing around the valve opening. A guillotine blade slides linearly along the blade track between an open position in which said fluid may pass through the valve opening and a closed position in which the fluid is restricted from passing through the valve opening. A reciprocating driver moves the guillotine blade along the blade track when actuated by an electronic control signal. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view, illustrating the present invention. 
           [0009]      FIG. 2  is sectioned perspective view, illustrating the present invention. 
           [0010]      FIG. 3  is a perspective view, illustrating the present invention. 
           [0011]      FIG. 4  is a sectioned perspective view, illustrating the present invention. 
           [0000]    
         
           
                 
               
                 
                 
                 
                 
               
             
                 
                     
                 
                 
                   REFERENCE NUMERALS IN THE DRAWINGS 
                 
                 
                     
                 
               
               
                 
                     
                 
               
            
             
                 
                   10 
                   powertrain control module 
                   12 
                   cable 
                 
                 
                   14 
                   combustion chamber 
                   16 
                   spark plug 
                 
                 
                   18 
                   reciprocating driver 
                   20 
                   connector 
                 
                 
                   22 
                   blade 
                   24 
                   valve body 
                 
                 
                   26 
                   valve port 
                   28 
                   reciprocating driver 
                 
                 
                   30 
                   connector 
                   32 
                   pin 
                 
                 
                   34 
                   valve body 
                   36 
                   valve port 
                 
                 
                   38 
                   blade 
                   40 
                   intake port 
                 
                 
                   42 
                   exhaust port 
                   44 
                   channel 
                 
                 
                     
                 
               
            
           
         
       
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    The present invention can be applied to virtually any type of internal combustion engine. Those skilled in the art will know that most such engines employ 4 or more cylinders. However, in order to convey the principles of the present invention in an uncluttered manner, a single cylinder engine is illustrated. Many conventional components of such an engine have likewise not been illustrated. 
         [0013]      FIG. 1  illustrates a single-cylinder internal combustion engine employing guillotine sliding valves. Combustion chamber  14  is equipped with two guillotine sliding valves—one regulating the flow of fluid from the atmosphere through the intake port of combustion chamber  14  and one regulating the flow of fluid from the interior of combustion chamber  14  to the atmosphere through the exhaust port of combustion chamber  14 . Combustion chamber  14  represents a single “cylinder” of a traditional four-stroke internal combustion engine. In the embodiment illustrated, two guillotine sliding valves (one for intake and one for exhaust) are provided on each cylinder of the internal combustion engine. Those skilled in the art will know that additional intake and exhaust valves could be provided using the same components. 
         [0014]      FIG. 1  illustrates combustion chamber  14  during the intake stroke. Valve body  24  which houses blade  22  is attached to the intake port of combustion chamber  14 . Blade  22  reciprocates within valve body  24  under the control of reciprocating driver  18 . The reciprocating driver can assume many forms. In this embodiment, it comprises a fast-acting solenoid which is electrically energized via one of the cables  12 . The reciprocating driver can be a single-acting solenoid with a return spring, or a pair of opposing solenoids with the motion being controlled by electrical energy during the opening and closing cycle. This approach has the advantage of being directly controlled by an electronic engine control unit (“ECU”). The ECU provides low-power control signals which can then be amplified to power the solenoid(s). 
         [0015]    Other forms of energy could also be used to actuate the reciprocating driver. As a second example, a hydraulic cylinder could be used to propel connector  20  in one or more directions. The hydraulic cylinder would be one part of a hydraulic circuit which would selectively connect reciprocating driver  18  to a high pressure hydraulic line. The selective connection could be made using a solenoid to open and close a valve. Thus, this second type of system can also be easily controlled by the ECU. 
         [0016]    Returning to the example of  FIG. 1 , powertrain control module  10  applies a voltage to cable  12  causing reciprocating driver  18  to retract connector  20  and blade  22  within valve body  24 . This opens valve port  26  and allows intake air to be drawn from the intake manifold (not shown) through valve port  26  into combustion chamber  14  as the piston is drawn from top dead center to bottom dead center. 
         [0017]    Valve body  34  is attached to the exhaust port of combustion chamber  14 . Valve body  34  controls the exhaust flow from combustion chamber  14  to the exhaust header of the engine. During the intake stroke, no voltage is applied to reciprocating driver  28 . As such, connector  30  and blade  38  remain in the fully extended position within valve body  34 . Blade  38  thus blocks valve port  36  preventing exhaust gases from leaking back into combustion chamber  14  as the piston exerts a vacuum in combustion chamber  14  during the intake stroke. 
         [0018]    Turning to  FIG. 2 , the interior of combustion chamber  14  is shown. The piston, connecting rod, crankshaft, and other conventional components are not illustrated. Spark plug  16  is situated at the top of the combustion chamber between intake port  40  and exhaust port  42 . Although not shown in  FIG. 1 , spark plug  16  is also energized at the control of powertrain control module  10 . Those that are skilled in the art know that an ignition coil is typically used to generate the high voltage required to create the spark from spark plug  16 . 
         [0019]    As shown more clearly in  FIG. 3 , the guillotine sliding valves control the flow of air in and out of the combustion chamber through the intake and exhaust ports. When reciprocating driver  18  retracts blade  22 , valve port  36  is opened allowing intake air to pass from the intake manifold through valve body  26  and intake port  40  into combustion chamber  14 . 
         [0020]      FIG. 4  is a detail view of the guillotine sliding valve with the near side of valve body  34  being cut away to reveal internal details. This valve controls the flow of gas between combustion chamber  14  and the engine&#39;s exhaust manifold. In  FIG. 4 , the valve is shown in the “open” position. The reader will note that reciprocating driver  28  has moved connector  30  from the extended position (shown in  FIG. 1 ) to a retracted position. Blade  38  is attached to connector  30  by pin  32 . Blade  38  moves within channel  44  of valve body  34  when reciprocating driver  28  moves connector  30 . Channel  44  therefore acts as a blade track to guide blade  38  as it moves between the closed an opened position. As such, blade  38  moves in a direction perpendicular to the direction of travel of the piston and thus perpendicular to the direction of the vacuum and expansion forces created in combustion chamber  14  during the combustion cycle. Because of this arrangement, reciprocating drivers  18  and  28  require only a minimal amount of power to operate (since they are not opening or closing in a direction which is parallel to the flow). Those that are skilled in the art know that this is an essential requirement for any performance or fuel economy advantages to be realized by such a valve configuration. 
         [0021]    Although  FIGS. 1-3  illustrate the present invention during the intake stroke, those that are skilled in the art will now appreciate how powertrain control module  10  may be configured to control the opening and closing of the sliding guillotine valves throughout the entirety of the combustion cycle. As previously described, powertrain control module  10  opens blade  22  and closes blade  38  during the intake stroke. Both blade  22  and blade  38  are then maintained in the closed position during the compression stroke (when the piston travels from bottom dead center to top dead center) and the power stroke (when the piston travels from top dead center to bottom dead center after ignition). Powertrain control module  10  then opens blade  38  and closes blade  22  during the exhaust stroke (when the piston travels from bottom dead center to top dead center immediately following the power stroke). 
         [0022]    With the general operating principles now described, the advantages offered by such a configuration may now be considered in greater detail. As mentioned previously, such a valve configuration is advantageous for optimizing performance and/or fuel economy. This is because the valve configuration of the present invention allows for nearly infinite control and variation of valve timing, lift and duration. 
         [0023]    Most modern vehicles utilize fuel and ignition “maps” which are stored in the memory of the vehicle&#39;s engine control unit to control the amount of fuel injected into each combustion chamber as well as the timing of the ignition spark. These quantity and timing values are typically a function of engine speed (in revolutions per minute) and load (commonly based on throttle position, intake air flow rates measured by a mass air flow sensor, or both). The vehicle&#39;s engine control unit reads the engine speed and load and then looks up the quantity of fuel to inject (usually expressed in terms of fuel injector activation time) and the timing of spark (usually correlating to the position of the piston relative to top dead center during the compression or power stroke). These fuel maps can typically be modified or “tuned” for improved performance or fuel economy. 
         [0024]    In much the same way that an engine control unit is able to read maps and control fuel and spark, it is contemplated that powertrain control module  10  may be configured to read maps and control valve timing, lift and duration. As mentioned previously, valve timing, lift and duration have historically been modified by changing mechanical parts of the engine&#39;s valvetrain (for example, changing the camshaft, valves, valve springs, retainers, rocker arms, and shafts). Such is not required with the present invention. The “valvetrain” of the present invention may be easily modified by changing the maps powertrain control module  10  uses for controlling timing, lift, and duration. It should be noted that the term “lift” as used in the context of the present invention does not refer to the degree of separation of the poppet valve from the valve seat. Instead, “lift” refers to the analogous degree of opening of the guillotine sliding valve of the present invention. In the context of the present invention, “lift” may be controlled by the voltage value applied to reciprocating drivers  18  and  28 . Higher voltages result in more lift (assuming a normally closed valve is used) or vice versa (assuming a normally open valve is used). Timing and duration are also controlled electronically based on the actual time and length of time voltage is applied to reciprocating rivers  18  and  28  relative to the combustion cycle. 
         [0025]    As with fuel and spark maps, the proposed valve maps may also be engine speed and load dependant. As such, when the engine control unit reads the engine speed and load data, the same values may be used by powertrain control module  10  to look up the programmed values for valve timing, lift, and duration. It is further contemplated that various selectable map packs may be provided for the user so that the user may select a desired map for a particular application. For example, the user may select a map that is optimized for fuel economy before driving a long trip. Alternatively, the user may select a map pack that is optimized for performance before driving on a track. 
         [0026]    The use of the guillotine valve also makes it possible to selectively open additional intake and exhaust valves. Those skilled in the art will know that engines achieve higher power outputs by using multiple intake and exhaust valves per cylinder (such as a pair of intake valves and a pair of exhaust valves). However, the use of both valve pair is relatively inefficient at low engine speeds. Thus, there are advantages to being able to selectively turn on and off one or more valves in a set. The guillotine valve allows this functionality. 
         [0027]    There are many other advantages that may be realized with the guillotine sliding valve valvetrain of the present invention. Because the present invention can accomplish infinite valve timing, lift and duration by simple electronic control, there is no need for traditional valvetrain components (including camshafts and rocker arms). The removal of these components reduces engine weight, complexity, and cost. The control variability afforded by the present invention not only allows for optimized valve tuning based on load and engine speed, but also enables optimized valve tuning based on the fuel source. This feature may become more valuable as refueling stations continue to offer different ethanol and gasoline blends. 
         [0028]    The reader should appreciate that the drawings show a relatively simplified embodiment of the invention. Many conventionally understood components—such as encapsulating housings with associated oil feedings and drainage ports—have not been illustrated. The present invention would preferably include such components. 
         [0029]    The preceding description contains significant detail regarding the novel aspects of the present invention. It should not be construed, however, as limiting the scope of the invention but rather as providing illustrations of the preferred embodiments of the invention. Such variations would not alter the function of the invention. Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.