Abstract:
The present invention discloses an air-entrainment mechanism for carbureted engine. The mechanism includes a plunger valve controlled by a solenoid. The solenoid is powered by a battery with a switch electrically coupled thereto. The plunger valve is interconnected to the carburetor to allow additional air entrainment. The solenoid is coupled to the valve for opening and closing the valve. The switch electrically couples the solenoid to the battery to activate the solenoid for movement of the valve. The switch disclosed herein includes a temperature sensor and an engine-running sensor. The switch is then closeable when the temperature sensor detects an engine temperature within a predetermined range as long as the engine is not already running.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates generally to Engine Management and, more specifically, to carburetion controls.  
         BACKGROUND OF THE INVENTION  
         [0002]    There are two current mechanisms used for hot-start valve manipulation: a cable and housing or cable operated systems used for manipulating a carburetor body-mounted valve or a manually manipulated carburetor body-mounted valve assembly  10   a  as is shown in FIG. 1 a.  The manually manipulated carburetor-mounted valve needle  18  requires the rider to take one hand off the handlebars and reach down to the valve location, grasp the valve handle  12  on the carburetor  30  to withdraw the valve needle  18  to admit atmospheric air  21 . The act of manipulation is necessary whenever a restart is required or desired when the engine assembly is at operating temperatures or hot-start conditions. The act of removing the rider&#39;s hand from the handlebars and looking at the carburetor  30  in order to locate and manipulate the valve is time consuming and can be difficult during racing when rapid restarts are desired. These movements must be reversed to again replace the valve needle  18  under running conditions.  
           [0003]    Cable-operated systems  10   b  allow for a handlebar located pull for remote activation and are an improvement over the carburetor-mounted valve as shown in FIG. 1 a.  This system uses a cable  13 , connected to a lever that is mounted to a handlebar-mounted clamp, usually the backside of a brake clamp or incorporated into a clutch mount. Clamping along a frame of a motorcycle fixedly holds a housing  14  for the cable  13 . The movement of the cable  13  within and relative to the housing  14  results in a precise movement used to open and close the valve needle  18 . Free play adjustment is required to ensure proper valve needle  18  positioning in the carburetor body  30 . This adjustment ensures that the valve needle  18  is not held out of its position in the carburetor body  30 , effectively activating the hot-start system and introducing air  21  into the intake passage during normal operating conditions. It also ensures that when the lever is pushed, the cable  13  is sufficiently withdrawn as to provide adequate removal of the valve needle  18  from the carburetor body allowing the additional air into the intake passage that facilitates starting. Because of the necessity of regular adjustment to optimize the operation, cable operation is not adequate for a robust system.  
           [0004]    What is needed in the art is a system that does not require adjustment. Additionally, there is an unmet need for a means of activation would allow for accurate sensing of the need for activation of a hot-start valve and would automatically activate or automatically allow activation of the valve. Additionally, an electrical system allows selective locking-out of the activation of the valve.  
         SUMMARY OF THE INVENTION  
         [0005]    A solenoid-operated plunger valve controls airflow from the external environment to the air fuel mixture of the carburetor for an internal combustion engine. During normal operation, the valve plunger extends into the carburetor body, blocking the air passage used for introduction of additional air into the intake passage. During restarts at operating temperatures, the normally open switch is closed by the operator&#39;s thumb at the handlebar when hot engine conditions require additional air into the intake passage. Closing the switch allows electrical current stored in the battery to energize the solenoid, removing the plunger from the carburetor body and introducing additional air into the intake passage. In another preferred embodiment, there is a toggle switch that allows for “hands free” operation of the hot-start valve during race conditions. The toggle switches the hot-start system between manual (push button) activation and thermal switch activation with a time-out circuit. The time-out circuit allows for a predetermined amount of time to pass with the hot start activated while the engine is not running and above a set operating temp. This further reduces the need to visually locate a hot-start activation switch when quick restarts are necessitated by engine stalls during competition.  
           [0006]    The preferred embodiment of the invention includes a hot-start mechanism for an internal combustion engine carburetor having an airflow passageway. The mechanism includes a valve, an electrically-operated valve-movement mechanism, and a valve switch. The valve is in fluid communication with the airflow passageway. The valve-movement mechanism is operatively connected to the valve to selectively move the valve. Activation of the valve-movement mechanism opens the valve to admit additional air into the airflow passageway. The valve switch is electrically coupled to the valve-movement mechanism for activation of the valve.  
           [0007]    In one preferred embodiment, the invention includes a processor electrically coupled to the switch. A processor controls the valve and a power source is electrically coupled to the processor. The power source is preferably a battery. A solar collector is coupled to the battery to keep it charged in one embodiment.  
           [0008]    A preferred embodiment of the valve-movement mechanism includes a solenoid. In such embodiment, the valve is more specifically a plunger valve.  
           [0009]    One preferred aspect of the invention includes a temperature sensor interconnected with the processor. The temperature sensor provides a signal indicative of the engine temperature. The processor only activates the solenoid to open the valve when the engine temperatures are within a predetermined range.  
           [0010]    Another preferred aspect of the invention includes an engine-running sensor interconnected with the processor. The engine-running sensor provides a signal to the processor indicative of whether the engine is running. The solenoid holds the valve closed upon an engine-running condition or a running condition at a certain RPM level. The engine-running sensor preferably includes a connection to an engine stator to magnetically sense the dynamic rotational state of the engine. Where both an engine-running sensor and a temperature sensor are employed, the processor opens the valve upon predetermined input from the sensors.  
           [0011]    In one preferred embodiment, a timer switch for closing the valve after a predetermined time lapse is provided. An indicator light is also provided to signal to the user whether the valve is open. In one embodiment, an override switch is interconnected with the valve-movement mechanism to control the position of the valve regardless of input from the sensors.  
           [0012]    In one embodiment where the engine includes a start switch, the valve switch is coupled to such start switch for opening of the valve if the engine temperatures are within a predetermined range and the start switch is activated.  
           [0013]    The present invention also includes a method of starting a carbureted engine. The method includes the steps of determining the need for additional air entrainment into the carburetor, electrically opening an air-entrainment valve allowing additional air into the carburetor, cranking the engine until a running state is achieved, and closing the valve. In the preferred embodiments, a plunger valve is employed. The step of opening the valve is carried out with a solenoid coupled to the plunger valve. Engine temperature is sensed as part of the step of determining the need for additional air entrainment. Oxygen senors and other engine state sensors such as manifold air pressure are advantageously used to sense the engine state while not adding significantly to the cost. Sensing the running state of the engine also comprises part of such step. Preferably, a timeout switch is employed to close the valve after it is opened. Furthermore, a vehicle start switch is used in one embodiment to open the air-entrainment valve after the step of determining the need for additional air entrainment. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.  
         [0015]    [0015]FIG. 1 a  is a side view of a prior-art manual plunger valve;  
         [0016]    [0016]FIG. 1 b  is a system schematic of the prior-art manual plunger valve;  
         [0017]    [0017]FIG. 2 a  is a side view of a prior-art engine assembly with a cable operated plunger valve installed;  
         [0018]    [0018]FIG. 2 b  is a system schematic of the prior-art engine assembly with a manual cable-controlled plunger valve installed;  
         [0019]    [0019]FIG. 3 a  is a side view of an engine assembly with a solenoid-controlled plunger valve installed;  
         [0020]    [0020]FIG. 3 b  is a system schematic of the engine assembly with a solenoid-controlled plunger valve installed;  
         [0021]    [0021]FIG. 4 is a system schematic of the engine assembly with a solenoid-controlled plunger valve installed;  
         [0022]    [0022]FIG. 5 is an alternate system schematic of the engine assembly with a solenoid-controlled plunger valve installed; and  
         [0023]    [0023]FIG. 6 is a flowchart of the method for a hot start of an engine using a solenoid-controlled plunger valve.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    [0024]FIG. 1 a  is a diagram showing a prior-art carburetor-mounted valve. This type of valve mounts directly to a carburetor body, which is located in the engine area near the rider&#39;s knee when in the riding position. The operative elements of the prior-art valve include a handle  12  attached to a shaft  16  passing through a retaining nut  17  and affixed to a valve needle  18 . A spring  11  urges the needle  18  into a seat on a carburetor body  30 . An operator pulls the handle axially away from the retaining nut  14  thereby admitting air  21  into the carburetor bore  32  through the seat (not shown).  
         [0025]    As illustrated in FIG. 1 b,  the plunger valve assembly  10  is incorporated onto a motorcycle internal combustion engine assembly  50  by installation into the carburetor body  56 . Placement of the plunger valve assembly  10   a  requires the rider to remove a hand from handlebars to manipulate the plunger handle  12  during hot-start conditions. The plunger valve assembly  10  must be manipulated at its location on the carburetor throat  56 , located near the rider&#39;s knee, while the rider is in the seated position, sitting on the motorcycle, in order to restart the engine  50 .  
         [0026]    Also shown is the air filter  52  in the airflow  54  into the engine  50 . The carburetor body  30  are portrayed as is a stator  24  on an engine shaft.  
         [0027]    Referring to FIGS. 2 a  and  2   b,  as with the manual system portrayed in FIGS. 1 a  and  1   b,  the plunger valve assembly  10  is incorporated onto a motorcycle internal combustion engine assembly  50  by installation into the carburetor throat  56 . The cable system allows remote activation of the plunger valve assembly  10  and no longer requires the rider to remove hand from handlebars to manipulate the plunger handle  12  (FIG. 1 a ) during hot-start conditions. Cable systems allow remote location of the activation lever  65  near the rider&#39;s hand on the handlebars  60 , but do require incorporation into the clutch or brake mounting hardware. A cable  13  and housing assembly  14  replaces the lever  12  and connects to the plunger valve assembly  10  on a first end and to the activation handle  67 , fastened by a clamp  65  mounted on a handlebar. The use of the cable  13  and housing  14  requires lever  12  free play adjustment and associated cable  13  and housing  14  maintenance.  
         [0028]    Also shown is the air filter  52  in the airflow  54  into the engine  50 . The carburetor body is portrayed as is a stator  24  on an engine shaft.  
         [0029]    Differing from the system portrayed in FIGS. 1 a  and  1   b  and the system portrayed in FIGS. 2 a  and  2   b,  the plunger valve assembly  10   c  of the present invention portrayed in FIGS. 3 a  and  3   b  is motivated by a solenoid  15  to allow electrical opening and closing of the needle valve  18 .  
         [0030]    In its simplest form, the invention is a solenoid actuator  15  for a hot start valve assembly  10   c.  Still present are the mounting nut  17 , the valve needle  18  selectively admitting the atmospheric air  21  into the carburetor bore  32 . A spring  10  optionally urges the valve needle  18  into a seat sealing the valve in opposition to the pull of the actuated solenoid  15 . A pair of leads  23  selectively conducts a current to activate the solenoid  15 .  
         [0031]    Principal elements of the solenoid plunger valve assembly  10  are shown in FIG. 4. The valve needle  18  is attached to a shaft  16  passing through a retaining nut  17 . Rather than using a handle  12  (FIG. 1), a solenoid coil draws the shaft  16  which, in turn, draws the needle  18  away from the seat in the carburetor body (not shown). Wire connections  255  and  256  selectively energize the solenoid  15 .  
         [0032]    A presently preferred embodiment is shown in FIG. 4. A processor  20  is electrically interposed between the battery  216  and the plunger valve assembly  10  with wire connections  221  through  264 . Specifically, the battery is connected by a positive wire connection  264  and a negative  260  or conventionally a ground wire connection. By two further wire connections  252  and  256 , the processor  20  is connected to selectively operate the plunger valve assembly  10 . The processor is also connected by two wire connections  244  and  248  to a stator  24  in magnetic proximity to an engine shaft for the purpose of indicating to the processor  20  the rotational state of the engine shaft thereby allowing the processor  20  to ascertain whether the engine is running. Still another pair of wire connections  236  and  240  connect a thermal sensor  28  to the processor  20  to indicate the temperature of the engine assembly  50 .  
         [0033]    Optionally a solar collector  265  is provided to charge the battery, ideally through a connection in the processor  20 . In this embodiment, where a battery is used, charging the battery does not increase the load on the engine. The solar collector  265  is preferably a solar panel secured externally to the vehicle. A flexible panel may be used, for instance secured to the top of the fuel tank. A rigid panel may alternatively be used, mounted to the vehicle in an out-of-the-way location. Indeed, the solar panel might advantageously be placed on a helmet of a rider conducting a charging current through a suitable set of leads to the battery  216 .  
         [0034]    Another embodiment allows the substitution of a capacitor for the battery  216 . Charging and discharging a capacitor to activate a solenoid  15  is advantageously used to form a no-maintenance package for such vehicles as may not require a more complex electrical system. In such a system, a current is generated by a rotor spinning with the engine shaft past the stator  24 . Pressing a switch  64  activates the solenoid  15  by discharging the capacitor.  
         [0035]    According to the presently preferred embodiment, the processor senses the temperature by means of the thermal sensor  28 , whether the engine is running by virtue of the stator  24 . Where the engine assembly  50  is suitably hot to require a hot-start strategy, when requested, the processor  20 , admits current from the battery  216  to the valve assembly  10  admitting air to the carburetor body  56  as the starter (not pictured) turns the engine over.  
         [0036]    The requesting mechanism in the presently preferred embodiment comprises the remaining four wire connections  221 ,  224 ,  228 , and  232 . Wire connections  221  and  224  connect to a switch  64  to request a hot-start activation of the plunger valve assembly.  
         [0037]    An indicator light  68  shows the activation state of the switch  64 . Both the indicator light  68  and the switch  64  are mounted on the handlebar  60  and communicate with the remainder of the system by means of a wire bundle  27 . Activation of the switch  64  is received at the processor  20  as a request for hot-start activation of the plunger valve assembly  10 . Additionally, a lock out switch  62 , also mounted on the handlebar, allows the operator to lock out any request to activate the plunger valve assembly  10  where the operator&#39;s judgment suggests that overriding the processor  20  is appropriate.  
         [0038]    Referring to FIGS. 5, 4,  3   a  and  3   b,  one embodiment of the invention includes a readily controllable interface between the rider and the invention. To further an object of the invention, the interface includes a switch  64  including a three-way activation system. The switch  64 , in this embodiment, has a single push button normally open switch that the rider will depress to activate the solenoid  15 . The single push button may also be moved from a position  42   a  to a position  42   b  to selectively enable an automatic feature of the invention. In the automatic mode, the timer circuits  20  will suitably and selectively activate the solenoid  15  to withdraw the valve needle  18  to allow hot starts. The position of the switch is conveyed by means of the wire bundle  27 .  
         [0039]    Advantageously, an LED  44  is included to indicate the interface state. Dual colored LEDs  44  might be used or a single colored LED  44 . The purpose of the LED  44  is to allow the rider to be aware of the recognized state of the timer circuit. Such an LED  44  would advantageously serve as a troubleshooting enunciator for service of the system. In another embodiment, the LED  44  could signal the state of the valve rather than the state of the timer circuit. Another embodiment might include both LEDs.  
         [0040]    [0040]FIG. 6 is a flowchart of the method for a hot start of an engine using a solenoid-controlled plunger valve. The method begins with sensing the engine state to determine if it is running and its temperature. The process proceeds to element  74 , a determination of the hot-start engine state. If the engine is in a hot-start, non-running engine state, the solenoid is energized to admit additional air into the carburetor. If it is not in a hot-start engine state then the solenoid is not activated and the engine is simply started without opening the valve with the solenoid. Under the hot-start state, once the solenoid is opened the engine is turned over. Once the engine is turned a check is made to see if the engine has started at which point the solenoid would be de-energized such that the valve is closed.  
         [0041]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, the system might further sense atmospheric pressure and compare it to manifold pressure for appropriate activation. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment.