Abstract:
The invention includes an additive injection system for automatically metering a liquid fuel additive into the fuel supply of a fuel burning device. The additive injection system may be adapted to maintain a constant additive concentration in the fuel over a series of random fuel depletion and refueling cycles. Further, the additive injection system may be in communication with an engine control module to precisely determine the amount of fuel that has been consumed.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/660,086, titled Engine Control Module Linked Additive Injection System, filed Mar. 9, 2005, the contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention generally relates to an additive injection system. More specifically, the invention relates to an additive injection system in communication with an engine control module.  
       BACKGROUND OF THE INVENTION  
       [0003]     Fuel treatment additives are used to modify fuels, for example, to improve efficiency, increase power, and/or achieve air quality benefits. Many additives must be present in a specific concentration to have the optimum desired effect. Traditionally, such additives have been mixed into the fuel manually by measuring out the recommended quantity of additive per volume of fuel taken on at the fuel pump and pouring it into a tank. This method of mixing an additive into the fuel is inconvenient, and often imprecise, due to human error or neglect. Further, in automatic systems, the quantity of fuel added to a fuel tank has traditionally been determined from a sending unit line to a vehicle&#39;s fuel gauge. However, this is not an optimum indicator, as worn or sticking contacts on the float swing arm of the sending unit often produce erratic and unreliable measures at various positions on the unit&#39;s resistor.  
       SUMMARY OF THE INVENTION  
       [0004]     Embodiments of the invention include a system for automatically metering a liquid fuel additive into the fuel supply of a fuel burning device such as an internal combustion (IC) engine. In some embodiments the system is adapted to maintain a constant additive concentration in the fuel over a series of random fuel depletion and refueling cycles. Embodiments of the system provide several advantages, including adding a precise amount of additive to achieve a desired additive concentration in the fuel. In some embodiments, the system determines the fuel consumed value from data obtained from an engine control module, rather than relying on unreliable data from a fuel tank sending unit. Such a system allows for maintaining a relatively stable concentration of additive in the fuel to improve the additive&#39;s performance. Further, such a system avoids requiring a user to directly calculate and measure the correct amount of additive and introduce it into the fuel system, thereby avoiding disadvantages such as user error. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIG. 1  shows an environmental view of a motor vehicle provided with an additive injection system in accordance with an embodiment of the invention.  
         [0006]      FIG. 2  is a schematic view of an engine control module in accordance with an embodiment of the invention.  
         [0007]      FIG. 3  is a schematic view of an additive injection system in communication with an engine control module in accordance with an embodiment of the invention.  
         [0008]      FIG. 4  is a schematic view of an additive injection system in communication with a vehicle monitoring and management system onboard subsystem in communication with an engine control module in accordance with an embodiment of the invention.  
         [0009]      FIG. 5  shows a schematic view of an additive injection system in accordance with an embodiment of the invention.  
         [0010]      FIG. 6  shows a front plan view of a fuel tank sending unit in accordance with an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]     For the purpose of promoting an understanding of the principles of the present invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications of the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated therein, are contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0012]     Some embodiments of the invention include an additive injection system (hereafter, “AIS”) useful for delivering a fuel additive to an IC engine in communication with an engine control module (hereafter, “ECM”). As used herein, the term “fuel additive” means a substance that is added to fuel and/or employed to treat effluent derived from the combustion of fuel. For example, the fuel additive may comprise a polymer adapted to improve the combustion efficiency of a fuel-burning device.  
         [0013]     Further, the IC engine may be of any type, such as a gasoline engine, a diesel engine, a jet engine, a marine engine, a furnace, or a burner. In addition, the IC engine may be stationary (e.g., a diesel electric generator) or utilized in a vehicle. The term “vehicle” is used in its broadest sense, referring to any means in or by which something is carried or conveyed, and includes automobiles, trucks, airplanes, marine vehicles, off-road vehicles, recreational vehicles, construction equipment and the like. As an example,  FIG. 1  shows an embodiment of an AIS  10  mounted on the rear of a cab  20  of a truck  30 . Of course, an AIS may be mounted in any suitable location on or within a vehicle.  
         [0014]     The ECM in communication with the AIS may be of any type. An embodiment of an ECM  40  is shown in  FIG. 2 . Generally, an ECM is a computerized electronic device designed to continuously monitor, analyze and govern engine performance based on inputs  50  from various sensors located in areas in and on the engine, such as throttle position, air inlet temperature, turbo-boost pressure, oil pressure, oil temperature, coolant level, coolant temperature, fuel temperature, and/or engine timing. A programmable read-only memory (PROM) that provides instructions for basic engine control functions may work in concert with an electronically erasable programmable read-only memory (EEPROM) that stores engine calibration values, allowing the ECM to record and adjust engine performance parameters, such as fuel consumption. As shown in  FIG. 2 , the ECM may also have several outputs  60 , such as command pulses to the fuel injectors or outputs to the stop-engine and check-engine lights. Further, the ECM may have a diagnostic data link  64  to transfer data collected by the ECM to a querying device. As shown, the ECM may be powered by a battery  70 .  
         [0015]     An embodiment of an AIS  10  in accordance with the invention is shown in  FIG. 3 . The AIS may include an additive control module  80  (hereafter, “ACM”) in communication with the ECM. The ACM may be useful for receiving information and providing commands useful for providing a correct amount of additive to a fuel tank. Such communication may occur either by wire or wirelessly. In some embodiments, an AIS receiver  90  may be provided as shown in  FIG. 3 . The AIS receiver may be any appropriate device that is capable of receiving and/or sending data either by wire or wirelessly. The ACM may also be in communication with an AIS pump  100 . The AIS pump may be in fluid communication with an additive tank  110  and a fuel tank  120 , and a valve  130  may be provided between the AIS pump and the fuel tank. Upon receiving a command, the AIS pump may pump additive from the additive tank to the fuel tank. The fuel tank may contain a sending unit  140  in communication with a vehicle fuel gauge and the ACM. The ACM may also be in communication with the sending unit.  
         [0016]     As shown in  FIG. 4 , the ACM may also be in communication with a vehicle monitoring and management system onboard subsystem (hereafter, “VMMSOS”)  160 . The VMMSOS may be used for at least one of logging, tracking, reporting information or remotely triggering operations pertaining to vehicles (e.g., fleet vehicles). An example of a typical VMMSOS is PeopleNet&#39;s PerformX™. PerformX™ is a real-time evaluation tool in the PeopleNet wireless fleet management system that monitors a vehicle&#39;s performance by communicating with the engine&#39;s ECM. In that example, the ECM captures data relating to vehicle and driver performance and transmits it via the J 1708 serial-data protocol. The J 1708 serial-data protocol is a modification of the RS-485 serial data communication standard for heavy duty vehicle applications. Of course, any other suitable protocol could be utilized. Further, the ACM may communicate with the VMMSOS either by wire or wirelessly via the AIS receiver using any suitable data communications protocol.  
         [0017]      FIG. 5  shows an embodiment of an AIS in more detail. As shown, the AIS  10  may comprise an additive tank  110  to hold the additive to be injected into a fuel tank  120 . The additive tank should be large enough to hold sufficient additive for several fuel depletion and refueling cycles, and should not contain a material that interacts with the additive. Further, the tank should be located in an area that is accessible to an operator for replenishing the additive supply. In some embodiments, a cap  170  is provided to close the additive tank. Such a cap may be vented to allow for pressure regulation. In some embodiments, various components of the AIS can be mounted to a mounting plate  180 .  
         [0018]     The additive tank may be in fluid communication with an AIS pump  100  through an additive line  190  to pump  100 . The AIS pump may be any device capable of transferring additive from the additive tank to a fuel tank. In some embodiments, the AIS pump is a 12 Volt DC diaphragm pump. The AIS pump can transfer the additive to a fuel tank via an additive line  200  to the fuel tank. In some embodiments, the additive line to the fuel tank can feed into a return fuel line  210  feeding into the fuel tank. As shown in  FIG. 5 , a valve  220  may be provided between the AIS pump and the fuel tank. In some embodiments, the valve comprises a 12 Volt DC solenoid valve.  
         [0019]     The AIS pump and valve may be controlled by an ACM  80 . In some embodiments, the ACM is in physical communication (e.g., electrical communication) with the AIS pump and valve via a wire  230 . The ACM may be any device suitable to perform its function, such as a microprocessor. In some embodiments, the ACM may include the processing, storage, and communications equipment to receive signals from the sending unit, query the ECM, receive data from the ECM, convert that data into an amount of additive to be added, instruct the pump to deliver the additive into the fuel system, and control any valves that may be present in the AIS. In some embodiments, the ACM may comprise a receiver  90  to receive and/or transmit data. Such a receiver may be powered by a 12 Volt DC power line. Further, the receiver may be adapted to receive communications either by wire or wirelessly. In some embodiments, a sending unit line  240  may be provided between the sending unit  140  and the receiver  90 . As described further below, this line may be used to signal to the ACM that fuel has been added to a fuel tank. The receiver may also be able to communicate with an ECM or a VMMSOS.  
         [0020]     The power requirements of the AIS may be met in any suitable way, such as connection to the power grid, single use batteries, rechargeable batteries, or using power from a vehicle&#39;s battery that is in turn charged from the IC engine. Power may be delivered to the AIS via input line  234 . In the AIS shown in  FIG. 5 , a fuse  250  may be provided to shield the components from electrical surges. In addition, a ground connection  260  may be provided.  
         [0021]     Such an AIS system can be installed in any suitable manner. For example, the components discussed above may be mounted to the mounting plate. The mounting plate may then be installed in any suitable location, such as on the rear of a cab as shown in  FIG. 1 . The AIS may then be connected to the vehicle&#39;s electrical system, the additive line may be directly or indirectly connected to the fuel tank, and the sending unit may be placed in communication with the ACM.  
         [0022]     An embodiment of a typical sending unit is shown in more detail in  FIG. 6 . As shown, the sending unit  140  may comprise a swing arm  270  having a float  280  at its distal end  290 . The float is adapted to rise and fall with changing fuel levels so as to pivot the swing arm about its proximal end  300 .  FIG. 6  shows the float in a relatively lower position in solid lines, indicating a low fuel level, and a relatively higher position in broken lines, indicating a high fuel level. The swing arm may be in contact with a resister  310 . As the swing arm pivots, the resistance changes and a variable electrical signal dependent on the position of the fuel is generated and sent to a fuel gauge. This signal may also be used to alert the ACM that fuel has been added to the fuel tank.  
         [0023]     In some embodiments, the AIS is in communication with the sending unit. In such embodiments, the AIS may determine when fuel has been added to the fuel tank. The AIS may use the signal that fuel has been added as a trigger mechanism to communicate with the ECM to determine the amount of fuel that has been added, as described further below, rather than determining the amount of fuel added from the sending unit itself.  
         [0024]     On receiving the alert from the sending unit, the ACM may read the quantity of fuel consumed since the previous alert (hereafter, the “fuel consumed value”) from the ECM via data link  64 . The ACM may then convert this reading to a numerical value, calculate the correct amount of additive to be injected into the vehicle&#39;s fuel system (hereafter, the “additive value”), and command the AIS pump to inject the additive value into the fuel tank.  
         [0025]     In use, a user would fill up the fuel tank, thereby activating the sending unit. In the embodiment shown in  FIG. 3 , on receiving the alert from the sending unit, the ACM reads the fuel consumed value from the ECM via a data link (e.g., a SAE J1587/J1708 data link) to the engine&#39;s diagnostic port. The ACM then converts this reading to a numerical value, calculates the additive value, and commands the AIS pump to inject the additive value into the fuel tank. In some embodiments, the ACM reads the fuel consumed value from the ECM wirelessly via the AIS receiver.  
         [0026]     In the embodiment shown in  FIG. 4 , on receiving the alert from the sending unit, the ACM may signal the VMMSOS to read the fuel consumed value from the ECM. On reading the fuel consumed value from the ECM, the VMMSOS may relay this value to the ACM where the command for the AIS pump to inject the additive value is processed. The ACM in turn may relay the command to the AIS pump to inject the additive value into the fuel tank. In other embodiments, on receiving the alert from the sending unit, the ACM may signal the VMMSOS to read the fuel consumed value from the ECM, whereupon the VMMSOS may convert the fuel consumed value to a numerical value, and process a command for the AIS pump to inject the additive value. The ACM may then relay the command from the VMMSOS to the AIS pump to inject the additive value into the fuel tank. Further, in some embodiments, the ACM communicates with the VMMSOS wirelessly via the AIS receiver.  
         [0027]     While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations, which fall within the spirit and broad scope of the invention.