Patent Application
20100252135
The subject matter disclosed herein relates generally to fuel control systems and methods for engines. More particularly, the subject matter disclosed herein relates to a fuel system that is adjustable to supply different fuels using a single carburetor.
Although gasoline is the predominant fuel used in many internal combustion engines, it is well known that such engines may be operated by any of a variety of different fuels. For instance, ethanol, methanol, butane, and others may also be used. In fact, with the increasing cost of hydrocarbon fuels (e.g., gasoline) and fluctuations in global supplies, the use of other fuels has received increased interest. However, since most internal combustion engines and their carburetors are designed for efficient use of gasoline, other fuels generally cannot be used effectively without changes to one or both of the engine itself or its carburetor. Such changes are necessary because each fuel operates on a particular air/fuel ratio (i.e., the stoichiometric mixture) for most efficient combustion.
For example, the stoichiometric air/fuel ratio of gasoline is about 14.6 units air to 1 unit of fuel. In contrast, the ratio for ethanol is about 9 to 1, and the ratio for methanol is about 6.5 to 1. Although many available fuel products are made up of mixtures of these materials (e.g., E20, E85), it is still apparent that the preferred operating conditions for using these different fuels in an internal combustion engine can vary greatly.
Accordingly, it would be advantageous for an internal combustion engine to be capable of operating using any of a variety of different fuels without requiring a dedicated carburetor for each fuel. Further, it would be favorable for the configuration of such an engine to be easily switched to provide the preferred operating conditions for the fuel being used.
In accordance with this disclosure, devices and methods for adjusting the configuration of a carburetor are provided. In one aspect, a multi-fuel carburetor for a combustion engine is provided. The multi-fuel carburetor can include a fuel source, a carburetor barrel, first and second fuel nozzles, and a fuel control device movable with respect to the second fuel nozzle. The first fuel nozzle can have a first inlet at and communicating with the fuel source and a first outlet at and communicating with the carburetor barrel, and the second fuel nozzle can have a second inlet at and communicating with the fuel source and a second outlet at and communicating with the carburetor barrel. The fuel control device can be movable between a closed position in which the second fuel nozzle is blocked and an open position in which the second fuel nozzle is unobstructed.
In another aspect, a multi-fuel carburetor for a combustion engine can include a fuel source, a carburetor barrel, a first fuel nozzle, a second fuel nozzle, a fuel control device, and a control rod connected to the fuel control device. The first fuel nozzle can have a first inlet at and communicating with the fuel source and a first outlet at and communicating with the carburetor barrel, and the first fuel nozzle being sized to provide an amount of fuel to the carburetor barrel for producing an air/fuel ratio in the carburetor barrel for the combustion of a first fuel type. The second fuel nozzle can have a second inlet at and communicating with the fuel source and a second outlet at and communicating with the carburetor barrel, and the second fuel nozzle being sized such that the combination of the first fuel nozzle and the second fuel nozzle provide an amount of fuel to the carburetor barrel for producing an air/fuel ratio in the carburetor barrel for the combustion of a second fuel type. The fuel control device can be movable with respect to the second fuel nozzle, and the fuel control device can include a plate movable between a closed position in which the fuel inlet of second fuel nozzle is blocked and an open position in which the fuel inlet of second fuel nozzle is unobstructed. The control rod can be provided such that rotation of the control rod moves the plate between the closed position and the open position.
In another aspect, a method for providing fuel to a multi-fuel carburetor for a combustion engine can include supplying fuel from a fuel source through a first fuel nozzle and into a carburetor barrel, supplying fuel from the fuel source through a second fuel nozzle and into the carburetor barrel, and moving a fuel control device with respect to the second fuel nozzle between a closed position in which the second fuel nozzle is blocked and an open position in which the second fuel nozzle is unobstructed.
Aspects of the subject matter disclosed herein having been stated hereinabove, and which is achieved in whole or in part by the presently disclosed subject matter, other aspects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.
The features and advantages of the present subject matter will be more readily understood from the following detailed description which should be read in conjunction with the accompanying drawings that are given merely by way of explanatory and non-limiting example, and in which:
The present subject matter provides multi-fuel carburetors and related methods for an internal combustion engine. As is illustrated in
Referring to
Regarding the fuel nozzles, first fuel nozzle 30 can have a first inlet 32 in communication with fuel source 20 and a first outlet 34 in communication with carburetor barrel 10. First fuel nozzle 30 can be sized to provide an appropriate amount of fuel to carburetor barrel 10 for a first fuel type. In other words, first fuel nozzle 30 can be designed to provide an amount of fuel to carburetor barrel 10 to create the correct stoichiometric air/fuel ratio in carburetor barrel 10 for the combustion of the first fuel type. For example, if the first fuel type is gasoline, first fuel nozzle 30 can be sized to create the stoichiometric air/fuel ratio for gasoline (e.g., about 14.6 to 1) in carburetor barrel 10.
If fuel source 20 contains a fuel type requiring a richer fuel mixture for combustion, however, first fuel nozzle 30 alone can be insufficient to efficiently provide adequate fuel flow. Accordingly, second fuel nozzle 40 can be operated to provide an additional fuel flow from fuel source 20. In this regard, second fuel nozzle 40 can similarly have a second inlet 42 in communication with fuel source 20 and a second outlet 44 in communication with carburetor barrel 10. Second fuel nozzle 40 can be sized to provide, in combination with first fuel nozzle 30, an appropriate amount of fuel to carburetor barrel 10 for combustion of a second fuel type. Stated otherwise, the amount of fuel that can be provided to carburetor barrel 10 through second fuel nozzle 40 can supplement the amount of fuel provided by first fuel nozzle 30 such that the air/fuel ratio in carburetor barrel 10 is decreased so as to have the proper stoichiometric ratio for the second fuel type. For example, second fuel nozzle 40 can be sized such that the combined flow of fuel through first fuel nozzle 30 and through second fuel nozzle 40 provides an air/fuel ratio in the carburetor barrel 10 for the efficient combustion of a second fuel type, such as ethanol (e.g., E100).
In addition, if the operator desires to operate the engine using a fuel type having a preferred air/fuel ratio that lies somewhere between the stoichiometric ratios for the first fuel type (i.e., first fuel nozzle 30 alone) and the second fuel type (i.e., first and second fuel nozzles 30 and 40 combined), second inlet 42 can be at least partially obstructed to reduce the amount of fuel that is provided to carburetor barrel 10. Depending on the precision in which this obstruction can be controlled, carburetor C can be operated using any of a wide variety of fuel types in fuel source 20.
In this regard, fuel control device 50 can be used to control the amount of fuel that is permitted to flow through second fuel nozzle 40 to carburetor barrel 10. In one aspect and as is shown in
For instance, in one exemplary embodiment depicted in
Alternatively, as is shown in
In addition, as noted above, carburetor C can be designed to allow adjustments to the air/fuel ratio to values between the maximum (first fuel nozzle alone) and the minimum (both first and second fuel nozzles) ratios. These intermediate mixtures can be created by fuel control device 50 being movable to at least one intermediate position between the open position and the closed position. For instance, and with respect to the regulating portion shown as regulating portion 52 with a rotatable plate, fuel control device 50 can be operated so that regulating portion 52 is positioned to only partially obstruct second inlet 42 of second fuel nozzle 40 as is shown in
In either configuration, movement of fuel control device 50 to an intermediate position provides more fuel to carburetor barrel 10 than is provided by first fuel nozzle 30 alone, but less fuel than is provided by the first and second fuel nozzles 30 and 40 together when fuel control device 50 is in an open position. For example, if first fuel nozzle 30 is sized to provide the proper air/fuel ratio for gasoline, and second fuel nozzle 40 is sized such that the combination of first and second fuel nozzles 30 and 40 produces an air/fuel ratio for pure ethanol, moving fuel control device 50 to an intermediate position can be advantageous to achieve the proper air/fuel ratio for a variety of ethanol blends (e.g., E20, E85) or any of a variety of other fuel types. As a result, the use of carburetor C according to the presently disclosed subject matter can allow an internal combustion engine to be operated using a wide variety of fuel types without requiring any substantial modifications to the engine or carburetor.
The present subject matter can be embodied in other forms without departure from the spirit and essential characteristics thereof. The embodiments described therefore are to be considered in all respects as illustrative and not restrictive. Although the present subject matter has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art are also within the scope of the present subject matter.
