Patent Application
20120042848
During prolonged periods of time in which an engine is not used, fuel remaining within the engine may become stale. Such stale fuel may cause corrosion of internal carburetor parts such as jets, seats, needles, o-rings and the like.
As shown by
Fuel stabilizer reservoir 24 comprises a tank, container, chamber or other volume configured to contain and store a fuel stabilizer. Fuel stabilizer reservoir 24 is connected to fuel stabilizer metering device 28 so as to deliver fuel stabilizer to fuel stabilizer metering device 28. Reservoir 24 may have various sizes, shapes and configurations. Reservoir 24 may comprise a reservoir that is refillable while connected to metering device 28 or may be a type that requires disconnection from metering device 28 for refilling or replacement.
Fuel stabilizer metering device 28 comprises a device configured to meter or supply a predetermined amount or volume of fuel stabilizer to bowl 32 of carburetor 30 after initiation of engine shutdown. In one embodiment, metering device 28 does not deliver any stabilizer to engine 20 or bowl 32 of carburetor 30 while engine 20 is running (prior to any initiation of shutdown of engine 20). In another embodiment, fuel stabilizer metering device 28 meters fuel stabilizer to bowl 32 of carburetor 30 only after engine shutdown has been completed. In some embodiments, metering device 28 may meter a predefined quantity of fuel stabilizer to bowl 32 of carburetor 30 while the engine is being shut down (but not prior to initiation of engine shutdown) and after shutdown has been completed.
Because of fuel stabilizer metering device 28 meters a predefined quantity or volume of fuel stabilizer, a user of the appliance having engine 20 is not inconvenienced by having to measure the appropriate amount of fuel stabilizer and by having to manually supply fuel stabilizer to anything other than reservoir 24. Because fuel stabilizer metering device 28 meters a predefined quantity or volume of fuel stabilizer only at least after initiation of engine shut down or after completion of engine shutdown, most, if not all, of the fuel stabilizer added to bowl 32 of carburetor 30 remains within bowl 32 to stabilize fuel and is not consumed immediately prior to shutdown of engine 20. As a result, wasteful consumption of fuel stabilizer is reduced.
According to one embodiment, fuel stabilizer metering device 28 delivers a metered amount of fuel stabilizer to bowl 32 in response to user input (either by a manual actuation of a mechanical input such as a lever, squeezing or compression of a compressible fluid fillable bulb filled with the fuel stabilizer or by actuation of an electrical switch or other electrical device causing release or metering of fuel stabilizer). In such embodiments, metering device 28 is configured to inhibit such manual input until at least after initiation of engine shutdown or is configured to delay the delivery of fuel stabilizer to bowl 32 from a time that the manual input is provided to at least after initiation of engine shutdown.
In yet other embodiments, fuel stabilizer metering device 28 may alternatively be configured to automatically deliver a metered amount of fuel stabilizer to bowl 32 of carburetor 30 until at least after initiation of engine shutdown. For purposes of this disclosure, such “automatic” delivery of fuel stabilizer means that the fuel stabilizer is delivered to carburetor 30 without a person (user) having to take any action to initiate the delivery of fuel stabilizer to carburetor 30, other than making sure that the fuel stabilizer reservoir 24 contains the fuel stabilizer and other than initiating engine shutdown. In one embodiment, parameters associated with the shutting down or completion of shutdown of engine 20 may be sensed by one or more sensors, wherein a controller generates control signals causing an actuator to deliver the metered fuel stabilizer to bowl 32 of carburetor 30. In yet another embodiment, the parameters associated with shutting down or completion of shutdown of engine 20 may themselves actuate or directly cause an actuator to deliver the metered amount of fuel stabilizer to bowl 32 of carburetor 30. Examples of such engine shutdown parameters may include, but are not limited to, vacuum or pressure, temperature, fuel flow, electrical current flow and the like.
As shown by
Sensor 234 comprises one or more sensors configured to sense or detect an engine shutdown parameter 239 and to transmit signals, such electrical signals, to controller 238 indicating the status of the sensed shutdown parameter. Shutdown parameter 239 comprises a parameter or characteristic of engine 220 that changes in response to initiation of engine shutdown or completion of engine shutdown. Examples of an engine shutdown parameter 239 include, but are not limited to, vacuum or pressure, temperature, fuel flow, electrical current flow and the like. For example, in one embodiment, sensor 234 senses a drop in negative pressure or vacuum in the intake manifold of engine 220. In response to detecting a drop in the vacuum in the intake manifold of engine 220, indicating that engine 220 is in the process of being shut down or has completed shut down, sensor 234 transmits a signal to controller 238. In other embodiments, other shutdown parameters 239 may be detected or sensed by sensor 234.
User input 236 comprises a mechanism or device associated with or provided as part of engine 220 which is configured to receive input from a person. In one embodiment, user input 236 is configured to receive such input from a person initiating or causing shutdown of engine 220. In yet another embodiment, input 236 is configured to receive such input for a person indicating that engine 220 has been shut down or is in process of being shut down or requesting metering of fuel stabilizer to carburetor 30 by metering device 228. User input 236 is operatively or communicatively connected or coupled to controller 238.
For purposes of this disclosure, the term “coupled” shall mean the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate member being attached to one another. Such joining may be permanent in nature or alternatively may be removable or releasable in nature. The term “operably coupled” or “operatively coupled” shall mean that two members are directly or indirectly joined such that motion may be transmitted from one member to the other member directly or via intermediate members. The term “fluidly coupled” shall mean that two or more fluid transmitting volumes are connected directly to one another or are connected to one another by intermediate volumes or spaces such that fluid may flow from one volume into the other volume. The term “communicatively coupled” shall mean that two devices are directly or indirectly connected on another such that electrical signals may be transmitted therebetween.
In one embodiment, user input 236 may comprise a lever, key ignition, a pushbutton, switch, touchpad, touch screen, keypad or an automatic shutdown mechanism. Examples of an automatic shutdown mechanism include a kill bar or other safety mechanism that automatically shuts down the engine such as when a sufficient amount of weight is no longer on the seat of the mower. In other embodiments, other mechanical or electrical mechanisms may be utilized for user input 236.
Controller 238 comprises one or more processing units configured to receive input or signals from sensor 234 and user input 236 and to further generate control signals for directing the operation of fuel stabilizer metering device 228 based upon such input from sensor 234 and user input 236. For purposes of this application, the term “processing unit” shall mean a presently developed or future developed processing unit that executes sequences of instructions contained in a memory. Execution of the sequences of instructions causes the processing unit to perform steps such as generating control signals. The instructions may be loaded in a random access memory (RAM) for execution by the processing unit from a read only memory (ROM), a mass storage device, or some other persistent storage. In other embodiments, hard wired circuitry may be used in place of or in combination with software instructions to implement the functions described. For example, controller 238 may be embodied as part of one or more application-specific integrated circuits (ASICs). Unless otherwise specifically noted, the controller is not limited to any specific combination of hardware circuitry and software, nor to any particular source for the instructions executed by the processing unit.
Fuel stabilizer metering device 228 is a particular embodiment of fuel stabilizer metering device 128. As shown by
In another embodiment, actuator 260 may comprise one or more mechanisms that utilize forces naturally produced by engine 220 to move volume 140. For example, negative and/or positive air or gas pressures within engine 220 may be utilized to move volume 140. Alternatively, force or motion produced by engine 220 may be transmitted via one or more cams, linkages, transmissions, power trains or the like so to move volume 140. In each of such embodiments, volume 140 may be biased to one of the loading or unloading positions by a spring or similar mechanism, wherein the hydraulic, pneumatic, electrical or engine produced force moves volume 140 against the bias to the other of the loading or unloading position. Actuator 260 moves volume 140 to the unloading position 145 at least after initiation of engine shut down or after completion of engine shutdown.
In the example illustrated, internal combustion engine system 210 is configured to operate in a selected one of multiple available modes or settings which may be set by the person using system 210. In a first selectable mode, controller 238 generates control signals causing actuator 260 to move volume 140 to the unloading position 145 in response to signals from user input 236 initiating or causing shutdown of engine 220. For example, in one embodiment a person may turn the ignition key to shut engine 220 off. Such action results in signals being transmitted to controller 238, where the controller 238 generates signals causing actuator 260 to move volume 140 to the unloading position 145 so as to discharge fuel stabilizer to bowl 32 of carburetor 30. In some embodiments, a delay timer or other delay mechanism may be provided such that the actual movement of volume 140 to the unloading position 145 occurs at a predetermined time period following receipt of user input 236 shutting down engine 220 by controller 238. During operation of engine 220, or during start up of engine 220, controller 238 generates control signals causing actuator 260 to move volume 140 to the filling or loading position 143, wherein volume 140 is filled with a predetermined volume of fuel stabilizer from reservoir 24.
In a second selectable mode, controller 238 generates control signals causing actuator 260 to move volume 140 to the unloading position 145 in response to signals received from user input 236 requesting that fuel stabilizer be provided to bowl 32 of carburetor 30 by metering device 228. In such an embodiment, if such user input is received prior to initiation of engine shut down, input of the request at user input 236 is inhibited or prevented or actual actuation of volume 140 to the unloading position by actuator 260 is paused or delayed until initiation of engine shutdown has occurred or until engine shutdown has been completed. In one embodiment, controller 238 may simply delay the transmission of control signals to actuator 260. In another embodiment, actuator 260, itself, may delay actuation or movement of volume 140.
In a third selectable mode, controller 238 generates control signals causing actuator 260 to move volume 140 to the unloading position 145 in response to receiving signals from sensor 234 based upon one of more sensed shut down parameters 239 indicating that engine shutdown has been initiated or has been completed. For example, in one embodiment, sensor 234 senses a drop in vacuum pressure in the intake manifold of engine 220. When the drop in vacuum is to such an extent that it indicates that engine 220 is being shutdown, controller 238 generates control signals causing actuator 260 to move volume 140 to the unloading position 145.
In a fourth selectable mode, actuator 260 is directly connected to engine 220 so as to utilize forces or changes in engine parameters such that the forces naturally occurring during engine shut down are what actually move volume 140. For example, negative and/or positive air or gas pressures within engine 220 may be utilized to move volume 140. Alternatively, force or motion produced by engine 220 may be transmitted via one or more cams, linkages, transmissions, power trains or the like so to move volume 140. In each of such embodiments, volume 140 may be biased to one of the loading or unloading positions by a spring or similar mechanism, wherein the hydraulic, pneumatic, electrical or engine produced force moves volume 140 against the bias to the other of the loading or unloading position. Actuator 260 moves volume 140 to the unloading position 145 at least after initiation of engine shut down or after completion of engine shutdown.
Although internal combustion engine system 210 is illustrated and described as having each of the above for selectable modes or settings, in other embodiments, internal combustion engine system 210 may include a fewer number of such available modes. Although fuel stabilizer metering device 228 is schematically illustrated as being separate from engine 220, in other embodiments, fuel stabilizer metering device 228 may be embodied as part of engine 220 or may be provided as a module or add-on including the illustrated components, including some of the components of engine 220 or including less than all the components illustrated. For example, in one embodiment, metering device 228 may be incorporated as part of a carburetor unit which is configured to be mounted to a remainder of an engine.
Actuator 360 comprises one or more actuators or mechanisms configured to selectively actuate valves 342, 344 between their open and closed states. In one embodiment, actuator 360 may comprise a pneumatically, hydraulically or electrically powered device. Examples of such devices include hydraulic or pneumatic piston-cylinder assemblies or electric solenoids.
In another embodiment, actuator 360 may include mechanisms that utilize forces naturally produced by engine 220 to move valves 342, 344. For example, negative and/or positive air or gas pressures within engine 220 are what actually move valves 342, 344. Alternatively, force or motion produced by engine 220 may be transmitted via one or more cams, linkages, transmissions, power trains or the like so to move valves 342, 344. In each of such embodiments, valves 342, 344 may be biased to one of the open or closed positions by a spring or similar mechanism, wherein the hydraulic, pneumatic, electrical or engine produced force moves valves 342, 344 against the bias to the other of the open or closed position. Actuator 360 moves or actuates valve 344 to the open state at least after initiation of engine shut down or after completion of engine shutdown. Prior to valve 344 being actuated to the open state, actuator 360 also actuates valve 342 to its closed state. Closing of valve 342 may occur immediately preceding the opening of valve 344 or may occur well before the opening of valve 344 during the operation of engine 220. Likewise, actuator 360 closes 344 prior to opening valve 342. Valve 342 may be actuated to its open state to at least partially fill volume 340 at any time while valve 344 is closed.
Internal combustion engine system 310 offers each of the selectable modes described above with respect to system 210. Unlike the modes described above with respect to system 210, the modes of operation for system 310 actuate valve 342, 344 instead of moving a metering volume. As with system 210, system 310 may include a fewer of such selectable modes. In one embodiment, system 310 may include a single mode of operation.
Intake manifold 434 comprises engine component that distributes the air-fuel mixture from carburetor 430 to cylinders of engine 420. As shown by
Fuel stabilizer reservoir 424 (shown in
Fuel stabilizer metering device 428 comprises a device configured to meter or supply a predetermined amount or volume of fuel stabilizer to bowl 432 of carburetor 430 after initiation of engine shutdown. In one embodiment, metering device 428 does not deliver any stabilizer to engine 420 or bowl 432 of carburetor 430 while engine 420 is running (prior to any initiation of shutdown of engine 420). In another embodiment, fuel stabilizer metering device 428 meters fuel stabilizer to bowl 432 of carburetor 430 only after engine shutdown has been completed. In some embodiments, metering device 428 may meter a predefined quantity of fuel stabilizer to bowl 432 of carburetor 430 while the engine is being shut down (but not prior to initiation of engine shutdown) and after shutdown has been completed.
Reservoir connecting portion 474 comprises that portion of metering device 428 configured to be connected to conduit 439 and ultimately to fuel stabilizer reservoir 424 (shown in
Discharge port 478 comprises an internal volume within portion 472 extending from plunger passage 482 and opening into an interior of bowl 432. Plunger guiding cavity 480 comprises a bore configured to receive and guide linear, translating movement of plunger 466. In some embodiments, body 464 may omit cavity 480 where other structures are provided for guiding movement of plunger 466. Plunger passage 482 comprises a passage through which plunger 466 extends and moves. In one embodiment, plunger passage 482 seals about outer circumferential portions of plunger 466. In the example illustrated, additional sealing rings 486 are provided on opposite sides of plunger passage 482 to seal about and against plunger 466 while allowing plunger 466 to slide or move through passage 482. Fill port 484 comprises a passage extending from an interior of portion 474 to an interior of plunger passage 482. In the example illustrated, metering device 428 is substantially T-shaped with plunger passage 482 extending along a central axis and fill port 484 extending substantially perpendicular to the central axis. In another embodiment, fill port 484 may have other configurations.
Plunger 466 comprises a member movable through plunger passage 482. Plunger 466 includes shank portion 490, head portion 492 and volume 440. Shank portion 490 extends from head portion 492 and extends through plunger passage 482. Volume 440 comprises an opening or chamber formed within a circumferential portion of shank portion 490. Volume 440 has a predefined volume configured for the purpose of metering a predetermined amount of fuel stabilizer. The actual predetermined volume of volume 440 may vary depending upon characteristics of engine 420 and carburetor 430. In the example illustrated, volume 440 comprises a circumferential groove completely encircling shank portion 490. In other embodiments, volume 440 may comprise a notch or other cavity only partially extending about shank portion 490. In yet another embodiment, volume 440 may comprise a bore partially or completely extending through shank portion 490 in a radial direction.
Head portion 492 extends from shank portion 490 and includes a neck portion 494 and a collar 496. Neck portion 494 extends from collar 496 and projects into bias 468 to seat bias 468 against plunger 466. Collar 496 projects radially outward from that portion 494 into contact with interior sides of cavity 480. Collar 496 outer peripheral surfaces that cooperate with surfaces of cavity 480 to guide movement of plunger 466. Collar 496 further provides a surface or shoulder against which bias 468 may apply force to plunger 466. In addition, collar 496 sufficiently seals against sides of cavity 480 such that changes in vacuum pressure communicated from intake manifold 434 by conduit 437 may move plunger 466. In other embodiments, plunger 466 may have other configurations.
As shown by
Bias 468 comprises a member configured to resiliently bias plunger 466 towards the unloading position shown in
In other embodiments, bias 468 may have other configurations. For example, in other embodiments, bias 468 may comprise a tension spring operatively couple to plunger 466 on an opposite side of plunger passage 482. In yet other embodiments, bias 468 may alternatively be configured to bias plunger 466 towards the loading position, wherein forces resulting from the shutdown of engine 420 are utilized to overcome the force of bias 468 to move plunger 466 to the unloading position when the engine is shut down.
Retainer 470 comprises a member inserted and fixedly retained in cavity 480. Retainer 470 is configured to capture bias 468 between retainer 470 and collar 496 of plunger 466. Retainer 470 includes an internal bore 499 through which vacuum pressure is transmitted through conduit 437 and may be applied to plunger 466 to retain plunger 466 in the loading position while the engine is running. In other embodiments, retainer 470 may have other configurations or may be omitted where other mechanisms or surfaces are used to bear against bias 468.
During running of engine 420, a vacuum pressure exists within intake manifold 434 (shown in
As shown by
Although the present disclosure has been described with reference to example embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the claimed subject matter. For example, although different example embodiments may have been described as including one or more features providing one or more benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example embodiments or in other alternative embodiments. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.
