The system of the present invention will now be described in conjunction with
As seen in
When the engine is not in operation, external temperatures on the fuel, tank 202 can cause an increase of the fuel 204 temperature within the tank 202 causing an increase in vapor pressure within the tank 202. Historically, this increased vapor pressure was simply released through vent holes in the cap. However, new emissions regulations do not allow untreated vapor pressure to be released into the atmosphere. Therefore, the vapor emissions system of the present invention cheers the vapor pressure in the fuel, tank 202 through a charcoal treatment section or canister 225. In the present invention, the vapor pressure is directed to a charcoal treatment canister or chamber 225 through a fuel tank valve assembly 230. The canister 225 typically uses activated carbon to treat the fuel vapor by removing the hydrocarbons. Once the engine is started the hydrocarbons from within the canister 225 are pulled into the carburetor 220 and burned.
The fuel tank emissions valve assembly 230 is located inside the tank and includes a top portion 232 and an emissions line 233. The emissions vapor exits the tank 202 from an exit location 236 such as a welded pipe fitting or threaded sealed fitting, A threaded sealed lining 234 is depleted hi
The top portion 232 of the emissions valve assembly 230 may be secured to the inside top or side surface of tank 202, Additionally, or as an alternative, the emissions line 233 may be secured to a bracket 235, such as through welding or placement in a grommet, where the bracket is secured to die inside of the tank 202. Securing the top 232 of the valve assembly 230 or securing the emissions line 233 prevents the emissions valve assembly 230 from significant movement thereby preventing or minimizing the emissions valve assembly 230 from becoming damaged. Still further, line or tube 233 may be a metal piping or some form of tubing which may be sealed or secured to the bottom of tank 202 through use of welding, a grommet or some other fitting.
When the engine is not running, pressure in the tank 202 will be released as the emissions vapor flows from the top portion 232 of the valve assembly 230 down the emissions line 233, exits the tank 202 at the emissions exit 234 and flows into the canister 225 though line 238. Once in the chamber 225, the evaporate emissions vapor is treated. Upon starting the utility engine, suction is created drawing outside air through vent 222 and pulling the evaporative emissions within the charcoal canister 225 through line 224 into carburetor 220 where the evaporative emissions and hydrocarbons can be burned. During operation of the engine, emissions vapor can also be drawn into the emission valve assembly 230, through treatment canister 225, and into carburetor 220 where the emissions will be burned. Once the engine is shut off the suction pulling air through dm charcoal canister 225 is removed and the canister 225 is set to receive and treat the evaporative emissions within tank 202 until the engine is started again and the evaporative emissions can be drawn into and burned by carburetor 220.
As fuel 204 is added to tank 202 the fuel 204 will reach or obtain a max fuel level 206. Exceeding the max fuel level 206 would cause fuel 204 to overflow from tank 202. The present invention incorporates a design to prevent fuel 204 from entering the vapor emissions valve assembly 230 by sizing the valve assembly 230 so that the top portion 232 of the valve assembly 230 is above the max fuel level 206. Specifically, the valve assembly 230 is sized so that a valve opening for receiving emissions vapor is located above the max fuel level 206 but below the top interior surface 207 of the tank 202. The valve opening is located within the top portion 232 of the valve assembly 230. By having the valve opening above the max fuel level 206 the opening is positioned in area 205 where vapor pressure resides but above the max fuel level 306 so that fuel does not easily flow into the emissions vapor valve assembly 230 or line 233. Proper sizing of the valve assembly 230 may require sizing of both the valve assembly 230 and fuel tank 202.
As shown in
Under normal conditions, the float bad 340 rest on the top of the fluid surface level 306 within chamber 346 at some distance from the tapered surface 348. The evaporative emissions are able to enter the chamber 346 from the top chamber holes 342 and flow through line 333 to the charcoal canister. The top portion 332 of the valve assembly 330 should be sized such that height “h” provides enough space to allow the evaporative emissions to escape when the float ball 340 is resting on the surface of the max fuel level 306.
As seen in
Additionally, all or a portion of valve assembly 230 could be placed in the tank 202 prior to complete assembly of the tank 202. In one exemplary embodiment, the top portion 232 of the valve assembly 230 is fastened to the top surface 202 of the fuel tank 202. The line 233 might also be fastened to a bracket 235 to support the valve assembly 330, Finally the two halves of the tank 202 would be mated and sealed together to from the tank 202 with all or a portion of the valve assembly 230 already in tank 202. The valve assembly or vapor exit 234 could be a welded fitting, grommet or threaded fitting to properly seal the vapor exit 234 from tank 202, In addition to metal, the tank 202 could also be constructed using a conventional blow molded plastic technique, or other known techniques, enabling proper sizing and fitting of the tank 202 for interaction with the valve assembly 230.
Tank 202 would likely have a generally flat bottom, a generally flat top with a recessed opening 210 for cap 208. The opening 210 for cap 208 would be lower than the highest point on the top surface of tank 202. The integral design of the fuel vapor valve assembly 230 located within the tank 202 allows for the top surface of the tank to be clean and free from valves and lines. The tank 202 would also have four sidewalk any or all of which may be inclined or configured with a unique shape as required for a particular application.
In addition to the snorkel or hall float valve depicted in
Still further, the evaporative emissions system of the present invention could use a valve assembly which comprises a much larger float device not within a defined valve assembly chamber. The large float would be connected or attached to the valve assembly and could have a sealing element connected or incorporated into the float design to provide a seal against the opening in the valve assembly leading to the vapor passage path or line.
The present invention provides an internal evaporative emissions valve assembly which is responsive to the fuel level with the fuel tank. Further, the top portion of the fuel valve assembly, and specifically the opening in the valve assembly for receiving the fuel vapor, is positioned such that the valve assembly opening is above the max fuel level of the tank but below the interior top surface of the fuel tank.
Although a preferred embodiment and exemplary embodiments of dm present invention has been described in detail the present invention is not limited to the embodiments described herein and can be modified in a variety of ways without departing from the spirit and scope of the present invention.
This application claims the benefit of U.S. Provisional Patent Application 60/791,324 filed on Apr. 12, 2006, the entirety of which is incorporated herein by reference. This application includes material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent disclosure, as it appears in the Patent and Trademark Office files or records, bat otherwise reserves all copyright rights whatsoever.
Number | Date | Country | |
---|---|---|---|
60791324 | Apr 2006 | US |