Abstract:
A carbon canister filter box having an integrated cap. The integrated cap incorporates one or more components, such as vent solenoids, pressure sensors, an internal honeycomb feature for assisting in trapping hydrocarbons from the fuel vapor, and purge ports. The integrated cap sealingly attaches to a carbon canister vapor recovery system and can be manufactured to be implemented on existing canister units. The cap connects to the automotive emission storage canister in relation to the fuel tank of the vehicle, used to recapture fuel vapor before it is released into the atmosphere. A sealing means is positioned between the cap and the canister, preventing the leakage of fuel vapor into the outside atmosphere.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 11/716,872 filed on Mar. 12, 2008. This application claims the benefit of U.S. Provisional Application No. 60/992,431, filed on Dec. 5, 2007. 
     
    
     FIELD 
       [0002]    The present disclosure relates to emission control devices for vehicles. More particularly, the present disclosure relates to a carbon canister with integrated emission devices such as filters, solenoids, and/or other sensors connected to the fuel storage unit of an automobile. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0004]    Canisters for storing emissions are provided on automotive vehicles to prevent the discharge of fuel vapors outside vehicles during refueling or normal operation. Often referred to as onboard refueling vapor recovery (ORVR), the typical canister contains activated carbon and is mounted within a vehicle in communication, via a first or vapor inlet port, with the headspace in the fuel tank; via a second or vapor outlet port, with a vacuum source in the engine intake manifold; and via a third or vent port, with the atmosphere outside the vehicle. During refueling, the fill pipe is sealed against vapor leakage, either by a flexible gasket surrounding the fill nozzle or by a liquid seal in the fill pipe. As the tank is filled, air and vapors in the headspace above the fuel are forced through the vapor inlet port into the canister. The vapors are adsorbed onto the charcoal bed, and the air is discharged through the vent port. During subsequent operation of the vehicle, the engine vacuum draws air through the vent port, gradually purging the adsorbed vapors via the vapor outlet port into the engine&#39;s combustion flow and preparing the canister for the next refueling. Air also flows back through the vent port into the fuel tank, as needed, to replace fuel being consumed by the engine. 
         [0005]    The air vent port is normally open during periods of non-operation of the vehicle. Fuel tank vapors must be adsorbed by the canister before reaching the vent port. This function is known in the art as diurnal adsorption. Such diurnally adsorbed fuel is also desorbed and conveyed by vacuum to the engine upon startup. 
         [0006]    Federal regulations require that each vehicle be equipped to conduct an onboard diagnostic (OBD) leak test of the evaporative emissions system. Several manufacturers use a vacuum decay OBD which requires an apparatus for closing off the vapor outlet and vent ports, the vapor inlet port being effectively sealed during testing by the fuel tank cap. 
         [0007]    Typically, an ORVR canister is mounted immediately adjacent the fuel tank to minimize vapor flow restriction into the canister. Since the fuel tank commonly is located near the rear of the vehicle and the engine at the front, a relatively long hose run is required to connect the canister to the engine intake. A first electric solenoid valve at the canister can close the canister vent port, and a second solenoid valve at the engine can close the vapor outlet line. To test the system for leaks, first the vent port is closed, exposing the system to full engine vacuum, and then the outlet line is closed. The OBD system monitors the rate of decay of the captured vacuum. 
         [0008]    Mounting the canister at the rear of the vehicle exposes the vent port to dust and debris which, if allowed to enter the canister, can foul the vent solenoid and internal passages, gradually clogging the solenoid valve and the canister and causing failure of the seal test. Entry of dust and debris can also cause operational problems with refueling of the vehicle, including failure to fill properly and premature shutoffs of the refueling nozzle. To prevent such entry, U.S. Pat. No. 5,878,729, issued Mar. 9, 1999 to Covert et al. (&#39;729) and incorporated herein by reference, discloses a canister providing two separate vent ports—an outlet vent port with a check valve for releasing fuel tank air during refueling and an inlet vent port connected to the downstream side of the engine air filter. An additional check valve is disposed between the inlet vent port and the engine to prevent vapors flowing into the air cleaner during refueling and causing an over-rich fuel/air mixture being fed to the engine at startup. 
         [0009]    U.S. Pat. No. 6,390,073, issued May 21, 2002 to Meiller et al. (&#39;073), discloses an onboard vapor recovery canister which utilizes a solenoid valve in association with a filter means, but requires being attached to the fuel system as a single assembly. Furthermore, the &#39;073 patent operates only with a foam filter and carbon absorption bed. Eventually, a higher pressure drop increase can result after prolonged use of the canister, which can often cause early shutoff of a refueling pump nozzle due to backed up fuel vapors in the fuel tank. 
         [0010]    Often it is desirous for the vapor recovery systems to be associated with various other emission control devices, such as vent solenoids, pressure sensors, and purge ports, which increase the efficiency and longevity of the systems. By incorporating theses additional devices within a single unit, which may be retrofitted on existing carbon canisters, the costs of manufacturing, assembly, and installation are greatly minimized. 
       SUMMARY 
       [0011]    The present disclosure overcomes the above shortcomings in the art, comprising a carbon canister filter box having an integrated cap. The integrated cap contains one or more components, such as a vent solenoid, a filter, a pressure sensor, an internal feature for assisting in trapping dust, and purge ports. The integrated cap attaches to a carbon canister vapor recovery system and can be designed to be implemented on existing manufactured units. The cap connects to the automotive emission storage canister in relation to the fuel tank of the vehicle, used to recapture fuel vapor before it is released into the atmosphere. A closed cell foam or rubber O-ring provides a sealing between the integrated cap and the filter housing. 
         [0012]    It is therefore an object of the present disclosure to provide an integrated cap for a carbon canister fuel vapor recovery system of vehicles comprising a plurality of emission control functions in a single unit. 
         [0013]    It is a further object of the present disclosure to provide an integrated cap for use in conjunction with a canister as herein described which is economical to manufacture. 
         [0014]    Another object of the present disclosure is to provide an integrated cap for a carbon canister which provides a universal fit to a plurality of canisters equipped on various vehicles. 
         [0015]    Another object of the present disclosure is to provide an integrated cap for a carbon canister which integrates a feature utilized to trap dust particles. 
         [0016]    Another object of the present disclosure is to provide an integrated cap for a carbon canister which integrates a vent solenoid. 
         [0017]    Another object of the present disclosure is to provide an integrated cap for a carbon canister which integrates a pressure sensor, utilized in conjunction with the vehicle emissions control system. 
         [0018]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0019]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
           [0020]      FIG. 1  is a perspective exploded view of the carbon canister, integrated cap, and various emission components associated therein; 
           [0021]      FIG. 2A  is an assembled, first side view of the carbon canister and integrated cap of  FIG. 1 ; 
           [0022]      FIG. 2B  is an assembled, second side view of the carbon canister and integrated cap illustrated in  FIG. 1 ; 
           [0023]      FIG. 3  is an assembled, first end view of the carbon canister and integrated cap illustrated in  FIG. 1 ; 
           [0024]      FIG. 4  is an assembled, second end view of the carbon canister and integrated cap illustrated in  FIG. 1 ; 
           [0025]      FIG. 5  is an assembled, overhead view of the carbon canister and integrated cap illustrated in  FIG. 1 ; 
           [0026]      FIG. 6  is a cross-sectional, split illustration of the carbon canister and integrated cap of  FIG. 1 ; 
           [0027]      FIG. 7  is a side view of a vapor storage canister having an integral filter box; 
           [0028]      FIG. 8  is a side view of the vapor storage canister having an integral filter box separated; 
           [0029]      FIG. 9  is a first cross sectional view of the vapor storage canister having the integral filter box attached; 
           [0030]      FIG. 10  is a perspective exploded view of the components comprising the integral filter box of the present disclosure; 
           [0031]      FIG. 11A  is first side view of the integral filter box of the present disclosure; 
           [0032]      FIG. 11B  is a second side view of the integral filter box of the present disclosure; 
           [0033]      FIG. 11C  is a first end view of the integral filter box of the present disclosure, illustrating the outlet to attach to a canister; 
           [0034]      FIG. 11D  is a third side view of the integral filter box of the present disclosure; 
           [0035]      FIG. 11E  is a second end view of the integral filter box of the present disclosure, illustrating the atmospheric port; 
           [0036]      FIG. 12  is a fourth side view of the integral filter box of the present disclosure; 
           [0037]      FIG. 12A  is a cross sectional view of  FIG. 12  taken along line  12 A; 
           [0038]      FIG. 12B  is a cross sectional view of  FIG. 12  taken along line  12 B; 
           [0039]      FIG. 13  is the first side view of the integral filter box of the present disclosure; 
           [0040]      FIG. 13A  is a cross sectional view of  FIG. 13  taken along line  13 A; and 
           [0041]      FIG. 13B  is a cross sectional view of  FIG. 13  taken along line  13 B. 
       
    
    
     DESCRIPTION 
       [0042]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that, throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
         [0043]    Referring now to the figures, a preferred embodiment of the present invention is shown comprising an integrated cap  10  attached to a housing of a vapor storage canister  30  of an automotive fuel vapor recovery system. The vapor storage canister  30  as mentioned is placed at the end of the vent system of a gasoline fuel tank on a vehicle. The vapor storage canister  30  adsorbs (buffers) the fuel vapors that are released from the fuel tank and enter the canister through the tank port  32  during normal operating or during refueling of the tank. From time to time, the vapor storage canister  30  is purged with clean air via purge port  34 , wherein clean air is drawn in through the vapor storage canister  30  from an atmospheric port  16 , desorbing the fuel vapors and transporting them to the combustion air of the engine through purge port  34 . 
         [0044]    The integrated cap  10  comprises an attachment portion  14  for attaching integrated cap  10  to vapor storage canister  30  by welding or any other process known in the art. The attachment of integrated cap  10  to vapor storage canister  30  creates a seal between these components. The integrated cap also includes a first end portion  11  which contains a filter having a honeycomb feature  12 . The honeycomb feature of filter  12  is a charcoal cylinder having an internal honeycomb structure, which captures very fine hydrocarbon molecules emitted through the tank port  32  of the cap. The honeycomb feature of filter  12  is integrated into the cap  10  which can be used alone or in conjunction with a foam filter element. A cover lid  13  is attached to the cap  10 , retaining the honeycomb feature  12  inside. The opposing end  9  of the cap  10  comprises a lateral aperture  25  for receiving a vent solenoid valve  20  there within. The vent solenoid valve  20  seals the fuel tank during the OBD-II testing to check for possible leaks in the complete fuel system. To protect the vent solenoid valve  20  and the canister against dust, especially during the purge process, the vent solenoid valve  20  is integrated into the cap  10 . 
         [0045]    Proximal the vent solenoid  20 , the atmospheric air port  16  is integrated into the cap, allowing atmospheric air within the vapor storage canister  30 . Located opposite the vent solenoid valve  20  on the cap  10 , a pressure sensor  33  is attached thereto, allowing for remote measurements of the air pressure building within the canister, indicating when maintenance should be performed. 
         [0046]    Referring now to  FIGS. 7-13 , a vapor storage canister  130  in accordance with another embodiment of the disclosure is illustrated. Vapor storage canister  130  includes an integral filter box cap assembly  110  that is releasably attached to vapor storage canister  130 . 
         [0047]    The vapor storage canister  130  as mentioned is placed at the end of the vent system of a gasoline fuel tank on a vehicle. The vapor storage canister  130  adsorbs (buffers) the fuel vapors that are released from the fuel tank and enter the canister through the tank port  132  during normal operating or during refueling of the tank. From time to time the vapor storage canister  130  is purged with clean air via an atmospheric or purge port  134 , wherein clean air is drawn in through the canister from the atmospheric port  116 , desorbing the fuel vapors and transporting them to the combustion air of the engine from an engine port. 
         [0048]    The filter box cap assembly  110  with integrated vent solenoid valve  120  comprises a main filter box cap  114  and is sealingly attached to the atmospheric port of the vapor storage canister  130  through an outlet  118  as part of the evaporative diagnostic known as OBD-II testing. The electrical operated valve seals the fuel tank during the OBD-II testing to check for possible leaks in the complete fuel system. To protect the vent solenoid and the canister against dust, especially during the purge process, the vent solenoid valve  120  is integrated into the filter box cap assembly  110 . A filter box top  115  is sealingly attached to the opposite end of filter box cap  114  and comprises an atmospheric port  116  therein. 
         [0049]    Referring now to  FIG. 9 , a longitudinal cross-sectional illustration of the filter box cap assembly  110  attached to vapor storage canister  130  is shown. The labyrinth walls  121  of filter box top  115  are apparent in  FIG. 9 , which provide for a means of separating dust from the gas flow. The advantage of the labyrinth walls  121  is to provide a further filter means (known in the art as a centrifugal-filter) which may be used alone or in combination with a foam filter. 
         [0050]      FIG. 10  illustrates an exploded view of the various components comprising the filter box cap assembly  110 . The filter box cap  114  comprises outlet  118  at one end for connecting with the vapor storage canister  30  and comprises a grove for retaining a sealing means  119  such as a resilient O-ring. On the top side of the filter box cap  114 , an aperture  125  sealingly receives the vent solenoid valve  120  which is locked into place within the filter box cap  114  when assembled. A plurality of locking ramps  117  are integrated in the outside of the filter box cap  114  which secure the housing to the canister as shown in  FIG. 9 . 
         [0051]    The optional filter foam pad  122  and sealing means  123  are received on the opposite end of the filter box cap  114  from the outlet  118 , and are retained in place by filter box top  115  which is detachably attachable to the housing. The filter box top  115  as stated above comprises a series of integrated labyrinth walls  121  which provide a labyrinth-type filtering system for the air which is received through the atmospheric port  116  of the filter box top  115 .  FIGS. 11A through 11E , show isolated perspective views of the filter box cap assembly  110  from each side and end to further illustrate the design and integrated components described herein. 
         [0052]      FIGS. 12 through 12B  show an isolated, side view of the filter box cap assembly  110 , and two cross-sectional views thereof. From these figures, the sealing means utilized to seal the filter box top  115  to the filter box cap  114  comprises an O-ring  112 , but it is intended to be within the scope of the present invention that any suitable sealing means known in the art may be implemented. Furthermore, the sealing means  119  around the outlet  118  of the filter box cap  114  also comprises an O-ring and as stated is retained within an annular grove within the outlet  118 . 
         [0053]    Lastly,  FIGS. 13 through 13B  show an isolated side view of the filter box cap assembly  110 , and two cross-sectional views thereof. From these illustrations, the position and orientation of the vent solenoid valve  120  is shown within filter box cap  114  located between the labyrinth walls  121  of the filter box top  115  and the outlet  118  on the opposite side of the filter box cap  114 . The solenoid is sealingly received within the filter box cap  114 , preventing air and vapor leakage there around during use. 
         [0054]    As noted, providing a cap integrating some or all of the features listed and described herein is advantageous in that the cost of manufacturing multiple components for a fuel vapor recovery system is minimized. Furthermore, the cost of implementation and assembly is also minimized. Lastly, in a preferred embodiment, the caps  10  and  110  are manufactured to fit standard vapor storage canisters  30  already implemented on vehicles, eliminating the need to remanufacture the canister, as well. 
         [0055]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.