The present invention relates to a fuel tank assembly and more particularly to a fuel pump subassembly of the fuel tank assembly for a motorcycle.
Large vehicles, such as the automobile, have a typically fuel injected engine and a fuel pump subassembly mounted inside a fuel tank. The fuel tank is generally hidden from view and mounted to the undercarriage of the vehicle. Various penetrations and protrusions, such as a tank access hole for insertion of the fuel pump subassembly into the tank, are typically located at the top of the tank to minimize any opportunity of fuel leakage. A top mounted flange supports the fuel pump subassembly and covers and seals the access hole. Location of the flange and various protrusions projecting outward from the flange at the top of the tank protects the flange from abusive road conditions. Because the tanks are concealed by the undercarriage of the vehicle, any negative cosmetic impact of the top mounted flange is of no consequence. Moreover, any noise produced by the fuel pump is likely not to disturb the vehicle occupants because of the remote location of the fuel tank and because of the vibration dampening and noise absorbing characteristics of the plastic used to manufacture the tank.
For smaller recreational vehicles such as motorcycles, industry trends are turning away from the typical gravity feed carburetors and are leaning toward the use of fuel injection systems similar to larger vehicles. Location of the fuel pump inside the relatively small tank of a motorcycle would be preferred because it could reduce the number of fuel hose and electrical connections and also decrease fuel vapor emissions and the chance of fuel leakage into the surrounding environment while providing a modular design which simplifies assembly and reduces manufacturing costs. Unfortunately, the introduction of a fuel pump subassembly inside the tank of such a small recreational vehicle is difficult because: the fuel tank is visually exposed and typically mounted near the top of the recreational vehicle making cosmetic appearance and thus the location of the pump subassembly flange a concern; the tank is relatively small making pump placement difficult; and the tank is typically made of metal which contributes to the proliferation of pump noise.
Because the fuel tank is visually exposed in a motorcycle application, the tank is traditionally decorated thus contributing to a cosmetic theme of the motorcycle. Often, the shape or general appearance of the tank is identifiable to a particular manufacturer, thus having trademark value, thus making cosmetic alterations for the addition of a fuel pump subassembly undesirable. Moreover, the operator of the recreational vehicle or motorcycle is often located directly adjacent to the fuel tank, hence, the tank is preferably smooth, having minimal protrusions which could potentially cause injury to the operator or rider. For example, the fuel tank of a motorcycle is disposed generally between the legs of the rider. Consequently, the tank is preferably “tear-drop” in shape having the larger globe portion positioned toward the front of the motorcycle while tapering off and sloping downward toward the motorcycle seat creating a substantially smooth transition between the tank and the seat. For motorcycle applications, the only protrusion which could typically come between the ergonomically friendly fuel tank and the rider is the fuel filler cap. However, the cap is relatively low and smooth in profile and is located toward the forward top of the tank at the larger globe portion of the “teardrop.” The visually exposed placement of a flange, with associated fuel hoses and a wire harness, at the top of the fuel tank would not only crowd the filler cap, but would destroy the pleasing cosmetic appearance of the tank, expose the flange to possible damage and expose the rider to possible injury.
Moreover, the close proximity of the fuel tank to the rider makes the rider sensitive to noise emanating from the fuel tank. Because the motorcycle tank is traditionally made of steel, for strength and the adherence of paint, vibration induced noise caused by a running pump inside the tank is likely to be annoying to the rider. Furthermore, the running vibration characteristics of the motorcycle can be transmitted to the pump causing damage to pump components.
A cosmetically attractive fuel tank assembly preferably for a motorcycle application has a fuel pump subassembly inserted into the fuel chamber of the tank through a bottom access hole thus preserving the overall appearance, tradedress value and identifying characteristics of any specific manufacturer's tank. The flange of the fuel pump subassembly sealably covers the bottom access hole of the fuel tank. Various fuel pump subassembly components, such as a fuel pressure regulator, a fuel level sensor and an outlet fuel filter mount directly to the flange along with a tripod like bracket with three feet to support the fuel pump. The bracket is flexible and resiliently contacts an internal surface of a bottom wall of the fuel tank via a resilient pad which encases a rearward foot of the three feet. Preferably, the other two forward feet of the bracket engage threadably to the flange, yet are preferably spaced from the flange by respective vibration dampening members. Preferably, the fuel pump subassembly is preassembled prior to insertion into the tank through the access hole. The elongated shape of the subassembly and the relatively small size of the preferable motorcycle fuel tank requires that the fuel pump subassembly be rotated vertically within an imaginary plane until a rearward foot of a bridging portion of the bracket engages the internal surface, preferably at a bottom wall. As the flange seals to the bottom wall, a resilient bridging portion remains flexed and isolated from the flange and tank via the rearward pad and vibration dampening members.
Objects, features, and advantages of this invention include a fuel tank assembly for a fuel injected engine application which maintains traditional fuel tank exterior appearance, a reduction in fuel hose and electrical connections, a reduction in vibration amplitude prolonging the operational life of the fuel pump and reducing noise, and a more robust and module design simplifying manufacturing and reducing cost.
These and other objects, features and advantages of the invention will be apparent from the following detailed description, appended claims, and accompanying drawings wherein:
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The tank 18 is generally rounded or “tear-drop” shaped having a substantially global portion 32 disposed toward the handle bars 34 of the motorcycle 10 and a converging portion 36 which converges rearward toward a seat 38 of the motorcycle 10 providing a smooth transition between the tank 18 and the seat 38 for rider comfort.
A substantially planar, and horizontally disposed, bottom support flange 40 of the fuel pump subassembly 16 has a peripheral edge 42 which carries a circumferentially extending and upward communicating groove 44 for seating a resilient O-ring 46 compressed against the external surface 30 of the bottom wall 26 at the global portion 32 of the tank 18 when assembled (as best shown is FIGS. 1 and 4). The O-ring 46 is fuel resistant and prevents the egress of fuel vapor, permeation, and/or gravity induced leakage of fuel out of the tank 18. Various fuel pump subassembly components project substantially upward from an interior face 48 of the flange 40 and into the fuel chamber 22. One of these components is a curved or arcuate bracket 50 which supports an elongated electric fuel pump 52 and projects generally from within the global portion 32 and into the converging portion 36 of the “tear-drop” tank 18. Because of the unique shape, low profile, and small volume of the fuel tank 18, the pump 52 is supported substantially horizontally along the top of the bracket 50 and is substantially disposed inside the converging portion 36 of the tank 18.
The fuel pump 52 of the fuel pump subassembly 16 has a rearward inlet 54 communicating with a bag-type fuel filter 56 capable of filtering out particles of approximately greater than thirty microns to protect the pump 52. The filter 56 generally touches the internal surface 24 of the tank 18 at the rearward-most region of the converging portion 36. This touching of the internal surface 24, which includes the bottom wall 26 and sidewalls 27, promotes the wetting or capillary action of the filter 56 for providing a constant supply of fuel to the pump inlet 54 even when portions of the filter 56 are not submerged in the liquid fuel. This partial exposure of the filter 56 to air is caused by excessive movement of fuel in a small tank, characteristic of recreational vehicles. Moreover, the filter 56 is conveniently located at the rear of the fuel tank 18 which is likely to see elevated levels of fuel during fast accelerations which is often characteristic of motorcycles 10.
The thirty micron filtered fuel flows out of the pump 52 in a super-atmospheric pressure condition via a fuel outlet or tube 58 disposed at a forward end 59 of the pump 52 opposite the inlet 54. The tube 58 projects generally forward from the pump 52 and downward to engage an upward unitarily projecting union 60 of the flange 40 which defines a channel (not shown) for flowing the fuel into an outlet filter 62. The outlet filter 62 projects unitarily upward from the interior face 48 of the flange 40 and filters approximately ten micron or greater particulate out of the super-atmospheric fuel to protect an upstream pressure regulator 64 of the fuel pump subassembly 16 and to protect the fuel injectors of the combustion engine 12. Similar to the outlet filter 62, the pressure regulator 64 projects upward from the bottom flange 40 and receives flowing fuel from the adjacent outlet filter 62 via a channel (not shown) integral to the flange. From the pressure regulator 64, fuel flows out of the tank 18 and through the bottom flange 40 via a nozzle or outlet 66 that projects unitarily downward from an exterior face 68 of the flange 40.
The bottom flange 40 also internally supports a fuel level sensor 70 via the bracket 50 and an integral electrical connector 72 which extends through the flange 40 and electrically connects to an internal wiring harness 74 for providing electric power to the fuel pump 52 and for carrying an electric signal from the fuel level sensor 70.
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The arcuate bracket 50 is preferably made of a stamped low carbon steel for resiliency and strength, and is generally tripod-like having a resilient mid-bridging portion or elongated ban 75 which carries a concave profile formed by a bottom side 76 that faces generally downward toward the tank bottom wall 26. An opposite convex or top side 78 of the ban 75 substantially extends longitudinally with, and engages, the elongated pump 52 disposed above it. A pair of straps 80, preferably made of plastic, engage the pump 52 to the bracket 50 generally preventing lateral and upward movement of the pump 52 with respect to the bracket 50. Each strap 80 generally extends perpendicular to the ban 75 and wraps about the ban and the pump 52. The plastic straps 80 are spaced longitudinally apart from one another with respect to the steel ban 75 and pump 52 in order to secure circumferentially about each end of the pump 52.
A pair of forward fingers 79 prevent forward or longitudinal movement of the pump 52 with respect to the bracket 50, and a second pair of rearward fingers 81 prevent rearward movement. Each finger of each pair of fingers 79, 81 is cantilevered laterally outward from opposite edges 83, 85 of the ban 75. The lateral projection of each finger is bent slightly upward forming a generally concave saddle or seat 87 for each pair which conforms and seats to the cylindrical shape of the fuel pump 52. Each finger of the forward fingers 79 project longitudinally forward to an upward bent distal end 89 which catches the forward end of the pump 52 preventing forward pump movement. Likewise, each finger of the rearward fingers 81 project longitudinally rearward to an upward bent distal end 91 which catches the rearward end of the pump 52 preventing rearward pump movement.
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Projecting rearward from an opposite end of the ban or bridging portion 75 is a third or rearward foot 98 which is engaged directly to a vibration absorbing pad or grommet 100. When the fuel tank assembly 14 is fully assembled, the steel bridging portion 75 is shaped to resiliently bias the rearward foot 98 and grommet 100 against the internal surface 24 of the bottom wall 26 to reduce vibration and eliminate resonating frequencies by eliminating any possibility of a clearance or space developing between the rearward foot 98 or grommet 100 and the bottom wall 26. Thus, with the resilient ban 75 placed under continuous stress, the foot 98 and grommet 100 are in continuous contact with the bottom wall 26 regardless of surrounding influences such as vibration and without the need for a fastening device or structure. Similar to the forward feet 82, the rearward foot 98 is spaced from the internal surface 24 by the resilient grommet 100 pressfitted into a hole 101 carried by the foot 98.
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The fuel pump subassembly 16 is preferably pre-assembled prior to insertion into the fuel tank 18 through the bottom access hole 28. During insertion, the elongated fuel pump 52 is substantially positioned vertically. As the inlet filter 56, bracket 50 and fuel pump 52 are inserted through the access hole 28, the subassembly 16 is simultaneously rotated approximately ninety degrees so that the leading inlet filter 56 disposed toward the rear of the fuel pump subassembly 16 does not hit the close confines or internal surface 24 at the top of the tank 18. This insertion, and simultaneous rotation places the filter 56, bracket 50 and pump 52 into the close confines of the converging portion 36 of the tank 18. As the peripheral edge 42 of the flange 40 and O-ring 46 seal against the external surface 30 of the bottom wall 26, the grommet 100, which is pre-fitted to the rearward foot 98 of the bracket 50 presses resiliently against the internal surface 24 of the bottom wall 26, and the bridging portion 75 resiliently flexes assuring continuous contact between the grommet 100 and the tank 18 and assuring unobstructed sealing between the flange 40 and the tank 18.
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While the forms of the invention herein disclosed constitute presently preferred embodiments many others are possible, it is not intended here in to mention all of the possible equivalent forms or ramifications of the invention, it is understood that the terms used herein are merely descriptive rather than limiting and that various changes may be made without departing from the spirit or scope of the invention as defined by the following claims.
Number | Name | Date | Kind |
---|---|---|---|
4871041 | Saito et al. | Oct 1989 | A |
4972875 | Beer et al. | Nov 1990 | A |
5249594 | Kizer | Oct 1993 | A |
5272918 | Gaston et al. | Dec 1993 | A |
5636616 | Okane et al. | Jun 1997 | A |
5785032 | Yamashita et al. | Jul 1998 | A |
6182640 | Nakashima et al. | Feb 2001 | B1 |
6253738 | Takahashi et al. | Jul 2001 | B1 |
6253790 | Hara | Jul 2001 | B1 |
6357424 | Sonoda et al. | Mar 2002 | B1 |
6378504 | Horiuchi et al. | Apr 2002 | B1 |
6401750 | Tokunaga | Jun 2002 | B2 |
6609503 | Nakagawa et al. | Aug 2003 | B1 |
6655363 | Kobayashi et al. | Dec 2003 | B2 |
6761193 | Cotton et al. | Jul 2004 | B1 |
20030102035 | Dasilva et al. | Jun 2003 | A1 |