US20070137729A1

US20070137729A1 - Sock inlet check valve for fuel tank

Info

Publication number: US20070137729A1
Application number: US11/304,009
Authority: US
Inventors: Darrin Hurley; Yarick Vitkovski
Original assignee: DaimlerChrysler Co LLC
Current assignee: Old Carco LLC
Priority date: 2005-12-15
Filing date: 2005-12-15
Publication date: 2007-06-21

Abstract

Reducing fuel vapor within a vehicle fuel tank is accomplished by employing a flexible fuel sock attached to spud near the top surface of the fuel tank. The fuel sock resides within the fuel tank and retains liquid fuel during tank refueling so that the fuel is confined within the fuel sock until the fuel reaches the bottom of the fuel tank or the current level of fuel within the tank. The fuel conduit may be flexible and buoyant to accommodate any level of fuel in the tank and reduction of fuel refueling vapors. A check valve may be situated within the spud.

Description

FIELD OF THE INVENTION

The present invention relates to a flexible extension for a fuel tank inlet check valve proximate a fuel tank top wall.

BACKGROUND OF THE INVENTION

Modern automotive vehicles typically have fuel tanks that are filled through a pipe at the top wall of the fuel tank. As liquid fuel passes through the top wall, the fuel may also pass through a check valve. The pipe and check valve permit liquid fuel to pass into and fill the fuel tank. However, the fuel is permitted to flow unrestrained from the check valve at the top of the fuel tank to the bottom of the fuel tank. Along this fuel path, fuel is able to atomize and generate fuel vapor. Additionally, fuel vapor is generated as the falling fuel meets the surface of the fuel already resident within the fuel tank. Fuel vapors generated during refueling of a vehicular fuel tank must be conditioned in a charcoal canister. Therefore, a reduction in fuel vapors generated during the filling of a fuel tank results in a reduction of fuel vapors that must be conditioned. Accordingly, a need exists for a device that efficiently manages liquid fuel flowing from a check valve, or top of a fuel tank, to the surface of the resident fuel within the fuel tank so that fuel vapor generation is minimized.

SUMMARY OF THE INVENTION

An apparatus for reducing fuel vapor generated within a fuel tank during tank refueling includes a flexible fuel conduit that extends from a spud attached to the fuel tank at a fuel inlet of the fuel tank. The fuel conduit extends within the fuel tank from the spud to a location proximate a bottom of the fuel tank. The fuel conduit may be flexible and buoyant to accommodate any fuel level with the fuel tank during refueling. A check valve may be situated within the spud within the tank to permit fuel to flow only one-way.
Further areas of applicability of the teachings of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a side view of a vehicle depicting a fuel system in phantom, including a fuel sock according to the present invention;
FIG. 2 is a side view of a fuel tank depicting a general location of a fuel sock and various fuel system components;
FIG. 3 is a side view of a fuel tank depicting a fuel sock engaging fuel within a fuel tank;
FIG. 4 is a side view of a fuel tank depicting a fuel sock engaging fuel within a fuel tank;
FIG. 5 is an enlarged view of the juncture of a fuel sock and a spud; and
FIG. 6 is a side view of a prior art fuel tank depicting fuel vapors during refueling.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Referencing FIGS. 1-5, a fuel sock according to the present invention is depicted; however, before turning to the teachings of the present invention a review of a prior art fuel tank undergoing refueling will be explained with reference to FIG. 6.
FIG. 6 is a side view of a prior art fuel tank depicting fuel vapors during fuel tank refueling. More specifically, a problem of the prior art fuel tank filling apparatus lies in delivering fuel within the tank which generally results in the generation of fuel vapors during refueling. A fuel tank 10 having a filler pipe 12 and a spud 14 permits liquid fuel to pass into the tank 10 from the top of the tank after the fuel passes through the filler pipe 12 and spud 14. That is, after the fuel passes through the spud 14, the fuel is permitted to fall into the fuel tank 10.
During fuel tank re-filling, fuel vapors 18 are generated as the fuel falls from the spud 14 toward the bottom of the fuel tank 10. Additionally, as the falling fuel 16 strikes the fuel 20 resident on the bottom of the tank 10, or strikes the bottom of the tank 10 itself, fuel vapors 22 are generated. The combination of the fuel vapors 18 generated during re-filling, results in vapors filling the area 24 of the fuel tank 10. Because the area 24 fills with fuel vapors 18, 22, the vapors must be managed by a vapor recovery system (not shown) to meet emission standards and to maintain acceptable pressure levels within the fuel tank 10. The teachings of the present invention reduce the generation of such fuel vapors.
Turning to FIGS. 1-5, the teachings of the present invention will be explained. FIG. 1 depicts a vehicle 30 having an engine 31 that is supplied by a fuel line 32. The fuel line 32 originates from the fuel tank 34, which is supplied fuel from filler pipe 40, an end of which resides in the fuel receptacle 36. After fuel passes through the fuel filler pipe 40, it passes into the fuel sock 48, which may be a flexible, bag-like structure. Additionally, the fuel sock 48 may be semi-flexible, or rigid. The fuel sock 48 may reach to the bottom of the fuel tank 34, or any position above the bottom of the fuel tank 34. At any position above the bottom, or at the bottom, the fuel sock 48 will reduce fuel splattering, and thus fuel vapors generated, during refueling of the fuel tank 34.
FIG. 2 depicts the fuel tank 34 having a fuel filler pipe 40 with a fuel inlet 38. The fuel inlet is normally resident in the fuel receptacle 36 (FIG. 1). The fuel filler pipe 40 leads from the fuel receptacle 36 to the neck 42. The neck 42 leads to a spud 44, which has a narrow fuel inlet portion 45 that fits within a fuel tank inlet hole at the top of the fuel tank 34. The narrow fuel inlet portion 45 may contain an inlet check valve 46, which may be spring-biased to a normally closed position; however, in FIG. 2 the inlet check valve 46 is shown in a partially open position. The inlet check valve 46 permits fuel to only flow into the fuel tank 34. Connected to the narrow fuel inlet portion 45 of the spud 44 is a first end of a fuel sock 48. The other, second end of the fuel sock, known as the free end 52, is shown in a horizontal position in FIG. 2. The parts depicted from the fuel receptacle 36 to the free end 50 of the fuel sock 48 are involved in delivering fuel into the fuel tank 34.
FIG. 2 also depicts additional fuel vapor management equipment, which will now be explained in more detail in conjunction with the above teachings. When a user desires to refuel the fuel tank 34, he or she places the refueling nozzle (not shown) into the fuel inlet 38. When fuel is dispensed, it travels through the fuel filler pipe 40 and the neck 42 of the spud 44. The liquid fuel then passes through an inlet check valve 46, also known as an ICV, which is situated in a narrow portion of the spud 44. After passing through the ICV 46, the fuel continues to pass through a fuel sock 48, which passes through the interior of the fuel tank 34. Upon passing through the main portion of the fuel sock 48 in accordance with arrow 50, the liquid fuel reaches the fuel sock aft end 52, which is also the free end of the fuel sock 48.
In the arrangement depicted in FIG. 2, the liquid fuel will strike the interior bottom surface 56 of the fuel tank 34. This will generally cause the generation of some fuel vapors; however, because the fuel sock 48 has its aft end 52 close to the interior bottom 56 of the fuel tank 34, the fuel vapors are minimized. Although not depicted, to further minimize vapors, the fuel sock aft end 52, may actually contact the interior bottom 56 of the fuel tank 34 as refueling commences. By arranging the fuel sock aft end 52 as close as possible to the interior bottom 56 of the fuel tank 34, the fuel has as short of a distance as possible to drop to the fuel tank bottom 56, thereby generating as few fuel vapors as possible. If the fuel sock aft end 52 is contacting the fuel tank interior bottom 56, the fuel outlet 54 will permit the fuel to smoothly exit the fuel sock 48. Generating as few fuel vapors as possible is advantageous because interior tank pressure is minimized and fewer fuel vapors must be processed by vehicular on-board vapor processing equipment.
Since fuel vapors are generated regardless of whether fuel drops to the fuel tank bottom 56, fuel vapor processing equipment 60 resides with the fuel tank 34 to manage any vapors. For instance, with continued reference to FIG. 2, fuel vapor processing system 60 may entail a multi-functional control valve 58, a grade vent valve 61, a charcoal canister 62, and a fresh air canister 64. In one configuration, the multi-functional control valve 58 and grade vent valve 61 are linked with a grade vent line 66. An inlet vent line 69 returns gaseous vapor from the multi-functional control valve 58 to the vapor inlet 70 at the fuel filler pipe 40 fuel inlet 38. Additionally, a vapor fuel line 32 delivers fuel vapor to an engine purge valve (not shown).
Although some fuel vapor is delivered to an engine purge valve, the multi-functional control valve 58 also delivers fuel vapor to the charcoal canister 62 via a charcoal canister line 68. To assist in cleansing the fuel vapor in the charcoal canister 62, a fresh air filter 64 is linked to the charcoal canister 62 via a fresh air line 66.
When fuel vapor is generated in the fuel tank 34, the fuel vapor enters either the grade vent valve 61 or multi-function control valve 58. In the case of fuel vapor entering via the grade vent valve 61, such vapor is forced by pressure through the grade vent line 66 toward the multi-functional control valve 58. From the multi-functional control valve 58, fuel vapors may be directed through the inlet vent line 69 and returned to the fuel filler pipe 40 via a vapor inlet 70. Alternatively, or additionally, fuel vapors may be directed from the multi-functional control valve 58 with vapor line 72 which supplies fuel vapor to the engine purge valve or the charcoal canister 62. Fuel vapors directed to the charcoal canister 62 are directed through the charcoal canister line 68 while fresh air is directed to the charcoal canister 62 via a fresh air line 66 from a fresh air filter 64.
FIGS. 3 and 4 depict fuel tank 34 having different levels of liquid fuel. For ease of illustration, the additional fuel vapor processing equipment depicted in FIG. 2, has been omitted from FIGS. 3 and 4. FIGS. 3 and 4 emphasize the advantages of employing a fuel sock 48 to reduce fuel vapors generated during refueling according to teachings of the present invention. More specifically, FIG. 3 depicts the aft end 52 of the fuel sock 48 delivering fuel in the direction of arrow 50. As depicted in FIG. 3, the fuel level 74 is such that the fuel outlet 54 of the fuel sock aft end 52 is partially submerged in liquid fuel. By partially submerging the fuel outlet 54 in liquid fuel, turbulent flow, and thus, fuel vapors are reduced in the fuel tank 34.
Similarly to FIG. 3, FIG. 4 depicts a refueling scenario in which the fuel outlet 54 of the aft end 52 of the fuel sock 48 lies completely submerged under the level of the fuel within the fuel tank 34. In this depiction, fuel vapors generated by the refueling fuel flow 50 are minimized. Fuel vapors within the fuel tank 34 may escape from the top surface of the fuel in the tank, but generally not from turbulent flow upon the fuel flow 50 striking the top surface 74 of the existing fuel in the tank. As a result of the refueling scenarios depicted in FIGS. 3 and 4, fuel is delivered to the interior of the fuel tank 34 via the fuel sock 48, with minimal or no sloshing upon the fuel flow 50 entering the fuel tank 34, thereby reducing or minimizing fuel vapors generated within the tank 34. The fuel sock 48, also known as a fuel conduit, may be flexible and buoyant to accommodate, or move up and down in accordance with any fuel level with the fuel tank 34 during refueling.
FIG. 5 is an enlarged view of the junction of the spud 44 and fuel sock 48. Furthermore, the fuel sock 48 may be connected to the narrow fuel inlet portion 45 of the spud 44 that is inside the confines of the fuel tank 34. More specifically, the material of the fuel sock 48 may be one that can be welded onto the narrow fuel inlet portion 45 of the spud 44. More specifically, the fuel sock 48 material may be a plastic that can tolerate the liquid and vapor fuel within the fuel tank 34 and that can be welded to the spud 44. Alternatively, the fuel sock 48 material may be a flexible, semi-rigid, or rigid rubber, or rubber-like material that is tolerable of fuel tank environments. Additionally, within the spud 44 the ICV 46 may reside, the ICV 46 permitting fuel to pass in one direction only, that is, into the fuel tank 34.
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.

Claims

1. In a vehicle having a fuel tank defining a fuel inlet, an apparatus for reducing fuel vapor generation in the fuel tank comprising:

a fuel conduit extending from the fuel inlet to a location proximate a bottom of the fuel tank.

2. The apparatus of claim 1, wherein the fuel conduit is flexible.

3. The apparatus of claim 1, wherein the fuel conduit is buoyant.

4. The apparatus of claim 1, wherein a rigid tube protrudes from the fuel inlet and into the fuel tank, the fuel conduit joined to the rigid tube.

5. The apparatus of claim 4, further comprising:

a check valve, the check valve situated within the rigid tube.

6. An apparatus for reducing fuel tank vapor generation in a fuel tank, comprising:

a rigid tube protruding through a fuel tank wall; and

a fuel conduit, the fuel conduit extending from the rigid tube to proximate a fuel tank bottom.

7. The apparatus of claim 6, wherein the fuel conduit is flexible.

8. The apparatus of claim 6, wherein the fuel conduit is buoyant.

9. The apparatus of claim 6, further comprising a check valve, the check valve situated within the rigid tube to permit one-way fuel flow into the fuel tank.

10. An apparatus for reducing fuel tank vapor generation in a fuel tank, comprising:

a rigid tube protruding through a fuel tank wall; and

a flexible fuel conduit, a first end of the fuel conduit connected to the rigid tube and extending from the rigid tube to proximate a fuel tank bottom.

11. The apparatus of claim 10, further comprising a one-way check valve, the one-way check valve situated within the rigid tube and permitting fuel to only flow into the fuel tank.

12. The apparatus of claim 11, wherein the flexible fuel conduit is buoyant.

13. The apparatus of claim 12, further comprising a second end of the fuel conduit, wherein the second end of the fuel conduit is proximate a bottom surface of the fuel tank.

14. The apparatus of claim 13, wherein the second end of the fuel conduit is located under a surface of fuel within the fuel tank.