WO2016130681A1

WO2016130681A1 - Vent line routing configuration for fuel system

Info

Publication number: WO2016130681A1
Application number: PCT/US2016/017356
Authority: WO
Inventors: Daniel Pifer
Original assignee: Eaton Corp
Current assignee: Eaton Corp
Priority date: 2015-02-10
Filing date: 2016-02-10
Publication date: 2016-08-18
Anticipated expiration: 2017-08-10

Abstract

A fuel tank system constructed in accordance to the present disclosure includes a fuel tank, a liquid trap and a vapor line assembly. The fuel tank is configured as a reservoir for holding fuel to be supplied to an internal combustion engine. The liquid trap can be disposed in the fuel tank and configured to separate vapor and liquid. The vapor line assembly can include a first vapor line, a second vapor line, a third vapor line and a fourth vapor line. The first vapor line can be connected between a first vent and the liquid trap. The first vapor line can have a first loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the first vent and the first loop portion.

Description

VENT LINE ROUTING CONFIGURATION FOR FUEL SYSTEM

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 62/114,552 filed on February 10, 2015, which is incorporated by reference in its entirety as if set forth herein.

FIELD

[0002] The present disclosure relates generally to fuel tanks on passenger vehicles and more particularly to a fuel tank having vent line routing configuration.

BACKGROUND

[0003] Fuel vapor emission control systems are becoming increasingly more complex, in large part in order to comply with environmental and safety regulations imposed on manufacturers of gasoline powered vehicles. Along with the ensuing overall system complexity, complexity of individual components within the system has also increased. Certain regulations affecting the gasoline-powered vehicle industry require that fuel vapor emission from a fuel tank's ventilation system be stored during periods of an engine's operation. In order for the overall vapor emission control system to continue to function for its intended purpose, periodic purging of stored hydrocarbon vapors is necessary during operation of the vehicle.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

[0005] A fuel tank system constructed in accordance to the present disclosure includes a fuel tank, a liquid trap and a vapor line assembly. The fuel tank is configured as a reservoir for holding fuel to be supplied to an internal combustion engine. The liquid trap can be disposed in the fuel tank and configured to separate vapor and liquid. The vapor line assembly can include a first vapor line, a second vapor line, a third vapor line and a fourth vapor line. The first vapor line can be connected between a first vent and the liquid trap. The first vapor line can have a first loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the first vent and the first loop portion. The second vapor line can be connected between a second vent and the liquid trap. The second vapor line can have a second loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the second vent and the second loop portion.

[0006] The third vapor line can be connected between a third vent and the liquid trap. The third vapor line can have a third loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the third vent and the third loop portion. The fourth vapor line can be connected between a fourth vent and the liquid trap. The fourth vapor line can have a fourth loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the fourth vent and the fourth loop portion. At least one of the first, second, third and fourth loop portions are configured to locate above a fuel level and inhibit liquid from entering the liquid trap while at least one of the first, second, third and fourth vents locate above the fuel level allowing equalized pressure and venting within the fuel tank for various vehicle grades.

[0007] According to other features, the fuel tank can be generally rectangular shaped. The fuel tank can comprise four distinct quadrants including a first quadrant, a second quadrant, a third quadrant and a fourth quadrant. The first vent can be disposed in the first quadrant. The second vent can be disposed in the second quadrant. The third vent can be disposed in the third quadrant. The fourth vent can be disposed in the fourth quadrant.

[0008] In one example, the first vent can be open and the third loop portion can at least partially contain air when the vehicle is at a first grade. The first vent and the third loop portion can cooperate to equalize pressure in the liquid trap. The second vent can be open and the fourth loop portion can at least partially contain air when the vehicle is at a second grade. The second vent and the fourth loop portion can cooperate to equalize pressure in the liquid trap. The third vent can be open and the first loop portion can at least partially contain air when the vehicle is at a third grade. The third vent and the first loop portion can cooperate to equalize pressure in the liquid trap. The fourth vent can be open and the second loop portion can at least partially contain air when the vehicle is at a fourth grade. The fourth vent and the second loop portion can cooperate to equalize pressure in the liquid trap.

[0009] According to various features, the first quadrant can be located opposite the third quadrant. The first vent line can extend along both of the first and third quadrants. The third vent line can extend along both of the third and first quadrants. The second quadrant can be located opposite the fourth quadrant. The second vent line can extend along both of the second and fourth quadrants. The fourth vent line can extend along both of the fourth and the second quadrants.

[0010] A fuel tank system constructed in accordance to another example of the present disclosure includes a fuel tank, a liquid trap and a vapor line assembly. The fuel tank is configured as a reservoir for holding fuel to be supplied to an internal combustion engine. The liquid trap can be disposed in the fuel tank and configured to separate vapor and liquid. The vapor line assembly can include a first vapor line, a second vapor line, a third vapor line and a fourth vapor line. The first vapor line can be connected between a first vent and the liquid trap. The first vapor line can have a first non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the first vent and the first non-linear portion. The second vapor line can be connected between a second vent and the liquid trap. The second vapor line can have a second non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the second vent and the second non-linear portion.

[0011] The third vapor line can be connected between a third vent and the liquid trap. The third vapor line can have a third non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the third vent and the third non-linear portion. The fourth vapor line can be connected between a fourth vent and the liquid trap. The fourth vapor line can have a fourth non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the fourth vent and the fourth non-linear portion. At least one of the first, second, third and fourth non-linear portions are configured to locate above a fuel level and inhibit liquid from entering the liquid trap while at least one of the first, second, third and fourth vents locate above the fuel level allowing equalized pressure and venting within the fuel tank for various vehicle grades.

[0012] According to other features, the fuel tank can be generally rectangular shaped. The fuel tank can comprise four distinct quadrants including a first quadrant, a second quadrant, a third quadrant and a fourth quadrant. The first vent can be disposed in the first quadrant. The second vent can be disposed in the second quadrant. The third vent can be disposed in the third quadrant. The fourth vent can be disposed in the fourth quadrant.

[0013] in one example, the first vent can be open and the third loop portion can at least partially contain air when the vehicle is at a first grade. The first vent and the third non-linear portion can cooperate to equalize pressure in the liquid trap. The second vent can be open and the fourth non-linear portion can at least partially contain air when the vehicle is at a second grade. The second vent and the fourth non-linear portion can cooperate to equalize pressure in the liquid trap. The third vent can be open and the first non-linear portion can at least partially contain air when the vehicle is at a third grade. The third vent and the non-linear portion can cooperate to equalize pressure in the liquid trap. The fourth vent can be open and the second loop portion can at least partially contain air when the vehicle is at a fourth grade. The fourth vent and the second nonlinear portion can cooperate to equalize pressure in the liquid trap.

[0014] According to various features, the first quadrant can be located opposite the third quadrant. The first vent line can extend along both of the first and third quadrants. The third vent line can extend along both of the third and first quadrants. The second quadrant can be located opposite the fourth quadrant. The second vent line can extend along both of the second and fourth quadrants. The fourth vent line can extend along both of the fourth and the second quadrants.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: [0016] FIG. 1 is a schematic illustration of a fuel tank system having a vapor line assembly constructed in accordance to one example of the present disclosure;

[0017] FIG. 2 is a side view of a fuel tank system having a fuel tank vapor line assembly constructed in accordance to Prior Art and shown with the fuel tank tilted on a grade; and

[0018] FIG. 3 is a side view of the fuel tank system of FIG. 1 and shown with the fuel tank tilted on a grade.

DETAILED DESCRIPTION

[0019] With initial reference to FIG. 1 a fuel tank system constructed in accordance to one example of the present disclosure is shown and generally identified at reference number 10. The fuel tank system 10 can generally include a fuel tank 12, a liquid trap 20 and a vapor line assembly 30. The fuel tank 12 is configured as a reservoir for holding fuel to be supplied to an internal combustion engine via a fuel delivery system which includes a fuel pump (not specifically shown). The vapor line assembly 30 constructed in accordance to one example of the present disclosure includes a plurality of vapor lines 40 and a corresponding plurality of vents 42. In the example shown four vapor lines 40A, 40B, 40C and 40D connect between four vents 42A, 42B, 42C and 42D and the liquid trap 20.

[0020] The liquid trap 20 can be centrally located and configured to vent the fuel tank 12. The liquid trap 20 separates the vapor and liquid. The vapor can flow out the top of the liquid trap 20 identified at reference 50, FIG. 3. The liquid can be pumped back into the fuel tank 12.

[0021] With reference now to FIG. 2, a fuel tank system 110 constructed in accordance to one prior art example is shown. The fuel tank system 110 includes a fuel tank 112, a liquid trap 120 and a vapor line assembly 130. The vapor line assembly 130 includes a plurality of vapor lines 140 and corresponding plurality of vents 142. In the example shown, two vapor lines 140A and 140B are specifically shown however it will be appreciated that more may be included. The vapor lines 140A, 140B connect between vents 142A and 142B and the liquid trap 120. The vapor lines 140 are generally linearly arranged from the respective vents 142 to the liquid trap 120. One problem with such prior art configurations is that when the vehicle is parked and the engine is off, the pump would be turned off. If the vapor lines 140 did not have liquid discriminating valves or if the valves were not fully leak tight the liquid could flow or leak into the lines through the vents 142. If the fuel tank 112 were full and the vehicle parked on a grade it is possible that the fuel could flow to the liquid trap 120 and fill it.

[0022] If the liquid trap 120 of the fuel tank 112 were normally open, fuel could exit the fuel tank 1 12 through the liquid trap 120 identified at reference 150. A filled liquid trap prevents any venting from the fuel tank 112 which could lead to emissions from the fuel cap. And in the normally open condition, the fuel could exit the fuel tank 112 and fill the vapor lines 140. Both cases need to be prevented. Unfortunately the configuration shown in Prior Art FIG. 2 has vapor lines 140 directly routed to the liquid trap 120. Since the liquid will seek the full level the bottom vapor line (140C) will fill with liquid and fill the liquid trap 120.

[0023] The configuration of the fuel tank system 10 of the present disclosure overcomes the shortcomings of the fuel tank system 1 10 shown in FIG. 2. Specifically, the fuel tank system 110 inhibits liquid from entering the liquid trap 20 in conditions where the vehicle is on a grade (FIG. 3). The vapor lines 40 will be described in greater detail. Each of the vapor lines 40A, 40B, 40C and 40D initiates at a respective vent 42A, 42B, 42C and 42D. The vents 42A, 42B, 42C and 42D are located generally around an outermost location of the fuel tank 12.

[0024] In the example shown, the fuel tank 12 is generally rectangular shaped generally having a first corner 60A, a second corner 60B, a third corner 60C and a fourth comer 60D. The liquid trap 20 is located generally in a central location of the fuel tank 12. The fuel tank 12 can generally include four areas or quadrants Q1 , Q2, Q3 and Q4. In the example shown, the first vent 42A is located in the first quadrant. The second vent 42B is located in the second quadrant. The third vent 42C is located in the third quadrant. The fourth vent 42D is located in the fourth quadrant. In the configuration shown, the first and third quadrants Q1 and Q3 are oppositely arranged relative to the liquid trap 20. The second and fourth quadrants Q2 and Q4 are oppositely arranged relative to the liquid trap 20. [0025] The first vapor fine 40A extends along the first quadrant Q1 , through the second quadrant Q2 and to the third quadrant Q3. Notably, the first vapor line 40A has a first loop portion 70A that extends past the liquid trap 20 into the third quadrant Q3 and loops back to the liquid trap 20. The liquid trap 20 is therefore positioned generally between the first vent 42A and the first loop portion 70A. The second vapor line 40B has a second loop portion 70B that extends past the liquid trap 20 into the fourth quadrant Q4 and loops back to the liquid trap 20. The liquid trap 20 is therefore positioned generally between the second vent 42B and the second loop portion 70B.

[0026] The third vapor line 40C has a third loop portion 70C that extends past the liquid trap 20 into the first quadrant Q1 and loops back to the liquid trap 20. The liquid trap 20 is therefore positioned generally between the third vent 42C and the third loop portion 70C. The fourth vapor line 40D has a fourth loop portion 70D that extends past the liquid trap 20 into the second quadrant Q2 and loops back to the liquid trap 20. The liquid trap 20 is therefore positioned generally between the fourth vent 42D and the fourth loop portion 70D. While description is made to loop portions generally having a first vapor line portion that follows a first direction and a second vapor line portion that follows a second direction, opposite the first direction, other geometrical configurations are contemplated. For example the loop portions can be configured as other non-linear sections that generally occupy an area of the fuel tank 12 above a liquid level at various locations in the fuel tank 12 to satisfy various vehicle grades.

[0027] With particular reference now to FIG. 3, operation of the vapor line assembly 30 of the fuel tank system 10 will be described. For illustrative purposes only the second vapor line 40B and third vapor line 40C are shown. The fuel tank 12 is shown on a grade. The liquid level is identified at the dashed line. Notably, the loop portion 70C of the vent line 40C extends above the liquid level. In this regard, fluid is inhibited from entering the liquid trap 20 from the vent line 40C. The loop portion 70C rises above the liquid level prior to entering the liquid trap 20 causing the liquid to stop negotiating through the vent line 40C and into the liquid trap 20. Moreover, since the uppermost vent 42B is open, the pressure in the fuel tank 12 and the pressure in the liquid trap 20 will equalize preventing pressure from pushing the liquid in the lowermost vent line (in this example vapor line 40C) into the liquid trap 20. Explained further, the first vent is open and the third loop portion at least partially contains air when the vehicle is at a first grade. The first vent and the third loop portion cooperate to equalize pressure in the liquid trap. The second vent is open and the fourth loop portion at least partially contains air when the vehicle is at a second grade. The second vent and the fourth loop portion cooperate to equalize pressure in the liquid trap. The third vent is open and the first loop portion at least partially contains air when the vehicle is at a third grade. The third vent and the first loop portion cooperate to equalize pressure in the liquid trap. The fourth vent is open and the second loop portion at least partially contains air when the vehicle is at a fourth grade. The fourth vent and the second loop portion cooperate to equalize pressure in the liquid trap.

[0028] it will be appreciated that similar results will occur with the other vapor lines based on the fuel tank 12 occupying other grades. In sum, the orientation of the vapor line assembly 30 accounts for equalized pressure and venting regardless of vehicle orientation and grade.

[0029] The foregoing description of the example has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to that particular example, but, where applicable, are interchangeable and can be used in a selected example, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMS What is claimed is:

1. A fuel tank system comprising:

a fuel tank configured as a reservoir for holding fuel to be supplied to an internal combustion engine;

a liquid trap disposed in the fuel tank and configured to separate vapor and liquid;

a vapor line assembly comprising:

a first vapor line connected between a first vent and the liquid trap, the first vapor line having a first loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the first vent and the first loop portion;

a second vapor line connected between a second vent and the liquid trap, the second vapor line having a second loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the second vent and the second loop portion;

a third vapor line connected between a third vent and the liquid trap, the third vapor line having a third loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the third vent and the third loop portion; and

a fourth vapor line connected between a fourth vent and the liquid trap, the fourth vapor line having a fourth loop portion that extends past the liquid trap such that the liquid trap is positioned generally between the fourth vent and the fourth loop portion; and

wherein at least one of the first, second, third and fourth loop portions are configured to locate above a fuel level and inhibit liquid from entering the liquid trap while at least one of the first, second, third and fourth vents locate above the fuel level allowing equalized pressure and venting within the fuel tank for various vehicle grades.

2. The fuel tank system of claim 1 wherein the fuel tank is generally rectangular shaped.

3. The fuel tank system of claim 1 wherein the fuel tank comprises four distinct quadrants including a first quadrant, a second quadrant, a third quadrant and a fourth quadrant, wherein the first vent is disposed in the first quadrant, the second vent is disposed in the second quadrant, the third vent is disposed in the third quadrant and the fourth vent is disposed in the fourth quadrant.

4. The fuel tank system of claim 3 wherein the first quadrant is located opposite the third quadrant, the first vent line extending along both of the first and third quadrants.

5. The fuel tank system of claim 4 wherein the third vent line extends along both of the third and first quadrants.

6. The fuel tank system of claim 4 wherein the second quadrant is located opposite the fourth quadrant, the second vent line extending along both of the second and fourth quadrants.

7. The fuel tank system of claim 6 wherein the fourth vent line extends along both of the fourth and second quadrants.

8. The fuel tank system of claim 3 wherein the first vent is open and the third loop portion at least partially contains air when the vehicle is at a first grade, the first vent and the third loop portion cooperating to equalize pressure in the liquid trap.

9. The fuel tank system of claim 8 wherein the second vent is open and the fourth loop portion at least partially contains air when the vehicle is at a second grade, the second vent and the fourth loop portion cooperating to equalize pressure in the liquid trap.

10. The fuel tank system of claim 9 wherein the third vent is open and the first loop portion at least partially contains air when the vehicle is at a third grade, the third vent and the first loop portion cooperating to equalize pressure in the liquid trap.

1 1. The fuel tank system of claim 10 wherein the fourth vent is open and the second loop portion at least partially contains air when the vehicle is at a fourth grade, the fourth vent and the second loop portion cooperating to equalize pressure in the liquid trap.

12. A fuel tank system comprising:

a vapor line assembly comprising:

a first vapor line connected between a first vent and the liquid trap, the first vapor line having a first non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the first vent and the first nonlinear portion;

a second vapor line connected between a second vent and the liquid trap, the second vapor line having a second non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the second vent and the second non-linear portion;

a third vapor line connected between a third vent and the liquid trap, the third vapor line having a third non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the third vent and the third non-linear portion; and

a fourth vapor line connected between a fourth vent and the liquid trap, the fourth vapor line having a fourth non-linear portion that extends to an area of the fuel tank such that the liquid trap is positioned generally between the fourth vent and the fourth non-linear portion; and wherein at least one of the first, second, third and fourth non-linear portions are configured to locate above a fuel level and inhibit liquid from entering the liquid trap while at least one of the first, second, third and fourth vents locate above the fuel level allowing equalized pressure and venting within the fuel tank for various vehicle grades.

13. The fuel tank system of claim 12 wherein the fuel tank is generally rectangular shaped.

14. The fuel tank system of claim 12 wherein the fuel tank comprises four distinct quadrants including a first quadrant, a second quadrant, a third quadrant and a fourth quadrant, wherein the first vent is disposed in the first quadrant, the second vent is disposed in the second quadrant, the third vent is disposed in the third quadrant and the fourth vent is disposed in the fourth quadrant.

15. The fuel tank system of claim 14 wherein the first quadrant is located opposite the third quadrant, the first vent line extending along both of the first and third quadrants.

16. The fuel tank system of claim 4 wherein the third vent line extends along both of the third and first quadrants.

17. The fuel tank system of claim 15 wherein the second quadrant is located opposite the fourth quadrant, the second vent line extending along both of the second and fourth quadrants.

18. The fuel tank system of claim 17 wherein the fourth vent line extends along both of the fourth and second quadrants.

19. The fuel tank system of claim 14 wherein the first vent is open and the third non-linear portion at least partially contains air when the vehicle is at a first grade, the first vent and the third non-linear portion cooperating to equalize pressure in the liquid trap.

20. The fuel tank system of claim 19 wherein the second vent is open and the fourth non-linear portion at least partially contains air when the vehicle is at a second grade, the second vent and the fourth non-linear portion cooperating to equalize pressure in the liquid trap.